using System.Collections.Generic;
using UnityEngine;
using NUnit.Framework;
using BaseGames.AI;
using BaseGames.Enemies;

namespace BaseGames.Tests.EditMode.AI
{
    /// <summary>
    /// PerceptionStateMachine 全感知↔状态矩阵测试（spec《敌人感知↔状态》）：
    /// 待机/巡逻(未发现) → 追击(优先)/警觉(次)；警觉 → 追击/降级R/保持；
    /// 追击 → 脱离全部感知才降级R(永不回警觉)；死亡=全局事件。
    /// 覆盖 HasAlert 分支、locomotion 意图、追击能力触发/中断、de-escalation。
    /// </summary>
    public class PerceptionStateMachineTests
    {
        // 实现 IAiContext + IEnemyActor(HasAlertState 可配)，复用 FakeAiContext.cs 的子 fake。
        sealed class Ctx : IAiContext, IEnemyActor
        {
            public FakeSensor S = new FakeSensor();
            public FakeLocomotion L = new FakeLocomotion();
            public FakeCombat C = new FakeCombat();
            public FakeVitals V = new FakeVitals();
            public Blackboard BB = new Blackboard();
            public bool HasAlert = true;

            public ISensor Sensor => S;
            public IEnemyLocomotion Locomotion => L;
            public ICombatant Combat => C;
            public IActorVitals Vitals => V;
            public Blackboard Blackboard => BB;
            public bool HasAlertState => HasAlert;
        }

        static AiGraph Graph(string entry = "Idle")
        {
            var b = new BrainBuilder();
            PerceptionStateMachine.Add(b, new PerceptionStateMachine.Config
            {
                Idle = "Idle", Patrol = "Patrol", Alert = "Alert", Chase = "Chase", Death = "Death",
                Entry = entry, Rest = "Patrol",
                IdleMode = LocomotionMode.Idle,
                PatrolMode = LocomotionMode.Patrol,
                AlertMode = LocomotionMode.Face,
                ChaseAbilityId = "chase",
            });
            return b.Build();
        }

        // PatrolBetweenChases 变体：冲刺打完→巡逻(CD)，冷却结束仍在追逐区→再冲刺。
        static AiGraph GraphCD()
        {
            var b = new BrainBuilder();
            PerceptionStateMachine.Add(b, new PerceptionStateMachine.Config
            {
                Idle = "Idle", Patrol = "Patrol", Alert = "Alert", Chase = "Chase", Death = "Death",
                Entry = "Idle", Rest = "Patrol",
                IdleMode = LocomotionMode.Idle, PatrolMode = LocomotionMode.Patrol, AlertMode = LocomotionMode.Face,
                ChaseAbilityId = "chase",
                PatrolBetweenChases = true,
            });
            return b.Build();
        }

        // ── 入口 / 待机 ───────────────────────────────────────────────────

        [Test]
        public void Entry_IsIdle_WithIdleLocomotion()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph(), ctx);
            Assert.AreEqual("Idle", rt.CurrentStateName);
            Assert.AreEqual(LocomotionMode.Idle, ctx.L.CurrentMode);
        }

        [Test]
        public void Idle_Stays_WhenNoPerception()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph(), ctx);
            rt.Tick(0.1f);
            Assert.AreEqual("Idle", rt.CurrentStateName);
        }

        [Test]
        public void Idle_ToChase_WhenInChaseZone()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph(), ctx);
            ctx.S.Chase = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void Idle_ToAlert_WhenInVision_AndHasAlert()
        {
            var ctx = new Ctx { HasAlert = true };
            var rt = new AiRuntime(Graph(), ctx);
            ctx.S.Vision = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Alert", rt.CurrentStateName);
        }

        [Test]
        public void Idle_StaysIdle_WhenInVision_ButNoAlertState()
        {
            var ctx = new Ctx { HasAlert = false }; // 无警觉态 → 不进警觉
            var rt = new AiRuntime(Graph(), ctx);
            ctx.S.Vision = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Idle", rt.CurrentStateName);
        }

