using System.Collections;
using System.Collections.Generic;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.TestTools;

namespace TKS.Tests
{
    /// <summary>병종 4종 규칙·턴 흐름·승리 판정을 실제 씬에서 검증한다(헤드리스 실행 가능).</summary>
    public class BattleFlowTests
    {
        BattleManager bm;
        BalanceConfig cfg;

        [UnitySetUp]
        public IEnumerator SetUp()
        {
            SceneManager.LoadScene("Battle");
            yield return null;
            yield return null;
            bm = BattleManager.Instance;
            Assert.IsNotNull(bm, "GameBootstrap 이 BattleManager 를 만들어야 한다");
            cfg = bm.Config;
            Time.timeScale = 20f;
        }

        [UnityTearDown]
        public IEnumerator TearDown()
        {
            Time.timeScale = 1f;
            yield return null;
        }

        IEnumerator Fresh()
        {
            bm.StopAllCoroutines();
            bm.ClearUnits();
            bm.ForcePhase(BattlePhase.PlayerTurn);
            yield return null; // 파괴된 콜라이더가 물리 월드에서 빠질 시간
        }

        [UnityTest]
        public IEnumerator Bootstrap_SpawnsHeroesAndStageEnemies()
        {
            Assert.AreEqual(BattlePhase.PlayerTurn, bm.Phase);
            Assert.AreEqual(Mathf.Min(5, cfg.heroes.Length), bm.AliveCount(Faction.Player));
            Assert.AreEqual(cfg.stages[0].enemies.Count, bm.AliveCount(Faction.Enemy));
            yield return null;
        }

        [Test]
        public void Matchup_TriangleAndArcherWeakness()
        {
            var c = cfg != null ? cfg : Resources.Load<BalanceConfig>("BalanceConfig");
            Assert.Greater(c.Matchup(UnitType.Infantry, UnitType.Spear), 1f);
            Assert.Greater(c.Matchup(UnitType.Spear, UnitType.Cavalry), 1f);
            Assert.Greater(c.Matchup(UnitType.Cavalry, UnitType.Infantry), 1f);
            Assert.Less(c.Matchup(UnitType.Spear, UnitType.Infantry), 1f);
            Assert.Less(c.Matchup(UnitType.Cavalry, UnitType.Spear), 1f);
            Assert.Less(c.Matchup(UnitType.Infantry, UnitType.Cavalry), 1f);
            Assert.Greater(c.Matchup(UnitType.Infantry, UnitType.Archer), 1f);
            Assert.Greater(c.Matchup(UnitType.Cavalry, UnitType.Archer), 1f);
            Assert.Greater(c.Matchup(UnitType.Spear, UnitType.Archer), 1f);
        }

        [UnityTest]
        public IEnumerator Infantry_AttacksFirstEnemyOnPath_BonusMoveOnFinalHit()
        {
            yield return Fresh();
            var inf = bm.SpawnUnit(UnitType.Infantry, Faction.Player, new Vector2(0f, -3f), "보병");
            var foe = bm.SpawnUnit(UnitType.Spear, Faction.Enemy, new Vector2(0f, 0f), "적창병");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(inf, foe.Position, false, o);

            Assert.Contains(foe, o.Attacked);
            Assert.Less(foe.Hp, foe.MaxHp, "경로 위 첫 적을 공격");
            Assert.IsTrue(o.BonusMove, "최종 목표점 명중 → 추가 이동");
            Assert.Less(Vector2.Distance(inf.Position, foe.Position), inf.Radius + foe.Radius + 0.2f, "적에 닿는 지점까지 이동");
            Assert.Less(inf.Hp, inf.MaxHp, "근접 공격은 반격 피해를 받는다");

            int foeHp = foe.Hp;
            var o2 = new ActionOutcome();
            yield return bm.ResolveForTest(inf, inf.Position + new Vector2(2.5f, 0f), true, o2);
            Assert.AreEqual(0, o2.Attacked.Count, "추가 이동은 이동만");
            Assert.AreEqual(foeHp, foe.Hp);
            Assert.IsTrue(o2.MovedOnly);
        }

        [UnityTest]
        public IEnumerator Infantry_NoBonus_WhenTargetBeyondEnemy()
        {
            yield return Fresh();
            var inf = bm.SpawnUnit(UnitType.Infantry, Faction.Player, new Vector2(0f, -3f), "보병");
            var foe = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 0f), "적보병");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(inf, new Vector2(0f, 1.4f), false, o);
            Assert.Contains(foe, o.Attacked);
            Assert.IsFalse(o.BonusMove);
        }

        [UnityTest]
        public IEnumerator Cavalry_PiercesAllOnPath_AndReturnsOnFinalHit()
        {
            yield return Fresh();
            var cav = bm.SpawnUnit(UnitType.Cavalry, Faction.Player, new Vector2(0f, -4f), "기병");
            var e1 = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, -1.5f), "적1");
            var e2 = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 1f), "적2");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(cav, e2.Position, false, o);
            Assert.Less(e1.Hp, e1.MaxHp, "경로 위 첫 적 관통 피해");
            Assert.Less(e2.Hp, e2.MaxHp, "경로 위 둘째 적 관통 피해");
            Assert.IsTrue(o.Returned, "최종 목표점 명중 → 제자리 복귀");
            Assert.Less(Vector2.Distance(cav.Position, new Vector2(0f, -4f)), 0.05f);
        }

