LunaOS Installer

local args = {...}

local gitProfile = {
    api = "https://api.github.com/repos",
    raw = "https://raw.githubusercontent.com",
    username = "Morganamilo",
    reponame = "LunaOS",
    access_token = "31b6f63ef3e86f2e9972e2dae485ea6b02442bea"
}

local blacklist = {
    ".gitignore",
    "README.md",
    "docs"
}

local function isBlacklisted(str)
    for k,v in pairs(blacklist) do
        if v == str:sub(1, #v) then
            return true
        end
    end

    return false
end

local git = {}
local utils = {}

local numToHex = {"1", "2", "3", "4", "5", "6", "7", "b", "9", "a", "b", "c", "d", "e", "f"}
numToHex[0] = "0"
numToHex[16] = "-"

local whitespace = {" ", "\t", "\n", "\r"}
local escapes = {["\\\""] = "\"", ["\\\\"] = "\\", ["\\b"] = "\b", ["\\f"] = "\f", ["\\n"] = "\n", ["\\r"] = "\r", ["\\t"] = "\t", ["\\/"] = "/"}
local control = {":",",","{", "}", "[", "]"}
local JSON = {}
local xSize, ySize = term.getSize()

local paneSize = 9
local paneStart = math.floor(ySize/2 - paneSize / 2)

local drawText
local drawBackground
local drawBar
local drawDots
local decodeImage
local drawImage

local width = xSize - 6

local imageStart = paneStart
local textStart = paneStart + 5
local barStart = paneStart + 9

local filesToDownload = 100
local filesDownloaded = 0

local image = "                  "

local function drawBackground()
    local backgroundPos = math.floor((xSize - width) / 2) + 1

    local whitespace = string.rep(" ", width)
    local textColour = string.rep("8", width)

    for y = 5, 8 do
        term.setCursorPos(backgroundPos, y)
        term.blit(whitespace, textColour, textColour)
    end

end

local function drawText(text)
    local width = width - 2
    local textPos = math.floor((xSize - width) / 2) + 1

    local textColour = string.rep("b", width)
    local backgroundColour = string.rep("7", width)

    for y = textStart, textStart + 3 do
        local t = text:sub(1  + (y - textStart) * width, (y - textStart + 1) * width)
        local prePad = string.rep(" ", math.floor(math.max(width - #t, 0) / 2))
        local postPad = string.rep(" ", width - #prePad - #t)

        t = prePad .. t .. postPad
        term.setCursorPos(textPos +  width - #t , y)
        term.blit(t, textColour, backgroundColour)
    end
end

local function drawBar(percent)
    local width = width - 2
    local percent = math.floor((percent * width) + 0.5)

    local backgroundPos = math.floor((xSize - width) / 2) + 1

    local whitespace = string.rep(" ", width)
    local textColour = string.rep("9", percent) ..  string.rep("8", width - percent)

    term.setCursorPos(backgroundPos, barStart)
    term.blit(whitespace, textColour, textColour)
end

local function decodeImage(image)
    local decodeImage = {size = {}, text = {}, textColour = {}, colour = {}}

    decodeImage.size[1] = string.byte(image:sub(1,1))
    decodeImage.size[2] = string.byte(image:sub(2,2))

    for n = 3, #image, 3 do
        local text = image:sub(n,n)
        local textColour = string.byte(image, n + 1)
        local colour = string.byte(image, n + 2)
        local l = #decodeImage.text + 1

        decodeImage.text[l] = text
        decodeImage.textColour[l] = numToHex[textColour]
        decodeImage.colour[l] = numToHex[colour]
    end

    return decodeImage
end

local function drawImage()
    for y = 1, image.size[2] do
        local pixel = ""
        local text = ""
        local textColour = ""

        for x = 1, image.size[1] do
            pixel = pixel .. image.colour[x + ((y - 1)* image.size[1])] or " "
            text = text .. image.text[x + ((y - 1)* image.size[1])] or "0"
            textColour = textColour .. image.textColour[x + ((y - 1)* image.size[1])] or "0"
        end

        term.setCursorPos(1 + math.floor(xSize/2 - image.size[1]/2), imageStart + y - 1)
        term.blit(text, textColour, pixel)
    end
end

function JSON.escape(str)
    for k, v in pairs(escapes) do
        str = str:gsub(v, k)
    end

    return str
end

function JSON.unescape(str)
    for k, v in pairs(escapes) do
        str = str:gsub(k, v)
    end

