-- Integration with MobDebug
-- Copyright 2011-12 Paul Kulchenko, ZeroBrane LLC
-- Original authors: Lomtik Software (J. Winwood & John Labenski)
-- Luxinia Dev (Eike Decker & Christoph Kubisch)

local copas = require "copas"
local socket = require "socket"
local mobdebug = require "mobdebug"

local ide = ide
local debugger = ide.debugger
debugger.server = nil -- DebuggerServer object when debugging, else nil
debugger.running = false -- true when the debuggee is running
debugger.listening = false -- true when the debugger is listening for a client
debugger.portnumber = ide.config.debugger.port or mobdebug.port -- the port # to use for debugging
debugger.watchWindow = nil -- the watchWindow, nil when not created
debugger.watchCtrl = nil -- the child ctrl in the watchWindow
debugger.stackWindow = nil -- the stackWindow, nil when not created
debugger.stackCtrl = nil -- the child ctrl in the stackWindow
debugger.hostname = ide.config.debugger.hostname or (function()
  local addr = wx.wxIPV4address() -- check what address is resolvable
  for _, host in ipairs({wx.wxGetHostName(), wx.wxGetFullHostName()}) do
    if host and #host > 0 and addr:Hostname(host) then return host end
  end
  return "localhost" -- last resort; no known good hostname
end)()

local notebook = ide.frame.notebook

local CURRENT_LINE_MARKER = StylesGetMarker("currentline")
local CURRENT_LINE_MARKER_VALUE = 2^CURRENT_LINE_MARKER
local BREAKPOINT_MARKER = StylesGetMarker("breakpoint")
local BREAKPOINT_MARKER_VALUE = 2^BREAKPOINT_MARKER

local function q(s) return s:gsub('([%(%)%.%%%+%-%*%?%[%^%$%]])','%%%1') end

local function updateWatchesSync(num)
  local watchCtrl = debugger.watchCtrl
  if watchCtrl and debugger.server and not debugger.running
  and not debugger.scratchpad and not (debugger.options or {}).noeval then
    for idx = 0, watchCtrl:GetItemCount() - 1 do
      if not num or idx == num then
        local expression = watchCtrl:GetItemText(idx)
        local _, values, error = debugger.evaluate(expression)
        if error then error = error:gsub("%[.-%]:%d+:%s+","")
        elseif #values == 0 then values = {'nil'} end

        local newval = error and ('error: '..error) or values[1]
        -- get the current value from a list item
        do local litem = wx.wxListItem()
          litem:SetMask(wx.wxLIST_MASK_TEXT)
          litem:SetId(idx)
          litem:SetColumn(1)
          watchCtrl:GetItem(litem)
          watchCtrl:SetItemBackgroundColour(idx,
            watchCtrl:GetItem(litem) and newval ~= litem:GetText()
            and ide.config.styles.caretlinebg
            and wx.wxColour(unpack(ide.config.styles.caretlinebg.bg))
            or watchCtrl:GetBackgroundColour())
        end

        watchCtrl:SetItem(idx, 1, newval)
      end
    end
  end
end

local simpleType = {['nil'] = true, ['string'] = true, ['number'] = true, ['boolean'] = true}
local stackItemValue = {}
local function checkIfExpandable(value, item)
  local expandable = type(value) == 'table' and next(value) ~= nil
    and not stackItemValue[value] -- only expand first time
  if expandable then -- cache table value to expand when requested
    stackItemValue[item:GetValue()] = value
    stackItemValue[value] = item:GetValue() -- to avoid circular refs
  end
  return expandable
end

local function updateStackSync()
  local stackCtrl = debugger.stackCtrl
  if stackCtrl and debugger.server
    and not debugger.running and not debugger.scratchpad then
    local stack, _, err = debugger.stack()
    if not stack or #stack == 0 then
      stackCtrl:DeleteAllItems()
      if err then -- report an error if any
        stackCtrl:AppendItem(stackCtrl:AddRoot("Stack"), "Error: " .. err, 0)
      end
      return
    end
    stackCtrl:Freeze()
    stackCtrl:DeleteAllItems()
    local params = {comment = false, nocode = true}
    local root = stackCtrl:AddRoot("Stack")
    stackItemValue = {} -- reset cache of items in the stack
    for _,frame in ipairs(stack) do
      -- "main chunk at line 24"
      -- "foo() at line 13 (defined at foobar.lua:11)"
      -- call = { source.name, source.source, source.linedefined,
      --   source.currentline, source.what, source.namewhat, source.short_src }
      local call = frame[1]
      local func = call[5] == "main" and "main chunk"
        or call[5] == "C" and (call[1] or "C function")
        or call[5] == "tail" and "tail call"
        or (call[1] or "anonymous function")
      local text = func ..
        (call[4] == -1 and '' or " at line "..call[4]) ..
        (call[5] ~= "main" and call[5] ~= "Lua" and ''
         or (call[3] > 0 and " (defined at "..call[2]..":"..call[3]..")"
                          or " (defined in "..call[2]..")"))
      local callitem = stackCtrl:AppendItem(root, text, 0)
      for name,val in pairs(frame[2]) do
        -- comment can be not necessarily a string for tables with metatables
        -- that provide its own __tostring method
        local value, comment = val[1], tostring(val[2])
        local text = ("%s = %s%s"):
          format(name, mobdebug.line(value, params),
                 simpleType[type(value)] and "" or ("  --[["..comment.."]]"))
        local item = stackCtrl:AppendItem(callitem, text, 1)
        if checkIfExpandable(value, item) then
          stackCtrl:SetItemHasChildren(item, true)
        end
      end
      for name,val in pairs(frame[3]) do
        local value, comment = val[1], val[2]
        local text = ("%s = %s%s"):
          format(name, mobdebug.line(value, params),
                 simpleType[type(value)] and "" or ("  --[["..comment.."]]"))
        local item = stackCtrl:AppendItem(callitem, text, 2)
        if checkIfExpandable(value, item) then
          stackCtrl:SetItemHasChildren(item, true)
        end
      end
      stackCtrl:SortChildren(callitem)
      stackCtrl:Expand(callitem)
    end
    stackCtrl:EnsureVisible(stackCtrl:GetFirstChild(root))
    stackCtrl:Thaw()
  end
end

