term.setCursorBlink(true)
local sNew = "|   [Make new file]    Open existing file   |"
local sOpen = "|    Make new file    [Open existing file]  |"
local sYes = "|               [Yes]    No                 |"
local sNo = "|                Yes    [No]                |"
local sSave = "|      [Save]    Quit     Save & Quit       |"
local sQuit = "|       Save    [Quit]    Save & Quit       |"
local sSaveAndQuit = "|       Save     Quit    [Save & Quit]      |"
local iMenuXCor = 0
local sFile = ""
local sLine = ""
local tLines = {}
local iScrollX, iScrollY = 0,0
local x, y = 1,1
local w, h = term.getSize()

local function fMenuXCor()
    iMenuXCor = (w/2)-21
end

local function fCheckDir()
    if not fs.isDir("/files") then
        fs.makeDir("/files")
    end
    if shell.dir() ~=  "/files" then
        shell.setDir("/files")
    end
end

local function fExitDir()
    term.clear()
    shell.setDir("")
end

local function fOpenNew()
    tLines = {}
    table.insert(tLines, "")
end

local function fLoad()
    sPath = shell.resolve(sFile)
    if fs.exists( sPath ) then
        local file = io.open( sPath , "r")
        local sLine = file:read()
        while sLine do
            table.insert(tLines, sLine)
            sLine = file:read()
        end
        file:close()
    else
        term.clear()
        term.setCursorBlink(false)
        local sYesOrNo = sYes
        term.setCursorPos(iMenuXCor,6)
        write(" ___________________________________________")
        term.setCursorPos(iMenuXCor,7)
        write("|                                           |")
        term.setCursorPos(iMenuXCor,8)
        write("|         Error: File doesn't exist.        |")
        term.setCursorPos(iMenuXCor,9)
        write("|          Do you want to make it?          |")
        term.setCursorPos(iMenuXCor,10)
        write("|                                           |")
        term.setCursorPos(iMenuXCor,11)
        write(sYesOrNo)
        term.setCursorPos(iMenuXCor,12)
        write("|___________________________________________|")
        repeat
            local sEvent, param = os.pullEvent()
            if sEvent == "key" then
                param = tostring(param)
                if param == "203" or param == "205" then
                    if sYesOrNo == sYes then
                        sYesOrNo = sNo
                        term.setCursorPos(iMenuXCor,11)
                        write(sYesOrNo)
                    elseif sYesOrNo == sNo then
                        sYesOrNo = sYes
                        term.setCursorPos(iMenuXCor,11)
                        write(sYesOrNo)
                    end
                end
            end
        until param == "28"
        if sYesOrNo == sYes then
            fOpenNew()
        elseif sYesOrNo == sNo then
            term.clear()
            term.setCursorPos(1,1)
            print("Quitting")
            sleep(1)
            fExitDir()
            shell.exit()
        end
    end
end

local function fMenuNew()
    term.clear()
    term.setCursorBlink(false)
    term.setCursorPos(iMenuXCor,1)
    write(" ___________________________________________")
    term.setCursorPos(iMenuXCor,2)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,3)
    write("|     How do you want to call the file?     |")
    term.setCursorPos(iMenuXCor,4)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,5)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,6)
    write("|___________________________________________|")
    term.setCursorPos(iMenuXCor+6,5)
    sFile = io.read()
    sFileExt = string.sub(sFile, -3)
    if sFileExt ~= ".txt" then
        sFile = sFile..".txt"
    end
    sPath = shell.resolve(sFile)
    if fs.exists(sPath) then
        term.clear()
        local sYesOrNo = sYes
        term.setCursorPos(iMenuXCor,6)
        write(" ___________________________________________")
        term.setCursorPos(iMenuXCor,7)
        write("|                                           |")
        term.setCursorPos(iMenuXCor,8)
        write("|         Error: File already exist.        |")
        term.setCursorPos(iMenuXCor,9)
        write("|          Do you want to edit it?          |")
        term.setCursorPos(iMenuXCor,10)
        write("|                                           |")
        term.setCursorPos(iMenuXCor,11)
        write(sYesOrNo)
        term.setCursorPos(iMenuXCor,12)
        write("|___________________________________________|")
        repeat
            local sEvent, param = os.pullEvent()
            if sEvent == "key" then
                param = tostring(param)
                if param == "203" or param == "205" then
                    if sYesOrNo == sYes then
                        sYesOrNo = sNo
                        term.setCursorPos(iMenuXCor,11)
                        write(sYesOrNo)
                    elseif sYesOrNo == sNo then
                        sYesOrNo = sYes
                        term.setCursorPos(iMenuXCor,11)
                        write(sYesOrNo)
                    end
                end
            end
        until param == "28"
        if sYesOrNo == sYes then
            fLoad()
        elseif sYesOrNo == sNo then
            term.clear()
            term.setCursorPos(1,1)
            print("Quitting")
            sleep(1)
            fExitDir()
            shell.exit()
        end
    else
        fOpenNew()
    end
    term.setCursorBlink(true)
end

