DEVELOPMENT

local component = require("component")
local event = require("event")
local term = require("term")
local unicode = require("unicode")
local gpu = component.gpu
local keyboard = require("keyboard")
local serialization = require("serialization")
local filesystem = require("filesystem")
local computer = require("computer")
local internet = component.internet

-- Constants
local IAC, DONT, DO, WONT, WILL = 255, 254, 253, 252, 251
local SB, SE = 250, 240
local ECHO, SGA, NAWS, TTYPE = 1, 3, 31, 24
local ESC, CSI = string.char(27), string.char(27) .. "["

-- Color scheme
local COLORS = {
    background = 0x1E1E1E,
    foreground = 0xFFFFFF,
    accent1 = 0x007ACC,
    accent2 = 0x5F5F5F,
    highlight = 0x3C3C3C,
    error = 0xCC0000,
}

-- Configuration
local config = {
    termType = "ANSI",
    autoWrap = true,
    localEcho = false,
    logFile = "/tmp/telnet.log",
    menuKey = keyboard.keys.f1,
    macros = {},
    backgroundColor = COLORS.background,
    foregroundColor = COLORS.foreground,
    ansiCompatMode = false,
}

-- ANSI state
local ansiState = {
    bold = false,
    underline = false,
    inverse = false,
    fg = config.foregroundColor,
    bg = config.backgroundColor,
}

-- Color mapping (extended for 256 colors)
local colors = {}
for i = 0, 15 do
    colors[i] = 2^24 - 1 - (i * 2^20)
end
for i = 16, 231 do
    local r = math.floor((i - 16) / 36) * 51
    local g = math.floor(((i - 16) % 36) / 6) * 51
    local b = ((i - 16) % 6) * 51
    colors[i] = (r * 2^16) + (g * 2^8) + b
end
for i = 232, 255 do
    local gray = (i - 232) * 10 + 8
    colors[i] = (gray * 2^16) + (gray * 2^8) + gray
end

-- UI Components
local UI = {}

function UI.drawBox(x, y, width, height, title, style)
    style = style or {}
    local bg = style.bg or COLORS.background
    local fg = style.fg or COLORS.foreground
    local borderColor = style.borderColor or COLORS.accent1

    gpu.setBackground(bg)
    gpu.setForeground(borderColor)
    gpu.fill(x, y, width, height, " ")
    gpu.set(x, y, "╔" .. string.rep("═", width-2) .. "╗")
    for i = 1, height-2 do
        gpu.set(x, y+i, "║")
        gpu.set(x+width-1, y+i, "║")
    end
    gpu.set(x, y+height-1, "╚" .. string.rep("═", width-2) .. "╝")

    if title then
        gpu.setForeground(fg)
        gpu.set(x + (width - #title) / 2, y, " " .. title .. " ")
    end
end

function UI.drawButton(x, y, text, active)
    local width = #text + 4
    local bg = active and COLORS.accent1 or COLORS.accent2
    gpu.setBackground(bg)
    gpu.setForeground(COLORS.foreground)
    gpu.fill(x, y, width, 3, " ")
    gpu.set(x, y, "┌" .. string.rep("─", width-2) .. "┐")
    gpu.set(x, y+1, "│ " .. text .. " │")
    gpu.set(x, y+2, "└" .. string.rep("─", width-2) .. "┘")
end

function UI.drawProgressBar(x, y, width, progress)
    local filledWidth = math.floor(width * progress)
    gpu.setBackground(COLORS.accent2)
    gpu.fill(x, y, width, 1, "─")
    gpu.setBackground(COLORS.accent1)
    gpu.fill(x, y, filledWidth, 1, "─")
end

function UI.input(x, y, width, prompt)
    gpu.setBackground(COLORS.background)
    gpu.setForeground(COLORS.foreground)
    gpu.fill(x, y, width, 1, " ")
    gpu.set(x, y, prompt)

    local input = ""
    local cursorPos = #prompt + 1
    local startTime = computer.uptime()

    while true do
        gpu.set(x + cursorPos - 1, y, "_")
        local evt, _, char, code = event.pull(0.5)
        gpu.set(x + cursorPos - 1, y, " ")

        if evt == "key_down" then
            if code == keyboard.keys.enter then
                break
            elseif code == keyboard.keys.back and #input > 0 then
                input = input:sub(1, -2)
                cursorPos = cursorPos - 1
            elseif char > 31 and char < 127 then
                input = input .. unicode.char(char)
                cursorPos = cursorPos + 1
            end
        end

        gpu.set(x + #prompt, y, input .. string.rep(" ", width - #prompt - #input))

        local currentTime = computer.uptime()
        local progress = (currentTime - startTime) % 2 / 2
        UI.drawProgressBar(x, y + 1, width, progress)
    end

    return input
end

function UI.showMenu()
    local w, h = gpu.getResolution()
    local menuWidth, menuHeight = 50, 15
    local x, y = (w - menuWidth) / 2, (h - menuHeight) / 2

