CCEdit

local cfname = "NEW"
local title = "\\___/ File: "..cfname

local clipboard = {}

local lastname = nil
local lastlines = nil

local lines = {" "}
local firstpoint = nil
local lastpoint = nil

local cursor = {1, 1}
local blink = true

local scroll = {1, 1}

local curtab = " "

local function drawMenu()
    local menu = {"|    \\__",
                  "| SAVE  |",
                  "| NEW   |",
                  "| LOAD  |",
                  "| PRINT |",
                  "+-------+"}

    for y=1,#menu do
        local line = menu[y]
        term.setCursorPos(1, y+1)
        term.write(line)
    end
end

local function drawLines()
    local oldx, oldy = term.getCursorPos()
    for y=scroll[2],#lines do
        local line = lines[y]
        for x=scroll[1],string.len(line) do
            local ch = string.sub(line, x, x)
            local color = colors.white
            if firstpoint ~= nil then
                if firstpoint[2] < y and lastpoint[2] > y then color = colors.yellow end
                if firstpoint[2] == y and firstpoint[1] <= x then color = colors.yellow end
                if lastpoint[2] == y and lastpoint[1] >= x then color = colors.yellow end
            end
            term.setCursorPos((x)-scroll[1]+1, (y+2)-scroll[2])
            term.setTextColor(color)
            term.write(ch)
            term.setTextColor(colors.white)
        end
    end
    term.setCursorPos(cursor[1]-scroll[1]+1, ((cursor[2])+2)-scroll[2])
    if blink then term.write("_") end
    term.setCursorPos(oldx, oldy)
end

local function type(ch)
    if firstpoint == nil then
        local line = lines[cursor[2]]
        local bef = string.sub(line, 1, cursor[1]-1)
        local aft = string.sub(line, cursor[1], -1)
        local nline = ""
        if bef ~= nil then nline = bef end
        nline = nline..ch
        if aft ~= nil then nline = nline..aft end
        lines[cursor[2]] = nline
        cursor[1] = cursor[1] + 1
    else
        local lns = {}
        for i=1,#lines do
            local line = lines[i]
            if i == firstpoint[2] then
                lns[#lns + 1] = string.sub(line, firstpoint[1], -1)..ch
            elseif i == lastpoint[2] then
                lns[#lns + 1] = string.sub(line, 1, lastpoint[1])
            elseif i > firstpoint[2] and i < lastpoint[2] then

            else
                lns[#lns + 1] = line
            end
        end
        lines = lns
        firstpoint = nil
        lastpoint = nil
        cursor[1] = cursor[1] + 1
    end
end

local function backspace()
    if firstpoint == nil then
        local line = lines[cursor[2]]
        if line == "" or line == nil then
            local lns = {}
            for i=1,#lines do
                local line = lines[i]
                if i ~= cursor[2] then
                    lns[#lns + 1] = line
                end
            end
            cursor[2] = cursor[2] - 1
        else
            local bef = string.sub(line, 1, cursor[1]-1)
            local aft = string.sub(line, cursor[1]+1, -1)
            local nline = ""
            if bef ~= nil then nline = bef end
            if aft ~= nil then nline = nline..aft end
            lines[cursor[2]] = nline
            cursor[1] = cursor[1] - 1
        end
    else
        local lns = {}
        for i=1,#lines do
            local line = lines[i]
            if i == firstpoint[2] then
                lns[#lns + 1] = string.sub(line, firstpoint[1], -1)
            elseif i == lastpoint[2] then
                lns[#lns + 1] = string.sub(line, 1, lastpoint[1])
            elseif i > firstpoint[2] and i < lastpoint[2] then

            else
                lns[#lns + 1] = line
            end
        end
        lines = lns
        firstpoint = nil
        lastpoint = nil
        cursor[1] = cursor[1] - 1
    end
end

local tabamt = "    "
local function tab()
    type(tabamt)
    curtab = curtab..tabamt
end

local function untab()
    local line = lines[cursor[2]]
    local sub = string.sub(line, cursor[1]-(string.len(tabat)), cursor[1])
    if sub ~= nil then
        if string.gsub(sub, " ", "") == "" then
            local bef = string.sub(line, 1, cursor[1]-(string.len(tabat)-1))
            local aft = string.sub(line, cursor[1], -1)
            local nline = ""
            if bef ~= nil then nline = bef end
            if aft ~= nil then nline = nline..aft end
            lines[cursor[2]] = nline
            if string.len(curtab) > string.len(tabamt) then
                curtab = string.sub(curtab, 1, string.len(curtab)-string.len(tabamt))
            end
            if curtab == "" then curtab = " " end
        end
    end
end

