using System.Collections;
using System.Collections.Generic;

using Colosseum.AI;
using Colosseum.Combat;
using Colosseum.Player;
using Colosseum.Skills;

using Unity.Behavior;
using Unity.Netcode;
using UnityEngine;
using UnityEngine.Serialization;

namespace Colosseum.Enemy
{
    /// <summary>
    /// 보스 공통 전투 BT가 참조하는 전투 컨텍스트입니다.
    /// 패턴 슬롯, 거리 기준, 페이즈별 주기, 공통 타겟 판정 정보를 제공합니다.
    /// </summary>
    [DisallowMultipleComponent]
    [RequireComponent(typeof(BossEnemy))]
    [RequireComponent(typeof(SkillController))]
    public abstract class BossCombatBehaviorContext : NetworkBehaviour
    {
        [Header("References")]
        [SerializeField] protected BossEnemy bossEnemy;
        [SerializeField] protected EnemyBase enemyBase;
        [SerializeField] protected SkillController skillController;
        [SerializeField] protected UnityEngine.AI.NavMeshAgent navMeshAgent;
        [SerializeField] protected BehaviorGraphAgent behaviorGraphAgent;

        [Header("Pattern Data")]
        [Tooltip("기본 근접 압박 패턴")]
        [FormerlySerializedAs("mainPattern")]
        [SerializeField] protected BossPatternData primaryPattern;

        [Tooltip("보조 근접 압박 패턴")]
        [FormerlySerializedAs("slamPattern")]
        [SerializeField] protected BossPatternData secondaryPattern;

        [Tooltip("기동 또는 거리 징벌 패턴")]
        [FormerlySerializedAs("leapPattern")]
        [SerializeField] protected BossPatternData mobilityPattern;

        [Tooltip("특정 상황에서 우선 발동하는 징벌 패턴")]
        [FormerlySerializedAs("downPunishPattern")]
        [SerializeField] protected BossPatternData punishPattern;

        [Header("Phase Thresholds")]
        [Tooltip("2페이즈 진입 체력 비율")]
        [Range(0f, 1f)] [SerializeField] protected float phase2HealthThreshold = 0.75f;

        [Tooltip("3페이즈 진입 체력 비율")]
        [Range(0f, 1f)] [SerializeField] protected float phase3HealthThreshold = 0.4f;

        [Header("Targeting")]
        [Tooltip("타겟 재탐색 주기")]
        [FormerlySerializedAs("targetRefreshInterval")]
        [Min(0.05f)] [SerializeField] protected float primaryTargetRefreshInterval = 0.2f;

        [Tooltip("기동 패턴을 고려하기 시작하는 거리")]
        [FormerlySerializedAs("leapDistanceThreshold")]
        [Min(0f)] [SerializeField] protected float mobilityTriggerDistance = 8f;

        [Tooltip("징벌 패턴을 고려할 최대 반경")]
        [FormerlySerializedAs("downPunishSearchRadius")]
        [Min(0f)] [SerializeField] protected float punishSearchRadius = 6f;

        [Header("Pattern Cadence")]
        [Tooltip("1페이즈에서 몇 번의 근접 패턴마다 보조 패턴을 섞을지")]
        [FormerlySerializedAs("phase1SlamInterval")]
        [Min(1)] [SerializeField] protected int phase1SecondaryInterval = 3;

        [Tooltip("2페이즈에서 몇 번의 근접 패턴마다 보조 패턴을 섞을지")]
        [FormerlySerializedAs("phase2SlamInterval")]
        [Min(1)] [SerializeField] protected int phase2SecondaryInterval = 2;

        [Tooltip("3페이즈에서 몇 번의 근접 패턴마다 보조 패턴을 섞을지")]
        [FormerlySerializedAs("phase3SlamInterval")]
        [Min(1)] [SerializeField] protected int phase3SecondaryInterval = 2;

        [Header("Behavior")]
        [Tooltip("전용 컨텍스트 사용 시 기존 BehaviorGraph를 비활성화할지 여부")]
        [SerializeField] protected bool disableBehaviorGraph = true;