    return str
end

function JSON.isArray(tbl)
    local size = 0

    for k in pairs(tbl) do
        if type(k) ~= "number" then return false end
        size = math.max(k, size)
    end

    return size
end

function JSON.valueToJson(value, indentLevel)
    local t = type(value)

    if t == "string" then
        return '"' .. JSON.escape(value) .. '"'
    elseif t == "number" then
        return value
    elseif t == "boolean" then
        return tostring(value)
    elseif t == 'table' then
        if indentLevel  then indentLevel = indentLevel + 2 end
        return JSON.encodeInternl(value, indentLevel)
    elseif t == "nil" then
        return "null"
    else
        error("Error: Unserializable type: " .. t, 0)
    end
end

function JSON.keyToJson(key)
    if type(key) == "string" then
        return '"' .. JSON.escape(key) .. '"'
    else
        error("Error: Key must be string, got " .. type(key), 0)
    end
end

function JSON.encodeInternl(tbl, indentLevel)
    assert(type(tbl) == "table", "Error: Table expected got " .. type(tbl), 2)
    local isA = JSON.isArray(tbl)
    local jsonStr = (isA and "[" or "{")
    local indent

    if indentLevel then
        indent = string.rep("\t", indentLevel + 1)
    end

    if isA then
        for i = 1, isA do
            if indentLevel then jsonStr = jsonStr.. "\n ".. indent end
            jsonStr = jsonStr .. JSON.valueToJson(tbl[i], indentLevel) .. ","
        end
    else
        for k,v in pairs(tbl) do
            if indentLevel then jsonStr =  jsonStr .. "\n ".. indent end
            jsonStr =  jsonStr .. JSON.keyToJson(k) .. ":" .. JSON.valueToJson(v, indentLevel) .. ","
        end
    end

    if isA ~= 0 then jsonStr = jsonStr:sub(1,#jsonStr - 1) end --remove last comma

    if indentLevel then jsonStr = jsonStr .. "\n" .. string.rep("\t", indentLevel) end
    return jsonStr ..(isA and "]" or "}"), indentLevel
end

function JSON.encode(tbl, readable)
    local encoded = JSON.encodeInternl(tbl, readable and 0 or nil)
    return encoded
end

-------------------------------------------------------------

function JSON.nextValue(str, start)
    local isIn = utils.indexOf

    for pos = start, #str do
        local c = str:sub(pos, pos)

        if not isIn(whitespace, c) then
            return c, pos
        end
    end

    error("Error: Unexpected end of input near" .. start, 0)
end

function JSON.parseArray(str, start)
    local array = {}
    local counter = 1

    local closeChar, closePos = JSON.nextValue(str, start + 1)
    if closeChar == "]" then
        closeChar, closePos = JSON.nextValue(str, closePos + 1)
        return array, closePos
    end

    while true do
        local c

        c, start = JSON.nextValue(str, start + 1)
        array[counter], start = JSON.parseValue(str, start)
        counter = counter + 1
        c, start = JSON.nextValue(str, start)

        if c == "]" then
            return array, start + 1
        elseif c ~= "," then
            error("Error: Expected ',' near" .. start, 0)
        end
    end
end

function JSON.parseObject(str, start)
    local c
    local object = {}

    if JSON.nextValue(str, start + 1) == "}" then return object, start + 2 end

    while true do
        local k, v

        c, start = JSON.nextValue(str, start + 1)

        k, v, start = JSON.parsePair(str, start)
        object[k] = v

        c, start = JSON.nextValue(str, start)

        if c == "}" then
            return object, start + 1
        elseif c ~= "," then
            error("Error: Expected ',' near " .. start, 0)
        end
    end
end

function JSON.parsePair(str, start)
    local key
    local val
    local c

    key, start = JSON.parseValue(str, start)
    c, start = JSON.nextValue(str, start)
    assert(type(key) == "string", "Error: key must be string near" .. start, 0)

    if c ~= ":" then
        error("Error: Expected ':' near " .. start, 0)
    else
        c, start = JSON.nextValue(str, start + 1)
    end

    value, start = JSON.parseValue(str, start)

    return key, value, start
end

function JSON.parseValue(str, start)
    if str:sub(start, start) == "\"" then
        return JSON.parseString(str, start + 1)
    else
        return JSON.parseNonString(str, start)
    end
end

function JSON.parseString(str, start)
    for pos = start, #str do
        local c = str:sub(pos, pos)