local function enter()
    local lns = {}
    local done = false
    if firstpoint == nil then
        for i=1,#lines do
            local line = lines[i]
            lns[#lns + 1] = line
            if i == cursor[2] and not done then
                lns[#lns + 1] = curtab
                cursor = {string.len(curtab), i+1}
                done = true
            end
        end
    else
        for i=1,#lines do
            local line = lines[i]
            if i == firstpoint[2] then
                lns[#lns + 1] = string.sub(line, 1, firstpoint[1])
                local nstr = " "
                local sub = string.sub(line, firstpoint[1], -1)
                if sub ~= nil and sub ~= "" then nstr = sub end
                lns[#lns + 1] = curtab
                cursor = {string.len(curtab), i+1}
            elseif i == lastpoint[2] then
                lns[#lns + 1] = string.sub(line, 1, lastpoint[1])
            elseif i > firstpoint[2] and i < lastpoint[2] then

            else
                lns[#lns + 1] = line
            end
        end
        firstpoint = nil
        lastpoint = nil
    end
    lines = lns
end

local function copy()
    local lns = {}
    for y=firstpoint[2],lastpoint[2] do
        local line = lines[y]
        if y == firstpoint[2] then
            line = string.sub(line, firstpoint[1], -1)
        elseif y == lastpoint[2] then
            line = string.sub(line, 1, lastpoint[1])
        else
            lns[#lns + 1] = line
        end
    end
    clipboard = lns
end

local function paste()
    local lns = {}
    for y=1,#lines do
        local line = lines[y]
        if y == cursor[2] then
            for i=1,#clipboard do
                if i == 1 then
                    line = line..clipboard[i]
                else
                    line = clipboard[i]
                end
                lns[#lns + 1] = line
            end
        else
            lns[#lns + 1] = line
        end
    end
    lastlines = lines
    lines = lns
end

local function undo()
    if lastlines ~= nil then
        local templines = lines
        lines = lastlines
        lastlines = templines
        if lastname ~= nil then
            cfname = lastname
            title = string.sub(title, 1, 5).." File: "..cfname
            lastname = nil
        end
    end
end

local timer = os.startTimer(0)
local interval = 0.1

local function save()
    term.setCursorPos(1, 1)
    local line = ""
    local mx, my = term.getSize()
    for i=1,mx do line = line.." " end
    term.write(line)
    term.setCursorPos(1, 1)
    local msg = "Enter Dir: "
    term.write(msg)
    term.setCursorPos(string.len(msg), 1)
    local input = read()
    while input == "" or input == nil do
        term.setCursorPos(1, 1)
        term.write(line)
        term.setCursorPos(1, 1)
        term.write(msg)
        term.setCursorPos(string.len(msg), 1)
        input = read()
    end
    if string.gsub(input, " ", "") == "" then else
        if fs.exists(input) then fs.delete(input) end
        local file = fs.open(input, "a")
        for i=1,#lines do
            local line = lines[i]
            file.writeLine(line)
        end
        file.close()
        cfname = input
        title = string.sub(title, 1, 5).." File: "..cfname
    end
    timer = os.startTimer(interval)
    title = "\\___/ File: "..cfname
end

local function load()
    term.setCursorPos(1, 1)
    local line = ""
    local mx, my = term.getSize()
    for i=1,mx do line = line.." " end
    term.write(line)
    term.setCursorPos(1, 1)
    local msg = "Enter Dir: "
    term.write(msg)
    term.setCursorPos(string.len(msg), 1)
    local input = read()
    while input == "" or input == nil do
        term.setCursorPos(1, 1)
        term.write(line)
        term.setCursorPos(1, 1)
        term.write(msg)
        term.setCursorPos(string.len(msg), 1)
        input = read()
    end
    if string.gsub(input, " ", "") == "" then else
        if fs.exists(input) then
            local file = fs.open(input, "r")
            local ln = file.readLine()
            local lns = {}
            while ln ~= nil do
                lns[#lns + 1] = ln
                ln = file.readLine()
            end
            file.close()
            lines = lns
            cfname = input
            title = string.sub(title, 1, 5).." File: "..cfname
        end
    end
    timer = os.startTimer(interval)
    title = "\\___/ File: "..cfname
end

local function new()
    title = "\\___/ File: NEW"

    clipboard = {}

    lastname = cfname
    lastlines = lines

    cfname = "NEW"

    lines = {" "}
    firstpoint = nil
    lastpoint = nil

    cursor = {1, 1}
    blink = true
end

local function round (x)
  if x >= 0 then
    return math.floor (x + 0.5)
  end  -- if positive

  return math.ceil (x - 0.5)
end

local function print()
    term.setCursorPos(1, 1)
    local line = ""
    local mx, my = term.getSize()
    for i=1,mx do line = line.." " end
    term.write(line)
    term.setCursorPos(1, 1)
    local msg = "Enter title: "
    term.write(msg)
    term.setCursorPos(string.len(msg), 1)
    while input == "" or input == nil do
        term.setCursorPos(1, 1)
        term.write(line)
        term.setCursorPos(1, 1)
        term.write(msg)
        term.setCursorPos(string.len(msg), 1)
        input = read()
    end