        [Tooltip("디버그 로그 출력 여부")]
        [SerializeField] protected bool debugMode = false;

        protected readonly Dictionary<BossPatternData, float> patternCooldownTracker = new Dictionary<BossPatternData, float>();

        protected Coroutine activePatternCoroutine;
        protected GameObject currentTarget;
        protected float nextTargetRefreshTime;
        protected int meleePatternCounter;

        /// <summary>
        /// 전용 컨텍스트 사용 시 BehaviorGraph를 비활성화할지 여부
        /// </summary>
        public bool DisableBehaviorGraph => disableBehaviorGraph;

        /// <summary>
        /// 기동 패턴을 고려하는 최소 거리
        /// </summary>
        public float MobilityTriggerDistance => mobilityTriggerDistance;

        /// <summary>
        /// 징벌 패턴을 고려하는 최대 반경
        /// </summary>
        public float PunishSearchRadius => punishSearchRadius;

        /// <summary>
        /// 디버그 로그 출력 여부
        /// </summary>
        public bool DebugModeEnabled => debugMode;

        /// <summary>
        /// 현재 보스 패턴 페이즈
        /// </summary>
        public int CurrentPatternPhase
        {
            get
            {
                float healthRatio = bossEnemy != null && bossEnemy.MaxHealth > 0f
                    ? bossEnemy.CurrentHealth / bossEnemy.MaxHealth
                    : 1f;

                if (healthRatio <= phase3HealthThreshold)
                    return 3;

                if (healthRatio <= phase2HealthThreshold)
                    return 2;

                return 1;
            }
        }

        protected virtual void Awake()
        {
            ResolveReferences();
        }

        public override void OnNetworkSpawn()
        {
            ResolveReferences();

            if (!IsServer)
                enabled = false;
        }

        protected virtual void Update()
        {
            if (!IsServer)
                return;

            ResolveReferences();
            if (bossEnemy == null || enemyBase == null || skillController == null)
                return;

            if (bossEnemy.IsDead || bossEnemy.IsTransitioning)
                return;

            if (!disableBehaviorGraph)
                return;

            RefreshTargetIfNeeded();
            UpdateMovement();

            if (skillController.IsPlayingAnimation)
                return;

            if (TryStartMobilityPattern())
                return;

            TryStartPrimaryLoopPattern();
        }

        /// <summary>
        /// 현재 역할의 패턴 데이터를 반환합니다.
        /// </summary>
        public BossPatternData GetPattern(BossCombatPatternRole role)
        {
            return role switch
            {
                BossCombatPatternRole.Primary => primaryPattern,
                BossCombatPatternRole.Secondary => secondaryPattern,
                BossCombatPatternRole.Mobility => mobilityPattern,
                BossCombatPatternRole.Punish => punishPattern,
                _ => null,
            };
        }

        /// <summary>
        /// 다음 근접 패턴 차례가 보조 패턴인지 여부
        /// </summary>
        public bool IsNextSecondaryPattern()
        {
            int secondaryInterval = GetSecondaryIntervalForPhase(CurrentPatternPhase);
            if (secondaryInterval <= 1)
                return true;

            return (meleePatternCounter + 1) % secondaryInterval == 0;
        }

        /// <summary>
        /// 현재 페이즈 기준의 보조 근접 패턴 주기를 반환합니다.
        /// </summary>
        public int GetSecondaryIntervalForPhase(int phase)
        {
            return phase switch
            {
                1 => Mathf.Max(1, phase1SecondaryInterval),
                2 => Mathf.Max(1, phase2SecondaryInterval),
                _ => Mathf.Max(1, phase3SecondaryInterval),
            };
        }

        /// <summary>
        /// 근접 패턴 사용 카운터를 갱신합니다.
        /// </summary>
        public void RegisterPatternUse(BossCombatPatternRole role)
        {
            if (!role.IsMeleeRole())
                return;

            meleePatternCounter++;
        }

        /// <summary>
        /// 살아 있는 적대 대상인지 확인합니다.
        /// </summary>
        public bool IsValidHostileTarget(GameObject candidate)
        {
            if (candidate == null || !candidate.activeInHierarchy)
                return false;

            if (Team.IsSameTeam(gameObject, candidate))
                return false;

            IDamageable damageable = candidate.GetComponent<IDamageable>();
            return damageable == null || !damageable.IsDead;
        }