local function updateStackAndWatches()
  -- check if the debugger is running and may be waiting for a response.
  -- allow that request to finish, otherwise updateWatchesSync() does nothing.
  if debugger.running then debugger.update() end
  if debugger.server and not debugger.running then
    copas.addthread(function() updateStackSync() updateWatchesSync() end)
  end
end

local function updateWatches(num)
  -- check if the debugger is running and may be waiting for a response.
  -- allow that request to finish, otherwise updateWatchesSync() does nothing.
  if debugger.running then debugger.update() end
  if debugger.server and not debugger.running then
    copas.addthread(function() updateWatchesSync(num) end)
  end
end

local function killClient()
  if (debugger.pid) then
    -- using SIGTERM for some reason kills not only the debugee process,
    -- but also some system processes, which leads to a blue screen crash
    -- (at least on Windows Vista SP2)
    local ret = wx.wxProcess.Kill(debugger.pid, wx.wxSIGKILL, wx.wxKILL_CHILDREN)
    if ret == wx.wxKILL_OK then
      DisplayOutputLn(TR("Program stopped (pid: %d)."):format(debugger.pid))
    elseif ret ~= wx.wxKILL_NO_PROCESS then
      DisplayOutputLn(TR("Unable to stop program (pid: %d), code %d.")
        :format(debugger.pid, ret))
    end
    debugger.pid = nil
  end
end

local function activateDocument(file, line, skipauto)
  if not file then return end

  if not wx.wxIsAbsolutePath(file) and debugger.basedir then
    file = debugger.basedir .. file
  end

  local activated
  local indebugger = file:find('mobdebug%.lua$')
  local fileName = wx.wxFileName(file)
  for _, document in pairs(ide.openDocuments) do
    -- skip those tabs that may have file without names (untitled.lua)
    if document.filePath and fileName:SameAs(wx.wxFileName(document.filePath)) then
      local editor = document.editor
      local selection = document.index
      notebook:SetSelection(selection)
      SetEditorSelection(selection)
      ClearAllCurrentLineMarkers()
      if line then
        editor:MarkerAdd(line-1, CURRENT_LINE_MARKER)
        editor:EnsureVisibleEnforcePolicy(line-1)
      end
      activated = editor
      break
    end
  end

  if not (activated or indebugger or debugger.loop or skipauto)
  and ide.config.editor.autoactivate then
    -- found file, but can't activate yet (because this part may be executed
    -- in a different co-routine), so schedule pending activation.
    if wx.wxFileName(file):FileExists() then
      debugger.activate = {file, line}
      return true -- report successful activation, even though it's pending
    end

    if not debugger.missing[file] then -- only report files once per session
      debugger.missing[file] = true
      DisplayOutputLn(TR("Couldn't activate file '%s' for debugging; continuing without it.")
        :format(file))
    end
  end

  return activated ~= nil
end

local function reSetBreakpoints()
  -- remove all breakpoints that may still be present from the last session
  -- this only matters for those remote clients that reload scripts
  -- without resetting their breakpoints
  debugger.handle("delallb")

  -- go over all windows and find all breakpoints
  if (not debugger.scratchpad) then
    for _, document in pairs(ide.openDocuments) do
      local editor = document.editor
      local filePath = document.filePath
      local line = editor:MarkerNext(0, BREAKPOINT_MARKER_VALUE)
      while line ~= -1 do
        debugger.handle("setb " .. filePath .. " " .. (line+1))
        line = editor:MarkerNext(line + 1, BREAKPOINT_MARKER_VALUE)
      end
    end
  end
end

debugger.shell = function(expression, isstatement)
  -- check if the debugger is running and may be waiting for a response.
  -- allow that request to finish, otherwise updateWatchesSync() does nothing.
  if debugger.running then debugger.update() end
  if debugger.server and not debugger.running
  and (not debugger.scratchpad or debugger.scratchpad.paused) then
    copas.addthread(function ()
        -- exec command is not expected to return anything.
        -- eval command returns 0 or more results.
        -- 'values' has a list of serialized results returned.
        -- as it is not possible to distinguish between 0 results and one
        -- 'nil' value returned, 'nil' is always returned in this case.
        -- the first value returned by eval command is not used;
        -- this may need to be taken into account by other debuggers.
        local addedret, forceexpression = true, expression:match("^%s*=%s*")
        expression = expression:gsub("^%s*=%s*","")
        local _, values, err = debugger.evaluate(expression)
        if not forceexpression and err and
          (err:find("'?<eof>'? expected near '") or
           err:find("'%(' expected near") or
           err:find("unexpected symbol near '")) then
          _, values, err = debugger.execute(expression)
          addedret = false
        end

        if err then
          if addedret then err = err:gsub('^%[string "return ', '[string "') end
          DisplayShellErr(err)
        elseif addedret or #values > 0 then
          if forceexpression then -- display elements as multi-line
            local mobdebug = require "mobdebug"
            for i,v in pairs(values) do -- stringify each of the returned values
              local func = loadstring('return '..v) -- deserialize the value first
              if func then -- if it's deserialized correctly
                values[i] = (forceexpression and i > 1 and '\n' or '') ..
                  mobdebug.line(func(), {nocode = true, comment = 0,
                    -- if '=' is used, then use multi-line serialized output
                    indent = forceexpression and '  ' or nil})
              end
            end
          end

