Firewolf 3.5

--
--  Firewolf
--  Made by GravityScore and 1lann and Towtow10
--



--    Variables

local startupSite = "autoupdate"











local version = "3.5"
local build = 20

local w, h = term.getSize()

local isMenubarOpen = true
local menubarWindow = nil

local allowUnencryptedConnections = true
local enableTabBar = true

local currentWebsiteURL = ""
local builtInSites = {}

local currentProtocol = ""
local protocols = {}

local currentTab = 1
local maxTabs = 5
local maxTabNameWidth = 8
local tabs = {}

local languages = {}

local history = {}

local publicDNSChannel = 9999
local publicResponseChannel = 9998
local responseID = 41738

local httpTimeout = 10
local searchResultTimeout = 1
local initiationTimeout = 2
local animationInterval = 0.125
local fetchTimeout = 3
local serverLimitPerComputer = 1

local websiteErrorEvent = "firewolf_websiteErrorEvent"
local redirectEvent = "firewolf_redirectEvent"

local baseURL = "https://raw.githubusercontent.com/Towtow10/Firewolf/master/src"
local buildURL = baseURL .. "/build.txt"
local firewolfURL = baseURL .. "/client.lua"
local serverURL = baseURL .. "/server.lua"

local originalTerminal = term.current()

local firewolfLocation = "/" .. shell.getRunningProgram()
local downloadsLocation = "/downloads"


local theme = {}

local colorTheme = {
    background = colors.gray,
    accent = colors.red,
    subtle = colors.orange,

    lightText = colors.gray,
    text = colors.white,
    errorText = colors.red,
}

local grayscaleTheme = {
    background = colors.black,
    accent = colors.black,
    subtle = colors.black,

    lightText = colors.white,
    text = colors.white,
    errorText = colors.white,
}



--    Utilities


local modifiedRead = function(properties)
    local text = ""
    local startX, startY = term.getCursorPos()
    local pos = 0

    local previousText = ""
    local readHistory = nil
    local historyPos = 0

    if not properties then
        properties = {}
    end

    if properties.displayLength then
        properties.displayLength = math.min(properties.displayLength, w - 2)
    else
        properties.displayLength = w - startX - 1
    end

    if properties.startingText then
        text = properties.startingText
        pos = text:len()
    end

    if properties.history then
        readHistory = {}
        for k, v in pairs(properties.history) do
            readHistory[k] = v
        end
    end

    if readHistory[1] == text then
        table.remove(readHistory, 1)
    end

    local draw = function(replaceCharacter)
        local scroll = 0
        if properties.displayLength and pos > properties.displayLength then
            scroll = pos - properties.displayLength
        end

        local repl = replaceCharacter or properties.replaceCharacter
        term.setTextColor(theme.text)
        term.setCursorPos(startX, startY)
        if repl then
            term.write(string.rep(repl:sub(1, 1), text:len() - scroll))
        else
            term.write(text:sub(scroll + 1))
        end

        term.setCursorPos(startX + pos - scroll, startY)
    end

    term.setCursorBlink(true)
    draw()
    while true do
        local event, key, x, y, param4, param5 = os.pullEvent()

        if properties.onEvent then
            -- Actions:
            -- - exit (bool)
            -- - text
            -- - nullifyText

            term.setCursorBlink(false)
            local action = properties.onEvent(text, event, key, x, y, param4, param5)
            if action then
                if action.text then
                    draw(" ")
                    text = action.text
                    pos = text:len()
                end if action.nullifyText then
                    text = nil
                    action.exit = true
                end if action.exit then
                    break
                end
            end
            draw()
        end

        term.setCursorBlink(true)
        if event == "char" then
            local canType = true
            if properties.maxLength and text:len() >= properties.maxLength then
                canType = false
            end

            if canType then
                text = text:sub(1, pos) .. key .. text:sub(pos + 1, -1)
                pos = pos + 1
                draw()
            end
        elseif event == "key" then
            if key == keys.enter then
                break
            elseif key == keys.left and pos > 0 then
                pos = pos - 1
                draw()
            elseif key == keys.right and pos < text:len() then
                pos = pos + 1
                draw()
            elseif key == keys.backspace and pos > 0 then
                draw(" ")
                text = text:sub(1, pos - 1) .. text:sub(pos + 1, -1)
                pos = pos - 1
                draw()
            elseif key == keys.delete and pos < text:len() then
                draw(" ")
                text = text:sub(1, pos) .. text:sub(pos + 2, -1)
                draw()
            elseif key == keys.home then
                pos = 0
                draw()
            elseif key == keys["end"] then
                pos = text:len()
                draw()
            elseif (key == keys.up or key == keys.down) and readHistory then
                local shouldDraw = false
                if historyPos == 0 then
                    previousText = text
                elseif historyPos > 0 then
                    readHistory[historyPos] = text
                end

                if key == keys.up then
                    if historyPos < #readHistory then
                        historyPos = historyPos + 1
                        shouldDraw = true
                    end
                else
                    if historyPos > 0 then
                        historyPos = historyPos - 1
                        shouldDraw = true
                    end
                end

                if shouldDraw then
                    draw(" ")
                    if historyPos > 0 then
                        text = readHistory[historyPos]
                    else
                        text = previousText
                    end
                    pos = text:len()
                    draw()
                end
            end
        elseif event == "mouse_click" then
            local scroll = 0
            if properties.displayLength and pos > properties.displayLength then
                scroll = pos - properties.displayLength
            end

            if y == startY and x >= startX and x <= math.min(startX + text:len(), startX + (properties.displayLength or 10000)) then
                pos = x - startX + scroll
                draw()
            elseif y == startY then
                if x < startX then
                    pos = scroll
                    draw()
                elseif x > math.min(startX + text:len(), startX + (properties.displayLength or 10000)) then
                    pos = text:len()
                    draw()
                end
            end
        end
    end

    term.setCursorBlink(false)
    print("")
    return text
end


local prompt = function(items, x, y, w, h)
    local selected = 1
    local scroll = 0

    local draw = function()
        for i = scroll + 1, scroll + h do
            local item = items[i]
            if item then
                term.setCursorPos(x, y + i - 1)
                term.setBackgroundColor(theme.background)
                term.setTextColor(theme.lightText)

                if scroll + selected == i then
                    term.setTextColor(theme.text)
                    term.write(" > ")
                else
                    term.write(" - ")
                end

                term.write(item)
            end
        end
    end

    draw()
    while true do
        local event, key, x, y = os.pullEvent()

        if event == "key" then
            if key == keys.up and selected > 1 then
                selected = selected - 1

                if selected - scroll == 0 then
                    scroll = scroll - 1
                end
            elseif key == keys.down and selected < #items then
                selected = selected + 1
            end

            draw()
        elseif event == "mouse_click" then

        elseif event == "mouse_scroll" then
            if key > 0 then
                os.queueEvent("key", keys.down)
            else
                os.queueEvent("key", keys.up)
            end
        end
    end
end



--    GUI


local clear = function(bg, fg)
    term.setTextColor(fg)
    term.setBackgroundColor(bg)
    term.clear()
    term.setCursorPos(1, 1)
end


local fill = function(x, y, width, height, bg)
    term.setBackgroundColor(bg)
    for i = y, y + height - 1 do
        term.setCursorPos(x, i)
        term.write(string.rep(" ", width))
    end
end


local center = function(text)
    local x, y = term.getCursorPos()
    term.setCursorPos(math.floor(w / 2 - text:len() / 2) + (text:len() % 2 == 0 and 1 or 0), y)
    term.write(text)
    term.setCursorPos(1, y + 1)
end


local centerSplit = function(text, width)
    local words = {}
    for word in text:gmatch("[^ \t]+") do
        table.insert(words, word)
    end

    local lines = {""}
    while lines[#lines]:len() < width do
        lines[#lines] = lines[#lines] .. words[1] .. " "
        table.remove(words, 1)

        if #words == 0 then
            break
        end

        if lines[#lines]:len() + words[1]:len() >= width then
            table.insert(lines, "")
        end
    end

    for _, line in pairs(lines) do
        center(line)
    end
end



--    Updating


local download = function(url)
    http.request(url)
    local timeoutID = os.startTimer(httpTimeout)
    while true do
        local event, fetchedURL, response = os.pullEvent()
        if (event == "timer" and fetchedURL == timeoutID) or event == "http_failure" then
            return false
        elseif event == "http_success" and fetchedURL == url then
            local contents = response.readAll()
            response.close()
            return contents
        end
    end
end


local downloadAndSave = function(url, path)
    local contents = download(url)
    if contents and not fs.isReadOnly(path) and not fs.isDir(path) then
        local f = io.open(path, "w")
        f:write(contents)
        f:close()
        return false
    end
    return true
end


local updateAvailable = function()
    local number = download(buildURL)
    if not number then
        return false, true
    end

    if number and tonumber(number) and tonumber(number) > build then
        return true, false
    end

    return false, false
end


local redownloadBrowser = function()
    return downloadAndSave(firewolfURL, firewolfLocation)
end



--    Display Websites


builtInSites["display"] = {}


builtInSites["display"]["firewolf"] = function()
    local logo = {
        "______                         _  __ ",
        "|  ___|                       | |/ _|",
        "| |_  _ ____ _____      _____ | | |_ ",
        "|  _|| |  __/ _ \\ \\ /\\ / / _ \\| |  _|",
        "| |  | | | |  __/\\ V  V / <_> | | |  ",
        "\\_|  |_|_|  \\___| \\_/\\_/ \\___/|_|_|  ",
    }

    clear(theme.background, theme.text)
    fill(1, 3, w, 9, theme.subtle)

    term.setCursorPos(1, 3)
    for _, line in pairs(logo) do
        center(line)
    end

    term.setCursorPos(1, 10)
    center(version)

    term.setBackgroundColor(theme.background)
    term.setTextColor(theme.text)
    term.setCursorPos(1, 14)
    center("Search using the Query Box above")
    center("Visit rdnt://help for help using Firewolf.")

