CodeEditor

--КОНСТАНТЫ--
local APIs_DESTINATION  = "MineCodeAPIs/"
local PERMANENT_INDENT = 1

--ЗАГРУЗКА СТОРОННИХ БИБЛИОТЕК, ПЕРВОНАЧАЛЬНАЯ ИНИЦИАЛИЗАЦИЯ ПРОГРАММЫ--
--os.loadAPI(apis_path .. "graphics")
os.loadAPI(APIs_DESTINATION .. "SyntaxHighlight")

--if (os.version() ~= "CraftOS 1.6") then error("Require " .. os.version() .. ".") end
if not term.isColor() or turtle or pocket then error("This program will run only on advanced computer.") end

term.clear()

--ПЕРЕМЕННЫЕ--
local sizeOfLineCounter = 1

local termWidth, termHeight = term.getSize()
local xAbsoluteCursor, yAbsoluteCursor = 4, 1
local xPrevDeltaCursor, yPrevDeltaCursor = 0, 0
local xDeltaCursor, yDeltaCursor = 0, 0

local linesArray = {}
local editedLine = nil

local GUIWindow =      window.create(term.current(), 1, 1, termWidth-1, termHeight-1)
      GUIWindow.clear()

local LineCounterWindow = window.create(term.current(), 1, 3, sizeOfLineCounter, termHeight-2)
      LineCounterWindow.clear()

local WorkspaceWindow = window.create(term.current(), sizeOfLineCounter+1, 3, termWidth-1, termHeight-2)
      WorkspaceWindow.setCursorPos(xAbsoluteCursor, yAbsoluteCursor)
      WorkspaceWindow.clear()
local workspaceWidth, workspaceHeight = WorkspaceWindow.getSize()

--РАБОТА С ФАЙЛАМИ--
local function openFile(filename)
    for readedLine in io.lines(filename) do
        table.insert(linesArray, readedLine)
    end

    editedLine = linesArray[1]
end

local function saveFile(filename)
    local _file = fs.open(filename, "w")

    for i = 1, #linesArray do
        _file.writeLine(linesArray[i])
    end

    _file.close()
end

--ОТРИСОВКА--
local function draw_gui()

end

local function draw_line(wWindow, iLine)
    WorkspaceWindow.setBackgroundColor(colors.white)
    WorkspaceWindow.setTextColor(colors.black)
    WorkspaceWindow.setCursorPos(PERMANENT_INDENT, iLine)

    local _tmpLine = linesArray[yDeltaCursor+iLine]:sub(xDeltaCursor+1, -1)

    WorkspaceWindow.write(" " .. _tmpLine .. string.rep(" ", workspaceWidth-1))

    SyntaxHighlight.syntaxString(WorkspaceWindow, iLine, PERMANENT_INDENT+1, _tmpLine)
end

local function drawLineCounter()
    LineCounterWindow.setBackgroundColor(colors.lightGray)
    LineCounterWindow.setTextColor(colors.white)
    LineCounterWindow.clear()

    for i = 1, #linesArray-yDeltaCursor do
        LineCounterWindow.setCursorPos(1, i)

        LineCounterWindow.write(yDeltaCursor+i .. string.rep(" ", sizeOfLineCounter))
    end
end

--draw_workspace() redraw all
--draw_workspace([startRedrawPos]) redraw startRedrawPos to workspaceHeight lines
--draw_workspace([startRedrawPos, [endRedrawPos]]) redraw startRedrawPos to endRedrawPos lines
local function draw_workspace(startRedrawPos, endRedrawPos)
    local prev_xCur, prev_yCur = WorkspaceWindow.getCursorPos()

    WorkspaceWindow.setCursorBlink(false)

    local prevSoLC = sizeOfLineCounter
    sizeOfLineCounter = #tostring(#linesArray)

    if prevSoLC ~= sizeOfLineCounter then
        WorkspaceWindow = window.create(term.current(), sizeOfLineCounter+1, 3, termWidth-1-sizeOfLineCounter, termHeight-2)
        workspaceWidth, workspaceHeight = WorkspaceWindow.getSize()
    end

    for i = startRedrawPos or 1, endRedrawPos or workspaceHeight do
        if linesArray[yDeltaCursor+i] then
            draw_line(WorkspaceWindow, i)
        else
            WorkspaceWindow.setCursorPos(PERMANENT_INDENT, i)
            write(string.rep(" ", workspaceWidth))
        end
    end

    if prevSoLC ~= sizeOfLineCounter then
        LineCounterWindow = window.create(term.current(), 1, 3, sizeOfLineCounter, termHeight-2)
        draw_workspace()
    end
    drawLineCounter()