          -- if empty table is returned, then show nil if this was an expression
          if #values == 0 and (forceexpression or not isstatement) then
            values = {'nil'}
          end
          DisplayShell((table.unpack or unpack)(values))
        end

        -- refresh Stack and Watch windows if executed a statement (and no err)
        if isstatement and not err and not addedret and #values == 0 then
          updateStackSync() updateWatchesSync() end
      end)
  end
end

debugger.listen = function()
  local server = socket.bind("*", debugger.portnumber)
  DisplayOutputLn(TR("Debugger server started at %s:%d.")
    :format(debugger.hostname, debugger.portnumber))
  copas.autoclose = false
  copas.addserver(server, function (skt)
      if debugger.server then
        DisplayOutputLn(TR("Refused a request to start a new debugging session as there is one in progress already."))
        return
      end

      copas.setErrorHandler(function(error)
        DisplayOutputLn(TR("Can't start debugging session due to internal error '%s'."):format(error))
        debugger.terminate()
      end)

      local options = debugger.options or {}
      if not debugger.scratchpad then SetAllEditorsReadOnly(true) end

      debugger.server = copas.wrap(skt)
      debugger.socket = skt
      debugger.loop = false
      debugger.scratchable = false
      debugger.stats = {line = 0}
      debugger.missing = {}

      local wxfilepath = GetEditorFileAndCurInfo()
      local startfile = options.startfile or options.startwith
        or (wxfilepath and wxfilepath:GetFullPath())

      if not startfile then
        DisplayOutputLn(TR("Can't start debugging without an opened file or with the current file not being saved ('%s').")
          :format(ide.config.default.fullname))
        return debugger.terminate()
      end

      local startpath = wx.wxFileName(startfile):GetPath(wx.wxPATH_GET_VOLUME + wx.wxPATH_GET_SEPARATOR)
      local basedir = options.basedir or FileTreeGetDir() or startpath
      -- guarantee that the path has a trailing separator
      debugger.basedir = wx.wxFileName.DirName(basedir):GetFullPath()

      -- load the remote file into the debugger
      -- set basedir first, before loading to make sure that the path is correct
      debugger.handle("basedir " .. debugger.basedir)

      reSetBreakpoints()

      if options.redirect then
        debugger.handle("output stdout " .. options.redirect, nil,
          { handler = function(m)
              if not debugger.server then return end

              -- if it's an error returned, then handle the error
              if m and m:find("stack traceback:", 1, true) then
                -- this is an error message sent remotely
                local func = loadstring("return "..m)
                if func then
                  DisplayOutputLn(func())
                  debugger.terminate()
                  return
                end
              end

              if ide.config.debugger.outputfilter then
                m = ide.config.debugger.outputfilter(m)
              elseif m then
                local max = 240
                m = #m < max+4 and m or m:sub(1,max) .. "...\n"
              end
              if m then DisplayOutputNoMarker(m) end
            end})
      end

      if (options.startwith) then
        local file, line, err = debugger.loadfile(options.startwith)
        if err then
          DisplayOutputLn(TR("Can't run the entry point script ('%s').")
            :format(options.startwith)
            .." "..TR("Compilation error")
            ..":\n"..err)
          return debugger.terminate()
        end
      elseif not (options.run or debugger.scratchpad) then
        local file, line, err = debugger.loadfile(startfile)
        -- "load" can work in two ways: (1) it can load the requested file
        -- OR (2) it can "refuse" to load it if the client was started
        -- with start() method, which can't load new files
        -- if file and line are set, this indicates option #2
        if file and line then
          local activated = activateDocument(file, line, true)

          -- if not found, check using full file path and reset basedir
          if not activated and not wx.wxIsAbsolutePath(file) then
            activated = activateDocument(startpath..file, line, true)
            if activated then
              debugger.basedir = startpath
              debugger.handle("basedir " .. debugger.basedir)
              -- reset breakpoints again as basedir has changed
              reSetBreakpoints()
            end
          end

          -- if not found and the files doesn't exist, it may be
          -- a remote call; try to map it to the project folder
          if not activated and not wx.wxFileName(file):FileExists() then
            -- file is /foo/bar/my.lua; basedir is d:\local\path\
            -- check for d:\local\path\my.lua, d:\local\path\bar\my.lua, ...
            -- wxwidgets on Windows handles \\ and / as separators, but on OSX
            -- and Linux it only handles 'native' separator;
            -- need to translate for GetDirs to work.
            local file = file:gsub("\\", "/")
            local parts = wx.wxFileName(file):GetDirs()
            local name = wx.wxFileName(file):GetFullName()

            -- find the longest remote path that can be mapped locally
            local longestpath, remotedir
            while true do
              local mapped = GetFullPathIfExists(basedir, name)
              if mapped then
                longestpath = mapped
                remotedir = file:gsub(q(name):gsub("/", ".").."$", "")
              end
              if #parts == 0 then break end
              name = table.remove(parts, #parts) .. "/" .. name
            end

            -- if found a local mapping under basedir
            activated = longestpath and activateDocument(longestpath, line, true)
            if activated then
              -- find remote basedir by removing the tail from remote file
              debugger.handle("basedir " .. debugger.basedir .. "\t" .. remotedir)
              -- reset breakpoints again as remote basedir has changed
              reSetBreakpoints()
              DisplayOutputLn(TR("Mapped remote request for '%s' to '%s'.")
                :format(remotedir, debugger.basedir))
            end
          end

          if not activated then
            DisplayOutputLn(TR("Can't find file '%s' in the current project to activate for debugging. Update the project or open the file in the editor before debugging.")
              :format(file))
            return debugger.terminate()
          end

