using System;
using System.Collections.Generic;
using BITKit.StateMachine;
using UnityEngine;
using UnityEngine.InputSystem;

namespace BITKit.Entities
{
    /// <summary>
    /// 期望状态与当前状态
    /// </summary>
    /// <typeparam name="T"></typeparam>
    [Serializable]
    public struct ExpectState<T>
    {
        /// <summary>
        /// 期望状态
        /// </summary>
        public T shouldBe;

        /// <summary>
        /// 当前状态
        /// </summary>
        public T being;

        /// <summary>
        /// 强制状态
        /// </summary>
        public T force;

        public bool UnExpect => !shouldBe.Equals(being);

      

        public void Reset()
        {
            shouldBe = being = force = default;
        }

        public void Release()
        {
            being = shouldBe;
        }

        public void Release(T value)
        {
            force = default;
            being = shouldBe = value;
        }
        public static implicit operator ExpectState<T>(T value)
        {
            return new ExpectState<T> { shouldBe = value, being = value };
        }
        public static implicit operator T(ExpectState<T> value)
        {
            return value.being;
        }
    }

    /// <summary>
    /// Entity移动组件接口定义
    /// </summary>
    public interface IEntityMovement:IStateMachine<IEntityMovementState>
    {
        Vector3 Position { get; set; }
        Quaternion Rotation { get; set; }
        Vector3 Forward { get; }
       /// <summary>
       /// 视角前方,通常是摄像机的前方
       /// </summary>
        Vector3 ViewForward { get; }
        /// <summary>
        /// 视角中心,通常是摄像机的位置
        /// </summary>
        Vector3 ViewCenter { get; }
        /// <summary>
        /// 注视点
        /// </summary>
        Vector3 FocusPoint { get; }
        /// <summary>
        /// 视角旋转,通常是摄像机的旋转
        /// </summary>
        Quaternion ViewRotation { get; }
        /// <summary>
        /// 基于运动的速度,是相对于标准化移动速度的相对速度
        /// </summary>
        Vector3 LocomotionBasedVelocity { get; }
        /// <summary>
        /// 世界空间的速度
        /// </summary>
        Vector3 Velocity { get; }
        /// <summary>
        /// 在地面的速度 = with <see cref="Velocity"/> {y=0}
        /// </summary>
        Vector3 GroundVelocity { get; }
        /// <summary>
        /// 旋转速度
        /// </summary>
        Vector3 AngularVelocity { get; }
        /// <summary>
        /// 是否在地面上
        /// </summary>
        bool IsGrounded { get; }
        /// <summary>
        /// 同步移动,用于网络或强制同步移动信息
        /// </summary>
        /// <param name="velocity"></param>
        /// <param name="position"></param>
        /// <param name="rotation"></param>
        /// <param name="isGrounded"></param>
        void SyncMovement(Vector3 velocity, Vector3 position,Quaternion rotation,bool isGrounded);
        /// <summary>
        /// 基于相对坐标的移动
        /// </summary>
        /// <param name="relativeVector"></param>
        void Movement(Vector3 relativeVector);
        /// <summary>
        /// 基于InputAction的移动
        /// </summary>
        /// <param name="context"></param>
        void Movement(InputAction.CallbackContext context);
        /// <summary>
        /// 执行命令
        /// </summary>
        /// <param name="command"></param>
        /// <typeparam name="T"></typeparam>
        void ExecuteCommand<T>(T command=default);
        /// <summary>
        /// 执行命令的回调
        /// </summary>
        event Action<object> OnCommand; 
    }
    public interface IEntityMovementState:IState
    {
        void UpdateVelocity(ref Vector3 currentVelocity,float deltaTime);
        void UpdateRotation(ref Quaternion currentRotation,float deltaTime);
        void BeforeUpdateMovement(float deltaTime);
        void AfterUpdateMovement(float deltaTime);
        void ExecuteCommand<T>(T command);
    }
}