    WorkspaceWindow.setBackgroundColor(colors.white)
    WorkspaceWindow.setTextColor(colors.black)
    WorkspaceWindow.setCursorPos(prev_xCur, prev_yCur)
    WorkspaceWindow.setCursorBlink(true)
end

local function range(bottom, top, value, step)
    if value + step > top then
        return top
    elseif value + step < bottom then
        return bottom
    end

    return value + step
end

--РАБОТА С КУРСОРАМИ--
local function checkEndLine()
    return xAbsoluteCursor + 1 > #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1
end

local function checkStartLine()
    return xAbsoluteCursor - 1 < PERMANENT_INDENT + 1
end

local function checkTopLinesArray()
    return yAbsoluteCursor - 1 < 1
end

local function checkBottomLinesArray()
    return yAbsoluteCursor + 1 > #linesArray
end



local function calculateCursors(xRelCur, yRelCur)
    WorkspaceWindow.setCursorPos(xRelCur, yRelCur)

    xPrevDeltaCursor = xDeltaCursor
    yPrevDeltaCursor = yDeltaCursor

    xDeltaCursor = xAbsoluteCursor - xRelCur
    yDeltaCursor = yAbsoluteCursor - yRelCur
end



local function moveCursorsToStartLine()
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    xAbsoluteCursor = PERMANENT_INDENT + 1
    xRelativeCursor = PERMANENT_INDENT + 1

    calculateCursors(xRelativeCursor, yRelativeCursor)
end

local function moveCursorsToEndLine()
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    xAbsoluteCursor = #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1
    xRelativeCursor = math.min(#linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1, workspaceWidth)

    calculateCursors(xRelativeCursor, yRelativeCursor)
end

local function moveCursorsUpAndDown(step)
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    yAbsoluteCursor = range(1, #linesArray, yAbsoluteCursor, step)
    yRelativeCursor = range(1, math.min(workspaceHeight, #linesArray), yRelativeCursor, step)

    if checkEndLine() then
        xAbsoluteCursor = #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1
        xRelativeCursor = #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1
    end

    calculateCursors(xRelativeCursor, yRelativeCursor)
end

local function moveCursorsRightAndLeft(step)
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    if step < 0 and checkStartLine() and yAbsoluteCursor > 1 then
        xAbsoluteCursor = #linesArray[yAbsoluteCursor - 1] + PERMANENT_INDENT + 2
        xRelativeCursor = math.min(#linesArray[yAbsoluteCursor - 1] + PERMANENT_INDENT + 2, workspaceWidth)

        yAbsoluteCursor = yAbsoluteCursor - 1
        yRelativeCursor = math.max(yRelativeCursor - 1, 1)
    end

    if step > 0 and checkEndLine() and yAbsoluteCursor < #linesArray then
        xAbsoluteCursor = PERMANENT_INDENT
        xRelativeCursor = PERMANENT_INDENT

        yAbsoluteCursor = yAbsoluteCursor + 1
        yRelativeCursor = math.min(yRelativeCursor + 1, workspaceHeight)
    end

    xAbsoluteCursor = range(PERMANENT_INDENT + 1, #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1, xAbsoluteCursor, step)
    xRelativeCursor = range(PERMANENT_INDENT + 1, math.min(workspaceWidth, #linesArray[yAbsoluteCursor] + PERMANENT_INDENT + 1), xRelativeCursor, step)

