LightText

term.setBackgroundColor(colors.black)
term.clear()
local codeColorIn, handleMovementKeys, handleMouseMenu, handleScreen, handleTimer, handleDelete, handleEnter, handleChar, handleBackspace, handleMouse, save, import
local text = {} -- text
local lastText = {}
local args = {...}
local e = {} -- event data
local textmt = {__index = function() return "" end} -- for new lines
setmetatable(text,textmt)
local MaxX,MaxY = term.getSize()
local fancy = false
local fileName = args[1]
function import(file) -- import or open
   for i=1,#text do
      text[i] = nil
      lastText[i] = nil
   end
   local doc = ""
    if fs.exists(file) then
      doc = fs.open(file,"r")
   else
      return false
   end
    for i = 1,16384 do
        text[i] = doc.readLine()
        if text[i] == nil then break end
    end
   doc.close()
    return true
end
if fileName then
   import(fileName)
end
if not fileName then fileName = "NONAME" end
function save(file) -- what could it mean?
    file = fs.open(file,"w")
    for i=1,(#text)+1 do
        file.writeLine(text[i])
    end
   file.close()
end
local settings = {}
if fs.exists("LightTextSettings") then
   local settingsFile = fs.open("LightTextSettings","r")
   settings = textutils.unserialize(settingsFile.readAll())
   settingsFile.close()
else
   settings.cursorString = "\149"
   settings.cursorColor = 2048
   settings.tabSize = 3
   local settingsFile = fs.open("LightTextSettings","w")
   settingsFile.writeLine(textutils.serialize(settings))
   settingsFile.close()
end
local cursorString = settings.cursorString
local tabSize = settings.tabSize
local KEYWORD = {
   ["if"] = colors.yellow,
   ["then"] = colors.yellow,
   ["else"] = colors.yellow,
   ["elseif"] = colors.yellow,
   ["for"] = colors.yellow,
   ["while"] = colors.yellow,
   ["do"] = colors.yellow,
   ["repeat"] = colors.yellow,
   ["return"] = colors.yellow,
   ["until"] = colors.yellow,
   ["end"] = colors.yellow,
   ["function"] = colors.lime,
   ["local"] = colors.yellow,
   ["break"] = colors.yellow,
   ["and"] = colors.blue,
   ["or"] = colors.blue,
   ["not"] = colors.blue,
   ["true"] = colors.blue,
   ["false"] = colors.blue,
   ["nil"] = colors.blue,
   ["in"] = colors.yellow,
   ["term"] = colors.orange,
   ["os"] = colors.orange,
   ["math"] = colors.orange,
   ["fs"] = colors.orange,
   ["io"] = colors.orange,
   ["string"] = colors.orange,
   ["sleep"] = colors.orange,
   ["print"] = colors.orange,
   ["write"] = colors.orange,
   ["shell"] = colors.orange,
   ["tostring"] = colors.orange,
   ["tonumber"] = colors.orange,
   ["setmetatable"] = colors.orange,
   ["getmetatable"] = colors.orange,
   ["..."] = colors.lightBlue, -- Not working properly
   [".."] = colors.brown,      -- Not working properly
   ["___LightTextCommentColor"] = colors.lightGray,
   ["___LightTextStringColor"] = colors.cyan         -- NYI
}
local SYNTAX = {
   ["."] = colors.green,
   [":"] = colors.green,
   [","] = colors.red,
   ["<"] = colors.lightBlue,
   [">"] = colors.lightBlue,
   ["="] = colors.lightBlue,
   ["+"] = colors.lightBlue,
   ["-"] = colors.lightBlue,
   ["/"] = colors.lightBlue,
   ["*"] = colors.lightBlue,
   ["^"] = colors.lightBlue,
   ["("] = colors.lime,
   [")"] = colors.lime,
   ["["] = colors.green,
   ["]"] = colors.green,
   ["{"] = colors.green,
   ["}"] = colors.green,
   ["'"] = colors.red,
   ["\""] = colors.red,
   ["#"] = colors.red
}
-- some variables
local menu = false
local codeMode = true
local DefaultBackgroundColor = colors.black
local DefaultTextColor = colors.white
local screen = {minX = 1,minY = 1,maxX = 51,maxY = 19}
local cursor = {x = 1,y = 1}
local cursorTimer = os.startTimer(0.3)
local isOnScreenCursor = false
-- modular functions for event handling
function handleMouseMenu()
   if e[4] == 3 and e[3] > 14 and e[3] < 18 then
      if codeMode then
         codeMode = false
      else
         codeMode = true
      end
   elseif e[4] == 8 and e[3] < 7 then
      save("TEMP")
      term.setCursorPos(1,1)
      term.setBackgroundColor(colors.black)
      term.setTextColor(colors.white)
      term.clear()
      error("",999)
   elseif e[4] == 5 and e[3] < 7 then
      save(fileName)
   elseif e[4] == 6 and e[3] < (11+#fileName) then
      local tempName = "]"
      while true do
      term.setCursorPos(1,6)
      term.clearLine()
      write("[Save as:"..tempName)
         e = {os.pullEvent()}
         if e[1] == "key" and e[2] == keys.enter then
            if #tempName < 2 then
               break
            else
               fileName = tempName:sub(1,#tempName-1)
               save(fileName)
               break
            end