          -- debugger may still be available for scratchpad,
          -- if the interpreter signals scratchpad support, so enable it.
          debugger.scratchable = ide.interpreter.scratchextloop ~= nil
        elseif err then
          DisplayOutputLn(TR("Can't debug the script in the active editor window.")
            .." "..TR("Compilation error")
            ..":\n"..err)
          return debugger.terminate()
        else
          debugger.scratchable = true
          activateDocument(startfile, 1)
        end
      end

      if (not options.noshell and not debugger.scratchpad) then
        ShellSupportRemote(debugger.shell)
      end

      updateStackSync()
      updateWatchesSync()

      DisplayOutputLn(TR("Debugging session started in '%s'."):format(debugger.basedir))

      if (debugger.scratchpad) then
        debugger.scratchpad.updated = true
      else
        if (options.runstart) then
          ClearAllCurrentLineMarkers()
          debugger.run()
        end
        if (options.run) then
          local file, line = debugger.handle("run")
          activateDocument(file, line)
        end
      end
    end)
  debugger.listening = true
end

debugger.handle = function(command, server, options)
  local verbose = ide.config.debugger.verbose
  local osexit, gprint
  osexit, os.exit = os.exit, function () end
  if (verbose) then
    gprint, _G.print = _G.print, function (...) DisplayOutputLn(...) end
  end

  debugger.running = true
  if verbose then DisplayOutputLn("Debugger sent (command):", command) end
  local file, line, err = mobdebug.handle(command, server or debugger.server, options)
  if verbose then DisplayOutputLn("Debugger received (file, line, err):", file, line, err) end
  debugger.running = false

  os.exit = osexit
  if (verbose) then _G.print = gprint end
  return file, line, err
end

debugger.exec = function(command)
  if debugger.server and not debugger.running then
    copas.addthread(function ()
        local out
        local attempts = 0
        while true do
          -- clear markers before running the command
          -- don't clear if running trace as the marker is then invisible,
          -- and it needs to be visible during tracing
          if not debugger.loop then ClearAllCurrentLineMarkers() end
          debugger.breaking = false
          local file, line, err = debugger.handle(out or command)
          if out then out = nil end
          if line == nil then
            if err then DisplayOutputLn(err) end
            DebuggerStop()
            return
          elseif not debugger.server then
            -- it is possible that while debugger.handle call was executing
            -- the debugging was terminated; simply return in this case.
            return
          else
            if activateDocument(file, line) then
              debugger.stats.line = debugger.stats.line + 1
              if debugger.loop then
                updateStackSync()
                updateWatchesSync()
              else
                updateStackAndWatches()
                return
              end
            else
              -- clear the marker as it wasn't cleared earlier
              if debugger.loop then ClearAllCurrentLineMarkers() end
              -- we may be in some unknown location at this point;
              -- If this happens, stop and report allowing users to set
              -- breakpoints and step through.
              if debugger.breaking then
                DisplayOutputLn(TR("Debugging suspended at %s:%s (couldn't activate the file).")
                  :format(file, line))
                return
              end
              -- redo now; if the call is from the debugger, then repeat
              -- the same command, except when it was "run" (switch to 'step');
              -- this is needed to "break" execution that happens in on() call.
              -- in all other cases get out of this file.
              -- don't get out of "mobdebug", because it may happen with
              -- start() or on() call, which will get us out of the current
              -- file, which is not what we want.
              -- Some engines (Corona SDK) report =?:0 as the current location.
              -- repeat the same command, but check if this has been tried
              -- too many times already; if so, get "out"
              out = ((tonumber(line) == 0 and attempts < 10) and command
                or (file:find('mobdebug%.lua$')
                  and (command == 'run' and 'step' or command) or "out"))
              attempts = attempts + 1
            end
          end
        end
      end)
  end
end

debugger.handleAsync = function(command)
  if debugger.server and not debugger.running then
    copas.addthread(function () debugger.handle(command) end)
  end
end

debugger.loadfile = function(file)
  return debugger.handle("load " .. file)
end
debugger.loadstring = function(file, string)
  return debugger.handle("loadstring '" .. file .. "' " .. string)
end
debugger.update = function()
  copas.step(0)
  -- if there are any pending activations
  if debugger.activate then
    local file, line = (table.unpack or unpack)(debugger.activate)
    if LoadFile(file) then activateDocument(file, line) end
    debugger.activate = nil
  end
end
debugger.terminate = function()
  if debugger.server then
    if debugger.pid then -- if there is PID, try local kill
      killClient()
    else -- otherwise, try graceful exit for the remote process
      debugger.breaknow("exit")
    end
    DebuggerStop()
  end
end
debugger.step = function() debugger.exec("step") end
debugger.trace = function()
  debugger.loop = true
  debugger.exec("step")
end
debugger.over = function() debugger.exec("over") end
debugger.out = function() debugger.exec("out") end
debugger.run = function() debugger.exec("run") end
debugger.evaluate = function(expression) return debugger.handle('eval ' .. expression) end
debugger.execute = function(expression) return debugger.handle('exec ' .. expression) end
debugger.stack = function() return debugger.handle('stack') end
debugger.breaknow = function(command)
  -- stop if we're running a "trace" command
  debugger.loop = false

