using System.Linq;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;

namespace AibisDream.Framework
{
    /// <summary>
    /// EventTrigger扩展
    /// </summary>
    [RequireComponent(typeof(Collider2D))]
    public class EventTriggerEx : EventTrigger
    {
        private IInteraction _interaction;
        
        private void Awake()
        {
            _interaction = GetComponent<IInteraction>();
        }

        /// <summary>
        /// 注册事件
        /// </summary>
        /// <param name="triggerType">事件类型</param>
        /// <param name="action">函数</param>
        public void Register(EventTriggerType triggerType, UnityAction<BaseEventData> action)
        {
            if (TryGetTriggerEvent(triggerType, out var triggerEvent))
            {
                triggerEvent.AddListener(action);
            }
            else
            {
                Debug.LogWarning($"{triggerType.ToString()}未添加");
            }
        }

        /// <summary>
        /// 卸载事件
        /// </summary>
        /// <param name="triggerType">事件类型</param>
        /// <param name="action">函数</param>
        public void UnRegister(EventTriggerType triggerType, UnityAction<BaseEventData> action)
        {
            if (TryGetTriggerEvent(triggerType, out var triggerEvent))
            {
                triggerEvent.RemoveListener(action);
            }
            else
            {
                Debug.LogWarning($"{triggerType.ToString()}未添加");
            }
        }

        /// <summary>
        /// 获取触发事件
        /// </summary>
        /// <param name="triggerType">事件类型</param>
        /// <param name="triggerEvent">事件</param>
        /// <returns>是否存在</returns>
        private bool TryGetTriggerEvent(EventTriggerType triggerType, out TriggerEvent triggerEvent)
        {
            var entry = triggers.FirstOrDefault(item => item.eventID == triggerType);
            if (entry == null)
            {
                triggerEvent = null;
                return false;
            }
            else
            {
                triggerEvent = entry.callback;
                return true;
            }
        }

        public override void OnPointerEnter(PointerEventData data)
        {
            EventSystemEx.Instance.OnPointerEnter(_interaction);
            base.OnPointerEnter(data);
        }

        public override void OnPointerExit(PointerEventData data)
        {
            EventSystemEx.Instance.OnPointerExit(_interaction);
            base.OnPointerExit(data);
        }

        public override void OnPointerDown(PointerEventData eventData)
        {
            if (_interaction.IsAvailable && !EventSystemEx.Instance.isLocked)
            {
                EventSystemEx.Instance.OnPointerDown(_interaction);
                base.OnPointerDown(eventData);
            }
        }

        public override void OnPointerUp(PointerEventData eventData)
        {
            if (_interaction.IsAvailable && !EventSystemEx.Instance.isLocked)
            {
                EventSystemEx.Instance.OnPointerUp(_interaction);
                base.OnPointerUp(eventData);
            }
        }
    }

    public interface IInteraction
    {
        // 判断是否激活，激活就正常显示鼠标，否则就显示禁用标志
        public bool IsActive { get; }

        // 判断是否可用，可用就正常显示鼠标，否则就保持原有标志不变
        public bool IsAvailable { get; }

        // 返回GameObject
        public GameObject GetGameObject();
    }
}