using System;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Assertions;

public partial class GamePlayBuffCoolTimeView : View
{
    [SerializeField] SlotUI[] slots;

    int activeBuffCount = 0;

    private void Start()
    {
        for(int i = 0; i < slots.Length; ++i)
        {
            slots[i].SetBuffData(null);
        }

        Show();
    }

    private void Update()
    {
        for(int i = 0; i < activeBuffCount; i++)
        {
            var slot = slots[i];
            if (slot.buffData is null) continue;

            slot.Update();

            if (slot.buffData.RemainTime <= 0)
            {
                for(int j = i; j < activeBuffCount - 1; j++)
                {
                    BuffData tmp;
                    tmp = slots[j].buffData;
                    slots[j].SetBuffData(slots[j + 1].buffData);
                    slots[j + 1].SetBuffData(tmp);
                }

                activeBuffCount--;
                slots[activeBuffCount].SetBuffData(null);
                i--;
            }
        }
    }

    public override void Show()
    {
        GamePlayBuffMgr.Instance.BuffGroup.OnChanged += RefreshBuffList;

        viewState = ViewState.Shown;
        gameObject.SetActive(true);
    }

    public override void Hide()
    {
        gameObject.SetActive(false);
        viewState = ViewState.Hidden;

        GamePlayBuffMgr.Instance.BuffGroup.OnChanged -= RefreshBuffList;
    }

    public void RefreshBuffList(BuffData buffData, bool added)
    {
        if(added)
        {
            Debug.Assert(activeBuffCount + 1 < slots.Length, "Buff count exid slot count");
            activeBuffCount++;
            slots[activeBuffCount - 1].SetBuffData(buffData);
        }
        else
        {
            for(int i = 0; i < activeBuffCount; i++)
            {
                if (slots[i].buffData == buffData)
                {
                    for(int j = i; j < activeBuffCount - 1; j++)
                    {
                        BuffData tmp;
                        tmp = slots[j].buffData;
                        slots[j].SetBuffData(slots[j + 1].buffData);
                        slots[j + 1].SetBuffData(tmp);
                    }

                    activeBuffCount--;
                    slots[activeBuffCount].SetBuffData(null);
                    break;
                }
            }
        }
    }
}

public partial class GamePlayBuffCoolTimeView : View
{
    [Serializable]
    struct SlotUI
    {
        public GameObject root;
        public ExtendImage backGroundImage;
        public ExtendImage buffImage;
        public Image remainTimeFillImg;
        public BuffData buffData { get; private set; }

        public void SetBuffData(BuffData buffData)
        {
            this.buffData = buffData;

            if(buffData is null)
            {
                root.SetActive(false);
            }
            else
            {
                root.SetActive(true);

                //TODO: Set buff image
            }
        }

        public void Update()
        {
            if (remainTimeFillImg is null) return;

            float fillRate = 0f;
            if(!buffData.IsInfiniteDuration)
                fillRate = buffData.ElapsedDuration / buffData.Duration;

            remainTimeFillImg.fillAmount = fillRate;
        }
    }
}