using System;
using System.Collections.Generic;
using System.Linq;
using Continentis.MainGame.Card;
using Continentis.MainGame.Character;
using DG.Tweening;
using SLSFramework.General;
using UniRx;
using UnityEngine;
using Random = UnityEngine.Random;

namespace Continentis.MainGame.Commands
{
    public class Cmd_UsePowerCards : CommandBase
    {
        private bool isPlayer;
        private readonly DeckSubmodule deck;
        private readonly List<CardInstance> cardsToUse;
        private readonly float interval;
        private readonly float singleCardAnimationDuration = 0.5f; // 单张卡牌的动画时长
        
        public Cmd_UsePowerCards(bool isPlayer, DeckSubmodule deck, List<CardInstance> cards, float interval)
        {
            this.isPlayer = isPlayer;
            this.deck = deck;
            this.cardsToUse = cards;
            this.interval = interval;
        }
        
        protected override IObservable<Unit> OnExecute(CommandContext outerContext)
        {
            if (cardsToUse == null || cardsToUse.Count == 0)
            {
                return Observable.Return(Unit.Default);
            }
            
            Func<CardInstance, IObservable<Unit>> exhaustAction = isPlayer ? PlayerUsePowers : NpcUsePowers;

            // --- 情况1：并行丢弃 (所有卡牌动画同时开始) ---
            if (interval <= 0f)
            {
                // 为每张卡牌创建一个“懒加载”的丢弃动画流。
                var allDiscardAnimations = cardsToUse.Select(card => 
                    Observable.Defer(() => exhaustAction(card))
                );
            
                // 使用 WhenAll 等待所有的并行任务都完成。
                // 只有当最后一个动画结束时，WhenAll 才会发出完成信号。
                return Observable.WhenAll(allDiscardAnimations).AsUnitObservable();
            }
        
            // --- 情况2：交错丢弃 (按固定间隔开始动画) ---
            else
            {
                var cardStream = cardsToUse.ToObservable();
                var timerStream = Observable.Timer(TimeSpan.Zero, TimeSpan.FromSeconds(interval));

                return timerStream
                    .Zip(cardStream, (_, card) => card)
                    // 核心：不再使用 .Do(..).Subscribe()，而是使用 Select 将每个 card 转换为
                    // 其对应的动画流。这样主流程就“知道”了每个动画的存在。
                    .Select(card => exhaustAction(card))
                    // 使用 Merge 将所有交错开始的动画流合并为一个流。
                    // Merge 会同时运行所有这些动画，并在最后一个动画也完成时，它才会完成。
                    .Merge()
                    // 使用 Last 来确保我们只在整个 Merge 流全部结束后，才发出最终的完成信号。
                    .Last()
                    .AsUnitObservable();
            }
        }
        
        
        private IObservable<Unit> PlayerUsePowers(CardInstance card)
        {
            deck.TransferCard(deck.Pile(card.cardLocation.pileName), deck.GravePile, card);
            
            card.handCardView.TransferCardView(CombatUIManager.Instance.combatMainPage.gravePile);
            
            RectTransform cardTransform = card.handCardView.cardTransform;
            Vector2 userViewPosition = card.cardLogic.user.characterView.hudContainer.GetComponent<RectTransform>().position;
            cardTransform.DOMove(userViewPosition, singleCardAnimationDuration).SetEase(Ease.Linear).Play();
            cardTransform.DOScale(Vector3.zero, singleCardAnimationDuration).SetEase(Ease.Linear).OnComplete(() =>
            {
                cardTransform.anchoredPosition = Vector2.zero;
            }).Play();

            return Observable.Timer(TimeSpan.FromSeconds(singleCardAnimationDuration)).AsUnitObservable();
        }

        private IObservable<Unit> NpcUsePowers(CardInstance card)
        {
            deck.TransferCard(deck.Pile(card.cardLocation.pileName), deck.GravePile, card);
            return Observable.Timer(TimeSpan.FromSeconds(singleCardAnimationDuration)).AsUnitObservable();
        }
    }
}