        [Test]
        public void Idle_ChaseBeatsAlert_WhenBothZones()
        {
            var ctx = new Ctx { HasAlert = true };
            var rt = new AiRuntime(Graph(), ctx);
            ctx.S.Chase = true; ctx.S.Vision = true; // 两者都满足 → 追击优先
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        // ── 巡逻（entry=Patrol）：与待机同规则 ─────────────────────────────

        [Test]
        public void Patrol_ToChase_WhenInChaseZone()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph("Patrol"), ctx);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
            Assert.AreEqual(LocomotionMode.Patrol, ctx.L.CurrentMode);
            ctx.S.Chase = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void Patrol_ToAlert_WhenInVision_AndHasAlert()
        {
            var ctx = new Ctx { HasAlert = true };
            var rt = new AiRuntime(Graph("Patrol"), ctx);
            ctx.S.Vision = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Alert", rt.CurrentStateName);
        }

        // ── 警觉 ──────────────────────────────────────────────────────────

        Ctx InAlert(out AiRuntime rt)
        {
            var ctx = new Ctx { HasAlert = true };
            rt = new AiRuntime(Graph(), ctx);
            ctx.S.Vision = true;          // Idle → Alert
            rt.Tick(0.1f);
            Assert.AreEqual("Alert", rt.CurrentStateName);
            return ctx;
        }

        [Test]
        public void Alert_AppliesFaceLocomotion()
        {
            var ctx = InAlert(out var rt);
            Assert.AreEqual(LocomotionMode.Face, ctx.L.CurrentMode);
            CollectionAssert.Contains(ctx.L.Calls, "Face");
        }

        [Test]
        public void Alert_ToChase_WhenInChaseZone()
        {
            var ctx = InAlert(out var rt);
            ctx.S.Chase = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void Alert_ToRest_WhenLeftVision()
        {
            var ctx = InAlert(out var rt);
            ctx.S.Vision = false;         // 脱离视野 → 降级 R(=Patrol)
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }

        [Test]
        public void Alert_Stays_WhenStillInVision()
        {
            var ctx = InAlert(out var rt);
            ctx.S.Vision = true; ctx.S.Chase = false;
            rt.Tick(0.1f);
            Assert.AreEqual("Alert", rt.CurrentStateName);
        }

        // ── 追击 ──────────────────────────────────────────────────────────

        Ctx InChase(out AiRuntime rt)
        {
            var ctx = new Ctx();
            rt = new AiRuntime(Graph(), ctx);
            ctx.S.Chase = true;           // Idle → Chase
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
            return ctx;
        }

        [Test]
        public void Chase_TriggersAbility_NotLocomotion()
        {
            var ctx = InChase(out var rt);
            CollectionAssert.Contains(ctx.C.Used, "chase"); // 触发追击能力
            // 进 Chase 后不应再有 locomotion 意图声明（追击移动归能力）
            int lastStop = ctx.L.Calls.FindLastIndex(s => s == "Stop");
            var afterEnter = ctx.L.Calls.GetRange(lastStop + 1, ctx.L.Calls.Count - lastStop - 1);
            CollectionAssert.IsEmpty(afterEnter);
        }

        [Test]
        public void Chase_ToRest_WhenLeftAllZones()
        {
            var ctx = InChase(out var rt);
            ctx.S.Chase = false; ctx.S.Vision = false; // 追逐区且视野区都不在 → R
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }

        [Test]
        public void Chase_Stays_WhenInChaseZoneOnly()
        {
            var ctx = InChase(out var rt);
            ctx.S.Chase = true; ctx.S.Vision = false; // 视野被墙挡漏检，但仍在追逐区
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void Chase_Stays_WhenInVisionZoneOnly()
        {
            var ctx = InChase(out var rt);
            ctx.S.Chase = false; ctx.S.Vision = true; // 出追逐区但仍在视野 → 不降级
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void Chase_NeverGoesToAlert()
        {
            // 追击中即便"在视野且有警觉态"，也绝不回警觉——只在脱离全部感知时降级 R。
            var ctx = InChase(out var rt);
            ctx.HasAlert = true;
            ctx.S.Chase = false; ctx.S.Vision = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName); // 不是 Alert
            Assert.AreNotEqual("Alert", rt.CurrentStateName);
        }