         elseif e[1] == "key" and e[2] == keys.backspace and #tempName > 1 then
            tempName = tempName:sub(1,#tempName-2).."]"
         elseif e[1] == "char" then
            tempName = tempName:sub(1,#tempName-1)..e[2].."]"
         end
      end
   elseif e[4] == 7 and e[3] < 8 then
      local tempName = "] "
      while true do
         term.setCursorPos(1,7)
         write("[Open:"..tempName)
         e = {os.pullEvent()}
         if e[1] == "key" and e[2] == keys.enter then
            if #tempName < 3 then
               break
            else
               fileName = tempName:sub(1,#tempName-1)
               import(fileName)
               break
            end
         elseif e[1] == "key" and e[2] == keys.backspace and #tempName > 2 then
            tempName = tempName:sub(1,#tempName-3).."] "
         elseif e[1] == "char" then
            tempName = tempName:sub(1,#tempName-2)..e[2].."] "
         end
      end
   end
end
function handleEnter()
   local lastLine = cursor.y
   if text[cursor.y+1] then
      for i=#text+1,cursor.y+1,-1 do --if there are lines below cursor.y
         text[i] = text[i-1] -- copy every line to one below (reverse order)
      end
   end
   text[cursor.y+1] = ""
   if cursor.x <= #text[cursor.y] then
      text[cursor.y+1] = text[cursor.y]:sub(cursor.x,#text[cursor.y]) -- copy text from cursor.x to end of line to next line
   end
   cursor.y = cursor.y + 1
   if cursor.y > screen.maxY then
      screen.maxY = screen.maxY + 1
      screen.minY = screen.minY + 1
      term.clear()
   end
   screen.maxX = MaxX
   screen.minX = 1
   cursor.x = 1
   if not menu then
      term.setTextColor(DefaultTextColor)
      term.setBackgroundColor(DefaultBackgroundColor)
      if codeMode then
         term.setCursorPos(1,lastLine+1-screen.minY)
         term.setTextColor(DefaultTextColor)
         term.clearLine()
         write(text[lastLine]:sub(screen.minX,screen.maxX))
         codeColorIn(lastLine+1-screen.minY)
      else
         term.setCursorPos(1,lastLine+1-screen.minY)
         term.setTextColor(DefaultTextColor)
         term.clearLine()
         write(text[lastLine]:sub(screen.minX,screen.maxX))
      end
   end
end
function handleChar()
   text[cursor.y] = text[cursor.y]:sub(1,cursor.x-1)..e[2]..text[cursor.y]:sub(cursor.x,#text[cursor.y]) --put char at x,y
   cursor.x = cursor.x + 1
   if cursor.y-1+screen.minY == MaxY and cursor.x-1+screen.minX > MaxX-11 then
      screen.maxX = screen.maxX + 1
      screen.minX = screen.minX + 1
   elseif cursor.x > screen.maxX then
      screen.maxX = screen.maxX + 1
      screen.minX = screen.minX + 1
   end
end
function handleMouse()
   if e[1] == "mouse_click" or e[1] == "mouse_drag" then
      if #text > e[4]-2+screen.minY then
         cursor.y = e[4]-1+screen.minY
         if #text[e[4]-1+screen.minY] > e[3] - 2 then
            cursor.x = e[3]-1+screen.minX
         else
            cursor.x = #text[e[4]-1+screen.minY]+1
         end
      else
         cursor.y = #text
      end
   elseif e[1] == "mouse_scroll" then
      if e[2] == 1 then
         if #text > screen.minY then
            screen.minY = screen.minY + 1
            screen.maxY = screen.maxY + 1
            if cursor.y < screen.minY then
               cursor.y = cursor.y + 1
               if cursor.x > #text[cursor.y] then
                  cursor.x = #text[cursor.y]+1
               end
            end
         end
      elseif e[2] == -1 then
         if screen.minY > 1 then
            screen.maxY = screen.maxY - 1
            screen.minY = screen.minY - 1
            if cursor.y > screen.maxY then
               cursor.y = cursor.y -1
               if #text[cursor.y] < cursor.x then
                  cursor.x = #text[cursor.y]+1
               end
            end
         end
      end
   end
end
function handleMovementKeys()
   if e[2] == keys.up then -- 1 of 4 movement keys
      if cursor.y > 1 then -- is cursor further down than line 1
         cursor.y = cursor.y - 1
         if text[cursor.y]:sub(cursor.x-1,cursor.x-1) == "" then -- is line above (current) as long as cursor.x
            cursor.x = #text[cursor.y]+1 -- place cursor at end of line (default is same x as before)
         end
      elseif cursor.x > 1 then -- if on first line
         cursor.x = 1
      end
   elseif e[2] == keys.down then -- similar to keys.up
      if #text > cursor.y then
         cursor.y = cursor.y + 1
         if #text[cursor.y] < cursor.x then
            cursor.x = #text[cursor.y]+1
         end
      else
          cursor.x = #text[cursor.y]+1
      end
   elseif e[2] == keys.left then
      if cursor.x > 1 then -- is cursor farther right than x = 1