    term.setCursorPos(1, h - 2)
    center("Made by GravityScore and 1lann and Towtow10")
end


builtInSites["display"]["credits"] = function()
    clear(theme.background, theme.text)

    fill(1, 6, w, 3, theme.subtle)
    term.setCursorPos(1, 7)
    center("Credits")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 11)
    center("Written by GravityScore and 1lann and Towtow10")
    print("")
    center("RC4 Implementation by AgentE382")
end


builtInSites["display"]["help"] = function()
    clear(theme.background, theme.text)

    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("Help")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 7)
    center("Click on the URL bar or press control to")
    center("open the query box")
    print("")
    center("Type in a search query or website URL")
    center("into the query box.")
    print("")
    center("Search for nothing to see all available")
    center("websites.")
    print("")
    center("Visit rdnt://server to setup a server.")
    center("Visit rdnt://update to update Firewolf.")
end


builtInSites["display"]["server"] = function()
    clear(theme.background, theme.text)

    fill(1, 6, w, 3, theme.subtle)
    term.setCursorPos(1, 7)
    center("Server Software")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 11)
    if not http then
        center("HTTP is not enabled!")
        print("")
        center("Please enable it in your config file")
        center("to download Firewolf Server.")
    else
        center("Press space to download")
        center("Firewolf Server to:")
        print("")
        center("/fwserver")

        while true do
            local event, key = os.pullEvent()
            if event == "key" and key == 57 then
                fill(1, 11, w, 4, theme.background)
                term.setCursorPos(1, 11)
                center("Downloading...")

                local err = downloadAndSave(serverURL, "/fwserver")

                fill(1, 11, w, 4, theme.background)
                term.setCursorPos(1, 11)
                center(err and "Download failed!" or "Download successful!")
            end
        end
    end
end


builtInSites["display"]["update"] = function()
    clear(theme.background, theme.text)

    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("Update")

    term.setBackgroundColor(theme.background)
    if not http then
        term.setCursorPos(1, 9)
        center("HTTP is not enabled!")
        print("")
        center("Please enable it in your config")
        center("file to download Firewolf updates.")
    else
        term.setCursorPos(1, 10)
        center("Checking for updates...")

        local available, err = updateAvailable()

        term.setCursorPos(1, 10)
        if available then
            term.clearLine()
            center("Update found!")
            center("Press enter to download.")

            while true do
                local event, key = os.pullEvent()
                if event == "key" and key == keys.enter then
                    break
                end
            end

            fill(1, 10, w, 2, theme.background)
            term.setCursorPos(1, 10)
            center("Downloading...")

            local err = redownloadBrowser()

            term.setCursorPos(1, 10)
            term.clearLine()
            if err then
                center("Download failed!")
            else
                center("Download succeeded!")
                center("Please restart Firewolf...")
            end
        elseif err then
            term.clearLine()
            center("Checking failed!")
        else
            term.clearLine()
            center("No updates found.")
        end
    end
end




builtInSites["display"]["autoupdate"] = function()
    clear(theme.background, theme.text)

    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("Update")

    term.setBackgroundColor(theme.background)
    if not http then
        term.setCursorPos(1, 9)
        center("HTTP is not enabled!")
        print("")
        center("Please enable it in your config")
        center("file to download Firewolf updates.")
    else
        term.setCursorPos(1, 10)
        center("Checking for updates...")

        local available, err = updateAvailable()

        term.setCursorPos(1, 10)
        if available then
            term.clearLine()
            center("Update found!")

            fill(1, 10, w, 2, theme.background)
            term.setCursorPos(1, 10)
            center("Downloading...")

            local err = redownloadBrowser()

            term.setCursorPos(1, 10)
            term.clearLine()
            if err then
                center("Download failed!")
            else
                center("Download succeeded!")
                center("Please restart Firewolf...")
            end
        elseif err then
            term.clearLine()
            center("Checking failed!")
        else
            term.clearLine()
            center("No updates found.")
        end
    end
    firewolf.redirect("firewolf")
end







--    Built In Websites


builtInSites["error"] = function(err)
    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("Failed to load page!")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 9)
    center(err)
    print("")
    center("Please try again.")
end


builtInSites["noresults"] = function()
    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("No results!")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 9)
    center("Your search didn't return")
    center("any results!")

    os.pullEvent("key")
    os.queueEvent("")
    os.pullEvent()
end


builtInSites["search advanced"] = function(results)
    local startY = 6
    local height = h - startY - 1
    local scroll = 0

    local draw = function()
        fill(1, startY, w, height + 1, theme.background)

        for i = scroll + 1, scroll + height do
            if results[i] then
                term.setCursorPos(5, (i - scroll) + startY)
                term.write(currentProtocol .. "://" .. results[i])
            end
        end
    end

    draw()
    while true do
        local event, but, x, y = os.pullEvent()

        if event == "mouse_click" and y >= startY and y <= startY + height then
            local item = results[y - startY + scroll]
            if item then
                os.queueEvent(redirectEvent, item)
                coroutine.yield()
            end
        elseif event == "key" then
            if but == keys.up then
                scroll = math.max(0, scroll - 1)
            elseif but == keys.down and #results > height then
                scroll = math.min(scroll + 1, #results - height)
            end

            draw()
        elseif event == "mouse_scroll" then
            if but > 0 then
                os.queueEvent("key", keys.down)
            else
                os.queueEvent("key", keys.up)
            end
        end
    end
end


builtInSites["search basic"] = function(results)
    local startY = 6
    local height = h - startY - 1
    local scroll = 0
    local selected = 1

    local draw = function()
        fill(1, startY, w, height + 1, theme.background)

        for i = scroll + 1, scroll + height do
            if results[i] then
                if i == selected + scroll then
                    term.setCursorPos(3, (i - scroll) + startY)
                    term.write("> " .. currentProtocol .. "://" .. results[i])
                else
                    term.setCursorPos(5, (i - scroll) + startY)
                    term.write(currentProtocol .. "://" .. results[i])
                end
            end
        end
    end

    draw()
    while true do
        local event, but, x, y = os.pullEvent()

        if event == "key" then
            if but == keys.up and selected + scroll > 1 then
                if selected > 1 then
                    selected = selected - 1
                else
                    scroll = math.max(0, scroll - 1)
                end
            elseif but == keys.down and selected + scroll < #results then
                if selected < height then
                    selected = selected + 1
                else
                    scroll = math.min(scroll + 1, #results - height)
                end
            elseif but == keys.enter then
                local item = results[scroll + selected]
                if item then
                    os.queueEvent(redirectEvent, item)
                    coroutine.yield()
                end
            end

            draw()
        elseif event == "mouse_scroll" then
            if but > 0 then
                os.queueEvent("key", keys.down)
            else
                os.queueEvent("key", keys.up)
            end
        end
    end
end


builtInSites["search"] = function(results)
    clear(theme.background, theme.text)

    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center(#results .. " Search " .. (#results == 1 and "Result" or "Results"))

    term.setBackgroundColor(theme.background)

    if term.isColor() then
        builtInSites["search advanced"](results)
    else
        builtInSites["search basic"](results)
    end
end


builtInSites["crash"] = function(err)
    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("The website crashed!")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 8)
    centerSplit(err, w - 4)
    print("\n")
    center("Please report this error to")
    center("the website creator.")
end



--    Menubar


local getTabName = function(url)
    local name = url:match("^[^/]+")

    if not name then
        name = "Search"
    end

    if name:sub(1, 3) == "www" then
        name = name:sub(5):gsub("^%s*(.-)%s*$", "%1")
    end

    if name:len() > maxTabNameWidth then
        name = name:sub(1, maxTabNameWidth):gsub("^%s*(.-)%s*$", "%1")
    end

    if name:sub(-1, -1) == "." then
        name = name:sub(1, -2):gsub("^%s*(.-)%s*$", "%1")
    end

    return name:gsub("^%s*(.-)%s*$", "%1")
end


local determineClickedTab = function(x, y)
    if y == 2 then
        local minx = 2
        for i, tab in pairs(tabs) do
            local name = getTabName(tab.url)

            if x >= minx and x <= minx + name:len() - 1 then
                return i
            elseif x == minx + name:len() and i == currentTab and #tabs > 1 then
                return "close"
            else
                minx = minx + name:len() + 2
            end
        end

        if x == minx and #tabs < maxTabs then
            return "new"
        end
    end

    return nil
end


local setupMenubar = function()
    if enableTabBar then
        menubarWindow = window.create(originalTerminal, 1, 1, w, 2, false)
    else
        menubarWindow = window.create(originalTerminal, 1, 1, w, 1, false)
    end
end


local drawMenubar = function()
    if isMenubarOpen then
        term.redirect(menubarWindow)
        menubarWindow.setVisible(true)

        fill(1, 1, w, 1, theme.accent)
        term.setTextColor(theme.text)

        term.setBackgroundColor(theme.accent)
        term.setCursorPos(2, 1)
        if currentWebsiteURL:match("^[^%?]+") then
            term.write(currentProtocol .. "://" .. currentWebsiteURL:match("^[^%?]+"))
        else
            term.write(currentProtocol .. "://" ..currentWebsiteURL)
        end

        term.setCursorPos(w - 5, 1)
        term.write("[===]")

        if enableTabBar then
            fill(1, 2, w, 1, theme.subtle)

            term.setCursorPos(1, 2)
            for i, tab in pairs(tabs) do
                term.setBackgroundColor(theme.subtle)
                term.setTextColor(theme.lightText)
                if i == currentTab then
                    term.setTextColor(theme.text)
                end

                local tabName = getTabName(tab.url)
                term.write(" " .. tabName)

                if i == currentTab and #tabs > 1 then
                    term.setTextColor(theme.errorText)
                    term.write("x")
                else
                    term.write(" ")
                end
            end

            if #tabs < maxTabs then
                term.setTextColor(theme.lightText)
                term.setBackgroundColor(theme.subtle)
                term.write(" + ")
            end
        end
    else
        menubarWindow.setVisible(false)
    end
end