  -- force suspend command; don't use copas interface as it checks
  -- for the other side "reading" and the other side is not reading anything.
  -- use the "original" socket to send "suspend" command.
  -- this will only break on the next Lua command.
  if debugger.socket then
    local running = debugger.running
    -- this needs to be short as it will block the UI
    debugger.socket:settimeout(0.25)
    local file, line, err = debugger.handle(command or "suspend", debugger.socket)
    debugger.socket:settimeout(0)
    -- restore running status
    debugger.running = running
    debugger.breaking = true
    -- don't need to do anything else as the earlier call (run, step, etc.)
    -- will get the results (file, line) back and will update the UI
    return file, line, err
  end
end
debugger.breakpoint = function(file, line, state)
  debugger.handleAsync((state and "setb " or "delb ") .. file .. " " .. line)
end
debugger.quickeval = function(var, callback)
  if debugger.server and not debugger.running
  and not debugger.scratchpad and not (debugger.options or {}).noeval then
    copas.addthread(function ()
      local _, values, err = debugger.evaluate(var)
      local val = err
        and err:gsub("%[.-%]:%d+:%s*","error: ")
        or (var .. " = " .. (#values > 0 and values[1] or 'nil'))
      if callback then callback(val) end
    end)
  end
end

----------------------------------------------
-- public api

function DebuggerAttachDefault(options)
  debugger.options = options
  if (debugger.listening) then return end
  debugger.listen()
end

function DebuggerShutdown()
  if debugger.server then debugger.terminate() end
  if debugger.pid then killClient() end
end

function DebuggerStop()
  if (debugger.server) then
    debugger.server = nil
    debugger.pid = nil
    SetAllEditorsReadOnly(false)
    ShellSupportRemote(nil)
    ClearAllCurrentLineMarkers()
    DebuggerScratchpadOff()
    local lines = TR("traced %d instruction", debugger.stats.line):format(debugger.stats.line)
    DisplayOutputLn(TR("Debugging session completed (%s)."):format(lines))
  else
    -- it's possible that the application couldn't start, or that the
    -- debugger in the application didn't start, which means there is
    -- no debugger.server, but scratchpad may still be on. Turn it off.
    DebuggerScratchpadOff()
  end
end

function DebuggerCloseStackWindow()
  if (debugger.stackWindow) then
    SettingsSaveFramePosition(debugger.stackWindow, "StackWindow")
    debugger.stackCtrl = nil
    debugger.stackWindow = nil
  end
end

function DebuggerCloseWatchWindow()
  if (debugger.watchWindow) then
    SettingsSaveFramePosition(debugger.watchWindow, "WatchWindow")
    debugger.watchCtrl = nil
    debugger.watchWindow = nil
  end
end

-- need imglist to be a file local variable as SetImageList takes ownership
-- of it and if done inside a function, icons do not work as expected
local imglist = wx.wxImageList(16,16)
do
  local getBitmap = (ide.app.createbitmap or wx.wxArtProvider.GetBitmap)
  local size = wx.wxSize(16,16)
  -- 0 = stack call
  imglist:Add(getBitmap(wx.wxART_GO_FORWARD, wx.wxART_OTHER, size))
  -- 1 = local variables
  imglist:Add(getBitmap(wx.wxART_LIST_VIEW, wx.wxART_OTHER, size))
  -- 2 = upvalues
  imglist:Add(getBitmap(wx.wxART_REPORT_VIEW, wx.wxART_OTHER, size))
end

function DebuggerCreateStackWindow()
  if (debugger.stackWindow) then return updateStackAndWatches() end
  local width = 360
  local stackWindow = wx.wxFrame(ide.frame, wx.wxID_ANY,
    TR("Stack Window"),
    wx.wxDefaultPosition, wx.wxSize(width, 200),
    wx.wxDEFAULT_FRAME_STYLE + wx.wxFRAME_FLOAT_ON_PARENT)

  debugger.stackWindow = stackWindow

  local stackCtrl = wx.wxTreeCtrl(stackWindow, wx.wxID_ANY,
    wx.wxDefaultPosition, wx.wxDefaultSize,
    wx.wxTR_LINES_AT_ROOT + wx.wxTR_HAS_BUTTONS + wx.wxTR_SINGLE + wx.wxTR_HIDE_ROOT)

  debugger.stackCtrl = stackCtrl

  stackCtrl:SetImageList(imglist)
  stackWindow:CentreOnParent()
  SettingsRestoreFramePosition(stackWindow, "StackWindow")
  stackWindow:Show(true)

  stackWindow:Connect(wx.wxEVT_CLOSE_WINDOW,
    function (event)
      DebuggerCloseStackWindow()
      stackWindow = nil
      stackCtrl = nil
      event:Skip()
    end)

  stackCtrl:Connect( wx.wxEVT_COMMAND_TREE_ITEM_EXPANDING,
    function (event)
      local item_id = event:GetItem()
      local count = stackCtrl:GetChildrenCount(item_id, false)
      if count > 0 then return true end

      local image = stackCtrl:GetItemImage(item_id)
      local num = 1
      for name,value in pairs(stackItemValue[item_id:GetValue()]) do
        local strval = mobdebug.line(value, {comment = false, nocode = true})
        local text = type(name) == "number"
          and (num == name and strval or ("[%s] = %s"):format(name, strval))
          or ("%s = %s"):format(tostring(name), strval)
        local item = stackCtrl:AppendItem(item_id, text, image)
        if checkIfExpandable(value, item) then
          stackCtrl:SetItemHasChildren(item, true)
        end
        num = num + 1
      end

      stackCtrl:SortChildren(item_id)
      return true
    end)
  stackCtrl:Connect( wx.wxEVT_COMMAND_TREE_ITEM_COLLAPSED,
    function() return true end)

