edit+

--[===============================================]

--edit+

os.unloadAPI("hilight")
os.loadAPI("hilight")

if hilight==nil then
  error("hilight not loaded?")
end

local args={...}

local filename=args[1]

if not filename then
  print("usage:\nedit+ <filename>")
  return
end

local filePath=shell.dir().."/"..filename
local lines={}

local prevState

do
  local prevState={}
  local file=io.open(filePath,"r")
  if file~=nil then
    for line in file:lines() do
      lines[#lines+1]=hilight.hilightToSpans(line,prevState)
      prevState=lines[#lines].state
    end
    file:close()
  else
    lines[1]={rawText="",state={}}
  end
end




term.clear()

local running=true
local w,h=term.getSize()
local scrollPos={x=1,y=1}
local curPos={x=1,y=1}
local selectBounds
local lastClickPos={x=1,y=1}
local clipboard

local function curToTextPos(curPos)
  local lineNum=curPos.y+scrollPos.y-1
  local index
  if lineNum>#lines then
    lineNum=#lines
    index=#lines[#lines].rawText+1
  else
    index=math.min(curPos.x+scrollPos.x-1,#lines[lineNum].rawText+1)
  end
  return {x=index,y=lineNum}
end


local function drawLineNum()
  lineNum=" "..tostring(scrollPos.y+curPos.y-1).." "
  term.setCursorPos(w-#lineNum+1,h)
  term.setBackgroundColor(colors.white)
  term.setTextColor(colors.black)
  term.write(lineNum)
  term.setBackgroundColor(colors.black)
  term.setTextColor(colors.white)
end

local function redrawLine(screenLine)
  local lineNum=screenLine+scrollPos.y-1
  if lineNum<=#lines then
    local selStart,selEnd=0,-1
    local spans=lines[lineNum]
    if selectBounds and selectBounds[1].y<=lineNum and selectBounds[2].y>=lineNum then
      --we'll be doing selecting here
      selStart,selEnd=1,#spans.rawText+1
      if selectBounds[1].y==lineNum then
        selStart=selectBounds[1].x
      end
      if selectBounds[2].y==lineNum then
        selEnd=selectBounds[2].x
      end
    end

    term.setCursorPos(2-scrollPos.x,screenLine)
    local index=1
    for i=1,#spans do
      local len=#spans[i].text
      local subStart,subEnd=1,len
      if index>selEnd or index+len-1<selStart then
        subStart,subEnd=len+1,len+1
      else
        if selStart>=index then
          subStart=selStart-index+1
        end
        if selEnd<index+len-1 then
          subEnd=len - (index+len-1 - selEnd)
        end
      end
      if subStart>1 then
        term.setTextColor(spans[i].color)
        term.write(spans[i].text:sub(1,subStart-1))
      end
      if subStart~=len+1 then
        term.setTextColor(term.isColor() and colors.white or colors.black)
        term.setBackgroundColor(term.isColor() and colors.blue or colors.white)
        term.write(spans[i].text:sub(subStart,subEnd))
        term.setBackgroundColor(colors.black)
      end
      if subEnd<len then
        term.setTextColor(spans[i].color)
        term.write(spans[i].text:sub(subEnd+1))
      end
      index=index+len
    end
    if selEnd>#spans.rawText then
      term.setBackgroundColor(term.isColor() and colors.blue or colors.white)
      term.write(" ")
      term.setBackgroundColor(colors.black)
    end

    local x,y=term.getCursorPos()
    term.write((" "):rep(math.max(0,w-x+1)))
  else
    term.setCursorPos(1,screenLine)
    term.write((" "):rep(w))
  end
  if screenLine==h then
    drawLineNum()
  end
end

local function redrawFrom(index)
  for y=index,h do
    redrawLine(y)
  end
end

local function updateSelect(newBounds)
  local startY,endY
  if selectBounds then
    if newBounds then
      startY,endY=math.min(selectBounds[1].y,newBounds[1].y),math.max(selectBounds[2].y,newBounds[2].y)
    else
      startY,endY=selectBounds[1].y,selectBounds[2].y
    end
  elseif newBounds then
    startY,endY=newBounds[1].y,newBounds[2].y
  else
    return
  end
  selectBounds=newBounds
  for i=startY-scrollPos.y+1,endY-scrollPos.y+1 do
    if i>=1 and i<=h then
      redrawLine(i)
    end
  end
end


local function cursorRow()
  return lines[curPos.y+scrollPos.y-1]
end

local function trueCurPos()
  local cx,cy=curPos.x,curPos.y
  local row=cursorRow()
  cx=math.min(cx,#row.rawText-scrollPos.x+2)
  return cx,cy
end