        [Test]
        public void Chase_OnExit_InterruptsAbility()
        {
            var ctx = InChase(out var rt);
            Assert.AreEqual("chase", ctx.C.Running); // 追击能力运行中
            ctx.S.Chase = false; ctx.S.Vision = false;
            rt.Tick(0.1f);                            // Chase → R，OnExit 中断能力
            Assert.IsNull(ctx.C.Running);
        }

        [Test]
        public void RestIsPatrol_AfterChaseDeescalation()
        {
            var ctx = InChase(out var rt);
            ctx.S.Chase = false; ctx.S.Vision = false;
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);            // R = Patrol
            Assert.AreEqual(LocomotionMode.Patrol, ctx.L.CurrentMode); // 落地即巡逻移动意图
        }

        // ── ApproachAttack 交战风格 ───────────────────────────────────────
        static AiGraph GraphApproach(string entry = "Idle")
        {
            var b = new BrainBuilder();
            PerceptionStateMachine.Add(b, new PerceptionStateMachine.Config
            {
                Idle = "Idle", Patrol = "Patrol", Alert = "Alert", Death = "Death",
                Entry = entry, Rest = "Patrol",
                IdleMode = LocomotionMode.Idle, PatrolMode = LocomotionMode.Patrol, AlertMode = LocomotionMode.Face,
                Engagement = PerceptionStateMachine.EngagementStyle.ApproachAttack,
                ApproachState = "Approach", AttackState = "Attack",
            });
            return b.Build();
        }

        [Test]
        public void Approach_EnteredFromChaseZone_UsesPursue()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Approach", rt.CurrentStateName);
            CollectionAssert.Contains(ctx.L.Calls, "Pursue");
        }

        [Test]
        public void Approach_ToAttack_WhenEligibleAttack()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);
            ctx.C.Eligible = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Attack", rt.CurrentStateName);
            CollectionAssert.Contains(ctx.C.Used, "best");
        }

        [Test]
        public void Attack_StopsLocomotion_OnEnter()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);
            ctx.C.Eligible = true; rt.Tick(0.1f);
            CollectionAssert.Contains(ctx.L.Calls, "Stop");
        }

        [Test]
        public void Attack_ToApproach_WhenAttackDone()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);
            ctx.C.Eligible = true; rt.Tick(0.1f);
            Assert.AreEqual("Attack", rt.CurrentStateName);
            ctx.C.Running = null;
            rt.Tick(0.1f);
            Assert.AreEqual("Approach", rt.CurrentStateName);
        }

        [Test]
        public void Approach_ToRest_WhenLeftAllZones()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);
            ctx.S.Chase = false; ctx.S.Vision = false;
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }

        [Test]
        public void ApproachAttack_Death_IsGlobal()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);
            rt.Send(AiSignal.Died); rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
        }

        // 进 Attack 后玩家脱离全部感知区：攻击仍在跑 → 不回 Approach，改判 leftAllZones → Rest(Patrol)。
        [Test]
        public void Attack_ToRest_WhenLeftAllZones()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);          // → Approach
            ctx.C.Eligible = true; rt.Tick(0.1f);       // → Attack, Running="best"
            Assert.AreEqual("Attack", rt.CurrentStateName);
            ctx.S.Chase = false; ctx.S.Vision = false;  // 攻击仍 running，但脱离全部感知
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }

        // 死亡是全局事件，从 Attack 态也能达 Death。
        [Test]
        public void ApproachAttack_Death_FromAttack()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(GraphApproach(), ctx);
            ctx.S.Chase = true; rt.Tick(0.1f);          // → Approach
            ctx.C.Eligible = true; rt.Tick(0.1f);       // → Attack
            Assert.AreEqual("Attack", rt.CurrentStateName);
            rt.Send(AiSignal.Died); rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
        }