--  RC4
--  Implementation by AgentE382


local cryptWrapper = function(plaintext, salt)
    local key = type(salt) == "table" and {unpack(salt)} or {string.byte(salt, 1, #salt)}
    local S = {}
    for i = 0, 255 do
        S[i] = i
    end

    local j, keylength = 0, #key
    for i = 0, 255 do
        j = (j + S[i] + key[i % keylength + 1]) % 256
        S[i], S[j] = S[j], S[i]
    end

    local i = 0
    j = 0
    local chars, astable = type(plaintext) == "table" and {unpack(plaintext)} or {string.byte(plaintext, 1, #plaintext)}, false

    for n = 1, #chars do
        i = (i + 1) % 256
        j = (j + S[i]) % 256
        S[i], S[j] = S[j], S[i]
        chars[n] = bit.bxor(S[(S[i] + S[j]) % 256], chars[n])
        if chars[n] > 127 or chars[n] == 13 then
            astable = true
        end
    end

    return astable and chars or string.char(unpack(chars))
end


local crypt = function(text, key)
    local resp, msg = pcall(cryptWrapper, text, key)
    if resp then
        return msg
    else
        return nil
    end
end



--  Base64
--
--  Base64 Encryption/Decryption
--  By KillaVanilla
--  http://www.computercraft.info/forums2/index.php?/topic/12450-killavanillas-various-apis/
--  http://pastebin.com/rCYDnCxn
--


local alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"


local function sixBitToBase64(input)
    return string.sub(alphabet, input+1, input+1)
end


local function base64ToSixBit(input)
    for i=1, 64 do
        if input == string.sub(alphabet, i, i) then
            return i-1
        end
    end
end


local function octetToBase64(o1, o2, o3)
    local shifted = bit.brshift(bit.band(o1, 0xFC), 2)
    local i1 = sixBitToBase64(shifted)
    local i2 = "A"
    local i3 = "="
    local i4 = "="
    if o2 then
        i2 = sixBitToBase64(bit.bor( bit.blshift(bit.band(o1, 3), 4), bit.brshift(bit.band(o2, 0xF0), 4) ))
        if not o3 then
            i3 = sixBitToBase64(bit.blshift(bit.band(o2, 0x0F), 2))
        else
            i3 = sixBitToBase64(bit.bor( bit.blshift(bit.band(o2, 0x0F), 2), bit.brshift(bit.band(o3, 0xC0), 6) ))
        end
    else
        i2 = sixBitToBase64(bit.blshift(bit.band(o1, 3), 4))
    end
    if o3 then
        i4 = sixBitToBase64(bit.band(o3, 0x3F))
    end

    return i1..i2..i3..i4
end


local function base64ToThreeOctet(s1)
    local c1 = base64ToSixBit(string.sub(s1, 1, 1))
    local c2 = base64ToSixBit(string.sub(s1, 2, 2))
    local c3 = 0
    local c4 = 0
    local o1 = 0
    local o2 = 0
    local o3 = 0
    if string.sub(s1, 3, 3) == "=" then
        c3 = nil
        c4 = nil
    elseif string.sub(s1, 4, 4) == "=" then
        c3 = base64ToSixBit(string.sub(s1, 3, 3))
        c4 = nil
    else
        c3 = base64ToSixBit(string.sub(s1, 3, 3))
        c4 = base64ToSixBit(string.sub(s1, 4, 4))
    end
    o1 = bit.bor( bit.blshift(c1, 2), bit.brshift(bit.band( c2, 0x30 ), 4) )
    if c3 then
        o2 = bit.bor( bit.blshift(bit.band(c2, 0x0F), 4), bit.brshift(bit.band( c3, 0x3C ), 2) )
    else
        o2 = nil
    end
    if c4 then
        o3 = bit.bor( bit.blshift(bit.band(c3, 3), 6), c4 )
    else
        o3 = nil
    end
    return o1, o2, o3
end


local function splitIntoBlocks(bytes)
    local blockNum = 1
    local blocks = {}
    for i=1, #bytes, 3 do
        blocks[blockNum] = {bytes[i], bytes[i+1], bytes[i+2]}
        blockNum = blockNum+1
    end
    return blocks
end


function base64Encode(bytes)
    local blocks = splitIntoBlocks(bytes)
    local output = ""
    for i=1, #blocks do
        output = output..octetToBase64( unpack(blocks[i]) )
    end
    return output
end


function base64Decode(str)
    local bytes = {}
    local blocks = {}
    local blockNum = 1

    for i=1, #str, 4 do
        blocks[blockNum] = string.sub(str, i, i+3)
        blockNum = blockNum+1
    end

    for i=1, #blocks do
        local o1, o2, o3 = base64ToThreeOctet(blocks[i])
        table.insert(bytes, o1)
        table.insert(bytes, o2)
        table.insert(bytes, o3)
    end

    return bytes
end



--  SHA-256
--
--  Adaptation of the Secure Hashing Algorithm (SHA-244/256)
--  Found Here: http://lua-users.org/wiki/SecureHashAlgorithm
--
--  Using an adapted version of the bit library
--  Found Here: https://bitbucket.org/Boolsheet/bslf/src/1ee664885805/bit.lua


local MOD = 2^32
local MODM = MOD-1


local function memoize(f)
    local mt = {}
    local t = setmetatable({}, mt)
    function mt:__index(k)
        local v = f(k)
        t[k] = v
        return v
    end
    return t
end


local function make_bitop_uncached(t, m)
    local function bitop(a, b)
        local res,p = 0,1
        while a ~= 0 and b ~= 0 do
            local am, bm = a % m, b % m
            res = res + t[am][bm] * p
            a = (a - am) / m
            b = (b - bm) / m
            p = p * m
        end
        res = res + (a + b) * p
        return res
    end

    return bitop
end


local function make_bitop(t)
    local op1 = make_bitop_uncached(t,2^1)
    local op2 = memoize(function(a)
        return memoize(function(b)
            return op1(a, b)
        end)
    end)
    return make_bitop_uncached(op2, 2 ^ (t.n or 1))
end


local customBxor1 = make_bitop({[0] = {[0] = 0,[1] = 1}, [1] = {[0] = 1, [1] = 0}, n = 4})

local function customBxor(a, b, c, ...)
    local z = nil
    if b then
        a = a % MOD
        b = b % MOD
        z = customBxor1(a, b)
        if c then
            z = customBxor(z, c, ...)
        end
        return z
    elseif a then
        return a % MOD
    else
        return 0
    end
end


local function customBand(a, b, c, ...)
    local z
    if b then
        a = a % MOD
        b = b % MOD
        z = ((a + b) - customBxor1(a,b)) / 2
        if c then
            z = customBand(z, c, ...)
        end
        return z
    elseif a then
        return a % MOD
    else
        return MODM
    end
end


local function bnot(x)
    return (-1 - x) % MOD
end


local function rshift1(a, disp)
    if disp < 0 then
        return lshift(a, -disp)
    end
    return math.floor(a % 2 ^ 32 / 2 ^ disp)
end


local function rshift(x, disp)
    if disp > 31 or disp < -31 then
        return 0
    end
    return rshift1(x % MOD, disp)
end


local function lshift(a, disp)
    if disp < 0 then
        return rshift(a, -disp)
    end
    return (a * 2 ^ disp) % 2 ^ 32
end


local function rrotate(x, disp)
    x = x % MOD
    disp = disp % 32
    local low = customBand(x, 2 ^ disp - 1)
    return rshift(x, disp) + lshift(low, 32 - disp)
end


local k = {
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
}


local function str2hexa(s)
    return (string.gsub(s, ".", function(c)
        return string.format("%02x", string.byte(c))
    end))
end


local function num2s(l, n)
    local s = ""
    for i = 1, n do
        local rem = l % 256
        s = string.char(rem) .. s
        l = (l - rem) / 256
    end
    return s
end


local function s232num(s, i)
    local n = 0
    for i = i, i + 3 do
        n = n*256 + string.byte(s, i)
    end
    return n
end


local function preproc(msg, len)
    local extra = 64 - ((len + 9) % 64)
    len = num2s(8 * len, 8)
    msg = msg .. "\128" .. string.rep("\0", extra) .. len
    assert(#msg % 64 == 0)
    return msg
end


local function initH256(H)
    H[1] = 0x6a09e667
    H[2] = 0xbb67ae85
    H[3] = 0x3c6ef372
    H[4] = 0xa54ff53a
    H[5] = 0x510e527f
    H[6] = 0x9b05688c
    H[7] = 0x1f83d9ab
    H[8] = 0x5be0cd19
    return H
end


local function digestblock(msg, i, H)
    local w = {}
    for j = 1, 16 do
        w[j] = s232num(msg, i + (j - 1)*4)
    end
    for j = 17, 64 do
        local v = w[j - 15]
        local s0 = customBxor(rrotate(v, 7), rrotate(v, 18), rshift(v, 3))
        v = w[j - 2]
        w[j] = w[j - 16] + s0 + w[j - 7] + customBxor(rrotate(v, 17), rrotate(v, 19), rshift(v, 10))
    end

    local a, b, c, d, e, f, g, h = H[1], H[2], H[3], H[4], H[5], H[6], H[7], H[8]
    for i = 1, 64 do
        local s0 = customBxor(rrotate(a, 2), rrotate(a, 13), rrotate(a, 22))
        local maj = customBxor(customBand(a, b), customBand(a, c), customBand(b, c))
        local t2 = s0 + maj
        local s1 = customBxor(rrotate(e, 6), rrotate(e, 11), rrotate(e, 25))
        local ch = customBxor (customBand(e, f), customBand(bnot(e), g))
        local t1 = h + s1 + ch + k[i] + w[i]
        h, g, f, e, d, c, b, a = g, f, e, d + t1, c, b, a, t1 + t2
    end

    H[1] = customBand(H[1] + a)
    H[2] = customBand(H[2] + b)
    H[3] = customBand(H[3] + c)
    H[4] = customBand(H[4] + d)
    H[5] = customBand(H[5] + e)
    H[6] = customBand(H[6] + f)
    H[7] = customBand(H[7] + g)
    H[8] = customBand(H[8] + h)
end


local function sha256(msg)
    msg = preproc(msg, #msg)
    local H = initH256({})
    for i = 1, #msg, 64 do
        digestblock(msg, i, H)
    end
    return str2hexa(num2s(H[1], 4) .. num2s(H[2], 4) .. num2s(H[3], 4) .. num2s(H[4], 4) ..
        num2s(H[5], 4) .. num2s(H[6], 4) .. num2s(H[7], 4) .. num2s(H[8], 4))
end


local protocolName = "Firewolf"