local function curTextPos()
  local lineNum=curPos.y+scrollPos.y-1
  local index=math.min(curPos.x+scrollPos.x-1,#lines[lineNum].rawText+1)
  return lineNum,index
end


local function doCursor()
  term.setCursorPos(trueCurPos())
  term.setCursorBlink(true)
end

local function setScrollX(pos)
  local lineNum,index=curTextPos()
  local target=math.max(math.min(pos,#lines[lineNum].rawText-w+2),1)
  if target~=scrollPos.x then
    scrollPos.x=target
    redrawFrom(1)
  end
end

local function scrollY(offset)
  local didScroll=false
  local target=math.max(math.min(scrollPos.y+offset,#lines-h+1),1)
  if target~=scrollPos.y then
    didScroll=true
    --correct if it was clamped
    offset=target-scrollPos.y
    term.scroll(offset)
    scrollPos.y=target
    for i=1,offset+1 do
      redrawLine(h-i+1)
    end
    for i=-1,offset,-1 do
      redrawLine(-i)
    end
  end
  return didScroll
end

local function gotoLine(lineNum)
  local curY=lineNum-scrollPos.y+1
  if curY<1 then
    scrollY(lineNum-scrollPos.y)
    curPos.y=1
    redraw=true
  elseif curY>h then
    scrollY(lineNum-h+1 - scrollPos.y)
    curPos.y=h
    redraw=true
  else
    curPos.y=lineNum-scrollPos.y+1
  end
  if curPos.x~=1 then
    curPos.x=1
    redraw=true
  end
  if redraw then
    redrawFrom(1)
  end
end


local function cursorDown(amt)
  updateSelect()
  amt=amt or 1
  if #lines<curPos.y+amt+scrollPos.y-1 then
    amt=#lines-curPos.y-scrollPos.y+1
  end
  if amt>0 then
    if curPos.y+amt>h then
      scrollY(amt-(h-curPos.y))
      curPos.y=h
    elseif curPos.y<#lines then
      curPos.y=curPos.y+amt
    end
  end
end

local function cursorUp(amt)
  updateSelect()
  amt=amt or 1
  if curPos.y-amt<1 then
    scrollY(curPos.y-1-amt)
    curPos.y=1
  else
    curPos.y=curPos.y-amt
  end
  drawLineNum()
end


local function updateLine(lineNum,newText,noProp)
local prevLineState={}
  if lineNum>1 then
    prevLineState=lines[lineNum-1].state
  end
  local line=lines[lineNum]
  local prevEndState=line.state
  line=hilight.hilightToSpans(newText,prevLineState)
  lines[lineNum]=line
  redrawLine(curPos.y)
  --check for an end state change and flag to propagate
  if not hilight.compareStates(line.state,prevEndState) then
    local prevState=line.state
    --for now just redoing whole file if needed, will make it incremental and/or deferred later
    if not noProp then
      for i=lineNum+1,#lines do
        prevEndState=lines[i].state
        lines[i]=hilight.hilightToSpans(lines[i].rawText,prevState)
        if i-scrollPos.y+1 <= h then
          redrawLine(i-scrollPos.y+1)
        end
        prevState=lines[i].state
        --stop iterating if the state returns to expected
        if hilight.compareStates(prevState,prevEndState) then
          break
        end
      end
    end
  end
end

local function deleteSelection()
  if selectBounds then
    local startY,endY=selectBounds[1].y,selectBounds[2].y
    local selectBounds=selectBounds
    updateSelect()
    if startY==endY then
      local text=lines[startY].rawText
      updateLine(startY,text:sub(1,selectBounds[1].x-1)..text:sub(selectBounds[2].x+1))
    else
      local newText=lines[startY].rawText:sub(1,selectBounds[1].x-1,noProp)..lines[endY].rawText:sub(selectBounds[2].x+1)
      for i=startY+1,endY do
        table.remove(lines,startY+1)
      end
      updateLine(startY,newText)
      redrawFrom(curPos.y+1)
    end
  end
end


local function save()
  file=io.open(filePath,"w")
  if file then
    for i=1,#lines do
      if i~=1 then
        file:write("\n")
      end
      file:write(lines[i].rawText)
    end
    file:close()
  end
end

local function load()
  --TODO: file dialog
end

local function new()
  --TODO: file dialog
  --actually, just make new, with filename nil'd, and do
  --file dialog on save if filename is nil.
  --will facilitate saveAs also.
end

local function help()
  --not much point for this until advanced mode is added, actually?
end