        /// <summary>
        /// 기동 패턴 대상으로 유효한지 확인합니다.
        /// </summary>
        public bool IsValidMobilityTarget(GameObject candidate)
        {
            if (!IsValidHostileTarget(candidate))
                return false;

            float maxDistance = enemyBase != null && enemyBase.Data != null ? enemyBase.Data.AggroRange : 20f;
            float distance = Vector3.Distance(transform.position, candidate.transform.position);
            return distance >= mobilityTriggerDistance && distance <= maxDistance;
        }

        /// <summary>
        /// 기동 패턴 대상으로 사용할 수 있는 가장 먼 유효 타겟을 찾습니다.
        /// </summary>
        public GameObject FindMobilityTarget()
        {
            GameObject[] candidates = GameObject.FindGameObjectsWithTag("Player");
            GameObject farthestTarget = null;
            float bestDistance = mobilityTriggerDistance;
            float maxDistance = enemyBase != null && enemyBase.Data != null ? enemyBase.Data.AggroRange : 20f;

            for (int i = 0; i < candidates.Length; i++)
            {
                GameObject candidate = candidates[i];
                if (!IsValidMobilityTarget(candidate))
                    continue;

                float distance = Vector3.Distance(transform.position, candidate.transform.position);
                if (distance > maxDistance || distance <= bestDistance)
                    continue;

                bestDistance = distance;
                farthestTarget = candidate;
            }

            return farthestTarget;
        }

        /// <summary>
        /// 가장 가까운 생존 플레이어를 찾습니다.
        /// </summary>
        public GameObject FindNearestLivingTarget()
        {
            PlayerNetworkController[] players = FindObjectsByType<PlayerNetworkController>(FindObjectsSortMode.None);

            GameObject nearestTarget = null;
            float nearestDistance = float.MaxValue;
            float aggroRange = enemyBase != null && enemyBase.Data != null ? enemyBase.Data.AggroRange : Mathf.Infinity;

            for (int i = 0; i < players.Length; i++)
            {
                PlayerNetworkController player = players[i];
                if (player == null || player.IsDead || !player.gameObject.activeInHierarchy)
                    continue;

                GameObject candidate = player.gameObject;
                if (!IsValidHostileTarget(candidate))
                    continue;

                float distance = Vector3.Distance(transform.position, candidate.transform.position);
                if (distance > aggroRange || distance >= nearestDistance)
                    continue;

                nearestDistance = distance;
                nearestTarget = candidate;
            }

            return nearestTarget;
        }

        /// <summary>
        /// 로그를 출력합니다.
        /// </summary>
        public void LogDebug(string source, string message)
        {
            if (debugMode)
                Debug.Log($"[{source}] {message}");
        }

        protected virtual bool TryStartPrimaryLoopPattern()
        {
            if (currentTarget == null)
                return false;

            float distanceToTarget = Vector3.Distance(transform.position, currentTarget.transform.position);
            float attackRange = enemyBase != null && enemyBase.Data != null ? enemyBase.Data.AttackRange : 2f;
            if (distanceToTarget > attackRange + 0.25f)
                return false;

            BossPatternData selectedPattern = SelectPrimaryLoopPattern();
            if (selectedPattern == null)
                return false;

            StartPattern(selectedPattern, currentTarget);
            return true;
        }

        protected virtual bool TryStartMobilityPattern()
        {
            BossPatternData pattern = GetPattern(BossCombatPatternRole.Mobility);
            if (!IsPatternReady(pattern))
                return false;

            GameObject target = FindMobilityTarget();
            if (target == null)
                return false;

            currentTarget = target;
            StartPattern(pattern, target);
            return true;
        }

        protected virtual BossPatternData SelectPrimaryLoopPattern()
        {
            BossPatternData primary = GetPattern(BossCombatPatternRole.Primary);
            BossPatternData secondary = GetPattern(BossCombatPatternRole.Secondary);

            bool canUsePrimary = IsPatternReady(primary);
            bool canUseSecondary = IsPatternReady(secondary);

            if (canUseSecondary && IsNextSecondaryPattern())
            {
                meleePatternCounter++;
                return secondary;
            }

            if (canUsePrimary)
            {
                meleePatternCounter++;
                return primary;
            }

            if (canUseSecondary)
            {
                meleePatternCounter++;
                return secondary;
            }

            return null;
        }

        protected virtual void StartPattern(BossPatternData pattern, GameObject target)
        {
            if (pattern == null || activePatternCoroutine != null)
                return;