--    Cryptography


local Cryptography = {}
Cryptography.sha = {}
Cryptography.base64 = {}
Cryptography.aes = {}


function Cryptography.bytesFromMessage(msg)
    local bytes = {}

    for i = 1, msg:len() do
        local letter = string.byte(msg:sub(i, i))
        table.insert(bytes, letter)
    end

    return bytes
end


function Cryptography.messageFromBytes(bytes)
    local msg = ""

    for i = 1, #bytes do
        local letter = string.char(bytes[i])
        msg = msg .. letter
    end

    return msg
end


function Cryptography.bytesFromKey(key)
    local bytes = {}

    for i = 1, key:len() / 2 do
        local group = key:sub((i - 1) * 2 + 1, (i - 1) * 2 + 1)
        local num = tonumber(group, 16)
        table.insert(bytes, num)
    end

    return bytes
end


function Cryptography.sha.sha256(msg)
    return sha256(msg)
end


function Cryptography.aes.encrypt(msg, key)
    return base64Encode(crypt(msg, key))
end


function Cryptography.aes.decrypt(msg, key)
    return crypt(base64Decode(msg), key)
end


function Cryptography.base64.encode(msg)
    return base64Encode(Cryptography.bytesFromMessage(msg))
end


function Cryptography.base64.decode(msg)
    return Cryptography.messageFromBytes(base64Decode(msg))
end


function Cryptography.channel(text)
    local hashed = Cryptography.sha.sha256(text)

    local total = 0

    for i = 1, hashed:len() do
        total = total + string.byte(hashed:sub(i, i))
    end

    return (total % 55530) + 10000
end


function Cryptography.sanatize(text)
    local sanatizeChars = {"%", "(", ")", "[", "]", ".", "+", "-", "*", "?", "^", "$"}

    for _, char in pairs(sanatizeChars) do
        text = text:gsub("%"..char, "%%%"..char)
    end
    return text
end



--  Modem


local Modem = {}
Modem.modems = {}


function Modem.exists()
    Modem.exists = false
    for _, side in pairs(rs.getSides()) do
        if peripheral.isPresent(side) and peripheral.getType(side) == "modem" then
            Modem.exists = true

            if not Modem.modems[side] then
                Modem.modems[side] = peripheral.wrap(side)
            end
        end
    end

    return Modem.exists
end


function Modem.open(channel)
    if not Modem.exists then
        return false
    end

    for side, modem in pairs(Modem.modems) do
        modem.open(channel)
        rednet.open(side)
    end

    return true
end


function Modem.close(channel)
    if not Modem.exists then
        return false
    end

    for side, modem in pairs(Modem.modems) do
        modem.close(channel)
    end

    return true
end


function Modem.closeAll()
    if not Modem.exists then
        return false
    end

    for side, modem in pairs(Modem.modems) do
        modem.closeAll()
    end

    return true
end


function Modem.isOpen(channel)
    if not Modem.exists then
        return false
    end

    local isOpen = false
    for side, modem in pairs(Modem.modems) do
        if modem.isOpen(channel) then
            isOpen = true
            break
        end
    end

    return isOpen
end


function Modem.transmit(channel, msg)
    if not Modem.exists then
        return false
    end

    if not Modem.isOpen(channel) then
        Modem.open(channel)
    end

    for side, modem in pairs(Modem.modems) do
        modem.transmit(channel, channel, msg)
    end

    return true
end



--    Handshake


local Handshake = {}

Handshake.prime = 625210769
Handshake.channel = 54569
Handshake.base = -1
Handshake.secret = -1
Handshake.sharedSecret = -1
Handshake.packetHeader = "["..protocolName.."-Handshake-Packet-Header]"
Handshake.packetMatch = "%["..protocolName.."%-Handshake%-Packet%-Header%](.+)"


function Handshake.exponentWithModulo(base, exponent, modulo)
    local remainder = base

    for i = 1, exponent-1 do
        remainder = remainder * remainder
        if remainder >= modulo then
            remainder = remainder % modulo
        end
    end

    return remainder
end


function Handshake.clear()
    Handshake.base = -1
    Handshake.secret = -1
    Handshake.sharedSecret = -1
end


function Handshake.generateInitiatorData()
    Handshake.base = math.random(10,99999)
    Handshake.secret = math.random(10,99999)
    return {
        type = "initiate",
        prime = Handshake.prime,
        base = Handshake.base,
        moddedSecret = Handshake.exponentWithModulo(Handshake.base, Handshake.secret, Handshake.prime)
    }
end


function Handshake.generateResponseData(initiatorData)
    local isPrimeANumber = type(initiatorData.prime) == "number"
    local isPrimeMatching = initiatorData.prime == Handshake.prime
    local isBaseANumber = type(initiatorData.base) == "number"
    local isInitiator = initiatorData.type == "initiate"
    local isModdedSecretANumber = type(initiatorData.moddedSecret) == "number"
    local areAllNumbersNumbers = isPrimeANumber and isBaseANumber and isModdedSecretANumber

    if areAllNumbersNumbers and isPrimeMatching then
        if isInitiator then
            Handshake.base = initiatorData.base
            Handshake.secret = math.random(10,99999)
            Handshake.sharedSecret = Handshake.exponentWithModulo(initiatorData.moddedSecret, Handshake.secret, Handshake.prime)
            return {
                type = "response",
                prime = Handshake.prime,
                base = Handshake.base,
                moddedSecret = Handshake.exponentWithModulo(Handshake.base, Handshake.secret, Handshake.prime)
            }, Handshake.sharedSecret
        elseif initiatorData.type == "response" and Handshake.base > 0 and Handshake.secret > 0 then
            Handshake.sharedSecret = Handshake.exponentWithModulo(initiatorData.moddedSecret, Handshake.secret, Handshake.prime)
            return Handshake.sharedSecret
        else
            return false
        end
    else
        return false
    end
end



--    Secure Connection


local SecureConnection = {}
SecureConnection.__index = SecureConnection


SecureConnection.packetHeaderA = "["..protocolName.."-"
SecureConnection.packetHeaderB = "-SecureConnection-Packet-Header]"
SecureConnection.packetMatchA = "%["..protocolName.."%-"
SecureConnection.packetMatchB = "%-SecureConnection%-Packet%-Header%](.+)"
SecureConnection.connectionTimeout = 0.1
SecureConnection.successPacketTimeout = 0.1


function SecureConnection.new(secret, key, identifier, distance, isRednet)
    local self = setmetatable({}, SecureConnection)
    self:setup(secret, key, identifier, distance, isRednet)
    return self
end


function SecureConnection:setup(secret, key, identifier, distance, isRednet)
    local rawSecret

    if isRednet then
        self.isRednet = true
        self.distance = -1
        self.rednet_id = distance
        rawSecret = protocolName .. "|" .. tostring(secret) .. "|" .. tostring(identifier) ..
        "|" .. tostring(key) .. "|rednet"
    else
        self.isRednet = false
        self.distance = distance
        rawSecret = protocolName .. "|" .. tostring(secret) .. "|" .. tostring(identifier) ..
        "|" .. tostring(key) .. "|" .. tostring(distance)
    end

    self.identifier = identifier
    self.packetMatch = SecureConnection.packetMatchA .. Cryptography.sanatize(identifier) .. SecureConnection.packetMatchB
    self.packetHeader = SecureConnection.packetHeaderA .. identifier .. SecureConnection.packetHeaderB
    self.secret = Cryptography.sha.sha256(rawSecret)
    self.channel = Cryptography.channel(self.secret)

    if not self.isRednet then
        Modem.open(self.channel)
    end
end


function SecureConnection:verifyHeader(msg)
    if msg:match(self.packetMatch) then
        return true
    else
        return false
    end
end


function SecureConnection:sendMessage(msg, rednetProtocol)
    local rawEncryptedMsg = Cryptography.aes.encrypt(self.packetHeader .. msg, self.secret)
    local encryptedMsg = self.packetHeader .. rawEncryptedMsg

    if self.isRednet then
        rednet.send(self.rednet_id, encryptedMsg, rednetProtocol)
        return true
    else
        return Modem.transmit(self.channel, encryptedMsg)
    end
end


function SecureConnection:decryptMessage(msg)
    if self:verifyHeader(msg) then
        local encrypted = msg:match(self.packetMatch)

        local unencryptedMsg = nil
        pcall(function() unencryptedMsg = Cryptography.aes.decrypt(encrypted, self.secret) end)
        if not unencryptedMsg then
            return false, "Could not decrypt"
        end

        if self:verifyHeader(unencryptedMsg) then
            return true, unencryptedMsg:match(self.packetMatch)
        else
            return false, "Could not verify"
        end
    else
        return false, "Could not stage 1 verify"
    end
end



