using NUnit.Framework;
using BaseGames.Combat.StatusEffects;

namespace BaseGames.Tests.EditMode
{
    /// <summary>
    /// StatusEffect 系统单元测试（EditMode，纯 C# 类，无需 MonoBehaviour）。
    /// 覆盖：叠加规则、互斥规则、阻断规则、到期检测。
    /// </summary>
    [TestFixture]
    public class StatusEffectTests
    {
        // ── 叠加规则 ─────────────────────────────────────────────────────────

        [Test]
        public void FireEffect_MaxStacks_IsOne()
        {
            var effect = new FireEffect();
            Assert.AreEqual(1, effect.MaxStacks);
        }

        [Test]
        public void PoisonEffect_MaxStacks_IsThree()
        {
            var effect = new PoisonEffect();
            Assert.AreEqual(3, effect.MaxStacks);
        }

        [Test]
        public void PoisonEffect_OnStack_IncreasesStackCount()
        {
            var effect = new PoisonEffect();
            effect.OnStack();
            Assert.AreEqual(2, effect.StackCount);
        }

        [Test]
        public void PoisonEffect_OnStack_ClampsAtMaxStacks()
        {
            var effect = new PoisonEffect();
            for (int i = 0; i < 10; i++) effect.OnStack();
            Assert.AreEqual(effect.MaxStacks, effect.StackCount);
        }

        [Test]
        public void StaggerEffect_MaxStacks_IsOne()
        {
            var effect = new StaggerEffect();
            Assert.AreEqual(1, effect.MaxStacks);
        }

        // ── 互斥规则 ─────────────────────────────────────────────────────────

        [Test]
        public void FireEffect_MutualExclusions_ContainsFreeze()
        {
            var effect = new FireEffect();
            Assert.Contains(StatusEffectType.Freeze, effect.MutualExclusions);
        }

        [Test]
        public void PoisonEffect_MutualExclusions_IsEmpty()
        {
            var effect = new PoisonEffect();
            Assert.IsEmpty(effect.MutualExclusions);
        }

        // ── 阻断规则 ─────────────────────────────────────────────────────────

        [Test]
        public void StaggerEffect_BlockedBy_ContainsStun()
        {
            var effect = new StaggerEffect();
            Assert.Contains(StatusEffectType.Stun, effect.BlockedBy);
        }

        [Test]
        public void FireEffect_BlockedBy_IsEmpty()
        {
            var effect = new FireEffect();
            Assert.IsEmpty(effect.BlockedBy);
        }

        // ── 到期检测 ─────────────────────────────────────────────────────────

        [Test]
        public void StatusEffect_IsExpired_AfterDurationDepleted()
        {
            var effect = new StaggerEffect(0.5f);
            effect.OnApply(null);          // Owner 可为 null，测试纯时间逻辑

            effect.Update(0.3f);
            Assert.IsFalse(effect.IsExpired);

            effect.Update(0.3f);           // 累计 0.6f > 0.5f
            Assert.IsTrue(effect.IsExpired);
        }

        [Test]
        public void FireEffect_OnStack_RefreshDuration()
        {
            var effectA = new FireEffect();
            effectA.OnApply(null);
            float initialDuration = effectA.Duration;

            effectA.Update(1.0f);          // 消耗部分时间
            Assert.Less(effectA.Duration, initialDuration);

            effectA.OnStack();             // 重叠施加，应刷新持续时间
            Assert.AreEqual(initialDuration, effectA.Duration, 0.001f);
        }

        // ── 类型标识 ─────────────────────────────────────────────────────────

        [Test]
        public void FireEffect_EffectType_IsFire()
        {
            Assert.AreEqual(StatusEffectType.Fire, new FireEffect().EffectType);
        }

        [Test]
        public void PoisonEffect_EffectType_IsPoison()
        {
            Assert.AreEqual(StatusEffectType.Poison, new PoisonEffect().EffectType);
        }

        [Test]
        public void StaggerEffect_EffectType_IsStagger()
        {
            Assert.AreEqual(StatusEffectType.Stagger, new StaggerEffect().EffectType);
        }

        // ── 补充测试 ──────────────────────────────────────────────────────────

        [Test]
        public void StatusEffect_StackCount_InitialValueIsOne()
        {
            var effect = new FireEffect();
            Assert.AreEqual(1, effect.StackCount, "新建 Effect 的初始 StackCount 应为 1");
        }

        [Test]
        public void StatusEffect_Update_RemainingTime_Decreases()
        {
            var effect = new StaggerEffect(2.0f);
            effect.OnApply(null);
            float initialDuration = effect.Duration;

            effect.Update(0.5f);

            Assert.Less(effect.Duration, initialDuration, "Update 后剩余时间应减少");
            Assert.IsFalse(effect.IsExpired, "0.5s Update 后 2.0s 效果不应过期");
        }

        [Test]
        public void StatusEffect_Update_ExactExpiry()
        {
            var effect = new StaggerEffect(1.0f);
            effect.OnApply(null);

            effect.Update(1.0f); // 恰好耗尽

            Assert.IsTrue(effect.IsExpired, "恰好耗尽 duration 后应 IsExpired == true");
        }

        [Test]
        public void MultipleEffects_IndependentTimers()
        {
            var fire   = new FireEffect();
            var poison = new PoisonEffect();
            fire.OnApply(null);
            poison.OnApply(null);

            float fireDuration   = fire.Duration;
            float poisonDuration = poison.Duration;

            fire.Update(0.5f);

            // poison 未调用 Update，时间不应变化
            Assert.AreEqual(poisonDuration, poison.Duration, 0.0001f,
                "未 Update 的 Effect 持续时间不应减少");
            Assert.Less(fire.Duration, fireDuration, "已 Update 的 Effect 持续时间应减少");
        }

        [Test]
        public void PoisonEffect_OnStack_DoesNotExceedMaxStacks_EdgeCase()
        {
            var effect = new PoisonEffect();
            // MaxStacks = 3，初始 StackCount = 1，再叠加 2 次达到上限
            effect.OnStack();
            effect.OnStack();
            Assert.AreEqual(3, effect.StackCount);

            // 再叠加，不应超过 3
            effect.OnStack();
            effect.OnStack();
            Assert.AreEqual(3, effect.StackCount, "StackCount 不应超过 MaxStacks");
        }

        [Test]
        public void FireEffect_OnApply_ThenExpire_DoesNotThrow()
        {
            var effect = new FireEffect();
            Assert.DoesNotThrow(() =>
            {
                effect.OnApply(null);
                effect.OnExpire();   // 注意：实际 API 为 OnExpire()，文档中误写为 OnRemove()
            });
        }
    }
}