local charKeys={[57]=' ', [43]='\\', [83]='.', [2]='1', [3]='2', [4]='3', [5]='4', [6]='5', [7]='6', [8]='7', [9]='8', [10]='9', [11]='0', [12]='-', [13]='=', [51]=',', [52]='.', [53]='/', [181]='/', [55]='*', [26]='[', [27]=']', [71]='7', [72]='8', [73]='9', [74]='-', [75]='4', [76]='5', [77]='6', [78]='+', [79]='1', [80]='2', [81]='3', [39]=';', [40]='"', [41]='`', [82]='0', [30]='a', [48]='b', [46]='c', [32]='d', [18]='e', [33]='f', [34]='g', [35]='h', [23]='i', [36]='j', [37]='k', [38]='l', [50]='m', [49]='n', [24]='o', [25]='p', [16]='q', [19]='r', [31]='s', [20]='t', [22]='u', [47]='v', [17]='w', [45]='x', [21]='y', [44]='z', }

local runEnv={shell=shell, multishell=multishell}
setmetatable(runEnv,{__index=_G})

local function run()
  --save changes first
  save()
  term.setTextColor(colors.white)
  term.setBackgroundColor(colors.black)
  term.clear()
  term.setCursorPos(1,1)

  local succ,err
  local func=loadfile(filePath)
  if not func then
    succ,err=pcall(dofile,filePath)
  else
    setfenv(func,runEnv)
    succ,err=pcall(func)
  end

  term.setTextColor(colors.white)
  term.setBackgroundColor(colors.black)
  term.setCursorPos(1,h)
  term.scroll(1)
  if not succ and err then
    print("Program '"..filePath.."' crashed with error:")
    printError(err)
  else
    print("program exited normally")
  end
  write("press a key to return to editor")
  e={os.pullEvent("key")}
  if charKeys[e[2]] then os.pullEvent() end
  if not succ then
    local lineNum,text=err:match(filename..":(%d+):(.-)")
    if lineNum then
      gotoLine(tonumber(lineNum))
    end
  end
  term.clear()
  redrawFrom(1)
  doCursor()
end

local function exit()
  return true
end

local function copy()
  if selectBounds then
    local startY,endY=selectBounds[1].y,selectBounds[2].y
    local selectBounds=selectBounds
    clipboard={}
    if startY==endY then
      clipboard[1]=lines[startY].rawText:sub(selectBounds[1].x,selectBounds[2].x)
    else
      clipboard[1]=lines[startY].rawText:sub(selectBounds[1].x)
      for y=startY+1,endY-1 do
        clipboard[#clipboard+1]=lines[y].rawText
      end
      clipboard[#clipboard+1]=lines[endY].rawText:sub(1,selectBounds[2].x)
    end
  end
end

local function cut()
  copy()
  deleteSelection()
end

local function paste()
  if clipboard then
    local lineNum,index=curTextPos()
    --delete selection, if any, as we'll replace
    deleteSelection()
    --split this line at cursor
    local before,after=lines[lineNum].rawText:sub(1,index-1),lines[lineNum].rawText:sub(index)
    local newLines={}
    --append first cb line to before for first line
    newLines[1]=before..clipboard[1]
    --rest will be new lines
    for i=2,#clipboard do
      newLines[i]=clipboard[i]
    end
    --append after to last
    local newX=#newLines[#newLines]+1
    newLines[#newLines]=newLines[#newLines]..after

    --ok, update first line
    updateLine(lineNum,newLines[1],true)
    --insert rest
    for i=2,#newLines do
      table.insert(lines,lineNum+i-1,{state={}})
      updateLine(lineNum+i-1,newLines[i],i==#newLines)
    end
    redrawFrom(lineNum)
    --new cursor pos will be in that last line
    if #newLines>1 then
      cursorDown(#newLines-1)
    end
    curPos.x=newX
  end
end


local basicMenu={
    "&save",
--    "&load",
--    "&new",
--    "help-&?",
    "&run",
    "&exit",
--    "&advanced",
    "&copy",
    "cut-&x",
    "paste-&v",
    funcs={
      save=save,
      load=load,
      new=new,
      help=help,
      run=run,
      exit=exit,

      copy=copy,
      cut=cut,
      paste=paste
    },
}

redrawFrom(1)
term.setCursorBlink(true)
doCursor()

