using UnityEngine;
using UnityEngine.Playables;
using UnityEngine.Timeline;

namespace uc.Timeline
{
    public sealed class MoviePlayerMixer : PlayableBehaviour
    {
        public override void OnBehaviourPlay(Playable playable, FrameData info)
        {
            //Debug.Log("MoviePlayerMixer OnBehaviourPlay");
            base.OnBehaviourPlay(playable, info);
        }

        public override void OnBehaviourPause(Playable playable, FrameData info)
        {
            //Debug.Log("MoviePlayerMixer OnBehaviourPause");
            base.OnBehaviourPlay(playable, info);
        }

        public override void ProcessFrame(Playable playable, FrameData info, object playerData)
        {
            base.ProcessFrame(playable, info, playerData);

            // Get the brain that this track controls.
            // Older versions of timeline sent the gameObject by mistake.
            GameObject go = playerData as GameObject;
            MoviePlayerBase movie = (go == null) ? (MoviePlayerBase)playerData : go.GetComponent<MoviePlayerBase>();
            if (movie == null)
                return;

            //Debug.Log("MoviePlayerMixer ProcessFrame");
            //Debug.Log(movie.gameObject.name);

            bool should_play = false;
            bool should_pause = true;
            double time = -1;

            //Debug.Log("play state: " + playable.GetPlayState());
            //Debug.Log("input states: ");
            for (int i = 0; i < playable.GetInputCount(); ++i)
            {
                Playable playerPlayable = playable.GetInput(i);
                //Debug.Log(playerPlayable.GetPlayState());

                float weight = playable.GetInputWeight(i);
                if (playable.GetPlayState() == PlayState.Playing && weight > 0.0001f)
                {
                    if(playerPlayable.GetPlayState() == PlayState.Playing)
                    {
                        should_play = true;
                        should_pause = false;
                        time = playerPlayable.GetTime();
                        //Debug.Log(time);
                    }
                }

                //Debug.Log(i + " " + playerPlayable.GetPlayState());
            }

            bool should_update_frame = time >= 0;
            should_pause |= info.deltaTime == 0;

            //Debug.Log("");
            //Debug.Log(info.evaluationType);
            //Debug.Log(info.seekOccurred);
            //Debug.Log(info.timeHeld);
            /*
            if (info.evaluationType == FrameData.EvaluationType.Evaluate && should_update_frame)
            {
                should_play = true;
                should_pause = true;
            }
            */

            if (should_play && movie.IsPlaying == false)
            {
                movie.Play();
            }

            if(should_update_frame)
            {
                uint target_frame = (uint)(movie.TotalNumFrames * time / movie.GetDuration);
				int frame_dist = (int)target_frame - (int)movie.Frame;
                if (Mathf.Abs(frame_dist) >= 2)
                {
					movie.Frame = target_frame;
				}
            }

            if(should_pause && movie.IsPaused == false)
            {
                movie.Pause();
            }
        }
    }
}