notepad for computercraft

local function clearScreen()
    term.clear()
    term.setCursorPos(1, 1)
end

local function drawMenu()
    clearScreen()
    print("=== Notepad ===")
    print("1. New File")
    print("2. Open File")
    print("3. Save File (Insert key)")
    print("4. Convert .nono to .lua")
    print("5. Exit")
end

local function readFile(filename)
    local file = fs.open(filename, "r")
    if file then
        local contents = file.readAll()
        file.close()
        return contents
    else
        return nil
    end
end

local function writeFile(filename, contents)
    -- Append ".nono" file extension if not present
    if not string.find(filename, "%.nono$") then
        filename = filename .. ".nono"
    end

    local file = fs.open(filename, "w")
    if file then
        file.write(contents)
        file.close()
        return true
    else
        return false
    end
end

local function editFile(filename)
    clearScreen()
    local contents = readFile(filename) or ""
    local cursorX, cursorY = 1, 1
    local cursorVisible = false

    local function redraw()
        clearScreen()
        print("=== Editing: " .. filename .. " ===")
        print("Press Insert to save and exit.")
        print("-----------------------")
        print(contents)
        term.setCursorPos(cursorX, cursorY)
        if cursorVisible then
            term.setCursorBlink(true)
        else
            term.setCursorBlink(false)
        end
    end

    redraw()

    while true do
        local event, key = os.pullEvent()
        if event == "char" then
            -- Insert the character at cursor position
            contents = contents:sub(1, cursorY * (cursorX - 1)) .. key .. contents:sub(cursorY * cursorX)
            cursorX = cursorX + 1
        elseif event == "key" then
            if key == keys.insert then
                -- Save and exit
                writeFile(filename, contents)
                break
            elseif key == keys.enter then
                -- Insert a newline character
                contents = contents:sub(1, cursorY * (cursorX - 1)) .. "\n" .. contents:sub(cursorY * cursorX)
                cursorY = cursorY + 1
                cursorX = 1
            elseif key == keys.backspace then
                -- Handle backspace
                if cursorX > 1 then
                    contents = contents:sub(1, cursorY * (cursorX - 2) + cursorX) .. contents:sub(cursorY * cursorX)
                    cursorX = cursorX - 1
                elseif cursorY > 1 then
                    local lineLength = contents:find("\n", (cursorY - 1) * cursorX) or #contents + 1
                    contents = contents:sub(1, cursorY * (cursorX - 2) + cursorX) .. contents:sub((cursorY - 1) * cursorX)
                    cursorY = cursorY - 1
                    cursorX = lineLength % (cursorY * cursorX)
                end
            elseif key == keys.left then
                -- Move cursor left
                if cursorX > 1 then
                    cursorX = cursorX - 1
                elseif cursorY > 1 then
                    cursorY = cursorY - 1
                    cursorX = #contents:sub(1, (cursorY - 1) * cursorX)
                end
            elseif key == keys.right then
                -- Move cursor right
                local lineLength = contents:find("\n", cursorY * cursorX) or #contents + 1
                if cursorX < lineLength % (cursorY * cursorX) then
                    cursorX = cursorX + 1
                elseif cursorY < contents:gsub("\n", "\n") then
                    cursorY = cursorY + 1
                    cursorX = 1
                end
            elseif key == keys.up then
                -- Move cursor up
                if cursorY > 1 then
                    cursorY = cursorY - 1
                    local lineLength = contents:find("\n", (cursorY - 1) * cursorX) or #contents + 1
                    cursorX = math.min(cursorX, lineLength % (cursorY * cursorX))
                end
            elseif key == keys.down then
                -- Move cursor down
                local lineCount = select(2, contents:gsub('\n', '\n'))
                if cursorY < lineCount then
                    cursorY = cursorY + 1
                    cursorX = math.min(cursorX, #contents:sub(cursorY * cursorX, cursorY * cursorX))
                end
            end
            redraw()
        elseif event == "monitor_touch" then
            if key == 1 then
                cursorX = math.min(term.getSize(), math.max(1, key))
                cursorY = math.min(select(2, contents:gsub('\n', '\n')), math.max(1, key))
            end
            redraw()
        end
        cursorVisible = not cursorVisible
    end
end

local function convertFile(nonoFilename, luaFilename)
    local contents = readFile(nonoFilename)
    if contents then
        writeFile(luaFilename, contents)
        print("Conversion successful.")
    else
        print("Error: Unable to read .nono file.")
    end
end

local function main()
    while true do
        drawMenu()
        local choice = tonumber(read())
        if choice == 1 then
            clearScreen()
            print("Enter filename:")
            local filename = read()
            editFile(filename)
        elseif choice == 2 then
            clearScreen()
            print("Enter filename to open:")
            local filename = read()
            editFile(filename)
        elseif choice == 3 then
            clearScreen()
            print("Enter filename to save:")
            local filename = read()
            local contents = readFile(filename) or ""
            writeFile(filename, contents)
            print("File saved.")
            sleep(2)
        elseif choice == 4 then
            clearScreen()
            print("Enter .nono filename to convert:")
            local nonoFilename = read()
            print("Enter .lua filename to save:")
            local luaFilename = read()
            convertFile(nonoFilename, luaFilename)
            sleep(2)
        elseif choice == 5 then
            clearScreen()
            print("Exiting...")
            sleep(1)
            clearScreen()
            break
        else
            print("Invalid choice. Please try again.")
            sleep(1)
        end
    end
end

main()