local function writeMenuLabel(menuItem,selected)
  local pre,pk,hk,post=menuItem:match("^(%a*)(%-?)&(.)(%a*)")
  if not pre then
    error("malformed menu label - '"..menuItem.."'")
  end
  local label=" "
  local func=pre
  term.setBackgroundColor(selected and colors.blue or colors.gray)
  term.setTextColor(colors.white)
  term.write(" "..pre)
  if pk~="-" then
    func=func..hk..post
    term.setTextColor(colors.yellow)
    term.write(hk)
    term.setTextColor(colors.white)
    term.write(post)
    label=label..pre..hk..post
  else
    term.write("-")
    term.setTextColor(colors.yellow)
    term.write(hk)
    label=label..pre.."-"..hk
  end
  term.write(" ")
  label=label.." "
  return func,hk,label
end

local function doMenu()
  --root menu
  --          |15                      |40(26)       |54(39)
  local buttonMap={}
  local hkMap={}
  local command
  local selected=1
  local function drawMenu(menu)
    local menuStr=""
    for i=1,#menu do
      local itemStr=(selected==i and "[" or " ")
      local pre,pk,hk,post=menu[i]:match("^(%a*)(%-?)&(.)(%a*)")
      itemStr=itemStr..pre
      local cmd=pre
      if pk=="" then
        itemStr=itemStr.."("..hk..")"..post
        cmd=cmd..hk..post
      else
        itemStr=itemStr.."("..hk..")"
      end
      itemStr=itemStr..(selected==i and "]" or " ")
      for j=1,#itemStr do
        buttonMap[#buttonMap+1]={i,cmd}
      end
      menuStr=menuStr..itemStr
    end
    term.setCursorPos(1,h)
    term.setTextColor(colors.black)
    term.setBackgroundColor(colors.white)
    term.write(menuStr)
    term.setBackgroundColor(colors.black)
  end
  if term.isColor() then
    drawMenu=function(menu)
      term.setCursorPos(1,h)
      for i=1,selected-1 do
        local cmd,hk,label=writeMenuLabel(menu[i])
        for j=1,#label do
          buttonMap[#buttonMap+1]={i,cmd}
          hkMap[hk]=cmd
        end
      end
      local cmd,hk,label=writeMenuLabel(menu[selected],true)
      command=cmd
      for j=1,#label do
        buttonMap[#buttonMap+1]={selected,cmd}
      end
      hkMap[hk]=cmd
      menuStr=""
      for i=selected+1,#menu do
        local cmd,hk,label=writeMenuLabel(menu[i])
        for j=1,#label do
          buttonMap[#buttonMap+1]={i,cmd}
        end
        hkMap[hk]=cmd
      end
      term.setTextColor(colors.black)
      term.setBackgroundColor(colors.lightGray)
      term.write(menuStr)
      term.setBackgroundColor(colors.black)
    end
  end

  --           new save load help exit more
  while true do
    drawMenu(basicMenu)
    local e={os.pullEvent()}
    if e[1]=="key" then
      if e[2]==keys.leftCtrl then
        command=nil
        break
      elseif e[2]==keys.right then
        selected=selected%#basicMenu+1
      elseif e[2]==keys.left then
        selected=selected==1 and #basicMenu or selected-1
      elseif e[2]==keys.enter then
        --do the thing
        break
      end
    elseif e[1]=="char" then
      if hkMap[e[2]] then
        command=hkMap[e[2]]
        break
      end
    elseif e[1]=="mouse_click" then
      local _,btn,x,y=unpack(e)
      if y==h and buttonMap[x] then
        selected=buttonMap[x][1]
        if btn==1 then
          command=buttonMap[x][2]
          break
        end
      else
        break
      end
    end

  end

  if basicMenu.funcs[command] and basicMenu.funcs[command]() then
    running=false
  else
    redrawLine(h)
    doCursor()
  end