            LogDebug(GetType().Name, $"패턴 시작: {pattern.PatternName} / Target={(target != null ? target.name : "None")} / Phase={CurrentPatternPhase}");
            activePatternCoroutine = StartCoroutine(RunPatternCoroutine(pattern, target));
        }

        protected virtual IEnumerator RunPatternCoroutine(BossPatternData pattern, GameObject target)
        {
            StopMovement();
            bool completed = true;

            for (int i = 0; i < pattern.Steps.Count; i++)
            {
                PatternStep step = pattern.Steps[i];
                if (step.Type == PatternStepType.Wait)
                {
                    yield return new WaitForSeconds(step.Duration);
                    continue;
                }

                if (step.Skill == null)
                {
                    completed = false;
                    Debug.LogWarning($"[{GetType().Name}] 패턴 스텝 스킬이 비어 있습니다. Pattern={pattern.PatternName}, Index={i}");
                    break;
                }

                if (step.Skill.JumpToTarget && target != null)
                {
                    enemyBase?.SetJumpTarget(target.transform.position);
                }

                if (!skillController.ExecuteSkill(step.Skill))
                {
                    completed = false;
                    LogDebug(GetType().Name, $"스킬 실행 실패: {step.Skill.SkillName}");
                    break;
                }

                yield return new WaitUntil(() => skillController == null || !skillController.IsPlayingAnimation || bossEnemy == null || bossEnemy.IsDead);
                if (bossEnemy == null || bossEnemy.IsDead)
                    break;
            }

            if (completed)
            {
                patternCooldownTracker[pattern] = Time.time + pattern.Cooldown;
            }

            activePatternCoroutine = null;
            currentTarget = target;
        }

        protected bool IsPatternReady(BossPatternData pattern)
        {
            if (pattern == null || pattern.Steps == null || pattern.Steps.Count == 0)
                return false;

            if (!patternCooldownTracker.TryGetValue(pattern, out float readyTime))
                return true;

            return Time.time >= readyTime;
        }

        protected virtual void RefreshTargetIfNeeded()
        {
            if (Time.time < nextTargetRefreshTime)
                return;

            nextTargetRefreshTime = Time.time + primaryTargetRefreshInterval;
            GameObject highestThreatTarget = enemyBase.GetHighestThreatTarget(currentTarget, null, enemyBase.Data != null ? enemyBase.Data.AggroRange : Mathf.Infinity);
            currentTarget = highestThreatTarget != null ? highestThreatTarget : FindNearestLivingTarget();
        }

        protected virtual void UpdateMovement()
        {
            if (navMeshAgent == null || !navMeshAgent.enabled)
                return;

            if (skillController != null && skillController.IsPlayingAnimation)
            {
                StopMovement();
                return;
            }

            if (currentTarget == null)
            {
                StopMovement();
                return;
            }

            float attackRange = enemyBase != null && enemyBase.Data != null ? enemyBase.Data.AttackRange : 2f;
            float distanceToTarget = Vector3.Distance(transform.position, currentTarget.transform.position);
            if (distanceToTarget <= attackRange)
            {
                StopMovement();
                return;
            }

            navMeshAgent.isStopped = false;
            navMeshAgent.stoppingDistance = attackRange;
            navMeshAgent.SetDestination(currentTarget.transform.position);
        }

        protected void StopMovement()
        {
            if (navMeshAgent == null || !navMeshAgent.enabled)
                return;

            navMeshAgent.isStopped = true;
            navMeshAgent.ResetPath();
        }

        protected virtual void ResolveReferences()
        {
            if (bossEnemy == null)
                bossEnemy = GetComponent<BossEnemy>();

            if (enemyBase == null)
                enemyBase = GetComponent<EnemyBase>();

            if (skillController == null)
                skillController = GetComponent<SkillController>();

            if (navMeshAgent == null)
                navMeshAgent = GetComponent<UnityEngine.AI.NavMeshAgent>();

            if (behaviorGraphAgent == null)
                behaviorGraphAgent = GetComponent<BehaviorGraphAgent>();
        }
    }
}