    calculateCursors(xRelativeCursor, yRelativeCursor)
end

--РЕДАКТИРОВАНЕ ТЕКСТА--
local function removeChar()
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    if xAbsoluteCursor > PERMANENT_INDENT + 1 then
        linesArray[yAbsoluteCursor] = linesArray[yAbsoluteCursor]:sub(1, xAbsoluteCursor-(PERMANENT_INDENT + 2)) .. linesArray[yAbsoluteCursor]:sub(xAbsoluteCursor-PERMANENT_INDENT, -1)
        xAbsoluteCursor = xAbsoluteCursor - 1
        xRelativeCursor = xRelativeCursor - 1
        draw_workspace(yRelativeCursor, yRelativeCursor)
    elseif yAbsoluteCursor > 1 then
        local _temp = #linesArray[yAbsoluteCursor - 1]

        linesArray[yAbsoluteCursor - 1] = linesArray[yAbsoluteCursor - 1] .. linesArray[yAbsoluteCursor]:sub(xAbsoluteCursor-PERMANENT_INDENT, -1)
        table.remove(linesArray, yAbsoluteCursor)

        yAbsoluteCursor = yAbsoluteCursor - 1
        yRelativeCursor = math.max(yRelativeCursor - 1, 1)
        xAbsoluteCursor = _temp + PERMANENT_INDENT + 1
        xRelativeCursor = math.min(_temp + PERMANENT_INDENT + 1, workspaceWidth)
        draw_workspace(yRelativeCursor, workspaceHeight)
    end

    calculateCursors(xRelativeCursor, yRelativeCursor)
end

local function writeChar(char)
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()
    linesArray[yAbsoluteCursor] = linesArray[yAbsoluteCursor]:sub(1, xAbsoluteCursor-(PERMANENT_INDENT + 1)) .. char .. linesArray[yAbsoluteCursor]:sub(xAbsoluteCursor-PERMANENT_INDENT, -1)
    draw_workspace(yRelativeCursor, yRelativeCursor)
end

local function newLine()
    local xRelativeCursor, yRelativeCursor = WorkspaceWindow.getCursorPos()

    table.insert(linesArray, yAbsoluteCursor + 1, linesArray[yAbsoluteCursor]:sub(xAbsoluteCursor-PERMANENT_INDENT, -1))
    linesArray[yAbsoluteCursor] = linesArray[yAbsoluteCursor]:sub(1, xAbsoluteCursor-(PERMANENT_INDENT + 1))

    yAbsoluteCursor = range(1, #linesArray, yAbsoluteCursor, 1)
    yRelativeCursor = range(1, math.min(workspaceHeight, #linesArray), yRelativeCursor, 1)
    xAbsoluteCursor = PERMANENT_INDENT + 1
    xRelativeCursor = PERMANENT_INDENT + 1

    calculateCursors(xRelativeCursor, yRelativeCursor)
    draw_workspace(yRelativeCursor-1, workspaceHeight)
end

--openFile("edt")
openFile("test")
draw_workspace()

--ГЛАВНЫЙ ЦИКЛ ПРОГРАММЫ--
while true do
    if xDeltaCursor ~= xPrevDeltaCursor or yDeltaCursor ~= yPrevDeltaCursor then
        draw_workspace()
    end

    --GUIWindow.clearLine()
    --GUIWindow.setCursorPos(1, 1)
    --GUIWindow.write("xDC: " .. xDeltaCursor .. ". yDC: " .. yDeltaCursor .. ". xpDC: " .. xPrevDeltaCursor .. ". ypDC: " .. yPrevDeltaCursor)

    local event, par1, par2, par3, par4 = os.pullEvent()

    if event == "key" then
        if par1 == keys.down then
            moveCursorsUpAndDown(1)
        elseif par1 == keys.up then
            moveCursorsUpAndDown(-1)
        elseif par1 == keys.left then
            moveCursorsRightAndLeft(-1)
        elseif par1 == keys.right then
            moveCursorsRightAndLeft(1)
        elseif par1 == keys.home then
            moveCursorsToStartLine()
        elseif par1 == keys["end"] then
            moveCursorsToEndLine()
        elseif par1 == keys.backspace then
            removeChar()
        elseif par1 == keys.enter then
            newLine()
        elseif par1 == keys.insert then
            saveFile("test")
        end
    end

    if event == "char" then
        writeChar(par1)
        moveCursorsRightAndLeft(1)
    end
end