         cursor.x = cursor.x - 1
      elseif cursor.y > 1 then --does the line above exist?
         cursor.y = cursor.y - 1
         cursor.x = #text[cursor.y]+1
      end
   elseif e[2] == keys.right then
      if #text[cursor.y] >= cursor.x then
         cursor.x = cursor.x + 1
      elseif #text > cursor.y then
         cursor.y = cursor.y + 1
         cursor.x = 1
      end
   elseif e[2] == keys.home then
      cursor.x = 1
   elseif e[2] == keys["end"] then
      cursor.x = #text[cursor.y]+1
   elseif e[2] == keys.pageUp then
      if text[cursor.y-MaxY+1] then
         cursor.y = cursor.y-MaxY+1
         if text[cursor.y]:sub(cursor.x-1,cursor.x-1) == "" then
            cursor.x = #text[cursor.y]
         end
      elseif cursor.y > 1 then
         cursor.y = 1
         if text[cursor.y]:sub(cursor.x-1,cursor.x-1) == "" then
            cursor.x = #text[cursor.y]
         end
      end
   end
   if cursor.x == 0 then
      cursor.x = 1
   end
end
function handleBackspace()
   if cursor.x > 1 then --is cursor in text
      text[cursor.y] = text[cursor.y]:sub(1,cursor.x-2)..text[cursor.y]:sub(cursor.x,#text[cursor.y]) --remove char in text
      cursor.x = cursor.x - 1
   elseif cursor.x == 1 and cursor.y > 1 then -- is cursor at start of line and not at line 1
      cursor.x = #text[cursor.y-1]+1 -- get length of above line
      text[cursor.y-1] = text[cursor.y-1]..text[cursor.y] -- copy line to line above
      text[cursor.y] = text[cursor.y+1]
      if text[cursor.y+2] then -- move all lines below one step up
         for i=cursor.y+1,#text-1 do -- from cursor.y to end of file
            text[i] = text[i+1] -- copy line below i to i
         end
         text[#text] = nil -- delete last line (copied)
      end
      cursor.y = cursor.y-1 -- move cursor up
   end
end
function handleDelete()
   if text[cursor.y]:sub(cursor.x,cursor.x) ~= "" then
      text[cursor.y] = text[cursor.y]:sub(1,cursor.x-1)..text[cursor.y]:sub(cursor.x+1,#text[cursor.y])
   elseif cursor.x > #text[cursor.y] and text[cursor.y+1] then
      text[cursor.y] = text[cursor.y]..text[cursor.y+1]
      for i=cursor.y+1,#text do -- from cursor.y to end of file
         text[i]=text[i+1] -- copy line below i to i
      end
      text[#text] = nil -- delete last line (copied)
   end
end
function handleTimer()
   if isOnScreenCursor then
      isOnScreenCursor = false
      if text[cursor.y]:sub(cursor.x,cursor.x) ~= "" then
         cursorString = text[cursor.y]:sub(cursor.x,cursor.x)
      else
         cursorString = " "
      end
      cursorColor = DefaultTextColor
   else
      isOnScreenCursor = true
      cursorString = settings.cursorString
      settings.cursorColor = colors.blue
   end
   cursorTimer = os.startTimer(0.05)
end
function handleScreen()
   while cursor.x < screen.minX do
      screen.minX = screen.minX - 1
      screen.maxX = screen.maxX - 1
   end
   while cursor.x > screen.maxX do
      screen.maxX = screen.maxX + 1
      screen.minX = screen.minX + 1
   end
   while cursor.y < screen.minY do
      screen.minY = screen.minY - 1
      screen.maxY = screen.maxY - 1
   end
   while cursor.y > screen.maxY do
      screen.maxY = screen.maxY + 1
      screen.minY = screen.minY + 1
   end
   while cursor.x-screen.minX+1 > MaxX-9 and cursor.y == screen.maxY do
      screen.minX = screen.minX + 1
      screen.maxX = screen.maxX + 1
   end
   if screen.minX < 1 or screen.minY < 1 then -- baaaad program! >=c      How doe? idk.
      term.clear()
      term.setCursorPos(1,1)
      write("ERROR: screen params incorrect\nPlease report this error.\nWait 10 seconds\n"..textutils.serialize(screen)..textutils.serialize(cursor))
      sleep(10)
      screen.minX = 1
      screen.minY = 1
      screen.maxX = MaxX
      screen.maxY = MaxY
   end
end
local allowedAdj = {
   [""] = true,
   [" "] = true,
   ["."] = true,
   [":"] = true,
   ["("] = true,
   ["["] = true,
   ["{"] = true,
   ["="] = true,
   ["<"] = true,
   [">"] = true,
   ["*"] = true,
   ["/"] = true,
   ["+"] = true,
   ["-"] = true
}
function codeColorIn(n)
   if #text[n-1+screen.minY] > 0 then
      for i=1,#text[n-1+screen.minY] do
         --[[if text[n]:sub(i,i) == "'" then
            term.setCursorPos(i+1-screen.minX,n+1-screen.minY)
            term.setTextColor(KEYWORD.___LightTextStringColor)
            local endstring = i + 1
            local startstring = i
            while i <= #text[n] do
               if text[n]:sub(i,i) == "'" then
                  endstring = endstring + 1
                  break
               end
               i = i + 1
               endstring = i