local function fMenuOpen()
    term.clear()
    term.setCursorBlink(false)
    term.setCursorPos(1,8)
    write("Files:")
    term.setCursorPos(iMenuXCor,10)
    shell.run("ls")
    term.setCursorPos(iMenuXCor,1)
    write(" ___________________________________________")
    term.setCursorPos(iMenuXCor,2)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,3)
    write("|      Which file do you want to open?      |")
    term.setCursorPos(iMenuXCor,4)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,5)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,6)
    write("|___________________________________________|")
    term.setCursorPos(iMenuXCor+7,5)
    term.setCursorBlink(true)
    sFile = read()
    sFileExt = string.sub(sFile, -3)
    if sFileExt ~= ".txt" then
        sFile = sFile..".txt"
    end

    term.setCursorBlink(true)
    fLoad()
end

local function fMenuStart()
    local sChoose = sNew
    fMenuXCor()
    term.clear()
    term.setCursorBlink(false)
    term.setCursorPos(iMenuXCor,6)
    write(" ___________________________________________")
    term.setCursorPos(iMenuXCor,7)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,8)
    write("| Welcome to the RedworksOS Word Processor, |")
    term.setCursorPos(iMenuXCor,9)
    write("|          what do you want to do?          |")
    term.setCursorPos(iMenuXCor,10)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,11)
    write(sChoose)
    term.setCursorPos(iMenuXCor,12)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,13)
    write("|         To access menu press Ctrl.        |")
    term.setCursorPos(iMenuXCor,14)
    write("|___________________________________________|\n")
    repeat
    local sEvent, param = os.pullEvent()
    if sEvent == "key" then
        param = tostring(param)
        if param == "203" or param == "205" then
            if sChoose == sNew then
                sChoose = sOpen
                term.setCursorPos(iMenuXCor,11)
                write(sChoose)
            elseif sChoose == sOpen then
                sChoose = sNew
                term.setCursorPos(iMenuXCor,11)
                write(sChoose)
            end
        end
    end
    until param == "28"
    if sChoose == sOpen then
        term.clear()
        fMenuOpen()
    elseif sChoose == sNew then
        term.clear()
        fMenuNew()
    end
    term.setCursorBlink(true)
end

local function fMenuExit()
    term.clear()
    term.setCursorBlink(false)
    local sSaveOrQuit = sSave
    term.setCursorPos(iMenuXCor,6)
    write(" ___________________________________________")
    term.setCursorPos(iMenuXCor,7)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,8)
    write("|          What do you want to do?          |")
    term.setCursorPos(iMenuXCor,9)
    write("|                                           |")
    term.setCursorPos(iMenuXCor,10)
    write(sSaveOrQuit)
    term.setCursorPos(iMenuXCor,11)
    write("|___________________________________________|")
    repeat
        local sEvent, param = os.pullEvent()
        if sEvent == "key" then
            if param == 203 then
                if sSaveOrQuit == sSave then
                    sSaveOrQuit = sSaveAndQuit
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                elseif sSaveOrQuit == sQuit then
                    sSaveOrQuit = sSave
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                elseif sSaveOrQuit == sSaveAndQuit then
                    sSaveOrQuit = sQuit
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                end
            elseif param == 205 then
                if sSaveOrQuit == sSave then
                    sSaveOrQuit = sQuit
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                elseif sSaveOrQuit == sQuit then
                    sSaveOrQuit = sSaveAndQuit
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                elseif sSaveOrQuit == sSaveAndQuit then
                    sSaveOrQuit = sSave
                    term.setCursorPos(iMenuXCor,10)
                    write(sSaveOrQuit)
                end
            end
        end
    until param == 28
    if sSaveOrQuit == sSave then
        fSave()
        term.setCursorBlink(true)
        bExit = false
    elseif sSaveOrQuit == sQuit then
        bExit = true
    elseif sSaveOrQuit == sSaveAndQuit then
        bExit = true
        fSave()
    end
end