--    RDNT Protocol


protocols["rdnt"] = {}

local header = {}
header.dnsPacket = "[Firewolf-DNS-Packet]"
header.dnsHeaderMatch = "^%[Firewolf%-DNS%-Response%](.+)$"
header.rednetHeader = "[Firewolf-Rednet-Channel-Simulation]"
header.rednetMatch = "^%[Firewolf%-Rednet%-Channel%-Simulation%](%d+)$"
header.responseMatchA = "^%[Firewolf%-"
header.responseMatchB = "%-"
header.responseMatchC = "%-Handshake%-Response%](.+)$"
header.requestHeaderA = "[Firewolf-"
header.requestHeaderB = "-Handshake-Request]"
header.pageRequestHeaderA = "[Firewolf-"
header.pageRequestHeaderB = "-Page-Request]"
header.pageResponseMatchA = "^%[Firewolf%-"
header.pageResponseMatchB = "%-Page%-Response%]%[HEADER%](.-)%[BODY%](.+)$"
header.closeHeaderA = "[Firewolf-"
header.closeHeaderB = "-Connection-Close]"


protocols["rdnt"]["setup"] = function()
    if not Modem.exists() then
        error("No modem found!")
    end
end


protocols["rdnt"]["fetchAllSearchResults"] = function()
    Modem.open(publicDNSChannel)
    Modem.open(publicResponseChannel)
    Modem.transmit(publicDNSChannel, header.dnsPacket)
    Modem.close(publicDNSChannel)

    rednet.broadcast(header.dnsPacket, header.rednetHeader .. publicDNSChannel)

    local uniqueServers = {}
    local uniqueDomains = {}

    local timer = os.startTimer(searchResultTimeout)

    while true do
        local event, id, channel, protocol, message, dist = os.pullEventRaw()
        if event == "modem_message" then
            if channel == publicResponseChannel and message:match(header.dnsHeaderMatch) then
                if not uniqueServers[tostring(dist)] then
                    uniqueServers[tostring(dist)] = true
                    local domain = message:match(header.dnsHeaderMatch)
                    if not uniqueDomains[domain] then
                        if not(domain:find("/") or domain:find(":") or domain:find("%?")) and #domain > 4 then
                            timer = os.startTimer(searchResultTimeout)
                            uniqueDomains[message:match(header.dnsHeaderMatch)] = tostring(dist)
                        end
                    end
                end
            end
        elseif event == "rednet_message" and allowUnencryptedConnections then
            if protocol and tonumber(protocol:match(header.rednetMatch)) == publicResponseChannel and channel:match(header.dnsHeaderMatch) then
                if not uniqueServers[tostring(id)] then
                    uniqueServers[tostring(id)] = true
                    local domain = channel:match(header.dnsHeaderMatch)
                    if not uniqueDomains[domain] then
                        if not(domain:find("/") or domain:find(":") or domain:find("%?")) and #domain > 4 then
                            timer = os.startTimer(searchResultTimeout)
                            uniqueDomains[domain] = tostring(id)
                        end
                    end
                end
            end
        elseif event == "timer" and id == timer then
            local results = {}
            for k, _ in pairs(uniqueDomains) do
                table.insert(results, k)
            end

            return results
        end
    end
end


protocols["rdnt"]["fetchConnectionObject"] = function(url)
    local serverChannel = Cryptography.channel(url)
    local requestHeader = header.requestHeaderA .. url .. header.requestHeaderB
    local responseMatch = header.responseMatchA .. Cryptography.sanatize(url) .. header.responseMatchB

    local serializedHandshake = textutils.serialize(Handshake.generateInitiatorData())

    local rednetResults = {}
    local directResults = {}

    local disconnectOthers = function(ignoreDirect)
        for k,v in pairs(rednetResults) do
            v.close()
        end
        for k,v in pairs(directResults) do
            if k ~= ignoreDirect then
                v.close()
            end
        end
    end

    local timer = os.startTimer(initiationTimeout)

    Modem.open(serverChannel)
    Modem.transmit(serverChannel, requestHeader .. serializedHandshake)

    rednet.broadcast(requestHeader .. serializedHandshake, header.rednetHeader .. serverChannel)

    -- Extendable to have server selection

    while true do
        local event, id, channel, protocol, message, dist = os.pullEventRaw()
        if event == "modem_message" then
            local fullMatch = responseMatch .. tostring(dist) .. header.responseMatchC
            if channel == serverChannel and message:match(fullMatch) and type(textutils.unserialize(message:match(fullMatch))) == "table" then
                local key = Handshake.generateResponseData(textutils.unserialize(message:match(fullMatch)))
                if key then
                    local connection = SecureConnection.new(key, url, url, dist)
                    table.insert(directResults, {
                        connection = connection,
                        fetchPage = function(page)
                            if not connection then
                                return nil
                            end

                            local fetchTimer = os.startTimer(fetchTimeout)

                            local pageRequest = header.pageRequestHeaderA .. url .. header.pageRequestHeaderB .. page
                            local pageResponseMatch = header.pageResponseMatchA .. Cryptography.sanatize(url) .. header.pageResponseMatchB

                            connection:sendMessage(pageRequest, header.rednetHeader .. connection.channel)

                            while true do
                                local event, id, channel, protocol, message, dist = os.pullEventRaw()
                                if event == "modem_message" and channel == connection.channel and connection:verifyHeader(message) then
                                    local resp, data = connection:decryptMessage(message)
                                    if not resp then
                                        -- Decryption error
                                    elseif data and data ~= page then
                                        if data:match(pageResponseMatch) then
                                            local head, body = data:match(pageResponseMatch)
                                            return body, textutils.unserialize(head)
                                        end
                                    end
                                elseif event == "timer" and id == fetchTimer then
                                    return nil
                                end
                            end
                        end,
                        close = function()
                            if connection ~= nil then
                                connection:sendMessage(header.closeHeaderA .. url .. header.closeHeaderB, header.rednetHeader..connection.channel)
                                Modem.close(connection.channel)
                                connection = nil
                            end
                        end
                    })

                    disconnectOthers(1)
                    return directResults[1]
                end
            end
        elseif event == "rednet_message" then
            local fullMatch = responseMatch .. os.getComputerID() .. header.responseMatchC
            if protocol and tonumber(protocol:match(header.rednetMatch)) == serverChannel and channel:match(fullMatch) and type(textutils.unserialize(channel:match(fullMatch))) == "table" then
                local key = Handshake.generateResponseData(textutils.unserialize(channel:match(fullMatch)))
                if key then
                    local connection = SecureConnection.new(key, url, url, id, true)
                    table.insert(rednetResults, {
                        connection = connection,
                        fetchPage = function(page)
                            if not connection then
                                return nil
                            end

                            local fetchTimer = os.startTimer(fetchTimeout)

                            local pageRequest = header.pageRequestHeaderA .. url .. header.pageRequestHeaderB .. page
                            local pageResponseMatch = header.pageResponseMatchA .. Cryptography.sanatize(url) .. header.pageResponseMatchB

                            connection:sendMessage(pageRequest, header.rednetHeader .. connection.channel)

                            while true do
                                local event, id, channel, protocol, message, dist = os.pullEventRaw()
                                if event == "rednet_message" and protocol and tonumber(protocol:match(header.rednetMatch)) == connection.channel and connection:verifyHeader(channel) then
                                    local resp, data = connection:decryptMessage(channel)
                                    if not resp then
                                        -- Decryption error
                                    elseif data and data ~= page then
                                        if data:match(pageResponseMatch) then
                                            local head, body = data:match(pageResponseMatch)
                                            return body, textutils.unserialize(head)
                                        end
                                    end
                                elseif event == "timer" and id == fetchTimer then
                                    return nil
                                end
                            end
                        end,
                        close = function()
                            connection:sendMessage(header.closeHeaderA .. url .. header.closeHeaderB, header.rednetHeader..connection.channel)
                            Modem.close(connection.channel)
                            connection = nil
                        end
                    })

                    if #rednetResults == 1 then
                        timer = os.startTimer(0.2)
                    end
                end
            end
        elseif event == "timer" and id == timer then
            -- Return
            if #directResults > 0 then
                disconnectOthers(1)
                return directResults[1]
            elseif #rednetResults > 0 then
                local lowestID = math.huge
                local lowestResult = nil
                for k,v in pairs(rednetResults) do
                    if v.connection.rednet_id < lowestID then
                        lowestID = v.connection.rednet_id
                        lowestResult = v
                    end
                end

                for k,v in pairs(rednetResults) do
                    if v.connection.rednet_id ~= lowestID then
                        v.close()
                    end
                end

                return lowestResult
            else
                return nil
            end
        end
    end
end



--    Fetching Raw Data


local fetchSearchResultsForQuery = function(query)
    local all = protocols[currentProtocol]["fetchAllSearchResults"]()
    local results = {}
    if query and query:len() > 0 then
        for _, v in pairs(all) do
            if v:find(query:lower()) then
                table.insert(results, v)
            end
        end
    else
        results = all
    end

    table.sort(results)
    return results
end


local getConnectionObjectFromURL = function(url)
    local domain = url:match("^([^/]+)")
    return protocols[currentProtocol]["fetchConnectionObject"](domain)
end


local determineLanguage = function(header)
    if type(header) == "table" then
        if header.language and header.language == "Firewolf Markup" then
            return "fwml"
        else
            return "lua"
        end
    else
        return "lua"
    end
end



--    History


local appendToHistory = function(url)
    if history[1] ~= url then
        table.insert(history, 1, url)
    end
end



--    Fetch Websites


local loadingAnimation = function()
    local state = -2

    term.setTextColor(theme.text)
    term.setBackgroundColor(theme.accent)

    term.setCursorPos(w - 5, 1)
    term.write("[=  ]")

    local timer = os.startTimer(animationInterval)

    while true do
        local event, timerID = os.pullEvent()
        if event == "timer" and timerID == timer then
            term.setTextColor(theme.text)
            term.setBackgroundColor(theme.accent)

            state = state + 1

            term.setCursorPos(w - 5, 1)
            term.write("[   ]")
            term.setCursorPos(w - 2 - math.abs(state), 1)
            term.write("=")

            if state == 2 then
                state = -2
            end

            timer = os.startTimer(animationInterval)
        end
    end
end


local normalizeURL = function(url)
    url = url:lower():gsub(" ", "")
    if url == "home" or url == "homepage" then
        url = "firewolf"
    end

    return url
end


local normalizePage = function(page)
    if not page then page = "" end
    page = page:lower()
    if page == "" then
        page = "/"
    end
    return page
end


local determineActionForURL = function(url)
    if url:len() > 0 and url:gsub("/", ""):len() == 0 then
        return "none"
    end

    if url == "exit" then
        return "exit"
    elseif builtInSites["display"][url] then
        return "internal website"
    elseif url == "" then
        local results = fetchSearchResultsForQuery()
        if #results > 0 then
            return "search", results
        else
            return "none"
        end
    else
        local connection = getConnectionObjectFromURL(url)
        if connection then
            return "external website", connection
        else
            local results = fetchSearchResultsForQuery(url)
            if #results > 0 then
                return "search", results
            else
                return "none"
            end
        end
    end
end


local fetchSearch = function(url, results)
    return languages["lua"]["runWithoutAntivirus"](builtInSites["search"], results)
end


