cldvChat

local programName = "cldvChat"
local args = {...}
local dtype = args[1]

local modemPosition
if pocket then
    modemPosition = "back"
else
    modemPosition = "right"
end

---
-- Helper Functions
function findDeviceIndex (t, target)
    for i = 1, #t, 1 do
        if t[i].id == target then
            return i
        end
    end
    return 0
end

function prettyPrint (prefix, text, prefixColor, textColor, bgColor)
    local colors = {
        ["white"] = "0",
        ["0"] = "0",
        ["orange"] = "1",
        ["1"] = "1",
        ["magenta"] = "2",
        ["2"] = "2",
        ["lightblue"] = "3",
        ["3"] = "3",
        ["yellow"] = "4",
        ["4"] = "4",
        ["lime"] = "5",
        ["5"] = "5",
        ["pink"] = "6",
        ["6"] = "6",
        ["gray"] = "7",
        ["7"] = "7",
        ["lightgray"] = "8",
        ["8"] = "8",
        ["cyan"] = "9",
        ["9"] = "9",
        ["purple"] = "a",
        ["a"] = "a",
        ["blue"] = "b",
        ["b"] = "b",
        ["brown"] = "c",
        ["c"] = "c",
        ["green"] = "d",
        ["d"] = "d",
        ["red"] = "e",
        ["e"] = "e",
        ["black"] = "f",
        ["f"] = "f"
    }

    prefixColor = colors[prefixColor] or "b"
    textColor = colors[textColor] or "0"
    bgColor = colors[bgColor] or "f"

    local deviceWidth, _ = term.current().getSize()

    local texts = {}
    texts[1] = text

    local idx = 1
    local maxLength = deviceWidth - #prefix

    -- Split text after last space or after maxLength if the string is too long
    -- Note: The prefix has to be smaller than the maxLength.
    while (#texts[idx] > maxLength) do
        local lastSpace = nil
        local offset = 0

        lastSpace = string.sub(texts[idx], 1, maxLength):match'^.*() '

        if string.find(texts[idx], "\n") then
            local start, _ = string.find(texts[idx], "\n")
            offset = 1
            lastSpace = math.min(lastSpace, start - 1)
        end

        if lastSpace == nil then lastSpace = maxLength end
        if idx == 1 then maxLength = deviceWidth end

        texts[idx + 1] = string.sub(texts[idx], lastSpace + 1 + offset)
        texts[idx] = string.sub(texts[idx], 1, lastSpace)
        idx = idx + 1
    end

    -- Setup color strings
    local tColorS = ""
    local bgColorS = ""

    for i = 1, #prefix, 1 do
        tColorS = tColorS .. prefixColor
        bgColorS = bgColorS .. bgColor
    end

    -- Print prefix
    term.blit(prefix, tColorS, bgColorS)

    -- Print texts
    for i = 1, #texts, 1 do
        tColorS = ""
        bgColorS = ""
        for j = 1, #texts[i], 1 do
            tColorS = tColorS .. textColor
            bgColorS = bgColorS .. bgColor
        end

        term.blit(texts[i], tColorS, bgColorS)
        print("")
    end

    return #texts
end

function printMessage (name, message, sender)
    sender = sender or false
    local nameColor = "b"

    if sender then
        nameColor = "5"
    end

    name = name .. ": "
    return prettyPrint(name, message, nameColor)
end
---

function client ()
    local protocol = args[2] or "cldvChat"
    local hostname = args[3] or "cldvChatServer"
    local clientName = args[4] or nil

    if not clientName then
        prettyPrint ("", "Please enter your name: ", nil, "8")
        clientName = read()
    end

    while #clientName > 20 do
        prettyPrint ("", "Your name is too long! Enter a smaller name: ", nil, "8")
        clientName = read()
    end

    local hosts = rednet.lookup(protocol, hostname)
    if tonumber(hosts) then
        local tmpHosts = hosts
        hosts = {}
        hosts[1] = tmpHosts
    end

