using UnityEngine;

namespace BaseGames.Input
{
    /// <summary>
    /// 帧级输入缓冲。持续 _bufferDuration 秒，允许玩家提前输入跳跃/攻击/冲刺。
    /// 须与 PlayerController 在同一 GameObject 上。
    /// </summary>
    public class InputBuffer : MonoBehaviour
    {
        // _inputReader 由 PlayerController.Awake 注入，无需在 Inspector 单独配置。
        private InputReaderSO _inputReader;
        [SerializeField] private float _jumpBufferDuration    = 0.15f;
        [SerializeField] private float _attackBufferDuration  = 0.12f;
        [SerializeField] private float _dashBufferDuration    = 0.10f;

        private float _jumpBuffer;
        private float _attackBuffer;
        private float _dashBuffer;

        // ── Named handlers to allow proper unsubscription ─────────────────────
        private void HandleJumpStarted()   => _jumpBuffer   = _jumpBufferDuration;
        private void HandleAttackStarted() => _attackBuffer = _attackBufferDuration;
        private void HandleDashStarted()   => _dashBuffer   = _dashBufferDuration;

        /// <summary>由 PlayerController 在 Awake 中注入 InputReader，无需在 Inspector 单独指定。</summary>
        public void Init(InputReaderSO reader)
        {
            _inputReader = reader;
        }

        private void OnEnable()
        {
            if (_inputReader == null) return;
            _inputReader.JumpStartedEvent += HandleJumpStarted;
            _inputReader.AttackEvent      += HandleAttackStarted;
            _inputReader.DashEvent        += HandleDashStarted;
        }

        private void OnDisable()
        {
            if (_inputReader == null) return;
            _inputReader.JumpStartedEvent -= HandleJumpStarted;
            _inputReader.AttackEvent      -= HandleAttackStarted;
            _inputReader.DashEvent        -= HandleDashStarted;
        }

        private void Update()
        {
            float dt = Time.deltaTime;
            _jumpBuffer   = Mathf.Max(0f, _jumpBuffer   - dt);
            _attackBuffer = Mathf.Max(0f, _attackBuffer - dt);
            _dashBuffer   = Mathf.Max(0f, _dashBuffer   - dt);
        }

        /// <summary>消耗跳跃缓冲（读取并清空）。</summary>
        public bool ConsumeJump()
        {
            if (_jumpBuffer <= 0f) return false;
            _jumpBuffer = 0f;
            return true;
        }

        /// <summary>消耗攻击缓冲（读取并清空）。</summary>
        public bool ConsumeAttack()
        {
            if (_attackBuffer <= 0f) return false;
            _attackBuffer = 0f;
            return true;
        }

        /// <summary>消耗冲刺缓冲（读取并清空）。</summary>
        public bool ConsumeDash()
        {
            if (_dashBuffer <= 0f) return false;
            _dashBuffer = 0f;
            return true;
        }
    }
}