using System.Collections;
using System.Threading.Tasks;
using UnityEngine;
using BaseGames.Core.Events;

namespace BaseGames.Core
{
    /// <summary>
    /// 死亡/复活流程服务接口。
    /// </summary>
    public interface IDeathRespawnService
    {
        /// <summary>玩家死亡时由 GameManager 调用，启动死亡演出流程。</summary>
        IEnumerator StartDeathSequenceCoroutine();

        /// <summary>DeathScreen 确认按钮点击后调用，执行复活流程。</summary>
        IEnumerator StartRespawnCoroutine();

        /// <summary>SteelSoul 模式：HP 归零后直接清档并返回主菜单。</summary>
        IEnumerator StartGameOverCoroutine();
    }

    /// <summary>
    /// 死亡/复活流程独立服务。
    /// </summary>
    public class DeathRespawnService : MonoBehaviour, IDeathRespawnService
    {
        [Header("Config")]
        [SerializeField] private float _deathAnimDuration   = 1.2f;
        [SerializeField] private float _deathScreenDelay    = 0.5f;
        [SerializeField] private float _respawnFadeDuration = 0.4f;

        [Header("Event Channels - Raise")]
        [SerializeField] private VoidEventChannelSO                  _onRespawnStarted;
        [SerializeField] private VoidEventChannelSO                  _onRespawnCompleted;
        [SerializeField] private SceneLoadRequestEventChannelSO      _onSceneLoadRequest;

        [Header("Event Channels - Listen")]
        [SerializeField] private VoidEventChannelSO _onDeathScreenConfirmed;

        public IEnumerator StartDeathSequenceCoroutine()
        {
            yield return new WaitForSeconds(_deathAnimDuration);
            yield return new WaitForSeconds(_deathScreenDelay);
            // 确认等待由 GameManager.DeathFlow 统一处理，此处仅负责动画延迟
        }

        public IEnumerator StartRespawnCoroutine()
        {
            _onRespawnStarted?.Raise();
            yield return new WaitForSeconds(_respawnFadeDuration);

            // 通过 SceneLoadRequest 频道触发场景重载，复用 SceneService / RoomTransition 路径
            var sm = ServiceLocator.GetOrDefault<ISaveService>();
            _onSceneLoadRequest?.Raise(new SceneLoadRequest
            {
                SceneName         = sm?.LastCheckpointScene,
                EntryTransitionId = sm?.LastCheckpointSpawnId,
                ShowLoadingScreen = true,
                IsRespawn         = true,
            });

            yield return new WaitForSeconds(_respawnFadeDuration);
            _onRespawnCompleted?.Raise();
        }

        public IEnumerator StartGameOverCoroutine()
        {
            // 1. 删除当前存档槽
            var saveManager = ServiceLocator.GetOrDefault<ISaveService>();
            if (saveManager != null)
            {
                var task = saveManager.DeleteSlotAsync(saveManager.ActiveSlot);
                yield return new WaitUntil(() => task.IsCompleted);
            }

            // 2. 返回主菜单
            var sceneService = ServiceLocator.GetOrDefault<ISceneService>();
            if (sceneService != null)
                yield return sceneService.LoadMainMenuCoroutine();
        }
    }
}