local fetchInternal = function(url)
    return languages["lua"]["runWithoutAntivirus"](builtInSites["display"][url])
end


local fetchError = function(err)
    return languages["lua"]["runWithoutAntivirus"](builtInSites["error"], err)
end


local fetchExternal = function(url, connection)
    if connection.multipleServers then
        -- Please forgive me
        -- GravityScore forced me to do it like this
        -- I don't mean it, I really don't.
        connection = connection.servers[1]
    end

    local page = normalizePage(url:match("^[^/]+/(.+)"))
    local contents, head = connection.fetchPage(page)
    if contents then
        if type(contents) ~= "string" then
            return fetchNone()
        else
            local language = determineLanguage(head)
            return languages[language]["run"](contents, page, connection)
        end
    else
        if connection then
            connection.close()
            return "retry"
        end
        return fetchError("A connection error/timeout has occurred!")
    end
end


local fetchNone = function()
    return languages["lua"]["runWithoutAntivirus"](builtInSites["noresults"])
end


local fetchURL = function(url, inheritConnection)
    url = normalizeURL(url)
    currentWebsiteURL = url

    if inheritConnection then
        local resp = fetchExternal(url, inheritConnection)
        if resp ~= "retry" then
            return resp, false, inheritConnection
        end
    end

    local action, connection = determineActionForURL(url)

    if action == "search" then
        return fetchSearch(url, connection), true
    elseif action == "internal website" then
        return fetchInternal(url), true
    elseif action == "external website" then
        local resp = fetchExternal(url, connection)
        if resp == "retry" then
            return fetchError("A connection error/timeout has occurred!"), false, connection
        else
            return resp, false, connection
        end
    elseif action == "none" then
        return fetchNone(), true
    elseif action == "exit" then
        os.queueEvent("terminate")
    end

    return nil
end



--    Tabs


local switchTab = function(index, shouldntResume)
    if not tabs[index] then
        return
    end

    if tabs[currentTab].win then
        tabs[currentTab].win.setVisible(false)
    end

    currentTab = index
    isMenubarOpen = tabs[currentTab].isMenubarOpen
    currentWebsiteURL = tabs[currentTab].url

    term.redirect(originalTerminal)
    clear(theme.background, theme.text)
    drawMenubar()

    term.redirect(tabs[currentTab].win)
    term.setCursorPos(1, 1)
    tabs[currentTab].win.setVisible(true)
    tabs[currentTab].win.redraw()

    if not shouldntResume then
        coroutine.resume(tabs[currentTab].thread)
    end
end


local closeCurrentTab = function()
    if #tabs <= 0 then
        return
    end

    table.remove(tabs, currentTab)

    currentTab = math.max(currentTab - 1, 1)
    switchTab(currentTab, true)
end


local loadTab = function(index, url, givenFunc)
    url = normalizeURL(url)

    local func = nil
    local isOpen = true
    local currentConnection = false

    isMenubarOpen = true
    currentWebsiteURL = url
    drawMenubar()

    if tabs[index] and tabs[index].connection and tabs[index].url then
        if url:match("^([^/]+)") == tabs[index].url:match("^([^/]+)") then
            currentConnection = tabs[index].connection
        else
            tabs[index].connection.close()
            tabs[index].connection = nil
        end
    end

    if givenFunc then
        func = givenFunc
    else
        parallel.waitForAny(function()
            func, isOpen, connection = fetchURL(url, currentConnection)
        end, function()
            while true do
                local event, key = os.pullEvent()
                if event == "key" and (key == 29 or key == 157) then
                    break
                end
            end
        end, loadingAnimation)
    end

    if func then
        appendToHistory(url)

        tabs[index] = {}
        tabs[index].url = url
        tabs[index].connection = connection
        tabs[index].win = window.create(originalTerminal, 1, 1, w, h, false)

        tabs[index].thread = coroutine.create(func)
        tabs[index].isMenubarOpen = isOpen
        tabs[index].isMenubarPermanent = isOpen

        tabs[index].ox = 1
        tabs[index].oy = 1

        term.redirect(tabs[index].win)
        clear(theme.background, theme.text)

        switchTab(index)
    end
end



--    Website Environments


local getWhitelistedEnvironment = function()
    local env = {}

    local function copy(source, destination, key)
        destination[key] = {}
        for k, v in pairs(source) do
            destination[key][k] = v
        end
    end

    copy(bit, env, "bit")
    copy(colors, env, "colors")
    copy(colours, env, "colours")
    copy(coroutine, env, "coroutine")

    copy(disk, env, "disk")
    env["disk"]["setLabel"] = nil
    env["disk"]["eject"] = nil

    copy(gps, env, "gps")
    copy(help, env, "help")
    copy(keys, env, "keys")
    copy(math, env, "math")

    copy(os, env, "os")
    env["os"]["run"] = nil
    env["os"]["shutdown"] = nil
    env["os"]["reboot"] = nil
    env["os"]["setComputerLabel"] = nil
    env["os"]["queueEvent"] = nil
    env["os"]["pullEvent"] = function(filter)
        while true do
            local event = {os.pullEvent(filter)}
            if not filter then
                return unpack(event)
            elseif filter and event[1] == filter then
                return unpack(event)
            end
        end
    end
    env["os"]["pullEventRaw"] = env["os"]["pullEvent"]

    copy(paintutils, env, "paintutils")
    copy(parallel, env, "parallel")
    copy(peripheral, env, "peripheral")
    copy(rednet, env, "rednet")
    copy(redstone, env, "redstone")
    copy(redstone, env, "rs")

    copy(shell, env, "shell")
    env["shell"]["run"] = nil
    env["shell"]["exit"] = nil
    env["shell"]["setDir"] = nil
    env["shell"]["setAlias"] = nil
    env["shell"]["clearAlias"] = nil
    env["shell"]["setPath"] = nil

    copy(string, env, "string")
    copy(table, env, "table")

    copy(term, env, "term")
    env["term"]["redirect"] = nil
    env["term"]["restore"] = nil

    copy(textutils, env, "textutils")
    copy(vector, env, "vector")

    if turtle then
        copy(turtle, env, "turtle")
    end

    if http then
        copy(http, env, "http")
    end

    env["assert"] = assert
    env["printError"] = printError
    env["tonumber"] = tonumber
    env["tostring"] = tostring
    env["type"] = type
    env["next"] = next
    env["unpack"] = unpack
    env["pcall"] = pcall
    env["xpcall"] = xpcall
    env["sleep"] = sleep
    env["pairs"] = pairs
    env["ipairs"] = ipairs
    env["read"] = read
    env["write"] = write
    env["select"] = select
    env["print"] = print
    env["setmetatable"] = setmetatable
    env["getmetatable"] = getmetatable

    env["_G"] = env

    return env
end


local overrideEnvironment = function(env)
    local localTerm = {}
    for k, v in pairs(term) do
        localTerm[k] = v
    end

    env["term"]["clear"] = function()
        localTerm.clear()
        drawMenubar()
    end

    env["term"]["scroll"] = function(n)
        localTerm.scroll(n)
        drawMenubar()
    end

    env["shell"]["getRunningProgram"] = function()
        return currentWebsiteURL
    end
end

local urlEncode = function(url)
    local result = url

    result = result:gsub("%%", "%%a")
    result = result:gsub(":", "%%c")
    result = result:gsub("/", "%%s")
    result = result:gsub("\n", "%%n")
    result = result:gsub(" ", "%%w")
    result = result:gsub("&", "%%m")
    result = result:gsub("%?", "%%q")
    result = result:gsub("=", "%%e")
    result = result:gsub("%.", "%%d")

    return result
end

local urlDecode = function(url)
    local result = url

    result = result:gsub("%%c", ":")
    result = result:gsub("%%s", "/")
    result = result:gsub("%%n", "\n")
    result = result:gsub("%%w", " ")
    result = result:gsub("%%&", "&")
    result = result:gsub("%%q", "%?")
    result = result:gsub("%%e", "=")
    result = result:gsub("%%d", "%.")
    result = result:gsub("%%m", "%%")

    return result
end

local applyAPIFunctions = function(env, connection)
    env["firewolf"] = {}
    env["firewolf"]["version"] = version
    env["firewolf"]["domain"] = currentWebsiteURL:match("^[^/]+")

    env["firewolf"]["redirect"] = function(url)
        if type(url) ~= "string" then
            return error("string (url) expected, got " .. type(url))
        end

        os.queueEvent(redirectEvent, url)
        coroutine.yield()
    end

    env["firewolf"]["download"] = function(page)
        if type(page) ~= "string" then
            return error("string (page) expected")
        end
        local bannedNames = {"ls", "dir", "delete", "copy", "move", "list", "rm", "cp", "mv", "clear", "cd", "lua"}

        local startSearch, endSearch = page:find(currentWebsiteURL:match("^[^/]+"))
        if startSearch == 1 then
            if page:sub(endSearch + 1, endSearch + 1) == "/" then
                page = page:sub(endSearch + 2, -1)
            else
                page = page:sub(endSearch + 1, -1)
            end
        end

        local filename = page:match("([^/]+)$")
        if not filename then
            return false, "Cannot download index"
        end

        for k, v in pairs(bannedNames) do
            if filename == v then
                return false, "Filename prohibited!"
            end
        end

        if not fs.exists(downloadsLocation) then
            fs.makeDir(downloadsLocation)
        elseif not fs.isDir(downloadsLocation) then
            return false, "Downloads disabled!"
        end

        contents = connection.fetchPage(normalizePage(page))
        if type(contents) ~= "string" then
            return false, "Download error!"
        else
            local f = io.open(downloadsLocation .. "/" .. filename, "w")
            f:write(contents)
            f:close()
            return true, downloadsLocation .. "/" .. filename
        end
    end

    env["firewolf"]["encode"] = function(vars)
        if type(vars) ~= "table" then
            return error("table (vars) expected, got " .. type(vars))
        end

        local startSearch, endSearch = page:find(currentWebsiteURL:match("^[^/]+"))
        if startSearch == 1 then
            if page:sub(endSearch + 1, endSearch + 1) == "/" then
                page = page:sub(endSearch + 2, -1)
            else
                page = page:sub(endSearch + 1, -1)
            end
        end