    for i = 1, #hosts, 1 do
        if not rednet.send(hosts[i], "/" .. clientName, protocol)  then
            error("Could not send message.")
        else
            prettyPrint ("", "Connected! Type /quit to disconnect", nil, "8")
        end
    end


    parallel.waitForAny(
        -- Receive messages
        function ()
            local message
            while true do
                _, message, _ = rednet.receive(protocol)
                local separator, _ = string.find(message, ":")
                local isCommand, _ = string.find(message, "/")
                if separator and not isCommand then
                    local name = string.sub(message, 1, separator - 1)
                    message = string.sub(message, separator + 2)
                    term.clearLine()
                    local x, y = term.getCursorPos()
                    term.setCursorPos(1, y)
                    printMessage(name, message, false)
                end
                --print (message)
            end
        end,
        -- Send messages
        function ()
            local message
            while true do
                message = read()
                if message == "/quit" then
                    prettyPrint ("", "Disconnected!", nil, "8")
                    return
                end

                -- Clear read output and write it prettier
                local x, y = term.getCursorPos()
                term.setCursorPos(x, y - 1)
                term.clearLine()
                local _, maxHeight = term.current().getSize()
                local offset = printMessage(clientName, message, true) - 1
                y = math.min(y + offset, maxHeight)
                term.setCursorPos(x, y)

                for i = 1, #hosts, 1 do
                    if not rednet.send(hosts[i], message, protocol)  then
                        error("Could not send message.")
                    end
                end
            end
        end
    )

    for i = 1, #hosts, 1 do
        if not rednet.send(hosts[i], "/quit", protocol)  then
            error("Could not send message.")
        end
    end
end

function server ()
    local protocol = args[2] or "cldvChat"
    local name = args[3] or "cldvChatServer"
    local devices = {}
    rednet.host(protocol, name)
    prettyPrint ("", "Server running!", nil, "8")

    while true do
        local deviceID
        local message
        deviceID, message, _ = rednet.receive(protocol)

        local index = findDeviceIndex(devices, deviceID)

        local isCommand, _ = string.find(message, "/")

        -- Add device
        if index == 0 then
            local device = {
                name = string.sub(message, 2),
                id = deviceID
            }
            table.insert(devices, device)
            prettyPrint ("", "Add client " .. device.name .. " with ID " .. tostring(deviceID), nil, "8")
        -- Remove device
        elseif message == "/quit" then
            if index == 0 then
                error("Could not remove device, index not found.")
            else
                local device = devices[index]
                table.remove(devices, index)
                prettyPrint ("", device.name .. " with ID " .. tostring(deviceID) .. " disconnected.", nil, "8")
                device = nil
            end
        elseif isCommand then
            prettyPrint ("", devices[index].name .. " tried to connect but is already connected.", nil, "8")
        -- Send message to all connected devices
        else
            -- Print to server log
            printMessage(devices[index].name, message, false)
            message = devices[index].name .. ": " .. message
            -- Send message to all clients
            for i = 1, #devices, 1 do
                if deviceID ~= devices[i].id then
                    if not rednet.send(devices[i].id, message, protocol) then
                        error("Could not send message.")
                    end
                end
            end
        end

    end


    rednet.unhost(protocol)
end

function main ()
    if not rednet.isOpen(modemPosition) then
        error("Could not open modem '".. modemPosition .. "'")
        return
    end

    if dtype == "client" then
        client()
    elseif dtype == "server" then
        server()
    elseif dtype == "update" then
        shell.run("pastebin", "run", "FuQ3WvPs 4izkdH5g " .. programName)
    elseif dtype == "help" then
        prettyPrint ("", "Arguments:\n - " .. programName .. " server <protocol> <hostname>\n - " .. programName .. " client <protocol> <hostname> <username>\n - " .. programName .. " update\n - " .. programName .. " help\n", nil, "8")
    else
        error("Please specify the device type as 'server' or 'client' by passing it as the first argument.")
    end
end

rednet.open(modemPosition)
main()
rednet.close(modemPosition)