bedit4

local tArgs = {...}
if #tArgs == 0 then
  error("No file specified.")
end

local editMode = 0
local file = tArgs[1]
local line,column = 1,1
local scrollX,scrollY = 0,0
local menuScroll,menuIndex = 0,1
local tw,th = term.getSize()
local curScreen = nil
local keyHandler = nil
local charHandler = nil
local menuKey = 197
local menuTimer = -1
local standardSpaces = 2
local menuOptions = { "New", "Open", "Save", "Save As...", "Save Copy As...", "Auto Indent", "Import", "Export", "Options", "Exit Menu", "Quit to Shell" }
local screens = { edit = {  }, menu = { } }
local done = false
local keys = { ["\""] = "STRING", ["("] = "KEY_PAR_OP", [")"] = "KEY_PAR_CLOSE", ["{"] = "KEY_BRACE_OPEN", ["}"] = "KEY_BRACE_CLOSE", ["THEN"] = "KEY_THEN", ["DO"] = "KEY_DO", ["END"] = "KEY_END", [" "] = "KEY_SPACE", ["FUNCTION"] = "KEY_FUNC_OP" }
local upperKeys = { "KEY_BRACE_OPEN", "KEY_THEN", "KEY_DO", "KEY_FUNC_OP", "KEY_PAR_OP" }
local lowerKeys = { "KEY_END", "KEY_BRACE_CLOSE", "KEY_PAR_CLOSE" }
local splitter = { "KEY_SPACE" }


th = th

term.clear()

lines = {}

function printCenteredText(line,text)
  term.setCursorPos(tw/2-string.len(text)/2,line)
  term.write(text)
end

function drawMenu()
  term.setCursorBlink(false)
  term.clear()
  printCenteredText(1,"Menu")
  printCenteredText(2,file)

  term.setCursorPos(3,2)
  for i=1,math.min(th-2,#menuOptions),1 do
    term.setCursorPos(3,i+2)
    term.write(menuOptions[i])
  end
  drawMenuCursor()
end

function setMenuStatus(text,timer)

  printCenteredText(th,text)
  restoreCursorPos()
  menuTimer = os.startTimer(timer)

end

function drawMenuCursor()
  for i=1,math.min(th-2,#menuOptions),1 do
    term.setCursorPos(1,i+2)
    term.write( ( i + menuScroll == menuIndex) and " >" or "  " )
  end
end

function setScreen(screen)
  curScreen = screen
  if curScreen.init then
    curScreen.init()
  end
end
--setScreen(screens.edit)

function restoreCursorPos()
  term.setCursorPos(column-scrollX,2+(line-scrollY)-1)
end

function loadFile(fileName)
  local file = io.open( fileName, "r" )
  lines = {}
  if not fs.exists(fileName) then lines = {""} return end
  for line in file:lines(fileName) do
    table.insert(lines,line)
  end
end
loadFile(file)
if #lines == 0 then lines = {""} end

function saveFile(saveName)
  saveName = saveName or file
  if fs.exists(saveName..".savbkp") then fs.delete(saveName..".savbkp") end
  if fs.exists( saveName ) then
    fs.copy(saveName,saveName..".savbkp")
  end
  local file = fs.open( saveName, "w")
  for _,v in ipairs(lines) do
    file.writeLine(v)
  end
  file.close()
  if fs.exists(saveName..".savbkp") then
    fs.delete(saveName..".savbkp")
  end
end

function redrawLine(lineNum)
  term.setCursorPos(1,lineNum)
  term.clearLine()
  local aIndex = scrollY - 1 + lineNum
  if lines[aIndex] and string.len(lines[aIndex]) > scrollX then
    if lineNum-1+scrollY <= #lines then
      local s = scrollX+1
      term.write(string.sub(lines[aIndex],s,s+tw-1))
    end
  end
  restoreCursorPos()
end

function redrawLines()
  for i=2,th,1 do
    redrawLine(i)

  end
  --restoreCursorPos()
end

function trim1(s)
  return (s:gsub("^%s*(.-)%s*$", "%1"))
end

function unIndentLines()
  for i,v in ipairs(lines) do
    lines[i] = trim1(lines[i])
  end
end

