-- Initial configurations and setup
term.setBackgroundColour(bgColour)
term.clear()
term.setCursorPos(x, y)
term.setCursorBlink(true)

-- Configuration File Paths
local configPath = "/disk/os/gui.config"
local menuItems = {"Save", "Print", "Run", "Exit"}

-- Load Configuration
local function loadConfig()
    if fs.exists(configPath) then
        local file = fs.open(configPath, "r")
        local config = file.readAll()
        file.close()
        -- Parse config if needed
    end
end

-- Utility Functions
local function set_status(message, isSuccess)
    -- Implementation of setting status messages
end

local function redrawMenu()
    -- Implementation of menu redraw
end

local function redrawText()
    -- Implementation of text redraw
end

local function setCursor(newX, newY)
    local _, oldY = x, y
    x, y = newX, newY
    local screenX = x - scrollX
    local screenY = y - scrollY

    local bRedraw = false
    if screenX < 1 then
        scrollX = x - 1
        screenX = 1
        bRedraw = true
    elseif screenX > w then
        scrollX = x - w
        screenX = w
        bRedraw = true
    end

    if screenY < 1 then
        scrollY = y - 1
        screenY = 1
        bRedraw = true
    elseif screenY > h - 1 then
        scrollY = y - (h - 1)
        screenY = h - 1
        bRedraw = true
    end

    recomplete()
    if bRedraw then
        redrawText()
    elseif y ~= oldY then
        redrawLine(oldY)
        redrawLine(y)
    else
        redrawLine(y)
    end
    term.setCursorPos(screenX, screenY)

    redrawMenu()
end

-- Menu Functions
local tMenuFuncs = {
    Save = function()
        if bReadOnly then
            set_status("Access denied", false)
        else
            local ok, _, fileerr  = save(sPath, function(file)
                for _, sLine in ipairs(tLines) do
                    file.write(sLine .. "\n")
                end
            end)
            if ok then
                set_status("Saved to " .. sPath)
            else
                if fileerr then
                    set_status("Error saving: " .. fileerr, false)
                else
                    set_status("Error saving to " .. sPath, false)
                end
            end
        end
        redrawMenu()
    end,
    Print = function()
        local printer = peripheral.find("printer")
        if not printer then
            set_status("No printer attached", false)
            return
        end

        local nPage = 0
        local sName = fs.getName(sPath)
        if printer.getInkLevel() < 1 then
            set_status("Printer out of ink", false)
            return
        elseif printer.getPaperLevel() < 1 then
            set_status("Printer out of paper", false)
            return
        end

        local screenTerminal = term.current()
        local printerTerminal = {
            getCursorPos = printer.getCursorPos,
            setCursorPos = printer.setCursorPos,
            getSize = printer.getPageSize,
            write = printer.write,
        }
        printerTerminal.scroll = function()
            if nPage == 1 then
                printer.setPageTitle(sName .. " (page " .. nPage .. ")")
            end

            while not printer.newPage() do
                if printer.getInkLevel() < 1 then
                    set_status("Printer out of ink, please refill", false)
                elseif printer.getPaperLevel() < 1 then
                    set_status("Printer out of paper, please refill", false)
                else
                    set_status("Printer output tray full, please empty", false)
                end

                term.redirect(screenTerminal)
                redrawMenu()
                term.redirect(printerTerminal)

                sleep(0.5)
            end

            nPage = nPage + 1
            if nPage == 1 then
                printer.setPageTitle(sName)
            else
                printer.setPageTitle(sName .. " (page " .. nPage .. ")")
            end
        end

        bMenu = false
        term.redirect(printerTerminal)
        local ok, error = pcall(function()
            term.scroll()
            for _, sLine in ipairs(tLines) do
                print(sLine)
            end
        end)
        term.redirect(screenTerminal)
        if not ok then
            print(error)
        end

        while not printer.endPage() do
            set_status("Printer output tray full, please empty")
            redrawMenu()
            sleep(0.5)
        end
        bMenu = true

        if nPage > 1 then
            set_status("Printed " .. nPage .. " Pages")
        else
            set_status("Printed 1 Page")
        end
        redrawMenu()
    end,
    Exit = function()
        bRunning = false
    end,
    Run = function()
        local sTitle = fs.getName(sPath)
        if sTitle:sub(-4) == ".lua" then
            sTitle = sTitle:sub(1, -5)
        end
        local sTempPath = bReadOnly and ".temp." .. sTitle or fs.combine(fs.getDir(sPath), ".temp." .. sTitle)
        if fs.exists(sTempPath) then
            set_status("Error saving to " .. sTempPath, false)
            return
        end
        local ok = save(sTempPath, function(file)
            file.write(runHandler:format(sTitle, table.concat(tLines, "\n"), "@/" .. sPath))
        end)
        if ok then
            local nTask = shell.openTab("/" .. sTempPath)
            if nTask then
                shell.switchTab(nTask)
            else
                set_status("Error starting Task", false)
            end
            fs.delete(sTempPath)
        else
            set_status("Error saving to " .. sTempPath, false)
        end
        redrawMenu()
    end,
}