            end
            term.setCursorPos(startstring+1-screen.minX,n+1-screen.minY)
            write(text[n]:sub(startstring,endstring))

         end]] --NYI

         for k,v in pairs(SYNTAX) do
            if text[n-1+screen.minY]:sub(i,i) == k then
               term.setCursorPos(i+1-screen.minX,n)
               term.setTextColor(v)
               write(k)
            end
         end
         for k,v in pairs(KEYWORD) do
            if allowedAdj[text[n-1+screen.minY]:sub(i-1,i-1)] and allowedAdj[text[n-1+screen.minY]:sub(i+#k,i+#k)] and text[n-1+screen.minY]:sub(i,i+#k-1) == k then
               term.setCursorPos(i+1-screen.minX,n)
               term.setTextColor(v)
               write(k:sub(1,math.min(#k+1,MaxX-i)))
               i = i+#k
            end
         end
         if text[n-1+screen.minY]:sub(i,i+1) == "--" then
            term.setTextColor(KEYWORD["___LightTextCommentColor"])
            term.setCursorPos(i+1-screen.minX,n)
            write(text[n-1+screen.minY]:sub(i,math.min(MaxX,#text[n-1+screen.minY]+screen.minX-1)))
            break
         end
      end
   end
end
while true do -- main loop
   local lastLine = cursor.y
   if not menu then
      term.setCursorPos(1,cursor.y+1-screen.minY)
      term.setTextColor(DefaultTextColor)
      term.clearLine()
      write(text[cursor.y]:sub(screen.minX,screen.maxX))
      codeColorIn(cursor.y+1-screen.minY)
      term.setTextColor(colors.gray)
      term.setCursorPos(MaxX-9,MaxY)
      write("Press ctrl")
   end
   if not menu and isOnScreenCursor then
      term.setCursorPos(cursor.x+1-screen.minX,cursor.y+1-screen.minY)
      if #cursorString ~= 1 then cursorString = " " end
      term.setBackgroundColor(DefaultBackgroundColor)
      term.setTextColor(settings.cursorColor)
      write(cursorString)
    end