    UI.drawBox(x, y, menuWidth, menuHeight, "Telnet Menu", {borderColor = COLORS.accent1})

    local options = {
        "1. Toggle Local Echo",
        "2. Toggle Auto Wrap",
        "3. Set Terminal Type",
        "4. Configure Macros",
        "5. Set Colors",
        "6. Toggle ANSI Compatibility Mode",
        "7. Exit"
    }

    for i, option in ipairs(options) do
        gpu.setForeground(COLORS.foreground)
        gpu.set(x + 2, y + i + 1, option)
    end

    return tonumber(UI.input(x + 2, y + #options + 3, menuWidth - 4, "Choice: "))
end

-- Load configuration
local function loadConfig()
    if filesystem.exists("/etc/telnet.cfg") then
        local file = io.open("/etc/telnet.cfg", "r")
        local content = file:read("*all")
        file:close()
        local loaded = serialization.unserialize(content)
        for k, v in pairs(loaded) do
            config[k] = v
        end
    end
end

-- Save configuration
local function saveConfig()
    local file = io.open("/etc/telnet.cfg", "w")
    file:write(serialization.serialize(config))
    file:close()
end

-- Handle telnet negotiations
local function handleNegotiation(socket, data)
    if data:byte(1) == IAC then
        local cmd, option = data:byte(2), data:byte(3)

        if cmd == DO then
            if option == ECHO or option == SGA or option == NAWS or option == TTYPE then
                socket.write(string.char(IAC, WILL, option))
                if option == ECHO then config.localEcho = false end
            else
                socket.write(string.char(IAC, WONT, option))
            end
        elseif cmd == WILL then
            if option == ECHO or option == SGA or option == NAWS or option == TTYPE then
                socket.write(string.char(IAC, DO, option))
                if option == ECHO then config.localEcho = true end
            else
                socket.write(string.char(IAC, DONT, option))
            end
        elseif cmd == SB then
            if option == TTYPE then
                socket.write(string.char(IAC, SB, TTYPE, 0) .. config.termType .. string.char(IAC, SE))
            elseif option == NAWS then
                local w, h = gpu.getResolution()
                socket.write(string.char(IAC, SB, NAWS, w // 256, w % 256, h // 256, h % 256, IAC, SE))
            end
        end
        return true
    end
    return false
end

-- ANSI escape sequence handler
local function handleANSI(sequence)
    local params = {}
    for param in sequence:gmatch("%d+") do
        params[#params + 1] = tonumber(param)
    end

    local command = sequence:sub(-1)
    if command == "m" then  -- SGR (Select Graphic Rendition)
        for i = 1, #params do
            local param = params[i]
            if param == 0 then
                ansiState = {bold = false, underline = false, inverse = false, fg = config.foregroundColor, bg = config.backgroundColor}
            elseif param == 1 then
                ansiState.bold = true
            elseif param == 4 then
                ansiState.underline = true
            elseif param == 7 then
                ansiState.inverse = true
            elseif param >= 30 and param <= 37 then
                ansiState.fg = colors[param - 30]
            elseif param >= 40 and param <= 47 then
                ansiState.bg = colors[param - 40]
            elseif param >= 90 and param <= 97 then
                ansiState.fg = colors[param - 82]
            elseif param >= 100 and param <= 107 then
                ansiState.bg = colors[param - 92]
            elseif param == 38 or param == 48 then
                if params[i+1] == 5 then  -- 256 color mode
                    local color = colors[params[i+2]] or 0
                    if param == 38 then ansiState.fg = color else ansiState.bg = color end
                    i = i + 2
                elseif params[i+1] == 2 then  -- RGB color mode
                    local r, g, b = params[i+2], params[i+3], params[i+4]
                    local color = (r * 2^16) + (g * 2^8) + b
                    if param == 38 then ansiState.fg = color else ansiState.bg = color end
                    i = i + 4
                end
            end
        end
        gpu.setForeground(ansiState.fg)
        gpu.setBackground(ansiState.bg)
    elseif command == "H" or command == "f" then  -- Cursor Position
        term.setCursor(params[2] or 1, params[1] or 1)
    elseif command == "J" then  -- Erase in Display
        local x, y = term.getCursor()
        local w, h = gpu.getResolution()
        if params[1] == 2 then
            gpu.fill(1, 1, w, h, " ")
        elseif params[1] == 1 then
            gpu.fill(1, 1, w, y, " ")
            gpu.fill(1, y, x, 1, " ")
        else
            gpu.fill(x, y, w - x + 1, 1, " ")
            gpu.fill(1, y + 1, w, h - y, " ")
        end
    elseif command == "K" then  -- Erase in Line
        local x, y = term.getCursor()
        local w = gpu.getResolution()
        if params[1] == 2 then
            gpu.fill(1, y, w, 1, " ")
        elseif params[1] == 1 then
            gpu.fill(1, y, x, 1, " ")
        else
            gpu.fill(x, y, w - x + 1, 1, " ")
        end
    elseif command == "A" then  -- Cursor Up
        local x, y = term.getCursor()
        term.setCursor(x, math.max(1, y - (params[1] or 1)))
    elseif command == "B" then  -- Cursor Down
        local x, y = term.getCursor()
        local _, h = gpu.getResolution()
        term.setCursor(x, math.min(h, y + (params[1] or 1)))
    elseif command == "C" then  -- Cursor Forward
        local x, y = term.getCursor()
        local w = gpu.getResolution()
        term.setCursor(math.min(w, x + (params[1] or 1)), y)
    elseif command == "D" then  -- Cursor Back
        local x, y = term.getCursor()
        term.setCursor(math.max(1, x - (params[1] or 1)), y)
    end
end

