using System.Collections.Generic;
using System.Linq;
using Continentis.MainGame;
using Continentis.MainGame.Card;
using Continentis.MainGame.Character;
using Continentis.MainGame.Combat;
using Continentis.MainGame.Commands;
using SLSUtilities.General;
using UnityEngine;

namespace Continentis.Mods.Basic.Cards
{
    /// <summary>
    /// 命令术：根据使用者与目标的等级差产生不同效果：
    /// <para>对敌人：等级差达到 High 门槛时随机移除一个意图；达到 Low 门槛时随机改变一个意图。</para>
    /// <para>对玩家英雄：等级差达到 High 门槛时将"扼制"卡牌放入目标抽牌堆；达到 Low 门槛时将"干扰"卡牌放入目标抽牌堆。</para>
    /// </summary>
    public class Command : CardLogicBase
    {
        private const string LEVEL_GAP_LOW  = "LevelGap_Low";
        private const string LEVEL_GAP_HIGH = "LevelGap_High";

        private static readonly Color HintGreen = new Color(0.2f, 0.85f, 0.3f);
        private static readonly Color HintRed   = new Color(0.9f, 0.2f, 0.2f);

        public override void Initialize(CardInstance cardInstance)
        {
            base.Initialize(cardInstance);

            // 战场角色变化时刷新 hintShadow，托管机制自动取消订阅
            CombatEventCollection events = CombatMainManager.Instance.eventCollection;
            SubscribeCombatEvent(events.onCharacterDeath, new PrioritizedAction<CharacterBase>(_ => InvalidateHint()));
            SubscribeCombatEvent(events.onCharacterJoin, new PrioritizedAction<CharacterBase>(_ => InvalidateHint()));
        }

        /// <summary>抽到此牌时刷新 hintShadow。</summary>
        protected override void OnDraw() => InvalidateHint();

        public override CommandGroup PlayEffect(List<CharacterBase> targetList)
        {
            return ForEachTarget(targetList, target => Cmd.Parallel(
                new Cmd_PlayAnimation(user.characterView, "Action"),
                Cmd.Do(() =>
                {
                    if (target is PlayerHero)
                        PlayEffectOnPlayer(target);
                    else
                        PlayEffectOnEnemy(target);
                })
            ));
        }

        /// <summary>
        /// 检查场上是否存在等级差达到 Low 门槛的可用目标。
        /// 有可用目标时返回绿色，无可用目标时返回红色。
        /// </summary>
        public override Color? GetHintColor()
        {
            if (user == null || card.handCardView == null) return null;

            card.DetectTargetsValidity(out List<CharacterBase> valid, out _, out _);
            if (valid.Count == 0) return HintRed;

            int userLevel = user.GetAttribute(CharacterAttributes.Level);
            int gapLow = GetAttribute(LEVEL_GAP_LOW);
            bool hasEffectiveTarget = valid.Any(t =>
                userLevel - t.GetAttribute(CharacterAttributes.Level) >= gapLow);

            return hasEffectiveTarget ? HintGreen : HintRed;
        }

        /// <summary>计算使用者与目标的等级差。</summary>
        private int GetLevelGap(CharacterBase target)
        {
            return user.GetAttribute(CharacterAttributes.Level) - target.GetAttribute(CharacterAttributes.Level);
        }

        /// <summary>对敌方目标：等级差达到 High 时移除意图，达到 Low 时改变意图。</summary>
        private void PlayEffectOnEnemy(CharacterBase target)
        {
            int levelGap = GetLevelGap(target);
            int gapHigh  = GetAttribute(LEVEL_GAP_HIGH);
            int gapLow   = GetAttribute(LEVEL_GAP_LOW);

            if (levelGap >= gapHigh)
                target.intentionSubmodule.RemoveRandomIntendedCard();
            else if (levelGap >= gapLow)
                target.intentionSubmodule.ChangeRandomIntendedCard();
        }

        /// <summary>对玩家英雄：等级差达到 High 时塞入扼制，达到 Low 时塞入干扰。</summary>
        private void PlayEffectOnPlayer(CharacterBase target)
        {
            int levelGap = GetLevelGap(target);
            int gapHigh  = GetAttribute(LEVEL_GAP_HIGH);
            int gapLow   = GetAttribute(LEVEL_GAP_LOW);

            if (levelGap >= gapHigh)
                CardInstance.GenerateCardInstance(GetDerivativeCardData(0), target, Piles.Draw);
            else if (levelGap >= gapLow)
                CardInstance.GenerateCardInstance(GetDerivativeCardData(1), target, Piles.Draw);
        }
    }
}