using UnityEngine;

namespace BaseGames.Enemies
{
    /// <summary>
    /// 地图固定巡逻/追击区域（矩形）。
    ///
    /// 放置于场景中（非敌人子节点），通过 EnemyBase Inspector 的 _patrolZone 字段引用。
    /// 同一区域可被多个敌人共享（哨兵组、竞技场等）。
    ///
    /// 区域层级：
    /// <list type="bullet">
    ///   <item><b>巡逻区域（Patrol）</b>：绿色矩形，巡逻点限制范围。</item>
    ///   <item><b>追击区域（Chase）</b>：橙色矩形 = 巡逻区域 + <see cref="ChaseExpandPadding"/>；
    ///     玩家进入/出此区域触发追击开始/放弃。</item>
    /// </list>
    /// </summary>
    public class EnemyPatrolZone : MonoBehaviour
    {
        [Header("巡逻区域")]
        [Tooltip("巡逻区域中心相对 transform.position 的偏移（局部偏移，方便在 Scene 中移动节点）")]
        public Vector2 PatrolOffset = Vector2.zero;

        [Tooltip("巡逻区域尺寸（宽 × 高，单位 m）")]
        public Vector2 PatrolSize = new Vector2(10f, 4f);

        [Header("追击区域")]
        [Tooltip("追击区域向四周扩展的边距（m）；追击区域 = 巡逻区域各边 + 此值。0 = 不扩展（追击 = 巡逻）")]
        [Min(0f)]
        public float ChaseExpandPadding = 8f;

        [Tooltip("自定义追击区域尺寸（宽×高）；保持 Vector2.zero 时使用巡逻区域 + ChaseExpandPadding 自动计算")]
        public Vector2 CustomChaseSize = Vector2.zero;

        // ── 计算属性 ──────────────────────────────────────────────────────

        /// <summary>巡逻区域中心（世界坐标）。</summary>
        public Vector2 PatrolCenter => (Vector2)transform.position + PatrolOffset;

        /// <summary>追击区域中心与巡逻区域共享。</summary>
        public Vector2 ChaseCenter => PatrolCenter;

        /// <summary>有效追击区域尺寸：自定义 > 0 时使用自定义，否则巡逻区域 + 边距。</summary>
        public Vector2 EffectiveChaseSize
        {
            get
            {
                if (CustomChaseSize.sqrMagnitude > 0f) return CustomChaseSize;
                return PatrolSize + Vector2.one * (ChaseExpandPadding * 2f);
            }
        }

        // ── 空间查询 ──────────────────────────────────────────────────────

        /// <summary>判断世界坐标 <paramref name="worldPos"/> 是否在巡逻区域内。</summary>
        public bool ContainsPatrol(Vector2 worldPos)
        {
            Vector2 delta = worldPos - PatrolCenter;
            Vector2 half  = PatrolSize * 0.5f;
            return Mathf.Abs(delta.x) <= half.x && Mathf.Abs(delta.y) <= half.y;
        }

        /// <summary>判断世界坐标 <paramref name="worldPos"/> 是否在追击区域内。</summary>
        public bool ContainsChase(Vector2 worldPos)
        {
            Vector2 delta = worldPos - ChaseCenter;
            Vector2 half  = EffectiveChaseSize * 0.5f;
            return Mathf.Abs(delta.x) <= half.x && Mathf.Abs(delta.y) <= half.y;
        }

        /// <summary>将 <paramref name="worldPos"/> 夹紧到巡逻区域内最近点（用于归位目标）。</summary>
        public Vector2 ClampToPatrol(Vector2 worldPos)
        {
            Vector2 center = PatrolCenter;
            Vector2 half   = PatrolSize * 0.5f;
            return new Vector2(
                Mathf.Clamp(worldPos.x, center.x - half.x, center.x + half.x),
                Mathf.Clamp(worldPos.y, center.y - half.y, center.y + half.y)
            );
        }

        // ── Gizmos ────────────────────────────────────────────────────────
#if UNITY_EDITOR
        private void OnDrawGizmos()
        {
            Vector2 patrol = PatrolCenter;
            Vector2 chase  = ChaseCenter;

            // 追击区域（橙色，后绘，垫在巡逻区域下方）
            Vector2 chaseSize = EffectiveChaseSize;
            Gizmos.color = new Color(1f, 0.55f, 0.1f, 0.07f);
            Gizmos.DrawCube(chase, chaseSize);
            Gizmos.color = new Color(1f, 0.55f, 0.1f, 0.7f);
            Gizmos.DrawWireCube(chase, chaseSize);

            // 巡逻区域（绿色，前绘，覆盖在追击区域上方）
            Gizmos.color = new Color(0.2f, 0.9f, 0.2f, 0.12f);
            Gizmos.DrawCube(patrol, PatrolSize);
            Gizmos.color = new Color(0.2f, 0.9f, 0.2f, 0.85f);
            Gizmos.DrawWireCube(patrol, PatrolSize);

            // 中心点
            Gizmos.color = new Color(0.2f, 0.9f, 0.2f, 1f);
            Gizmos.DrawSphere(patrol, 0.15f);
        }

        private void OnDrawGizmosSelected()
        {
            // 选中时用更鲜艳的线框突出显示
            Vector2 patrol = PatrolCenter;
            Gizmos.color = Color.green;
            Gizmos.DrawWireCube(patrol, PatrolSize);

            Gizmos.color = new Color(1f, 0.7f, 0f);
            Gizmos.DrawWireCube(ChaseCenter, EffectiveChaseSize);

            // 标注尺寸（仅在 Selected 时绘制）
            UnityEditor.Handles.color = Color.green;
            UnityEditor.Handles.Label(patrol + Vector2.right * PatrolSize.x * 0.5f,
                $"Patrol {PatrolSize.x:F1}×{PatrolSize.y:F1}");
            UnityEditor.Handles.color = new Color(1f, 0.7f, 0f);
            Vector2 cs = EffectiveChaseSize;
            UnityEditor.Handles.Label(ChaseCenter + Vector2.right * cs.x * 0.5f,
                $"Chase {cs.x:F1}×{cs.y:F1}");
        }
#endif
    }
}