        if c == "\"" then
            local isEscped = false

            for p = pos - 1, start +1, -1 do
                if str:sub(p,p) == "\\" then  isEscped = not isEscped
                else break end
            end

            if not isEscped then
                return JSON.unescape(str:sub(start, pos - 1)), pos + 1
            end

        end
    end
end

function JSON.parseNonString(str, start)
    local endPos
    local isIn = utils.indexOf
    local prevC

    if str:sub(start, start) == "{" then
        return JSON.parseObject(str, start)
    elseif str:sub(start, start) == "[" then
        return JSON.parseArray(str, start)
    end

    for pos = start, #str do
        local c = str:sub(pos, pos)

        if isIn(control, c) or isIn(whitespace, c) then
            endPos = pos
            break
        end
    end

    if not endPos then error("Error: Unexpected end of input near" .. start, 0) end
    prevC = str:sub(start, endPos - 1)

    if prevC == "null" then
        return nil, endPos
    elseif prevC == "true" then
        return true, endPos
    elseif prevC== "false" then
        return false, endPos
    elseif tonumber(prevC) then
        return tonumber(prevC), endPos
    end

    error("Error: Invalid value near" .. start, 0)
end

-----------------------------------------------------------------------------
function JSON.decode(str)
    local result
    local c, start = JSON.nextValue(str, 1)

    if c == "{" then
        result = JSON.parseObject(str, start)
    elseif c == "[" then
        result = JSON.parseArray(str, start)
    else
        error("Error: No Object or Array", 2)
    end

    return result
end

function JSON.download(url, name)
    local data = utils.download(url, name)

    return JSON.decode(data)
end

function git.getTreeName()
    if args[1] == "latest" then
        gitProfile.tree = "master"
    elseif args[1] == "stable" then
        gitProfile.tree = "stable"
    else
        gitProfile.tree = git.getLatestRelease()
    end
end

function git.getTree()
    local tree =  JSON.download(gitProfile.api .. "/" .. gitProfile.username .. "/" .. gitProfile.reponame .. "/git/trees/" .. gitProfile.tree .. "?recursive=1&access_token=" .. gitProfile.access_token, "Tree " .. gitProfile.tree).tree
    filesToDownload = #tree
    return tree
end

function git.getLatestRelease()
    local release = JSON.download(gitProfile.api .. "/" .. gitProfile.username .. "/" .. gitProfile.reponame .. "/releases?access_token=" .. gitProfile.access_token, "Releases")[1]
    return release.tag_name
end

function git.downloadFiles()
    local tree = git.getTree()
    for _,object in pairs(tree) do

        if not isBlacklisted(object.path) then
            if object.type == "blob" then
                git.downloadBlob(object.path)
            else
                fs.makeDir(object.path)
            end
        end

        filesDownloaded = filesDownloaded + 1
    end
end

function git.downloadBlob(path)
    local url = gitProfile.raw .. "/" .. gitProfile.username .. "/" .. gitProfile.reponame .. "/" .. gitProfile.tree .. "/"
    local urlPath = ""

    for match in path:gmatch("[^/]+") do
        urlPath = urlPath .. textutils.urlEncode(match) .. "/"
    end

    urlPath = urlPath:sub(1, -2):gsub("%+", "%%20")

    local data = utils.download(url .. urlPath, path)
    local file = fs.open(path, "w")

    if not file then
        error("Error: Failed to create file" .. path)
    end

    file.write(data)
    file.close()
end

function utils.indexOf(tbl, value)
    for k, v in pairs(tbl) do
        if v == value then return k end
    end
end

function utils.download(url, name)
    local tries = 0

    --drawBackground()
    drawText("Downloading: " .. (name or url))
    drawBar(filesDownloaded/filesToDownload)

    while tries < 5 do
        http.request(url)

        local event, _url, data = coroutine.yield()

        if event == "http_success" and url == _url then
            return data.readAll()
        elseif event == "http_failure" then
            tries = tries + 1
        end
    end

    drawText("Error: Download failed " .. url)
    term.setCursorPos(1, ySize)
    error()
end

if not term.blit then
    error("ComputerCraft version it too old", 0)
end

if not http then
    error("HTTP API is required to download LunaOS.", 0)
end

if not term.native().isColour() then
    error("An advanced computer is required to install LunaOS.", 0)
end

term.setBackgroundColour(colours.grey)
term.clear()
image = decodeImage(image)
drawImage()
git.getTreeName()
git.downloadFiles()
term.setCursorPos(1, ySize)
os.reboot()