end


while running do

  local e={os.pullEvent()}

  if e[1]=="key" then
    local key=e[2]
    if key==keys.down then
      cursorDown()
      drawLineNum()
      doCursor()
    elseif key==keys.up then
      cursorUp()
      drawLineNum()
      doCursor()
    elseif key==keys.right then
      local lineNum,index=curTextPos()
      if curPos.x>index then
        curPos.x=index
      end
      if curPos.x+scrollPos.x-1>#lines[lineNum].rawText then
        cursorDown()
        drawLineNum()
        setScrollX(1)
        curPos.x=1
      else
        if curPos.x==w then
          setScrollX(scrollPos.x+1)
        else
          curPos.x=curPos.x+1
        end
      end
      updateSelect()
      doCursor()
    elseif key==keys.left then
      if curPos.x==1 then
        cursorUp()
        curPos.x=#cursorRow().rawText+1
        if curPos.x>w then
          setScrollX(curPos.x-w+1)
          curPos.x=w
        end
        drawLineNum()
      else
        curPos.x=curPos.x-1
      end
      updateSelect()
      doCursor()
    elseif key==keys.pageDown then
      if not scrollY(h) then
        curPos.y=math.min(h,#lines)
      end
      updateSelect()
      doCursor()
    elseif key==keys.pageUp then
      if not scrollY(-h) then
        curPos.y=1
      end
      updateSelect()
      doCursor()
    elseif key==keys.leftCtrl then
      doMenu()
    elseif key==keys.enter then
      if selectBounds then
        deleteSelection()
      end
      --carry on with the cr
      local lineNum,index=curTextPos()
      local curText=lines[lineNum].rawText
      local pre,post=curText:sub(1,index-1),curText:sub(index)
      updateLine(lineNum,pre,true)
      table.insert(lines,lineNum+1,{state={}})
      updateLine(lineNum+1,post)
      if curPos.y==h then
        cursorDown()
      else
        curPos.y=curPos.y+1
      end
      curPos.x=1
      redrawFrom(curPos.y-1)
      doCursor()
    elseif key==keys.backspace then
      if selectBounds then
        deleteSelection()
      else
        local lineNum,index=curTextPos()
        if index==1 then
          if lineNum>1 then
            local prevLine=lines[lineNum-1]
            curPos.x=#prevLine.rawText+1
            local curLine=table.remove(lines,lineNum)

            updateLine(lineNum-1,prevLine.rawText..curLine.rawText)
            curPos.y=curPos.y-1
            redrawFrom(curPos.y)
            drawLineNum()
          end
        else
          local curText=lines[lineNum].rawText
          local newText=curText:sub(1,index-2)..curText:sub(index)
          updateLine(lineNum,newText)
          curPos.x=index-1
        end
      end
      doCursor()
    elseif key==keys.delete then
      if selectBounds then
        deleteSelection()
      else
        local lineNum,index=curTextPos()
        local curText=lines[lineNum].rawText
        if index==#curText+1 then
          if lineNum<#lines then
            local nextLine=table.remove(lines,lineNum+1)
            updateLine(lineNum,curText..nextLine.rawText)
            redrawFrom(curPos.y)
          end
        else
          local newText=curText:sub(1,index-1)..curText:sub(index+1)
          updateLine(lineNum,newText)
          curPos.x=index
        end
      end
      doCursor()
    elseif key==keys.home then
      setScrollX(1)
      curPos.x=1
      updateSelect()
      doCursor()
    elseif key==keys["end"] then
      local max=#cursorRow().rawText+1
      if max>w then
        local target=max-w+1
        if target>scrollPos.x then
          setScrollX(target)
          curPos.x=w
        else
          curPos.x=max - scrollPos.x
        end
      else
        curPos.x=max
      end
      updateSelect()
      doCursor()
    end

  elseif e[1]=="char" then
    local char=e[2]
    if selectBounds then
      deleteSelection()
    end
    --get the affected line and actual x position in line
    local lineNum, index = curTextPos()
    local line=lines[lineNum]
    --insert our char!
    local newText=line.rawText:sub(1,index-1)..char..line.rawText:sub(index)
    curPos.x=index+1
    updateLine(lineNum,newText)
    doCursor()

  elseif e[1]=="mouse_scroll" then
    if e[2]>0 then
      cursorDown()
    else
      cursorUp()
    end
    drawLineNum()
    doCursor()

  elseif e[1]=="mouse_click" then
    if e[2]==1 then
      local x,y=math.min(math.max(e[3],1),w),math.min(math.max(e[4],1),h)
      if y+scrollPos.y-1 > #lines then
        curPos.y=#lines
        curPos.x=#lines[#lines].rawText+1
      else
        curPos.x=x
        curPos.y=y
      end
      updateSelect()
      drawLineNum()
      doCursor()
      lastClickPos={x=x,y=y}
    elseif e[2]==2 then

    elseif e[2]==3 then

    end
  elseif e[1]=="mouse_drag" then
    local dragTo=curToTextPos({x=math.min(math.max(e[3],1),w),y=math.min(math.max(e[4],1),h)})
    dragTo.x=math.min(dragTo.x,#lines[dragTo.y].rawText)
    local newBounds
    local dragFrom=lastClickPos
    if dragTo.y<dragFrom.y or (dragTo.y==dragFrom.y and dragTo.x<dragFrom.x) then
      newBounds={dragTo,curToTextPos(dragFrom)}
    else
      newBounds={curToTextPos(dragFrom),dragTo}
    end
    updateSelect(newBounds)
  elseif e[1]=="term_resize" then
    w,h=term.getSize()
    redrawFrom(1)
    doCursor()
  end

end

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