    tSides = {"left","right","bottom","top","front","back"}
    local printer = nil
    for i=1,#tSides do
        local side = tSides[i]
        if peripheral.getType(side) == "printer" and printer == nil then
            printer = peripheral.wrap(side)
        end
    end
    if printer ~= nil then
        printer.newPage()
        local px, py = printer.getPageSize()
        local pages = round(#lines / py)
        if printer.getInkLevel() >= pages then
            if printer.getPaperLevel() >=  pages then
                local cur = 0
                for i=1,#lines do
                    cur = cur + 1
                    if cur > py then
                        printer.endPage()
                        printer.newPage()
                        printer.setPageTitle(input)
                    end
                    local line = lines[i]
                    while string.len(line) > px do
                        local ln = string.sub(line, 1, px)
                        printer.write(ln)
                        cur = cur + 1
                        if cur > py then
                            printer.endPage()
                            printer.newPage()
                            printer.setPageTitle(input)
                        end
                        line = string.sub(line, px+1, -1)
                        if line == nil then line = "" end
                    end
                    printer.write(line)
                end
                printer.endPage()
            end
        end
    end
    timer = os.startTimer(interval)
    title = "\\___/ File: "..input
end

local function checkCurs()

    local mx, my = term.getSize()

    if cursor[1] < scroll[1] then scroll[1] = scroll[1] - 1 end
    if cursor[1] > scroll[1]+mx then scroll[1] = scroll[1] + 1 end
    if cursor[2] < scroll[2] then scroll[2] = scroll[2] - 1 end
    if cursor[2] > scroll[2]+my then scroll[2] = scroll[2] + 1 end

    if cursor[2] < 1 then cursor[2] = 1 end
    if cursor[2] > #lines then cursor[2] = #lines end
    if cursor[1] < 1 then cursor[1] = 1 end
    if cursor[1] > string.len(lines[cursor[2]]) then cursor[1] = string.len(lines[cursor[2]]) end

    if scroll[1] < 1 then scroll[1] = 1 end
    if scroll[1] > cursor[1] then scroll[1] = cursor[1] end
    if scroll[2] < 1 then scroll[2] = 1 end
    if scroll[2] > #lines then scroll[2] = #lines end

end

local showtab = false

local on = true

local dochar = true

local ticks = 0
while on do
    local event, p1, p2, p3 = os.pullEvent()
    if event == "timer" and p1 == timer then
        checkCurs()
        term.clear()
        term.setCursorPos(1, 1)
        term.write(title)
        drawLines()
        if showtab then
            drawMenu()
        end
        ticks = ticks + 1
        if ticks >= 3 then
            if blink then blink = false else blink = true end
            ticks = 0
        end
        timer = os.startTimer(interval)
    elseif event == "key" then
        local key = p1
        if key == 29 then
            on = false
        elseif key == 15 then
            tab()
        elseif key == 41 then
            untab()
        elseif key == 54 then
            dochar = false
        elseif key == 28 then
            enter()
        elseif key == 14 then
            backspace()
        elseif key == 157 then
            if showtab then
                showtab = false
                title = "\\___/"..string.sub(title, 6, -1)
            else
                showtab = true
                title = " ____"..string.sub(title, 6, -1)
            end
        elseif key == 200 then --up
            local x = string.len(lines[cursor[2]])
            cursor[2] = cursor[2] - 1
            checkCurs()
            if x > string.len(lines[cursor[2]]) then x = string.len(lines[cursor[2]]) end
            cursor[1] = x
        elseif key == 203 then --left
            cursor[1] = cursor[1] - 1
        elseif key == 208 then --down
            local x = string.len(lines[cursor[2]])
            cursor[2] = cursor[2] + 1
            checkCurs()
            if x > string.len(lines[cursor[2]]) then x = string.len(lines[cursor[2]]) end
            cursor[1] = x
        elseif key == 205 then --right
            cursor[1] = cursor[1] + 1
        end
    elseif event == "char" then
        local char = p1
        if dochar then
            type(char)
        elseif not showtab then
            char = string.lower(char)
            if char == "c" then copy() end
            if char == "v" then paste() end
            if char == "p" then print() end
            if char == "s" then save() end
            if char == "l" then load() end
            if char == "n" then new() end
            if char == "y" or char == "u" then undo() end
        end
        dochar = true
    elseif event == "mouse_click" then
        local button = p1
        local y = p3
        local x = p2
        if y == 1 and x >= 1 and x <= 5 then
            if showtab then
                showtab = false
                title = "\\___/"..string.sub(title, 6, -1)
            else
                showtab = true
                title = " ____"..string.sub(title, 6, -1)
            end
        elseif showtab then
            local cy = y - 2
            if cy == 1 then --save
                save()
                showtab = false
            elseif cy == 2 then --new
                new()
                showtab = false
            elseif cy == 3 then --load
                load()
                showtab = false
            elseif cy == 4 then --print
                print()
                showtab = false
            end
        else
            if button == 2 then
                firstpoint = {cursor[1], cursor[2]}
                lastpoint = {x, y}
            elseif button == 3 then
                firstpoint = nil
                lastpoint = nil
            else
                cursor[1] = x
                cursor[2] = y
            end
        end
    elseif event == "mouse_drag" then
        local x = p1
        local y = p2
        local firstpoint = {cursor[1], cursor[2]}
        local lastpoint = {x, y}
    end
end

term.clear()
term.setCursorPos(1, 1)