        local construct = "?"
        for k,v in pairs(vars) do
            construct = construct .. urlEncode(tostring(k)) .. "=" .. urlEncode(tostring(v)) .. "&"
        end
        -- Get rid of that last ampersand
        construct = construct:sub(1, -2)

        return construct
    end

    env["firewolf"]["query"] = function(page, vars)
        if type(page) ~= "string" then
            return error("string (page) expected, got " .. type(page))
        end
        if vars and type(vars) ~= "table" then
            return error("table (vars) expected, got " .. type(vars))
        end

        local startSearch, endSearch = page:find(currentWebsiteURL:match("^[^/]+"))
        if startSearch == 1 then
            if page:sub(endSearch + 1, endSearch + 1) == "/" then
                page = page:sub(endSearch + 2, -1)
            else
                page = page:sub(endSearch + 1, -1)
            end
        end

        local construct = page .. "?"
        if vars then
            for k,v in pairs(vars) do
                construct = construct .. urlEncode(tostring(k)) .. "=" .. urlEncode(tostring(v)) .. "&"
            end
        end
        -- Get rid of that last ampersand
        construct = construct:sub(1, -2)

        contents = connection.fetchPage(normalizePage(construct))
        if type(contents) == "string" then
            return contents
        else
            return false
        end
    end

    env["firewolf"]["loadImage"] = function(page)
        if type(page) ~= "string" then
            return error("string (page) expected, got " .. type(page))
        end

        local startSearch, endSearch = page:find(currentWebsiteURL:match("^[^/]+"))
        if startSearch == 1 then
            if page:sub(endSearch + 1, endSearch + 1) == "/" then
                page = page:sub(endSearch + 2, -1)
            else
                page = page:sub(endSearch + 1, -1)
            end
        end

        local filename = page:match("([^/]+)$")
        if not filename then
            return false, "Cannot load index as an image!"
        end

        contents = connection.fetchPage(normalizePage(page))
        if type(contents) ~= "string" then
            return false, "Download error!"
        else
            local colorLookup = {}
            for n = 1, 16 do
                colorLookup[string.byte("0123456789abcdef", n, n)] = 2 ^ (n - 1)
            end

            local image = {}
            for line in contents:gmatch("[^\n]+") do
                local lines = {}
                for x = 1, line:len() do
                    lines[x] = colorLookup[string.byte(line, x, x)] or 0
                end
                table.insert(image, lines)
            end

            return image
        end
    end

    env["center"] = center
    env["fill"] = fill
end


local getWebsiteEnvironment = function(antivirus, connection)
    local env = {}

    if antivirus then
        env = getWhitelistedEnvironment()
        overrideEnvironment(env)
    else
        setmetatable(env, {__index = _G})
    end

    applyAPIFunctions(env, connection)

    return env
end



--    FWML Execution


local render = {}

render["functions"] = {}
render["functions"]["public"] = {}
render["alignations"] = {}

render["variables"] = {
    scroll,
    maxScroll,
    align,
    linkData = {},
    blockLength,
    link,
    linkStart,
    markers,
    currentOffset,
}


local function getLine(loc, data)
    local _, changes = data:sub(1, loc):gsub("\n", "")
    if not changes then
        return 1
    else
        return changes + 1
    end
end


local function parseData(data)
    local commands = {}
    local searchPos = 1

    while #data > 0 do
        local sCmd, eCmd = data:find("%[[^%]]+%]", searchPos)
        if sCmd then
            sCmd = sCmd + 1
            eCmd = eCmd - 1

            if (sCmd > 2) then
                if data:sub(sCmd - 2, sCmd - 2) == "\\" then
                    local t = data:sub(searchPos, sCmd - 1):gsub("\n", ""):gsub("\\%[", "%["):gsub("\\%]", "%]")
                    if #t > 0 then
                        if #commands > 0 and type(commands[#commands][1]) == "string" then
                            commands[#commands][1] = commands[#commands][1] .. t
                        else
                            table.insert(commands, {t})
                        end
                    end
                    searchPos = sCmd
                else
                    local t = data:sub(searchPos, sCmd - 2):gsub("\n", ""):gsub("\\%[", "%["):gsub("\\%]", "%]")
                    if #t > 0 then
                        if #commands > 0 and type(commands[#commands][1]) == "string" then
                            commands[#commands][1] = commands[#commands][1] .. t
                        else
                            table.insert(commands, {t})
                        end
                    end

                    t = data:sub(sCmd, eCmd):gsub("\n", "")
                    table.insert(commands, {getLine(sCmd, data), t})
                    searchPos = eCmd + 2
                end
            else
                local t = data:sub(sCmd, eCmd):gsub("\n", "")
                table.insert(commands, {getLine(sCmd, data), t})
                searchPos = eCmd + 2
            end
        else
            local t = data:sub(searchPos, -1):gsub("\n", ""):gsub("\\%[", "%["):gsub("\\%]", "%]")
            if #t > 0 then
                if #commands > 0 and type(commands[#commands][1]) == "string" then
                    commands[#commands][1] = commands[#commands][1] .. t
                else
                    table.insert(commands, {t})
                end
            end

            break
        end
    end

    return commands
end


local function proccessData(commands)
    searchIndex = 0

    while searchIndex < #commands do
        searchIndex = searchIndex + 1

        local length = 0
        local origin = searchIndex

        if type(commands[searchIndex][1]) == "string" then
            length = length + #commands[searchIndex][1]
            local endIndex = origin
            for i = origin + 1, #commands do
                if commands[i][2] then
                    local command = commands[i][2]:match("^(%w+)%s-")
                    if not (command == "c" or command == "color" or command == "bg"
                            or command == "background" or command == "newlink" or command == "endlink") then
                        endIndex = i
                        break
                    end
                elseif commands[i][2] then

                else
                    length = length + #commands[i][1]
                end
                if i == #commands then
                    endIndex = i
                end
            end

            commands[origin][2] = length
            searchIndex = endIndex
            length = 0
        end
    end

    return commands
end


local function parse(original)
    return proccessData(parseData(original))
end


render["functions"]["display"] = function(text, length, offset, center)
    if not offset then
        offset = 0
    end

    return render.variables.align(text, length, w, offset, center);
end


render["functions"]["displayText"] = function(source)
    if source[2] then
        render.variables.blockLength = source[2]
        if render.variables.link and not render.variables.linkStart then
            render.variables.linkStart = render.functions.display(
                source[1], render.variables.blockLength, render.variables.currentOffset, w / 2)
        else
            render.functions.display(source[1], render.variables.blockLength, render.variables.currentOffset, w / 2)
        end
    else
        if render.variables.link and not render.variables.linkStart then
            render.variables.linkStart = render.functions.display(source[1], nil, render.variables.currentOffset, w / 2)
        else
            render.functions.display(source[1], nil, render.variables.currentOffset, w / 2)
        end
    end
end


render["functions"]["public"]["br"] = function(source)
    if render.variables.link then
        return "Cannot insert new line within a link on line " .. source[1]
    end

    render.variables.scroll = render.variables.scroll + 1
    render.variables.maxScroll = math.max(render.variables.scroll, render.variables.maxScroll)
end


render["functions"]["public"]["c "] = function(source)
    local sColor = source[2]:match("^%w+%s+(.+)$") or ""
    if colors[sColor] then
        term.setTextColor(colors[sColor])
    else
        return "Invalid color: \"" .. sColor .. "\" on line " .. source[1]
    end
end


render["functions"]["public"]["color "] = render["functions"]["public"]["c "]


render["functions"]["public"]["bg "] = function(source)
    local sColor = source[2]:match("^%w+%s+(.+)$") or ""
    if colors[sColor] then
        term.setBackgroundColor(colors[sColor])
    else
        return "Invalid color: \"" .. sColor .. "\" on line " .. source[1]
    end
end


render["functions"]["public"]["background "] = render["functions"]["public"]["bg "]


render["functions"]["public"]["newlink "] = function(source)
    if render.variables.link then
        return "Cannot nest links on line " .. source[1]
    end

    render.variables.link = source[2]:match("^%w+%s+(.+)$") or ""
    render.variables.linkStart = false
end


render["functions"]["public"]["endlink"] = function(source)
    if not render.variables.link then
        return "Cannot end a link without a link on line " .. source[1]
    end

    local linkEnd = term.getCursorPos()-1
    table.insert(render.variables.linkData, {render.variables.linkStart,
        linkEnd, render.variables.scroll, render.variables.link})
    render.variables.link = false
    render.variables.linkStart = false
end


render["functions"]["public"]["offset "] = function(source)
    local offset = tonumber((source[2]:match("^%w+%s+(.+)$") or ""))
    if offset then
        render.variables.currentOffset = offset
    else
        return "Invalid offset value: \"" .. (source[2]:match("^%w+%s+(.+)$") or "") .. "\" on line " .. source[1]
    end
end


render["functions"]["public"]["marker "] = function(source)
    render.variables.markers[(source[2]:match("^%w+%s+(.+)$") or "")] = render.variables.scroll
end


render["functions"]["public"]["goto "] = function(source)
    local location = source[2]:match("%w+%s+(.+)$")
    if render.variables.markers[location] then
        render.variables.scroll = render.variables.markers[location]
    else
        return "No such location: \"" .. (source[2]:match("%w+%s+(.+)$") or "") .. "\" on line " .. source[1]
    end
end


render["functions"]["public"]["box "] = function(source)
    local sColor, align, height, width, offset, url = source[2]:match("^box (%a+) (%a+) (%-?%d+) (%-?%d+) (%-?%d+) ?([^ ]*)")
    if not sColor then
        return "Invalid box syntax on line " .. source[1]
    end

    local x, y = term.getCursorPos()
    local startX

    if align == "center" or align == "centre" then
        startX = math.ceil((w / 2) - width / 2) + offset
    elseif align == "left" then
        startX = 1 + offset
    elseif align == "right" then
        startX = (w - width + 1) + offset
    else
        return "Invalid align option for box on line " .. source[1]
    end

    if not colors[sColor] then
        return "Invalid color: \"" .. sColor .. "\" for box on line " .. source[1]
    end