function isInTable(tabl,element,caseSensitive)
  caseSensitive = caseSensitive or false
  for k,v in pairs(tabl) do
    if type(element) == "string" and type(v) == "string" then
      if caseSenstive then
        if element == v then return true end
      else
        if string.lower(element) == string.lower(v) then return true end
      end
    else
      if element == v then return true end
    end
  end
  return false
end

function indentProc(chr,buffer,indentLevel,newIndentLevel,inString)
  chr = string.upper(chr)
  if inString then
    if keys[chr] == "STRING" then
      return chr,buffer,indentLevel,newIndentLevel,false
    else
      return chr,buffer,indentLevel,newIndentLevel,inString
    end
  else
    if keys[chr] == "STRING" then
      inString = true
    elseif isInTable(upperKeys,keys[chr]) then
      newIndentLevel = newIndentLevel + 1
    elseif isInTable(lowerKeys, keys[chr]) then
      if newIndentLevel > 0 then
        newIndentLevel = newIndentLevel - 1
      else
        indentLevel = indentLevel -1
        --newIndentLevel = newIndentLevel - 1
      end
    elseif isInTable(splitter,keys[chr]) then
      buffer = ""
    end
    return chr,buffer,indentLevel,newIndentLevel,inString
  end
end

function autoIndent()
  unIndentLines()
  local spacing = standardSpaces
  local inString = false

  local indentLevel = 0
  for i,_ in ipairs(lines) do
    --lines[i] = string.rep(" ",height*spacing) .. lines[i]
    local buffer = ""
    --local indentLevel = indentLevel
    local newIndentLevel = 0
    --local nextIndentLevel = indentLevel

    for k=1,string.len(lines[i]),1 do
      local chr = string.sub(lines[i],k,k)
      if keys[chr] then

        _,buffer,indentLevel,newIndentLevel,inString = indentProc(chr,buffer,indentLevel,newIndentLevel,inString)
        buffer = ""
      else
        buffer = buffer .. chr
        --
        if keys[string.upper(buffer)] then
          --print(buffer) read()
          _,buffer,indentLevel,newIndentLevel,inString = indentProc(buffer,buffer,indentLevel,newIndentLevel,inString)
          buffer = ""
        end
      end

    end

    lines[i] = string.rep(" ",math.max(0,indentLevel)*spacing) .. lines[i]
    indentLevel = indentLevel + newIndentLevel
  end
end



function redrawBar()
  local entries = { "C:"..column, "L:" .. line, ( editMode == 0 and "INS" or "OVR" ), scrollX.."/"..scrollY  }
  local entryWidth = tw / #entries
  term.setCursorPos(1,1)
  term.clearLine()
  for i,v in ipairs(entries) do
    term.setCursorPos(i*entryWidth-(entryWidth/2)-(string.len(v)/2),1)
    term.write(v)
  end
  restoreCursorPos()
end

function scroll(nScrollX,nScrollY)
  scrollY = nScrollY
  scrollX = nScrollX
  redrawLines()
end

function setCursor(nColumn,nLine)
  column = nColumn
  line = nLine
  local nX,nY = scrollX,scrollY
  if nColumn <= scrollX then
    nX = nColumn - 1
  elseif nColumn > scrollX + tw then
    nX = nColumn-tw
  end
  if nLine > scrollY and nLine <= scrollY + th - 1 then

  else
    if nLine <= scrollY then
      nY = nLine -1
      --scroll(column,nLine-1)

    elseif nLine > scrollY + th - 1 then
      nY = nLine - (th-1)
      --scroll(column,nLine - (th-1))
    end
  end
  scroll(nX,nY)
  redrawBar()
end

function jumpToLine(lineNum)
  setCursor(column,lineNum)
end

function countIndention(str)

  for i=1,string.len(str),1 do
    if string.byte(str,i,i) ~= 32 and string.byte(str,i,i) ~= 9 then return i-1 end
  end
  return 0
end

jumpToLine(tonumber(tArgs[2]) or line)
redrawLines()
term.setCursorBlink(true)