  updateStackAndWatches()
end

function DebuggerCreateWatchWindow()
  if (debugger.watchWindow) then return updateWatches() end
  local width = 360
  local watchWindow = wx.wxFrame(ide.frame, wx.wxID_ANY,
    TR("Watch Window"),
    wx.wxDefaultPosition, wx.wxSize(width, 200),
    wx.wxDEFAULT_FRAME_STYLE + wx.wxFRAME_FLOAT_ON_PARENT)

  debugger.watchWindow = watchWindow

  local watchMenu = wx.wxMenu{
    { ID_ADDWATCH, TR("&Add Watch")..KSC(ID_ADDWATCH) },
    { ID_EDITWATCH, TR("&Edit Watch")..KSC(ID_EDITWATCH) },
    { ID_REMOVEWATCH, TR("&Remove Watch")..KSC(ID_REMOVEWATCH) },
    { ID_EVALUATEWATCH, TR("Evaluate &Watches")..KSC(ID_EVALUATEWATCH) }}

  local watchMenuBar = wx.wxMenuBar()
  watchMenuBar:Append(watchMenu, TR("&Watches"))
  watchWindow:SetMenuBar(watchMenuBar)

  local watchCtrl = wx.wxListCtrl(watchWindow, wx.wxID_ANY,
    wx.wxDefaultPosition, wx.wxDefaultSize,
    wx.wxLC_REPORT + wx.wxLC_EDIT_LABELS)

  debugger.watchCtrl = watchCtrl

  local info = wx.wxListItem()
  info:SetMask(wx.wxLIST_MASK_TEXT + wx.wxLIST_MASK_WIDTH)
  info:SetText(TR("Expression"))
  info:SetWidth(width * 0.32)
  watchCtrl:InsertColumn(0, info)

  info:SetText(TR("Value"))
  info:SetWidth(width * 0.56)
  watchCtrl:InsertColumn(1, info)

  watchWindow:CentreOnParent()
  SettingsRestoreFramePosition(watchWindow, "WatchWindow")
  watchWindow:Show(true)

  local function findSelectedWatchItem()
    local count = watchCtrl:GetSelectedItemCount()
    if count > 0 then
      for idx = 0, watchCtrl:GetItemCount() - 1 do
        if watchCtrl:GetItemState(idx, wx.wxLIST_STATE_FOCUSED) ~= 0 then
          return idx
        end
      end
    end
    return -1
  end

  local defaultExpr = ""

  watchWindow:Connect(wx.wxEVT_CLOSE_WINDOW,
    function (event)
      DebuggerCloseWatchWindow()
      watchWindow = nil
      watchCtrl = nil
      event:Skip()
    end)

  watchWindow:Connect(ID_ADDWATCH, wx.wxEVT_COMMAND_MENU_SELECTED,
    function ()
      local row = watchCtrl:InsertItem(watchCtrl:GetItemCount(), TR("Expr"))
      watchCtrl:SetItem(row, 0, defaultExpr)
      watchCtrl:SetItem(row, 1, TR("Value"))
      watchCtrl:EditLabel(row)
    end)

  watchWindow:Connect(ID_EDITWATCH, wx.wxEVT_COMMAND_MENU_SELECTED,
    function ()
      local row = findSelectedWatchItem()
      if row >= 0 then
        watchCtrl:EditLabel(row)
      end
    end)
  watchWindow:Connect(ID_EDITWATCH, wx.wxEVT_UPDATE_UI,
    function (event)
      event:Enable(watchCtrl:GetSelectedItemCount() > 0)
    end)

  watchWindow:Connect(ID_REMOVEWATCH, wx.wxEVT_COMMAND_MENU_SELECTED,
    function ()
      local row = findSelectedWatchItem()
      if row >= 0 then
        watchCtrl:DeleteItem(row)
      end
    end)
  watchWindow:Connect(ID_REMOVEWATCH, wx.wxEVT_UPDATE_UI,
    function (event)
      event:Enable(watchCtrl:GetSelectedItemCount() > 0)
    end)

  watchWindow:Connect(ID_EVALUATEWATCH, wx.wxEVT_COMMAND_MENU_SELECTED,
    function () updateWatches() end)
  watchWindow:Connect(ID_EVALUATEWATCH, wx.wxEVT_UPDATE_UI,
    function (event)
      event:Enable(watchCtrl:GetItemCount() > 0)
    end)

  watchCtrl:Connect(wx.wxEVT_COMMAND_LIST_END_LABEL_EDIT,
    function (event)
      local row = event:GetIndex()
      if event:IsEditCancelled() then
        if watchCtrl:GetItemText(row) == defaultExpr then
          watchCtrl:DeleteItem(row)
        end
      else
        watchCtrl:SetItem(row, 0, event:GetText())
        updateWatches(row)
      end
      event:Skip()
    end)
end

function DebuggerAddWatch(watch)
  if (not debugger.watchWindow) then DebuggerCreateWatchWindow() end

  local watchCtrl = debugger.watchCtrl
  -- check if this expression is already on the list
  for idx = 0, watchCtrl:GetItemCount() - 1 do
    if watchCtrl:GetItemText(idx) == watch then return end
  end

  local row = watchCtrl:InsertItem(watchCtrl:GetItemCount(), TR("Expr"))
  watchCtrl:SetItem(row, 0, watch)
  watchCtrl:SetItem(row, 1, TR("Value"))

  updateWatches(row)
end

function DebuggerMakeFileName(editor, filePath)
  return filePath or ide.config.default.fullname
end

function DebuggerToggleBreakpoint(editor, line)
  -- ignore requests to toggle when the debugger is running
  if debugger.server and debugger.running then return end
  local markers = editor:MarkerGet(line)
  if markers >= CURRENT_LINE_MARKER_VALUE then
    markers = markers - CURRENT_LINE_MARKER_VALUE
  end
  local id = editor:GetId()
  local filePath = DebuggerMakeFileName(editor, ide.openDocuments[id].filePath)
  if markers >= BREAKPOINT_MARKER_VALUE then
    editor:MarkerDelete(line, BREAKPOINT_MARKER)
    if debugger.server then
      debugger.breakpoint(filePath, line+1, false)
    end
  else
    editor:MarkerAdd(line, BREAKPOINT_MARKER)
    if debugger.server then
      debugger.breakpoint(filePath, line+1, true)
    end
  end
end