function fSave()
    local file = io.open( sPath, "w" )
    if file then
        for n, sLine in ipairs( tLines ) do
            file:write( sLine .. "\n" )
        end
        file:close()
        bSave = true
    else
        bSave = false
    end
end

local function fPrintText()
    for y=1,h do
        term.setCursorPos( 1 - iScrollX, y )
        term.clearLine()

        local sLine = tLines[ y + iScrollY ]
        if sLine ~= nil then
            write( sLine )
        end
    end
    term.setCursorPos( x - iScrollX, y - iScrollY )
end

local function fPrintLine()
    local sLine = tLines[y]
    term.setCursorPos( 1 - iScrollX, y - iScrollY )
    term.clearLine()
    term.write( sLine )
    term.setCursorPos( x - iScrollX, y - iScrollY )
end

local function fSetCursor(x, y)
    local screenX = x - iScrollX
    local screenY = y - iScrollY

    if screenX < 1 then
        iScrollX = x - 1
        screenX = 1
        fPrintText()
    elseif screenX > w then
        iScrollX = x - w
        screenX = w
        fPrintText()
    end

    if screenY < 1 then
        iScrollY = y - 1
        screenY = 1
        fPrintText()
    elseif screenY > h then
        iScrollY = y - (h)
        screenY = h
        fPrintText()
    end

    term.setCursorPos( screenX, screenY )
end

fCheckDir()
fMenuStart()
term.clear()
term.setCursorPos(x,y)
term.setCursorBlink(true)
fPrintText()
while true do
    local sEvent, param = os.pullEvent()
    if sEvent == "key" then
        if param == 200 then
            if y > 1 then
                y = y - 1
                x = math.min( x, string.len( tLines[y] ) + 1 )
                fSetCursor( x, y )
            end

        elseif param == 208 then
            if y < #tLines then
                    y = y + 1
                    x = math.min( x, string.len( tLines[y] ) + 1 )
                    fSetCursor( x, y )
            end

        elseif param == 203 then
            if x > 1 then
                x = x - 1
                fSetCursor( x, y )
            end

        elseif param == 205 then
            if x < string.len( tLines[y] ) + 1 then
                x = x + 1
                fSetCursor( x, y )
            end

        elseif param == 14 then
             if x > 1 then
                local sLine = tLines[y]
                tLines[y] = string.sub(sLine,1,x-2) .. string.sub(sLine,x)
                fPrintLine()

                x = x - 1
                fSetCursor( x, y )

            elseif y > 1 then
                local sPrevLen = string.len( tLines[y-1] )
                tLines[y-1] = tLines[y-1] .. tLines[y]
                table.remove( tLines, y )
                fPrintText()

                x = sPrevLen + 1
                y = y - 1
                fSetCursor( x, y )
            end

        elseif param == 28 then
            local sLine = tLines[y]
            tLines[y] = string.sub(sLine,1,x-1)
            table.insert( tLines, y+1, string.sub(sLine,x) )
            fPrintText()

            x = 1
            y = y + 1
            fSetCursor( x, y )


        elseif param == 29 then
            fMenuExit()
            if bExit then
                break
            else
                fPrintText()
            end
        end

    elseif sEvent == "char" then
        local sLine = tLines[y]
        tLines[y] = string.sub(sLine,1,x-1) .. param .. string.sub(sLine,x)
        fPrintLine()

        x = x + string.len( param )
        fSetCursor(x, y)
    end
end

fExitDir()
term.clear()
term.setCursorBlink(false)
term.setCursorPos(1,1)