--- **Utils** - Lua Profiler.
--
-- Find out how many times functions are called and how much real time it costs.
--
-- ===
--
-- ### Author: **TAW CougarNL**, *funkyfranky*
-- 
-- @module Utilities.PROFILER
-- @image MOOSE.JPG


--- PROFILER class.
-- @type PROFILER
-- @field #string ClassName Name of the class.
-- @field #table Counters Function counters.
-- @field #table dInfo Info.
-- @field #table fTime Function time.
-- @field #table fTimeTotal Total function time.
-- @field #table eventhandler Event handler to get mission end event.
-- @field #number TstartGame Game start time timer.getTime().
-- @field #number TstartOS OS real start time os.clock.
-- @field #boolean logUnknown Log unknown functions. Default is off.
-- @field #number lowCpsThres Low calls per second threashold. Only write output if function has more calls per second than this value.
-- @field #string fileNamePrefix Output file name prefix, e.g. "MooseProfiler".
-- @field #string fileNameSuffix Output file name prefix, e.g. "txt"

--- *The emperor counsels simplicity. First principles. Of each particular thing, ask: What is it in itself, in its own constitution? What is its causal nature? *
--
-- ===
--
-- ![Banner Image](..\Presentations\Utilities\PROFILER_Main.jpg)
--
-- # The PROFILER Concept
-- 
-- Profile your lua code. This tells you, which functions are called very often and which consume most real time.
-- With this information you can optimize the perfomance of your code.
-- 
-- # Prerequisites
-- 
-- The modules **os** and **lfs** need to be desanizied.
-- 
-- 
-- # Start
-- 
-- The profiler can simply be started with the @{#PROFILER.Start}(*Delay, Duration*) function
-- 
--     PROFILER.Start()
--    
-- The optional parameter *Delay* can be used to delay the start by a certain amount of seconds and the optional parameter *Duration* can be used to
-- stop the profiler after a certain amount of seconds.
-- 
-- # Stop
-- 
-- The profiler automatically stops when the mission ends. But it can be stopped any time with the @{#PROFILER.Stop}(*Delay*) function
-- 
--     PROFILER.Stop()
--    
-- The optional parameter *Delay* can be used to specify a delay after which the profiler is stopped.
-- 
-- When the profiler is stopped, the output is written to a file.
-- 
-- # Output
-- 
-- The profiler output is written to a file in your DCS home folder
-- 
--     X:\User\<Your User Name>\Saved Games\DCS OpenBeta\Logs
-- 
-- The default file name is "MooseProfiler.txt". If that file exists, the file name is "MooseProfiler-001.txt" etc.
-- 
-- ## Data
-- 
-- The data in the output file provides information on the functions that were called in the mission.
-- 
-- It will tell you how many times a function was called in total, how many times per second, how much time in total and the percentage of time.
-- 
-- If you only want output for functions that are called more than X times per second, you can set
-- 
--     PROFILER.lowCpsThres=1.5
-- 
-- With this setting, only functions which are called more than 1.5 times per second are displayed.
-- 
-- @field #PROFILER
PROFILER = {
  ClassName      = "PROFILER",
  Counters       = {},
  dInfo          = {},
  fTime          = {},
  fTimeTotal     = {},
  eventHandler   = {},
  logUnknown     = false,
  lowCpsThres    = 0.0,
  fileNamePrefix = "MooseProfiler",
  fileNameSuffix = "txt"
}

--- Waypoint data.
-- @type PROFILER.Data
-- @field #string func The function name.
-- @field #string src The source file.
-- @field #number line The line number
-- @field #number count Number of function calls.
-- @field #number tm Total time in seconds.

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Start/Stop Profiler
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

--- Start profiler.
-- @param #number Delay Delay in seconds before profiler is stated. Default is immediately.
-- @param #number Duration Duration in (game) seconds before the profiler is stopped. Default is when mission ends.
function PROFILER.Start(Delay, Duration)

  if Delay and Delay>0 then
    BASE:ScheduleOnce(Delay, PROFILER.Start, 0, Duration)
  else
  
    -- Check if os and lfs are available.
    local go=true
    if not os then
      error("Profiler needs os to be desanitized")
      go=false
    end
    if not lfs then
      error("Profiler needs lfs to be desanitized")
      go=false
    end
    if not go then
      return
    end

    -- Set start time.
    PROFILER.TstartGame=timer.getTime()
    PROFILER.TstartOS=os.clock()
    
    -- Add event handler.
    world.addEventHandler(PROFILER.eventHandler)
    
    --[[
    -- Message to screen.
    local function showProfilerRunning()
      timer.scheduleFunction(showProfilerRunning, nil, timer.getTime()+600)
      trigger.action.outText("### Profiler running ###", 600)
    end    
    -- Message.
    showProfilerRunning()
    ]]
    