-- scratchpad functions

function DebuggerRefreshScratchpad()
  if debugger.scratchpad and debugger.scratchpad.updated and not debugger.scratchpad.paused then

    local scratchpadEditor = debugger.scratchpad.editor
    local compiled, code = CompileProgram(scratchpadEditor, true)
    if not compiled then return end

    if debugger.scratchpad.running then
      -- break the current execution first
      -- don't try too frequently to avoid overwhelming the debugger
      local now = TimeGet()
      if now - debugger.scratchpad.running > 0.250 then
        debugger.breaknow()
        debugger.scratchpad.running = now
      end
    else
      local clear = ide.frame.menuBar:IsChecked(ID_CLEAROUTPUT)
      local filePath = DebuggerMakeFileName(scratchpadEditor,
        ide.openDocuments[scratchpadEditor:GetId()].filePath)

      -- wrap into a function call to make "return" to work with scratchpad
      code = "(function()"..code.."\nend)()"

      -- this is a special error message that is generated at the very end
      -- of each script to avoid exiting the (debugee) scratchpad process.
      -- these errors are handled and not reported to the user
      local errormsg = 'execution suspended at ' .. TimeGet()
      local stopper = "error('" .. errormsg .. "')"
      -- store if interpreter requires a special handling for external loop
      local extloop = ide.interpreter.scratchextloop

      local function reloadScratchpadCode()
        debugger.scratchpad.running = TimeGet()
        debugger.scratchpad.updated = false
        debugger.scratchpad.runs = (debugger.scratchpad.runs or 0) + 1

        if clear then ClearOutput() end

        -- the code can be running in two ways under scratchpad:
        -- 1. controlled by the application, requires stopper (most apps)
        -- 2. controlled by some external loop (for example, love2d).
        -- in the first case we need to reload the app after each change
        -- in the second case, we need to load the app once and then
        -- "execute" new code to reflect the changes (with some limitations).
        local _, _, err
        if extloop then -- if the execution is controlled by an external loop
          if debugger.scratchpad.runs == 1
          then _, _, err = debugger.loadstring(filePath, code)
          else _, _, err = debugger.execute(code) end
        else   _, _, err = debugger.loadstring(filePath, code .. stopper) end

        -- when execute() is used, it's not possible to distinguish between
        -- compilation and run-time error, so just report as "Scratchpad error"
        local prefix = extloop and TR("Scratchpad error") or TR("Compilation error")

        if not err then
          _, _, err = debugger.handle("run")
          prefix = TR("Execution error")
        end
        if err and not err:find(errormsg) then
          local fragment, line = err:match('.-%[string "([^\010\013]+)"%]:(%d+)%s*:')
          -- make the code shorter to better see the error message
          if prefix == TR("Scratchpad error") and fragment and #fragment > 30 then
            err = err:gsub(q(fragment), function(s) return s:sub(1,30)..'...' end)
          end
          DisplayOutputLn(prefix
            ..(line and (" "..TR("on line %d"):format(line)) or "")
            ..":\n"..err:gsub('stack traceback:.+', ''):gsub('\n+$', ''))
        end
        debugger.scratchpad.running = false
      end

      copas.addthread(reloadScratchpadCode)
    end
  end
end

local numberStyle = wxstc.wxSTC_LUA_NUMBER

function DebuggerScratchpadOn(editor)
  -- first check if there is already scratchpad editor.
  -- this may happen when more than one editor is being added...

  if debugger.scratchpad and debugger.scratchpad.editors then
    debugger.scratchpad.editors[editor] = true
  else
    debugger.scratchpad = {editor = editor, editors = {[editor] = true}}

    -- check if the debugger is already running; this happens when
    -- scratchpad is turned on after external script has connected
    if debugger.server then
      debugger.scratchpad.updated = true
      ClearAllCurrentLineMarkers()
      SetAllEditorsReadOnly(false)
      ShellSupportRemote(nil) -- disable remote shell
      DebuggerRefreshScratchpad()
    elseif not ProjectDebug(true, "scratchpad") then
      debugger.scratchpad = nil
      return
    end
  end

  local scratchpadEditor = editor
  scratchpadEditor:StyleSetUnderline(numberStyle, true)
  debugger.scratchpad.margin = scratchpadEditor:GetMarginWidth(0) +
    scratchpadEditor:GetMarginWidth(1) + scratchpadEditor:GetMarginWidth(2)

  scratchpadEditor:Connect(wxstc.wxEVT_STC_MODIFIED, function(event)
    local evtype = event:GetModificationType()
    if (bit.band(evtype,wxstc.wxSTC_MOD_INSERTTEXT) ~= 0 or
        bit.band(evtype,wxstc.wxSTC_MOD_DELETETEXT) ~= 0 or
        bit.band(evtype,wxstc.wxSTC_PERFORMED_UNDO) ~= 0 or
        bit.band(evtype,wxstc.wxSTC_PERFORMED_REDO) ~= 0) then
      debugger.scratchpad.updated = true
      debugger.scratchpad.editor = scratchpadEditor
    end
    event:Skip()
  end)

  scratchpadEditor:Connect(wx.wxEVT_LEFT_DOWN, function(event)
    local scratchpad = debugger.scratchpad

    local point = event:GetPosition()
    local pos = scratchpadEditor:PositionFromPoint(point)