-- Menu Item Handler
local function doMenuItem(_n)
    tMenuFuncs[tMenuItems[_n]]()
    if bMenu then
        bMenu = false
        term.setCursorBlink(true)
    end
    redrawMenu()
end

-- Main Loop
local function acceptCompletion()
    if nCompletion then
        local sCompletion = tCompletions[nCompletion]
        tLines[y] = tLines[y] .. sCompletion
        setCursor(x + #sCompletion , y)
    end
end

-- Handle input
while bRunning do
    local sEvent, param, param2, param3 = os.pullEvent()
    if sEvent == "key" then
        if param == keys.up then
            if not bMenu then
                if nCompletion then
                    nCompletion = nCompletion - 1
                    if nCompletion < 1 then
                        nCompletion = #tCompletions
                    end
                    redrawLine(y)
                elseif y > 1 then
                    setCursor(math.min(x, #tLines[y - 1] + 1), y - 1)
                end
            end

        elseif param == keys.down then
            if not bMenu then
                if nCompletion then
                    nCompletion = nCompletion + 1
                    if nCompletion > #tCompletions then
                        nCompletion = 1
                    end
                    redrawLine(y)
                elseif y < #tLines then
                    setCursor(math.min(x, #tLines[y + 1] + 1), y + 1)
                end
            end

        elseif param == keys.tab then
            if not bMenu and not bReadOnly then
                if nCompletion and x == #tLines[y] + 1 then
                    acceptCompletion()
                else
                    local sLine = tLines[y]
                    tLines[y] = string.sub(sLine, 1, x - 1) .. "    " .. string.sub(sLine, x)
                    setCursor(x + 4, y)
                end
            end

        elseif param == keys.pageUp then
            if not bMenu then
                local newY = y - (h - 1)
                if newY < 1 then newY = 1 end
                setCursor(math.min(x, #tLines[newY] + 1), newY)
            end

        elseif param == keys.pageDown then
            if not bMenu then
                local newY = y + (h - 1)
                if newY > #tLines then newY = #tLines end
                local newX = math.min(x, #tLines[newY] + 1)
                setCursor(newX, newY)
            end

        elseif param == keys.home then
            if not bMenu then
                setCursor(1, y)
            end

        elseif param == keys.end then
            if not bMenu then
                setCursor(#tLines[y] + 1, y)
            end

        elseif param == keys.delete then
            if not bMenu and not bReadOnly then
                local sLine = tLines[y]
                tLines[y] = string.sub(sLine, 1, x - 1) .. string.sub(sLine, x + 1)
                redrawLine(y)
            end

        elseif param == keys.backspace then
            if not bMenu and not bReadOnly then
                if x > 1 then
                    local sLine = tLines[y]
                    tLines[y] = string.sub(sLine, 1, x - 2) .. string.sub(sLine, x)
                    setCursor(x - 1, y)
                end
            end

        elseif param == keys.enter then
            if not bMenu and not bReadOnly then
                table.insert(tLines, y + 1, "")
                setCursor(1, y + 1)
            end

        elseif param == keys.left then
            if not bMenu then
                if x > 1 then
                    setCursor(x - 1, y)
                end
            end

        elseif param == keys.right then
            if not bMenu then
                if x < #tLines[y] + 1 then
                    setCursor(x + 1, y)
                end
            end

        elseif param == keys.f1 then
            if not bMenu then
                bMenu = true
                term.setCursorBlink(false)
            end

        elseif param == keys.f2 then
            if bMenu then
                doMenuItem(1)
            end

        elseif param == keys.f3 then
            if bMenu then
                doMenuItem(2)
            end

        elseif param == keys.f4 then
            if bMenu then
                doMenuItem(3)
            end

        elseif param == keys.f5 then
            if bMenu then
                doMenuItem(4)
            end
        end

    elseif sEvent == "mouse_click" then
        if bMenu then
            -- Handle menu clicks
        else
            -- Handle text area clicks
        end

    elseif sEvent == "mouse_scroll" then
        -- Handle mouse scroll
    elseif sEvent == "term_resize" then
        -- Handle terminal resize
    end
end