screens.menu.keyHandler = function(p1)
  if p1 == 208 then
    menuIndex = math.min(menuIndex+1,#menuOptions)
    drawMenuCursor()
    --down
  elseif p1 == 200 then
    menuIndex = math.max(1,menuIndex-1)
    drawMenuCursor()
    --up
  elseif p1 == 28 then
    local opt = menuOptions[menuIndex]
    if opt == "New" then
      lines = {""}
      file = "new"
      local count = 0
      while fs.exists(file) do
        count = count + 1
        file = "new-"..count
      end
      column,line=1,1
      setScreen(screens.edit)
    elseif opt == "Exit Menu" then
      setScreen(screens.edit)
    elseif opt == "Quit to Shell" then
      done = true
      os.queueEvent("done")
    elseif opt == "Auto Indent" then
      autoIndent()
      setScreen(screens.edit)
    elseif opt == "Save" then
      saveFile()
      setMenuStatus("Saved.",2.5)
    else
      setMenuStatus("Not implemented yet.", 1.5)
    end
  elseif p1 == menuKey then
    setScreen(screens.edit)
  end
end

screens.menu.charHandler = function()
  menuIndex = 1
  term.setCursorBlink(false)
  drawMenu()
end

screens.menu["timerHandler"] = function(p1)
  if p1 == menuTimer then
    term.setCursorPos(1,th-1)
    term.clearLine()
    restoreCursorPos()
    menuTimer = nil
  end
end

screens.edit.keyHandler = function(p1)
  if p1 == 200 then
    if line > 1 then
      setCursor(math.min(column,string.len(lines[line-1])+1),line-1)
    end
    --up
  elseif p1 == 203 then
    if column > 1 then
      setCursor(column-1,line)
    elseif line > 1 then
      setCursor(string.len(lines[line-1])+1,line-1)
    end
    --left
  elseif p1 == 205 then
    if column < string.len(lines[line]) + 1 then
      setCursor(column+1,line)
    elseif line < #lines then
      setCursor(1,line+1)
    end
    --right
  elseif p1 == 208 then
    if line < #lines then
      setCursor(math.min(column,string.len(lines[line+1])+1),line+1)
    end
    --down
  elseif p1 == 207 then
    setCursor(string.len(lines[line])+1,line)
    --end
  elseif p1 == 199 then
    setCursor(1,line)
    --home
  elseif p1 == 14 then
    --backspace
    local tarX,tarY = column-1,line
    if tarX < 1 then
      if line > 1 then
        lines[line-1] = lines[line-1]..lines[line]
        setCursor(string.len(lines[line-1])+1-string.len(table.remove(lines,line)),line-1)
        redrawLines()
      end

    else
      lines[tarY] = string.sub(lines[tarY],0,tarX-1)..string.sub(lines[tarY],tarX+1)
      redrawLine(tarY-scrollY+1)
      setCursor(column-1,line)
    end
  elseif p1 == 28 then
    --enter
    local wSpaces = countIndention(lines[line])
    local nL = string.rep(" ",wSpaces) .. string.sub(lines[line],column)
    lines[line] = string.sub(lines[line],0,column-1)
    table.insert(lines,line+1,nL)
    redrawLines()
    setCursor(1+wSpaces,line+1)
  elseif p1 == 210 then
    --INS
    if editMode == 0 then editMode = 1
    else editMode = 0 end
    redrawBar()
  elseif p1 == 211 then
    --DEL
    if column < string.len(lines[line])+1 then
      lines[line] = string.sub(lines[line],0,column-1)..string.sub(lines[line],column+1)
      redrawLine(line-scrollY+1)
    elseif line < #lines then
      lines[line] = lines[line] .. table.remove(lines,line+1)
      redrawLines()
    end
  elseif p1 == 15 then
    --tab
    for i=1,standardSpaces,1 do
      os.queueEvent("char"," ")
    end
  elseif p1 == menuKey then
    setScreen(screens.menu)
    drawMenu()
  end
end

screens.edit.charHandler = function(p1)
  if editMode == 0 then
    lines[line] = string.sub(lines[line],0,column-1)..p1..string.sub(lines[line],column)
  else
    lines[line] = string.sub(lines[line],0,column-1)..p1..string.sub(lines[line],column+1)
  end
  setCursor(column+1,line)
  redrawLine(line-scrollY+1)
end

screens.edit.init = function()
  term.setCursorBlink(true)
  redrawLines()
  redrawBar()
  setCursor(column,line)

end



setScreen(screens.edit)

while not done do
  local ev,p1 = os.pullEvent()
  if curScreen[ev.."Handler"] then
    curScreen[ev.."Handler"](p1)
  end

end

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