   e = {os.pullEventRaw()}
   if e[1] == "term_resize" then
        MaxX,MaxY = term.getSize()

    elseif e[1] == "terminate" then
        save("TEMP")
      term.setCursorPos(1,1)
      term.setBackgroundColor(colors.black)
      term.setTextColor(colors.white)
      term.clear()
      error("",999)

   elseif e[1] == "timer" and not menu then
      handleTimer()

   elseif e[1] == "char" and not menu then
      handleChar()

   elseif e[1] == "mouse_click" or e[1] == "mouse_scroll" or e[1] == "mouse_drag" then
    if not menu then
         handleMouse()
      elseif e[1] == "mouse_click" then
         handleMouseMenu()
      end

   elseif e[1] == "key" then
    if not menu and e[2] == keys.up or e[2] == keys.down or e[2] == keys.left or e[2] == keys.right or e[2] == keys.pgUp or e[2] == keys.pgDn or e[2] == keys.home or e[2] == keys["end"] then
         handleMovementKeys()
      elseif not menu and e[2] == keys.enter then
        handleEnter()
      elseif not menu and e[2] == keys.backspace then
        handleBackspace()
      elseif not menu and e[2] == keys.delete then
        handleDelete()
      elseif not menu and e[2] == keys.f1 then
        save(fileName)
      elseif not menu and e[2] == keys.tab then
        text[cursor.y] = text[cursor.y]:sub(1,cursor.x-1)..string.rep(" ",tabSize)..text[cursor.x]:sub(cursor.x,#text[cursor.y]) --put char at x,y
         cursor.x = cursor.x + tabSize
      elseif e[2] == keys.rightCtrl then
         if menu then
            menu = false
            term.setBackgroundColor(colors.black)
            term.clear()
            cursorTimer = os.startTimer(0.3)
            if lastText and #lastText > 0 then
               for i = 1,16384 do
                  lastText[i] = nil
               end
            end
         else
            menu = true
            term.clear()
         end
      end

   elseif e[1] == "something else idk" then

   end
   handleScreen()
   if not menu then
      term.setTextColor(DefaultTextColor)
      term.setBackgroundColor(DefaultBackgroundColor)
      for i=1,MaxY do
         if lastText[i-1+screen.minY] ~= text[i-1+screen.minY] or i == lastLine+1-screen.minY or e[1] == "mouse_scroll" or e[2] == keys.up or e[2] == keys.down or e[2] == keys.enter then
            term.setCursorPos(1,i)
            term.setTextColor(DefaultTextColor)
            term.clearLine()
            write(text[i-1+screen.minY]:sub(screen.minX,screen.maxX))
            if codeMode then
               codeColorIn(i)
            end
          end
         lastText[i-1+screen.minY] = text[i-1+screen.minY]
      end
      term.setBackgroundColor(DefaultBackgroundColor)
      term.setCursorPos(MaxX-9,MaxY)
      term.setTextColor(colors.gray)
      write("Press ctrl")
      term.setTextColor(DefaultTextColor)
   elseif menu then
      term.setBackgroundColor(colors.gray)
      term.setTextColor(colors.blue)
      term.clear()
      term.setCursorPos(math.max(1,math.floor(MaxX/2-(#fileName/2)-5)),1)
      write(string.sub("LightText "..fileName,1,MaxX))
      term.setCursorPos(1,3)
      write("Code Mode:")
      term.setCursorPos(15,3)
      if codeMode then
         term.blit(" X","8f","85")
      else
         term.blit("X ","f8","e8")
      end
      term.setCursorPos(1,8)
      write("[Exit]")
      term.setCursorPos(1,5)
      write("[Save]        Press f1")
      term.setCursorPos(1,6)
      write("[Save as:"..fileName.."]")
      term.setCursorPos(1,7)
      write("[Open:]")
      term.setCursorPos(MaxX-9,MaxY)
      write("Press ctrl")
   end
end