    -- Info in log.
    env.info('############################   Profiler Started   ############################')
    if Duration then
      env.info(string.format("Duration %d seconds", Duration))
    else
      env.info(string.format("Stopped when mission ends"))
    end
    env.info(string.format("Calls per second threshold %.3f/sec", PROFILER.lowCpsThres))
    env.info(string.format("Log file \"%s.%s\"", PROFILER.fileNamePrefix, PROFILER.fileNameSuffix))
    env.info('###############################################################################')
    
    
    -- Message on screen
    local duration=Duration or 600
    trigger.action.outText("### Profiler running ###", duration)
  
    -- Set hook.
    debug.sethook(PROFILER.hook, "cr")
    
    -- Auto stop profiler.
    if Duration then
      PROFILER.Stop(Duration)
    end
    
  end
  
end

--- Stop profiler.
-- @param #number Delay Delay before stop in seconds.
function PROFILER.Stop(Delay)

  if Delay and Delay>0 then
    
    BASE:ScheduleOnce(Delay, PROFILER.Stop)
  
  else

    -- Remove hook.
    debug.sethook()
  
    
    -- Run time game.
    local runTimeGame=timer.getTime()-PROFILER.TstartGame
    
    -- Run time real OS.
    local runTimeOS=os.clock()-PROFILER.TstartOS
    
    -- Show info.
    PROFILER.showInfo(runTimeGame, runTimeOS)
    
  end

end

--- Event handler.
function PROFILER.eventHandler:onEvent(event)
  if event.id==world.event.S_EVENT_MISSION_END then
    PROFILER.Stop()
  end
end

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Hook
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

--- Debug hook.
-- @param #table event Event.
function PROFILER.hook(event)

  local f=debug.getinfo(2, "f").func
  
  if event=='call' then
  
    if PROFILER.Counters[f]==nil then
    
      PROFILER.Counters[f]=1
      PROFILER.dInfo[f]=debug.getinfo(2,"Sn")
      
      if PROFILER.fTimeTotal[f]==nil then
        PROFILER.fTimeTotal[f]=0
      end
      
    else
      PROFILER.Counters[f]=PROFILER.Counters[f]+1
    end
    
    if PROFILER.fTime[f]==nil then
      PROFILER.fTime[f]=os.clock()
    end
    
  elseif (event=='return') then
  
    if PROFILER.fTime[f]~=nil then
      PROFILER.fTimeTotal[f]=PROFILER.fTimeTotal[f]+(os.clock()-PROFILER.fTime[f])
      PROFILER.fTime[f]=nil
    end
    
  end
  
end

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-- Data
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

--- Get data.
-- @param #function func Function.
-- @return #string Function name.
-- @return #string Source file name.
-- @return #string Line number.
-- @return #number Function time in seconds.
function PROFILER.getData(func)

  local n=PROFILER.dInfo[func]
  
  if n.what=="C" then
    return n.name, "?", "?", PROFILER.fTimeTotal[func]
  end
  
  return n.name, n.short_src, n.linedefined, PROFILER.fTimeTotal[func]  
end

--- Write text to log file.
-- @param #function f The file.
-- @param #string txt The text.
function PROFILER._flog(f, txt)
  f:write(txt.."\r\n")
end

--- Show table.
-- @param #table data Data table.
-- @param #function f The file.
-- @param #number runTimeGame Game run time in seconds.
function PROFILER.showTable(data, f, runTimeGame)

  -- Loop over data.
  for i=1, #data do  
    local t=data[i] --#PROFILER.Data
  
    -- Calls per second.
    local cps=t.count/runTimeGame
    
    if (cps>=PROFILER.lowCpsThres) then
    
      -- Output
      local text=string.format("%30s: %8d calls %8.1f/sec   -   Time %8.3f sec (%.3f %%)  %s line %s", t.func, t.count, cps, t.tm, t.tm/runTimeGame*100, tostring(t.src), tostring(t.line))
      PROFILER._flog(f, text)
      
    end
  end
    
end

--- Write info to output file.
-- @return #string File name.
function PROFILER.getfilename()

  local dir=lfs.writedir()..[[Logs\]]
  
  local file=dir..PROFILER.fileNamePrefix.."."..PROFILER.fileNameSuffix
  
  if not UTILS.FileExists(file) then
    return file
  end
  
  for i=1,999 do
  
    local file=string.format("%s%s-%03d.%s", dir,PROFILER.fileNamePrefix, i, PROFILER.fileNameSuffix)

    if not UTILS.FileExists(file) then
      return file
    end
    
  end

end

--- Write info to output file.
-- @param #number runTimeGame Game time in seconds.
-- @param #number runTimeOS OS time in seconds.
function PROFILER.showInfo(runTimeGame, runTimeOS)

  -- Output file.
  local file=PROFILER.getfilename()
  local f=io.open(file, 'w')  
  
