using TriInspector;
using UnityEngine;
using UnityEngine.Video;

namespace R0bbie.Timeline
{
    /// <summary>
    /// Video StepCmd type, used to control a video
    /// </summary>
    [AddComponentMenu("Timeline/Commands/Video (Step Command)")]
    [RequireComponent(typeof(Step))]
    public class VideoCmd : StepCmd, IPausable
    {
        // Exposed variables
        
        [Title("Video Settings")]
        [SerializeField] protected VideoPlayer videoPlayer;
        [SerializeField] protected VideoClip clip;
        
        bool eventSubscribed_VideoEndReached;
        
        
        /// <summary>
        /// Initialise command (called before Activate)
        /// </summary>
        protected override void Init()
        {
            init = true;
        }
        
        
        public override void Activate(Step _parentStep)
        {
            base.Activate(_parentStep);
            
            // TODO: Consider what the command itself should control, or pass to an external controller
            // What about looping videos etc? Would you want the command to start a video looping and leave it looping once the command was complete?
            
            // Complete conditions - On video end, on number of loops?

            // Ensure video player component is active, and set clip to the one we want to play
            videoPlayer.gameObject.SetActive(true);
            videoPlayer.clip = clip;
            
            // Listen for event when video reaches end
            videoPlayer.loopPointReached += VideoEndReached;
            eventSubscribed_VideoEndReached = true;
            
            // Play video
            videoPlayer.Play();
            
        }
        
        
        private void VideoEndReached(VideoPlayer _videoPlayer)
        {
            // Unsubscribe from event
            videoPlayer.loopPointReached -= VideoEndReached;
            eventSubscribed_VideoEndReached = false;
            
            // Ensure video stopped
            videoPlayer.Stop();
            
            // Clear clip
            videoPlayer.clip = null;
            
            // Complete command
            Complete();
        }
        
        
        protected override void Cleanup()
        {
            active = false;
        }
        
        
        public void Pause()
        {
            if (!active)
                return;
            
            // Pause video
            videoPlayer.Pause();
        }

        
        public void Resume(float _elapsedTime)
        {
            if (!active)
                return;
            
            // If the time paused is longer than RepeatOnResumeDelay const, then we'll repeat the animation from the start
            if (_elapsedTime >= StepTimeline.RepeatOnResumeDelay && !dontRepeatOnPauseResume)
            {
                RepeatFromStart();
            }
            else
            {
                // Resume video (if currently paused)
                if (videoPlayer.isPaused)
                {
                    videoPlayer.Play();
                }
            }
        }
        
        
        void RepeatFromStart()
        {
            // Ensure we're still subscribed to video end event
            if (!eventSubscribed_VideoEndReached)
            {
                videoPlayer.loopPointReached += VideoEndReached;
                eventSubscribed_VideoEndReached = true;
            }
            
            // Reset video player to start then play
            videoPlayer.frame = 0;
            videoPlayer.Play();
        }
        
        
    }
}