using NUnit.Framework;
using BaseGames.AI;
using BaseGames.Enemies;

namespace BaseGames.Tests.EditMode.AI
{
    public class RushEngagementTests
    {
        const string Rest = "Rest";

        // 单独跑交战模块：手搓一个最小 rest 态，直接以交战入口为图入口。
        static AiRuntime RunAlone(RushEngagement m, FakeAiContext ctx)
        {
            var b = new BrainBuilder();
            AiStateFragments.Locomotion(b, Rest, LocomotionMode.Patrol);
            m.Build(b, Rest);
            b.Entry(m.EntryState);
            return new AiRuntime(b.Build(), ctx);
        }

        [Test]
        public void OnLostTarget_CanEngage_IsChaseZoneOnly()
        {
            var m = new RushEngagement("rush", RushExit.OnLostTarget);
            var ctx = new FakeAiContext();
            ctx.C.CanUse = false;          // 冷却中
            ctx.S.Chase = true;
            Assert.IsTrue(m.CanEngage(ctx));   // 不看冷却
            Assert.AreEqual("InChaseZone", m.EngageLabel);
        }

        [Test]
        public void Committed_CanEngage_AlsoRequiresOffCooldown()
        {
            var m = new RushEngagement("rush", RushExit.Committed);
            var ctx = new FakeAiContext();
            ctx.S.Chase = true;
            ctx.C.CanUse = false;
            Assert.IsFalse(m.CanEngage(ctx));  // CD 中不进
            ctx.C.CanUse = true;
            Assert.IsTrue(m.CanEngage(ctx));
            Assert.AreEqual("InChaseZone+offCD", m.EngageLabel);
        }

        [Test]
        public void OnLostTarget_ExitsWhenAllZonesLost()
        {
            var ctx = new FakeAiContext { };
            ctx.S.Chase = true;
            var rt = RunAlone(new RushEngagement("rush", RushExit.OnLostTarget), ctx);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName);
            rt.Tick(0.1f);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName);  // 还在追逐区
            ctx.S.Chase = false; ctx.S.Vision = false;
            rt.Tick(0.1f);
            Assert.AreEqual(Rest, rt.CurrentStateName);
        }

        [Test]
        public void Committed_NotInterruptedByLosingTarget()
        {
            var ctx = new FakeAiContext();
            ctx.S.Chase = true;
            var rt = RunAlone(new RushEngagement("rush", RushExit.Committed), ctx);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName);
            ctx.S.Chase = false; ctx.S.Vision = false;   // 中途丢失感知
            rt.Tick(0.1f);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName); // 冲锋不被打断
            ctx.C.Running = null;                         // 冲锋跑完
            rt.Tick(0.1f);
            Assert.AreEqual(Rest, rt.CurrentStateName);
        }

        [Test]
        public void Build_Throws_WhenAbilityMissing()
        {
            var b = new BrainBuilder();
            AiStateFragments.Locomotion(b, Rest, LocomotionMode.Patrol);
            var m = new RushEngagement();     // 未配能力
            Assert.Throws<System.InvalidOperationException>(() => m.Build(b, Rest));
        }

        [Test]
        public void Committed_CooldownGate_BreaksRushRestThrashLoop()
        {
            // Committed 存在的全部理由：冲锋打完回未发现态后，若进入条件不带冷却门，
            // 下一帧仍在追逐区就会立刻再冲，形成 Rush↔Rest 每帧抖动。
            // 本用例补上骨架会挂的那条进入边，跑完整循环。
            var m = new RushEngagement("rush", RushExit.Committed);
            var ctx = new FakeAiContext();
            var b = new BrainBuilder();
            AiStateFragments.Locomotion(b, Rest, LocomotionMode.Patrol)
                .To(m.EntryState).When(m.CanEngage, m.EngageLabel);   // 骨架的升级边
            m.Build(b, Rest);
            b.Entry(Rest);
            var rt = new AiRuntime(b.Build(), ctx);

            ctx.S.Chase = true;                       // 进追逐区且冷却就绪
            rt.Tick(0.1f);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName);

            ctx.C.Running = null;                     // 冲锋跑完
            ctx.C.CanUse  = false;                    // 能力进入冷却
            rt.Tick(0.1f);
            Assert.AreEqual(Rest, rt.CurrentStateName);

            // 关键断言：仍在追逐区、但冷却未好 → 不得再冲（否则就是每帧抖动）
            rt.Tick(0.1f);
            rt.Tick(0.1f);
            Assert.AreEqual(Rest, rt.CurrentStateName);

            ctx.C.CanUse = true;                      // 冷却结束，仍在追逐区
            rt.Tick(0.1f);
            Assert.AreEqual(RushEngagement.Rush, rt.CurrentStateName);
        }
    }
}