{-# LANGUAGE OverloadedStrings #-}
import Control.Concurrent
import Graphics.GL
import Linear
import System.Random
import Data.Time
import Control.Monad
import Data.Bits

import Halive.Utils
import Cube
import Shader
import Window

import SDL


import qualified Green as Green -- Try changing the green amount
                                -- while the program is running

main :: IO ()
main = do
    putStrLn "MAIN BEGIN"
    -- error "DANG!" -- It's ok if your program crashes, it shouldn't crash Halive

    -- Wrap any persistent state in 'reacquire' plus a unique asset ID.
    -- Reacquire uses foreign-store to only run your setup function once,
    -- and then return it again on subsequent recompilations.
    -- In this case, GLFW doesn't like being initialized more than once
    -- per process, so this solves the problem handily.
    -- (Our window stays persistent as well thanks to this,
    -- so it would probably be a good idea anyway!)

    (win, _ctx) <- reacquire 0 $ createGLWindow "Hot SDL"

    -- You can change the window title here.
    --GLFW.setWindowTitle win "Hot Swap!"

    -- Changing the shaders' contents will trigger Halive as well!
    program <- createShaderProgram "demo/cube.vert" "demo/cube.frag"
    cube <- makeCube program

    -- Any GL state will stick around, so be aware of that.
    glEnable GL_DEPTH_TEST

    -- Sometimes it's useful to know if we're running under Halive or not
    putStrLn . ("Running under Halive: " ++ ) . show =<< isHaliveActive

    -- do -- swap this with the next line to test immediately-returning mains
    whileWindow win $ \events -> do
        now <- realToFrac . utctDayTime <$> getCurrentTime
        -- print now -- Try turning on a stream of now logs
        let redFreq  = 0.6 * pi -- Try changing the red and blue frequencies.
            red      = sin (now * redFreq)
            blueFreq = 0.5 * pi
            blue     = sin (now * blueFreq)
        --putStrLn "glClearColor"
        glClearColor red 0.3 blue 1
        --putStrLn "glClear"
        glClear (GL_COLOR_BUFFER_BIT .|. GL_DEPTH_BUFFER_BIT)
        -- Render our scene
        --putStrLn "getWinSize"
        V2 w h <- get (SDL.windowSize win)
        let projection = perspective 45 (fromIntegral w / fromIntegral h) 0.01 1000
            model      = mkTransformation (axisAngle (V3 0 1 1) now) (V3 (sin now) 0 (-4))
            view       = lookAt (V3 0 2 5) (V3 0 0 (-4)) (V3 0 1 0)
            mvp        = projection !*! view !*! model

        --putStrLn "renderCube"
        renderCube cube mvp
        --putStrLn "glSwapWindow"
        SDL.glSwapWindow win