using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace RimWorldAnimationStudio
{
    public class KeyframeSlider : Slider, IPointerClickHandler, IBeginDragHandler, IEndDragHandler
    {
        public AnimationTimeline timeline;
        public Transform ghostSliders;
        public Slider ghostSliderPrefab;
        public int maxGhosts = 4;

        public int actorID;
        public int keyframeID;

        private PawnAnimationClip clip;
        private PawnKeyframe keyframe;

        public void Initialize(AnimationTimeline timeline, int actorID,  int keyframeID)
        {
            this.timeline = timeline;
            this.clip = Workspace.Instance.GetPawnAnimationClip(actorID);
            this.keyframe = Workspace.Instance.GetPawnKeyframe(actorID, keyframeID);

            this.actorID = actorID;
            this.keyframeID = keyframeID;

            PawnKeyframe keyframe = Workspace.Instance.GetPawnKeyframe(actorID, keyframeID);
            maxValue = Workspace.StageWindowSize;
            value = keyframe.atTick.Value;
           
            OnValueChanged();

            onValueChanged.AddListener(delegate (float value) { OnValueChanged(); });
        }

        public void OnValueChanged()
        {
            keyframe.atTick = (int)value;

            UpdateGhostFrames();

            clip.BuildSimpleCurves();

            AnimationController.Instance.stageTick = keyframe.atTick.Value;
        }  

        // Ghost sliders are non-interactable slider handle
        public void UpdateGhostFrames()
        {
            if (maxGhosts == 0)
            { return; }

            int nGhosts = GetGhostFramesRequired();

            for (int i = 0; i < Mathf.Max(nGhosts, ghostSliders.childCount); i++)
            {
                if ((i - 1) * clip.duration + keyframe.atTick <= Workspace.StageWindowSize)
                {
                    if (ghostSliders.childCount <= i)
                    { Instantiate(ghostSliderPrefab, ghostSliders); }

                    GameObject ghostSliderObject = ghostSliders.GetChild(i).gameObject;
                    Debug.Log(ghostSliderObject);
                    ghostSliderObject.SetActive(true);

                    Slider ghostSlider = ghostSliderObject.GetComponent<Slider>();
                    Debug.Log(ghostSlider);
                    ghostSlider.value = (int)((i + 1) * clip.duration + keyframe.atTick);

                    float mult = 1f - Mathf.Pow((float)i / maxGhosts, 2);
                    ghostSlider.transform.FindDeepChild("Handle").GetComponent<Image>().color = new Color(0, 0.5f, 0.5f, 0.5f * mult);
                }

                if (i >= nGhosts)
                { transform.GetChild(i).gameObject.SetActive(false); }
            }
        }

        public int GetGhostFramesRequired()
        {
            if (Workspace.animationDef.animationStages[Workspace.stageID].isLooping == false)
            { return 0; }

            if (clip.duration <= 1)
            { return 0; }

            return Math.Min(Mathf.CeilToInt((float)Workspace.StageWindowSize / clip.duration), maxGhosts);
        }

        public void OnPointerClick(PointerEventData eventData)
        {
            Activate();
        }

        public void OnBeginDrag(PointerEventData eventData)
        {
            Activate();

            if (keyframe.atTick == 1)
            { return; }

            interactable = true;
        }

        public override void OnDrag(PointerEventData eventData)
        {
            base.OnDrag(eventData);

            Activate();
        }

        public void OnEndDrag(PointerEventData eventData)
        {
            interactable = false;
        }

        public void Activate()
        {
            AnimationController.Instance.stageTick = keyframe.atTick.Value;

            Workspace.keyframeID = keyframeID;

            foreach (AnimationTimeline _timeline in AnimationController.Instance.animationTimelines.GetComponentsInChildren<AnimationTimeline>())
            {
                foreach (KeyframeSlider keyframeSlider in _timeline.GetComponentsInChildren<KeyframeSlider>())
                {
                    if (keyframeSlider.keyframe.atTick.Value == keyframe.atTick.Value)
                    { keyframeSlider.transform.FindDeepChild("Handle").GetComponent<Image>().color = new Color(0f, 1f, 0f); }

                    else
                    { keyframeSlider.transform.FindDeepChild("Handle").GetComponent<Image>().color = new Color(1f, 1f, 1f); }
                }
            }
        }
    }
}