    term.setBackgroundColor(colors[sColor])
    for i = 0, height - 1 do
        term.setCursorPos(startX, render.variables.scroll + i)
        term.write(string.rep(" ", width))
        if url:len() > 3 then
            table.insert(render.variables.linkData, {startX, startX + width - 1, render.variables.scroll + i, url})
        end
    end

    render.variables.maxScroll = math.max(render.variables.scroll + height - 1, render.variables.maxScroll)
    term.setCursorPos(x, y)
end


render["alignations"]["left"] = function(text, length, _, offset)
    local x, y = term.getCursorPos()
    if length then
        term.setCursorPos(1 + offset, render.variables.scroll)
        term.write(text)
        return 1 + offset
    else
        term.setCursorPos(x, render.variables.scroll)
        term.write(text)
        return x
    end
end


render["alignations"]["right"] = function(text, length, width, offset)
    local x, y = term.getCursorPos()
    if length then
        term.setCursorPos((width - length + 1) + offset, render.variables.scroll)
        term.write(text)
        return (width - length + 1) + offset
    else
        term.setCursorPos(x, render.variables.scroll)
        term.write(text)
        return x
    end
end


render["alignations"]["center"] = function(text, length, _, offset, center)
    local x, y = term.getCursorPos()
    if length then
        term.setCursorPos(math.ceil(center - length / 2) + offset, render.variables.scroll)
        term.write(text)
        return math.ceil(center - length / 2) + offset
    else
        term.setCursorPos(x, render.variables.scroll)
        term.write(text)
        return x
    end
end


render["render"] = function(data, startScroll)
    if startScroll == nil then
        render.variables.startScroll = 0
    else
        render.variables.startScroll = startScroll
    end

    render.variables.scroll = startScroll + 1
    render.variables.maxScroll = render.variables.scroll

    render.variables.linkData = {}

    render.variables.align = render.alignations.left

    render.variables.blockLength = 0
    render.variables.link = false
    render.variables.linkStart = false
    render.variables.markers = {}
    render.variables.currentOffset = 0

    for k, v in pairs(data) do
        if type(v[2]) ~= "string" then
            render.functions.displayText(v)
        elseif v[2] == "<" or v[2] == "left" then
            render.variables.align = render.alignations.left
        elseif v[2] == ">" or v[2] == "right" then
            render.variables.align = render.alignations.right
        elseif v[2] == "=" or v[2] == "center" then
            render.variables.align = render.alignations.center
        else
            local existentFunction = false

            for name, func in pairs(render.functions.public) do
                if v[2]:find(name) == 1 then
                    existentFunction = true
                    local ret = func(v)
                    if ret then
                        return ret
                    end
                end
            end

            if not existentFunction then
                return "Non-existent tag: \"" .. v[2] .. "\" on line " .. v[1]
            end
        end
    end

    return render.variables.linkData, render.variables.maxScroll - render.variables.startScroll
end



--    Lua Execution


languages["lua"] = {}
languages["fwml"] = {}


languages["lua"]["runWithErrorCatching"] = function(func, ...)
    local _, err = pcall(func, ...)
    if err then
        os.queueEvent(websiteErrorEvent, err)
    end
end


languages["lua"]["runWithoutAntivirus"] = function(func, ...)
    local args = {...}
    local env = getWebsiteEnvironment(false)
    setfenv(func, env)
    return function()
        languages["lua"]["runWithErrorCatching"](func, unpack(args))
    end
end


languages["lua"]["run"] = function(contents, page, connection, ...)
    local func, err = loadstring("sleep(0) " .. contents, page)
    if err then
        return languages["lua"]["runWithoutAntivirus"](builtInSites["crash"], err)
    else
        local args = {...}
        local env = getWebsiteEnvironment(true, connection)
        setfenv(func, env)
        return function()
            languages["lua"]["runWithErrorCatching"](func, unpack(args))
        end
    end
end


languages["fwml"]["run"] = function(contents, page, connection, ...)
    local err, data = pcall(parse, contents)
    if not err then
        return languages["lua"]["runWithoutAntivirus"](builtInSites["crash"], data)
    end

    return function()
        local currentScroll = 0
        local err, links, pageHeight = pcall(render.render, data, currentScroll)
        if type(links) == "string" or not err then
            term.clear()
            os.queueEvent(websiteErrorEvent, links)
        else
            while true do
                local e, scroll, x, y = os.pullEvent()
                if e == "mouse_click" then
                    for k, v in pairs(links) do
                        if x >= math.min(v[1], v[2]) and x <= math.max(v[1], v[2]) and y == v[3] then
                            os.queueEvent(redirectEvent, v[4])
                            coroutine.yield()
                        end
                    end
                elseif e == "mouse_scroll" then
                    if currentScroll - scroll - h >= -pageHeight and currentScroll - scroll <= 0 then
                        currentScroll = currentScroll - scroll
                        clear(theme.background, theme.text)
                        links = render.render(data, currentScroll)
                    end
                elseif e == "key" and scroll == keys.up or scroll == keys.down then
                    local scrollAmount

                    if scroll == keys.up then
                        scrollAmount = 1
                    elseif scroll == keys.down then
                        scrollAmount = -1
                    end

                    local scrollLessHeight = currentScroll + scrollAmount - h >= -pageHeight
                    local scrollZero = currentScroll + scrollAmount <= 0
                    if scrollLessHeight and scrollZero then
                        currentScroll = currentScroll + scrollAmount
                        clear(theme.background, theme.text)
                        links = render.render(data, currentScroll)
                    end
                end
            end
        end
    end
end



--    Query Bar


local readNewWebsiteURL = function()
    local onEvent = function(text, event, key, x, y)
        if event == "mouse_click" then
            if y == 2 then
                local index = determineClickedTab(x, y)
                if index == "new" and #tabs < maxTabs then
                    loadTab(#tabs + 1, "firewolf")
                elseif index == "close" then
                    closeCurrentTab()
                elseif index then
                    switchTab(index)
                end

                return {["nullifyText"] = true, ["exit"] = true}
            elseif y > 2 then
                return {["nullifyText"] = true, ["exit"] = true}
            end
        elseif event == "key" then
            if key == 29 or key == 157 then
                return {["nullifyText"] = true, ["exit"] = true}
            end
        end
    end

    isMenubarOpen = true
    drawMenubar()
    term.setCursorPos(2, 1)
    term.setTextColor(theme.text)
    term.setBackgroundColor(theme.accent)
    term.clearLine()
    term.write(currentProtocol .. "://")

    local website = modifiedRead({
        ["onEvent"] = onEvent,
        ["displayLength"] = w - 9,
        ["history"] = history,
    })

    if not website then
        if not tabs[currentTab].isMenubarPermanent then
            isMenubarOpen = false
            menubarWindow.setVisible(false)
        else
            isMenubarOpen = true
            menubarWindow.setVisible(true)
        end

        term.redirect(tabs[currentTab].win)
        tabs[currentTab].win.setVisible(true)
        tabs[currentTab].win.redraw()

        return
    elseif website == "exit" then
        error()
    end

    loadTab(currentTab, website)
end



--    Event Management


local handleKeyDown = function(event)
    if event[2] == 29 or event[2] == 157 then
        readNewWebsiteURL()
        return true
    end

    return false
end


local handleMouseDown = function(event)
    if isMenubarOpen then
        if event[4] == 1 then
            readNewWebsiteURL()
            return true
        elseif event[4] == 2 then
            local index = determineClickedTab(event[3], event[4])
            if index == "new" and #tabs < maxTabs then
                loadTab(#tabs + 1, "firewolf")
            elseif index == "close" then
                closeCurrentTab()
            elseif index then
                switchTab(index)
            end

            return true
        end
    end

    return false
end


local handleEvents = function()
    loadTab(1, startupSite)
    currentTab = 1

    while true do
        drawMenubar()
        local event = {os.pullEventRaw()}
        drawMenubar()

        local cancelEvent = false
        if event[1] == "terminate" then
            break
        elseif event[1] == "key" then
            cancelEvent = handleKeyDown(event)
        elseif event[1] == "mouse_click" then
            cancelEvent = handleMouseDown(event)
        elseif event[1] == websiteErrorEvent then
            cancelEvent = true

            loadTab(currentTab, tabs[currentTab].url, function()
                builtInSites["crash"](event[2])
            end)
        elseif event[1] == redirectEvent then
            cancelEvent = true

            if (event[2]:match("^rdnt://(.+)$")) then
                event[2] = event[2]:match("^rdnt://(.+)$")
            end

            loadTab(currentTab, event[2])
        end

        if not cancelEvent then
            term.redirect(tabs[currentTab].win)
            term.setCursorPos(tabs[currentTab].ox, tabs[currentTab].oy)

            coroutine.resume(tabs[currentTab].thread, unpack(event))

            local ox, oy = term.getCursorPos()
            tabs[currentTab].ox = ox
            tabs[currentTab].oy = oy
        end
    end
end



--    Main


local main = function()
    currentProtocol = "rdnt"
    currentTab = 1

    if term.isColor() then
        theme = colorTheme
        enableTabBar = true
    else
        theme = grayscaleTheme
        enableTabBar = false
    end

    setupMenubar()
    protocols[currentProtocol]["setup"]()

    clear(theme.background, theme.text)
    handleEvents()
end


local handleError = function(err)
    clear(theme.background, theme.text)

    fill(1, 3, w, 3, theme.subtle)
    term.setCursorPos(1, 4)
    center("Firewolf has crashed!")

    term.setBackgroundColor(theme.background)
    term.setCursorPos(1, 8)
    centerSplit(err, w - 4)
    print("\n")
    center("Please report this error to")
    center("Towtow10.")
    print("")
    center("Press any key to exit.")

    os.pullEvent("key")
    os.queueEvent("")
    os.pullEvent()
end

local _, err = pcall(main)
term.redirect(originalTerminal)

Modem.closeAll()

if err and not err:lower():find("terminate") then
    handleError(err)
end


clear(colors.black, colors.white)
center("Thanks for using Firewolf " .. version)
center("Made by GravityScore and 1lann and Towtow10")
print("")