-- Main telnet function
local function telnet(host, port)
    local socket = internet.connect(host, port)
    if not socket then error("Could not connect to " .. host .. ":" .. port) end

    local buffer = ""
    local w, h = gpu.getResolution()

    -- Draw UI
    UI.drawBox(1, 1, w, h, "Telnet: " .. host .. ":" .. port, {borderColor = COLORS.accent1})
    UI.drawButton(w-10, h-3, "Menu", false)

    -- Set up a scrollable area for telnet output
    local scrollArea = {x = 2, y = 2, width = w-4, height = h-5}
    local lines = {}

    local function drawScrollArea()
        gpu.setBackground(COLORS.background)
        gpu.setForeground(COLORS.foreground)
        for i = 1, scrollArea.height do
            local line = lines[#lines - scrollArea.height + i] or ""
            gpu.set(scrollArea.x, scrollArea.y + i - 1, line .. string.rep(" ", scrollArea.width - #line))
        end
    end

    local function addLine(text)
        for line in (text .. "\n"):gmatch("([^\n]*)\n") do
            table.insert(lines, line)
        end
        while #lines > 1000 do table.remove(lines, 1) end
        drawScrollArea()
    end

    local function processData(data)
        buffer = buffer .. data
        while true do
            local escStart, escEnd = buffer:find(ESC .. "%[" .. "[%d;]*[A-Za-z]")
            if escStart then
                addLine(buffer:sub(1, escStart - 1))
                if config.ansiCompatMode then
                    handleANSI(buffer:sub(escStart + 1, escEnd))
                else
                    addLine(buffer:sub(escStart, escEnd))
                end
                buffer = buffer:sub(escEnd + 1)
            else
                addLine(buffer)
                buffer = ""
                break
            end
        end
    end

    local inputBuffer = ""
    local cursorPos = 1

    local function drawInputArea()
        gpu.setBackground(COLORS.background)
        gpu.setForeground(COLORS.foreground)
        gpu.set(2, h-2, string.rep(" ", w-4))
        gpu.set(2, h-2, inputBuffer)
        gpu.set(1 + cursorPos, h-2, "_")
    end

    local startTime = computer.uptime()
    while true do
        local currentTime = computer.uptime()
        local progress = (currentTime - startTime) % 5 / 5  -- 5-second cycle
        UI.drawProgressBar(2, h-1, w-4, progress)

        local data = socket.read(1024)
        if data then
            if not handleNegotiation(socket, data) then
                processData(data)
            end
        end

        drawInputArea()

        local eventType, _, char, code = event.pull(0.05)
        if eventType == "key_down" then
            if char == 3 then  -- Ctrl-C
                break
            elseif code == keyboard.keys.enter then
                socket.write(inputBuffer .. "\r\n")
                addLine("> " .. inputBuffer)
                inputBuffer = ""
                cursorPos = 1
            elseif code == keyboard.keys.back and #inputBuffer > 0 then
                inputBuffer = inputBuffer:sub(1, -2)
                cursorPos = math.max(1, cursorPos - 1)
            elseif code == config.menuKey then
                local choice = UI.showMenu()
                if choice == 7 then break end
                -- Handle other menu choices here (as before)
                UI.drawBox(1, 1, w, h, "Telnet: " .. host .. ":" .. port, {borderColor = COLORS.accent1})
                drawScrollArea()
            elseif char > 31 and char < 127 then
                local newChar = unicode.char(char)
                inputBuffer = inputBuffer:sub(1, cursorPos - 1) .. newChar .. inputBuffer:sub(cursorPos)
                cursorPos = cursorPos + 1
                if config.localEcho then
                    addLine(newChar)
                end
            end
        end
    end

    socket.close()
end
-- Main telnet function
local function telnet(host, port)
    local socket = internet.connect(host, port)
    if not socket then error("Could not connect to " .. host .. ":" .. port) end

    local buffer = ""
    local w, h = gpu.getResolution()