        [UnityTest]
        public IEnumerator Cavalry_StaysAtEnd_WithoutFinalHit()
        {
            yield return Fresh();
            var cav = bm.SpawnUnit(UnitType.Cavalry, Faction.Player, new Vector2(0f, -4f), "기병");
            var e1 = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, -1f), "적1");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(cav, new Vector2(0f, 2f), false, o);
            Assert.Less(e1.Hp, e1.MaxHp);
            Assert.IsFalse(o.Returned);
            Assert.Greater(cav.Position.y, 1.5f, "목표점까지 이동");
            Assert.GreaterOrEqual(Vector2.Distance(cav.Position, e1.Position), cav.Radius + e1.Radius - 0.05f, "적과 겹치지 않음");
        }

        [UnityTest]
        public IEnumerator Archer_MovesIntoRange_ShootsWithoutCounter()
        {
            yield return Fresh();
            var arc = bm.SpawnUnit(UnitType.Archer, Faction.Player, new Vector2(0f, -5f), "궁병");
            var foe = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 0f), "적보병");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(arc, new Vector2(0f, -1f), false, o);
            Assert.Contains(foe, o.Attacked, "목표 방향의 적을 사거리까지 이동 후 사격");
            Assert.Less(foe.Hp, foe.MaxHp);
            Assert.AreEqual(arc.MaxHp, arc.Hp, "궁병은 반격을 받지 않는다");
            Assert.LessOrEqual(Vector2.Distance(arc.Position, foe.Position), arc.AttackRange + 0.1f);
            Assert.IsFalse(o.Crit);
        }

        [UnityTest]
        public IEnumerator Archer_CritOnFinalHit()
        {
            yield return Fresh();
            var arc = bm.SpawnUnit(UnitType.Archer, Faction.Player, new Vector2(0f, -3f), "궁병");
            var foe = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 0f), "적보병");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(arc, foe.Position, false, o);
            Assert.Contains(foe, o.Attacked);
            Assert.IsTrue(o.Crit, "최종 목표점 명중 → 크리티컬");
            Assert.AreEqual(arc.MaxHp, arc.Hp);
        }

        [UnityTest]
        public IEnumerator Spear_OverwatchOnFinalHit_DamagesMovingEnemy()
        {
            yield return Fresh();
            var spear = bm.SpawnUnit(UnitType.Spear, Faction.Player, new Vector2(0f, -3f), "창병");
            var foe = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 0f), "적보병");
            var o = new ActionOutcome();
            yield return bm.ResolveForTest(spear, foe.Position, false, o);
            Assert.IsTrue(o.Overwatch && spear.Overwatch, "최종 목표점 명중 → 대기(견제)");

            int hp = foe.Hp;
            var path = new List<Vector2> { foe.Position, foe.Position + new Vector2(1.5f, 0f) };
            yield return bm.ApplyOverwatch(foe, path);
            Assert.Less(foe.Hp, hp, "반경 안에서 움직인 적에게 피해");

            // 반경 밖에서만 움직인 적은 피해 없음
            var far = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(5f, 6f), "먼적");
            int farHp = far.Hp;
            yield return bm.ApplyOverwatch(far, new List<Vector2> { far.Position, far.Position + new Vector2(-1f, 0f) });
            Assert.AreEqual(farHp, far.Hp);
        }

        [UnityTest]
        public IEnumerator EnemyTurn_RunsAndReturnsToPlayerTurn()
        {
            yield return Fresh();
            var p = bm.SpawnUnit(UnitType.Infantry, Faction.Player, new Vector2(0f, -3f), "아군");
            var e = bm.SpawnUnit(UnitType.Infantry, Faction.Enemy, new Vector2(0f, 3f), "적군");
            p.MarkActed();
            int turn = bm.TurnNumber;
            yield return bm.RunEnemyTurn();
            Assert.AreEqual(BattlePhase.PlayerTurn, bm.Phase);
            Assert.AreEqual(turn + 1, bm.TurnNumber);
            Assert.IsFalse(p.ActedThisTurn, "새 턴에 행동 플래그 초기화");
            Assert.IsTrue(e.Position.y < 2.9f || p.Hp < p.MaxHp, "적이 접근하거나 공격했다");
        }

        [UnityTest]
        public IEnumerator PlayerActions_AutoEndTurn_ThenEnemyTurn()
        {
            yield return Fresh();
            var p = bm.SpawnUnit(UnitType.Infantry, Faction.Player, new Vector2(-3f, -5f), "아군");
            var e = bm.SpawnUnit(UnitType.Archer, Faction.Enemy, new Vector2(3f, 6f), "적궁병");
            Assert.IsTrue(bm.RequestPlayerAction(p, p.Position + new Vector2(0f, 2f)));
            float t0 = Time.realtimeSinceStartup;
            while (bm.Phase != BattlePhase.PlayerTurn && Time.realtimeSinceStartup - t0 < 10f) yield return null;
            Assert.AreEqual(BattlePhase.PlayerTurn, bm.Phase, "버튼 없이 모든 유닛 행동 → 적군 턴 → 아군 턴");
            Assert.AreEqual(2, bm.TurnNumber);
            Assert.IsTrue(e.IsAlive);
        }

        [UnityTest]
        public IEnumerator Win_WhenAllEnemiesDead()
        {
            yield return Fresh();
            var p = bm.SpawnUnit(UnitType.Infantry, Faction.Player, new Vector2(0f, -3f), "아군");
            var e = bm.SpawnUnit(UnitType.Archer, Faction.Enemy, new Vector2(0f, -1f), "적궁병");
            e.Hp = 1;
            Assert.IsTrue(bm.RequestPlayerAction(p, e.Position));
            float t0 = Time.realtimeSinceStartup;
            while (bm.Phase == BattlePhase.Resolving && Time.realtimeSinceStartup - t0 < 10f) yield return null;
            Assert.AreEqual(BattlePhase.StageClear, bm.Phase);
            Assert.IsFalse(e.IsAlive);
        }
    }
}