  -- Gather data.
  local Ttot=0
  local Calls=0
  
  local t={}
  
  local tcopy=nil --#PROFILER.Data
  local tserialize=nil --#PROFILER.Data
  local tforgen=nil --#PROFILER.Data
  local tpairs=nil --#PROFILER.Data
  
  
  for func, count in pairs(PROFILER.Counters) do
  
    local s,src,line,tm=PROFILER.getData(func)
    
    if PROFILER.logUnknown==true then
      if s==nil then s="<Unknown>" end
    end
        
    if s~=nil then
    
      -- Profile data.
      local T=
      { func=s,
        src=src,
        line=line,
        count=count,
        tm=tm,
      } --#PROFILER.Data
      
      -- Collect special cases. Somehow, e.g. "_copy" appears multiple times so we try to gather all data.
      if s=="_copy" then
        if tcopy==nil then
          tcopy=T
        else
          tcopy.count=tcopy.count+T.count
          tcopy.tm=tcopy.tm+T.tm
        end
      elseif s=="_Serialize" then
        if tserialize==nil then
          tserialize=T
        else
          tserialize.count=tserialize.count+T.count
          tserialize.tm=tserialize.tm+T.tm
        end      
      elseif s=="(for generator)" then
        if tforgen==nil then
          tforgen=T
        else
          tforgen.count=tforgen.count+T.count
          tforgen.tm=tforgen.tm+T.tm
        end      
      elseif s=="pairs" then
        if tpairs==nil then
          tpairs=T
        else
          tpairs.count=tpairs.count+T.count
          tpairs.tm=tpairs.tm+T.tm
        end      
      else
        table.insert(t, T)
      end
      
      -- Total function time.
      Ttot=Ttot+tm
      
      -- Total number of calls.
      Calls=Calls+count
      
    end
        
  end

  -- Add special cases.  
  if tcopy then
    table.insert(t, tcopy)
  end
  if tserialize then
    table.insert(t, tserialize)      
  end
  if tforgen then
    table.insert(t, tforgen)
  end
  if tpairs then
    table.insert(t, tpairs)
  end  
  
  env.info("**************************************************************************************************")
  env.info(string.format("Profiler"))
  env.info(string.format("--------"))
  env.info(string.format("* Runtime Game     : %s = %d sec", UTILS.SecondsToClock(runTimeGame, true), runTimeGame))
  env.info(string.format("* Runtime Real     : %s = %d sec", UTILS.SecondsToClock(runTimeOS, true), runTimeOS))
  env.info(string.format("* Function time    : %s = %.1f sec (%.1f percent of runtime game)", UTILS.SecondsToClock(Ttot, true), Ttot, Ttot/runTimeGame*100))
  env.info(string.format("* Total functions  : %d", #t))
  env.info(string.format("* Total func calls : %d", Calls))
  env.info(string.format("* Writing to file  : \"%s\"", file))
  env.info("**************************************************************************************************")  
      
  -- Sort by total time.
  table.sort(t, function(a,b) return a.tm>b.tm end)
  
  -- Write data.
  PROFILER._flog(f,"")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"")
  PROFILER._flog(f,"-------------------------")
  PROFILER._flog(f,"---- Profiler Report ----")
  PROFILER._flog(f,"-------------------------")
  PROFILER._flog(f,"")
  PROFILER._flog(f,string.format("* Runtime Game     : %s = %.1f sec", UTILS.SecondsToClock(runTimeGame, true), runTimeGame))
  PROFILER._flog(f,string.format("* Runtime Real     : %s = %.1f sec", UTILS.SecondsToClock(runTimeOS, true), runTimeOS))
  PROFILER._flog(f,string.format("* Function time    : %s = %.1f sec (%.1f %% of runtime game)", UTILS.SecondsToClock(Ttot, true), Ttot, Ttot/runTimeGame*100))
  PROFILER._flog(f,"")
  PROFILER._flog(f,string.format("* Total functions  = %d", #t))
  PROFILER._flog(f,string.format("* Total func calls = %d", Calls))
  PROFILER._flog(f,"")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"")
  PROFILER.showTable(t, f, runTimeGame)
  
  -- Sort by number of calls.
  table.sort(t, function(a,b) return a.count>b.count end)
  
  -- Detailed data.
  PROFILER._flog(f,"")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"")
  PROFILER._flog(f,"------------------------------")
  PROFILER._flog(f,"---- Data Sorted by Calls ----")
  PROFILER._flog(f,"------------------------------")
  PROFILER._flog(f,"")
  PROFILER.showTable(t, f, runTimeGame)
  
  -- Closing.
  PROFILER._flog(f,"")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"************************************************************************************************************************")
  PROFILER._flog(f,"************************************************************************************************************************")
  -- Close file.
  f:close()
end