    -- Draw UI
    UI.drawBox(1, 1, w, h, "Telnet: " .. host .. ":" .. port, {borderColor = COLORS.accent1})
    UI.drawButton(w-10, h-3, "Menu", false)

    -- Set up a scrollable area for telnet output
    local scrollArea = {x = 2, y = 2, width = w-4, height = h-5}
    local lines = {}

    local function drawScrollArea()
        gpu.setBackground(COLORS.background)
        gpu.setForeground(COLORS.foreground)
        for i = 1, scrollArea.height do
            local line = lines[#lines - scrollArea.height + i] or ""
            gpu.set(scrollArea.x, scrollArea.y + i - 1, line .. string.rep(" ", scrollArea.width - #line))
        end
    end

    local function addLine(text)
        for line in (text .. "\n"):gmatch("([^\n]*)\n") do
            table.insert(lines, line)
        end
        while #lines > 1000 do table.remove(lines, 1) end
        drawScrollArea()
    end

    local function processData(data)
        buffer = buffer .. data
        while true do
            local escStart, escEnd = buffer:find(ESC .. "%[" .. "[%d;]*[A-Za-z]")
            if escStart then
                addLine(buffer:sub(1, escStart - 1))
                if config.ansiCompatMode then
                    handleANSI(buffer:sub(escStart + 1, escEnd))
                else
                    addLine(buffer:sub(escStart, escEnd))
                end
                buffer = buffer:sub(escEnd + 1)
            else
                addLine(buffer)
                buffer = ""
                break
            end
        end
    end

    local inputBuffer = ""
    local cursorPos = 1

    local function drawInputArea()
        gpu.setBackground(COLORS.background)
        gpu.setForeground(COLORS.foreground)
        gpu.set(2, h-2, string.rep(" ", w-4))
        gpu.set(2, h-2, inputBuffer)
        gpu.set(1 + cursorPos, h-2, "_")
    end

    local startTime = computer.uptime()
    while true do
        local currentTime = computer.uptime()
        local progress = (currentTime - startTime) % 5 / 5  -- 5-second cycle
        UI.drawProgressBar(2, h-1, w-4, progress)

        local data = socket.read(1024)
        if data then
            if not handleNegotiation(socket, data) then
                processData(data)
            end
        end

        drawInputArea()

        local eventType, _, char, code = event.pull(0.05)
        if eventType == "key_down" then
            if char == 3 then  -- Ctrl-C
                break
            elseif code == keyboard.keys.enter then
                socket.write(inputBuffer .. "\r\n")
                addLine("> " .. inputBuffer)
                inputBuffer = ""
                cursorPos = 1
            elseif code == keyboard.keys.back and #inputBuffer > 0 then
                inputBuffer = inputBuffer:sub(1, -2)
                cursorPos = math.max(1, cursorPos - 1)
            elseif code == config.menuKey then
                local choice = UI.showMenu()
                if choice == 7 then break end
                -- Handle other menu choices here (as before)
                UI.drawBox(1, 1, w, h, "Telnet: " .. host .. ":" .. port, {borderColor = COLORS.accent1})
                drawScrollArea()
            elseif char > 31 and char < 127 then
                local newChar = unicode.char(char)
                inputBuffer = inputBuffer:sub(1, cursorPos - 1) .. newChar .. inputBuffer:sub(cursorPos)
                cursorPos = cursorPos + 1
                if config.localEcho then
                    addLine(newChar)
                end
            end
        end
    end

    socket.close()
end


-- Main menu
local function mainMenu()
    local w, h = gpu.getResolution()
    UI.drawBox(1, 1, w, h, "Modern Telnet Client", {borderColor = COLORS.accent1})

    local options = {
        "1. Connect to server",
        "2. Configure settings",
        "3. Exit"
    }

    for i, option in ipairs(options) do
        local x = (w - #option) / 2
        local y = h/2 - #options/2 + i*3
        UI.drawButton(x, y, option, i == 1)
    end

    local choice = tonumber(UI.input((w - 20) / 2, h/2 + #options*2, 20, "Choice: "))
    if choice == 1 then
        local host = UI.input(2, h-2, w-4, "Enter server address: ")
        local port = tonumber(UI.input(2, h-1, w-4, "Enter port: "))
        telnet(host, port)
    elseif choice == 2 then
        UI.showMenu()
    elseif choice == 3 then
        return false
    end
    return true
end

-- Load configuration
loadConfig()

-- Set initial color scheme
gpu.setBackground(COLORS.background)
gpu.setForeground(COLORS.foreground)

-- Start the client
while true do
    if not mainMenu() then break end
end

-- Save configuration
saveConfig()