    -- are we over a number in the scratchpad? if not, it's not our event
    if ((not scratchpad) or
        (bit.band(scratchpadEditor:GetStyleAt(pos),31) ~= numberStyle)) then
      event:Skip()
      return
    end

    -- find start position and length of the number
    local text = scratchpadEditor:GetText()

    local nstart = pos
    while nstart >= 0
      and (bit.band(scratchpadEditor:GetStyleAt(nstart),31) == numberStyle)
      do nstart = nstart - 1 end

    local nend = pos
    while nend < string.len(text)
      and (bit.band(scratchpadEditor:GetStyleAt(nend),31) == numberStyle)
      do nend = nend + 1 end

    -- check if there is minus sign right before the number and include it
    if nstart >= 0 and scratchpadEditor:GetTextRange(nstart,nstart+1) == '-' then 
      nstart = nstart - 1
    end
    scratchpad.start = nstart + 1
    scratchpad.length = nend - nstart - 1
    scratchpad.origin = scratchpadEditor:GetTextRange(nstart+1,nend)
    if tonumber(scratchpad.origin) then
      scratchpad.point = point
      scratchpadEditor:CaptureMouse()
    end
  end)

  scratchpadEditor:Connect(wx.wxEVT_LEFT_UP, function(event)
    if debugger.scratchpad and debugger.scratchpad.point then
      debugger.scratchpad.point = nil
      scratchpadEditor:ReleaseMouse()
      wx.wxSetCursor(wx.wxNullCursor) -- restore cursor
    else event:Skip() end
  end)

  scratchpadEditor:Connect(wx.wxEVT_MOTION, function(event)
    local point = event:GetPosition()
    local pos = scratchpadEditor:PositionFromPoint(point)
    local scratchpad = debugger.scratchpad
    local ipoint = scratchpad and scratchpad.point

    -- record the fact that we are over a number or dragging slider
    scratchpad.over = scratchpad and
      (ipoint ~= nil or (bit.band(scratchpadEditor:GetStyleAt(pos),31) == numberStyle))

    if ipoint then
      local startpos = scratchpad.start
      local endpos = scratchpad.start+scratchpad.length

      -- calculate difference in point position
      local dx = point.x - ipoint.x

      -- calculate the number of decimal digits after the decimal point
      local origin = scratchpad.origin
      local decdigits = #(origin:match('%.(%d+)') or '')

      -- calculate new value
      local value = tonumber(origin) + dx * 10^-decdigits

      -- convert new value back to string to check the number of decimal points
      -- this is needed because the rate of change is determined by the
      -- current value. For example, for number 1, the next value is 2,
      -- but for number 1.1, the next is 1.2 and for 1.01 it is 1.02.
      -- But if 1.01 becomes 1.00, the both zeros after the decimal point
      -- need to be preserved to keep the increment ratio the same when
      -- the user wants to release the slider and start again.
      origin = tostring(value)
      local newdigits = #(origin:match('%.(%d+)') or '')
      if decdigits ~= newdigits then
        origin = origin .. (origin:find('%.') and '' or '.') .. ("0"):rep(decdigits-newdigits)
      end

      -- update length
      scratchpad.length = #origin

      -- update the value in the document
      scratchpadEditor:SetTargetStart(startpos)
      scratchpadEditor:SetTargetEnd(endpos)
      scratchpadEditor:ReplaceTarget(origin)
    else event:Skip() end
  end)

  scratchpadEditor:Connect(wx.wxEVT_SET_CURSOR, function(event)
    if (debugger.scratchpad and debugger.scratchpad.over) then
      event:SetCursor(wx.wxCursor(wx.wxCURSOR_SIZEWE))
    elseif debugger.scratchpad and ide.osname == 'Unix' then
      -- restore the cursor manually on Linux since event:Skip() doesn't reset it
      local ibeam = event:GetX() > debugger.scratchpad.margin
      event:SetCursor(wx.wxCursor(ibeam and wx.wxCURSOR_IBEAM or wx.wxCURSOR_RIGHT_ARROW))
    else event:Skip() end
  end)

  return true
end

function DebuggerScratchpadOff()
  if not debugger.scratchpad then return end

  for scratchpadEditor in pairs(debugger.scratchpad.editors) do
    scratchpadEditor:StyleSetUnderline(numberStyle, false)
    scratchpadEditor:Disconnect(wx.wxID_ANY, wx.wxID_ANY, wxstc.wxEVT_STC_MODIFIED)
    scratchpadEditor:Disconnect(wx.wxID_ANY, wx.wxID_ANY, wx.wxEVT_MOTION)
    scratchpadEditor:Disconnect(wx.wxID_ANY, wx.wxID_ANY, wx.wxEVT_LEFT_DOWN)
    scratchpadEditor:Disconnect(wx.wxID_ANY, wx.wxID_ANY, wx.wxEVT_LEFT_UP)
    scratchpadEditor:Disconnect(wx.wxID_ANY, wx.wxID_ANY, wx.wxEVT_SET_CURSOR)
  end

  wx.wxSetCursor(wx.wxNullCursor) -- restore cursor

  debugger.scratchpad = nil
  debugger.terminate()

  -- disable menu if it is still enabled
  -- (as this may be called when the debugger is being shut down)
  local menuBar = ide.frame.menuBar
  if menuBar:IsChecked(ID_RUNNOW) then menuBar:Check(ID_RUNNOW, false) end

  return true
end