-- +-----------------+
-- | Benchmark Mod 2 |
-- |    by Zamiel    |
-- +-----------------+

-- This is a mod that will benchmark two different functions to calculate how much more efficient
-- one function is over the other.

local socket = require("socket")
local constants = require("constants")

local mod = RegisterMod("test-benchmark", 1)

-- Benchmark configuration
local NUM_TRIALS_PER_FUNCTION = 100000
local THRESHOLD_IN_SECONDS = 0.001 -- 1 millisecond

-- Variables
local enabled = true
local totalTimeTaken = 0
local i = 0

-- ModCallbacks.MC_POST_RENDER (2)
function mod:postRender()
  if not enabled then
    return
  end

  i = i + 1

  local elapsedTimeSeconds1 = mod:GetExecutionTimeInSeconds(mod.Function1)
  local elapsedTimeSeconds2 = mod:GetExecutionTimeInSeconds(mod.Function2)

  local difference = elapsedTimeSeconds2 - elapsedTimeSeconds1
  totalTimeTaken = totalTimeTaken + difference
  if totalTimeTaken >= NUM_TRIALS_PER_FUNCTION * THRESHOLD_IN_SECONDS then
    Isaac.DebugString("i = " .. tostring(i))
    enabled = false
    return
  end

  if i % 10 == 0 then
    Isaac.DebugString("On invocation: " .. tostring(i))
    Isaac.DebugString("Total time taken: " .. tostring(totalTimeTaken))
    Isaac.DebugString("Total time needs to be: " .. tostring(NUM_TRIALS_PER_FUNCTION * THRESHOLD_IN_SECONDS))
  end
end

function mod:GetExecutionTimeInSeconds(func)
  local startTimeSeconds = socket:gettime()
  for i = 1, NUM_TRIALS_PER_FUNCTION do
    func()
  end
  local endTimeSeconds = socket:gettime()

  return endTimeSeconds - startTimeSeconds
end

-- Faster function
function mod:Function1()
  local gameFrameCount = constants.GAME:GetFrameCount()
  return gameFrameCount
end

-- Slower function
function mod:Function2()
  local game = Game()
  local gameFrameCount = game:GetFrameCount()
  return gameFrameCount
end

mod:AddCallback(ModCallbacks.MC_POST_RENDER, mod.postRender)