        // ── 死亡（全局事件，任意态可达）───────────────────────────────────

        [Test]
        public void Death_OnDiedSignal_FromIdle()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph(), ctx);
            rt.Send(AiSignal.Died);
            rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
        }

        [Test]
        public void Death_OnDiedSignal_FromChase()
        {
            var ctx = InChase(out var rt);
            rt.Send(AiSignal.Died);
            rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
        }

        [Test]
        public void Death_IsTerminal_NoTransitionOut()
        {
            var ctx = new Ctx();
            var rt = new AiRuntime(Graph(), ctx);
            rt.Send(AiSignal.Died); rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
            ctx.S.Chase = true; ctx.S.Vision = true; // 即便重新满足感知也不复活
            rt.Tick(0.1f);
            Assert.AreEqual("Death", rt.CurrentStateName);
        }

        // ── PatrolBetweenChases（CD 期巡逻）───────────────────────────────

        // 驱动到 Chase 后模拟冲刺进行中(能力 running)。
        Ctx InCD_Chase(out AiRuntime rt)
        {
            var ctx = new Ctx();
            rt = new AiRuntime(GraphCD(), ctx);
            ctx.S.Chase = true; ctx.C.CanUse = true;
            rt.Tick(0.1f);                       // Idle → Chase，OnEnter 触发冲刺(Running="chase")
            Assert.AreEqual("Chase", rt.CurrentStateName);
            Assert.AreEqual("chase", ctx.C.Running);
            return ctx;
        }

        [Test]
        public void CD_Chase_Stays_WhileDashRunning()
        {
            var ctx = InCD_Chase(out var rt);
            ctx.S.Chase = false; ctx.S.Vision = false; // 冲刺是 committed 冲锋：感知丢失也不中途打断
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);
        }

        [Test]
        public void CD_Chase_ToPatrol_WhenDashDone()
        {
            var ctx = InCD_Chase(out var rt);
            ctx.C.Running = null; ctx.C.CanUse = false; // 冲刺打完，进入冷却
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName); // 冲完→CD 期巡逻
        }

        [Test]
        public void CD_Patrol_Stays_DuringCooldown_NoOscillation()
        {
            var ctx = InCD_Chase(out var rt);
            ctx.C.Running = null; ctx.C.CanUse = false;
            rt.Tick(0.1f);                        // → Patrol
            Assert.AreEqual("Patrol", rt.CurrentStateName);
            // CD 中仍在追逐区：不能回追击，多帧保持巡逻(不抖)
            ctx.S.Chase = true; ctx.C.CanUse = false;
            for (int i = 0; i < 5; i++) rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }

        [Test]
        public void CD_Patrol_ToChase_WhenCooldownEnds_AndStillInChaseZone()
        {
            var ctx = InCD_Chase(out var rt);
            ctx.C.Running = null; ctx.C.CanUse = false;
            rt.Tick(0.1f);                        // → Patrol
            ctx.S.Chase = true; ctx.C.CanUse = true; // 冷却结束 + 仍在追逐区
            rt.Tick(0.1f);
            Assert.AreEqual("Chase", rt.CurrentStateName);   // 再次冲刺
            Assert.AreEqual("chase", ctx.C.Running);
        }

        [Test]
        public void CD_Patrol_StaysHome_WhenPlayerLost()
        {
            var ctx = InCD_Chase(out var rt);
            ctx.C.Running = null; ctx.C.CanUse = false;
            rt.Tick(0.1f);                        // → Patrol
            // 玩家丢失(脱离追逐区)：即便冷却结束也不回追击，留在巡逻(降级回家)
            ctx.S.Chase = false; ctx.S.Vision = false; ctx.C.CanUse = true;
            rt.Tick(0.1f);
            Assert.AreEqual("Patrol", rt.CurrentStateName);
        }
    }
}