using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace YKMoon
{
	/// <summary>
	/// 左下开始逆时针的顺序
	/// </summary>
	public enum Corner4Pos
    {
		LowerLeft = 0,
		UpperLeft = 1,
		UpperRight = 2,
		LowerRight = 3,
    }
	[System.Serializable]
	public struct Corner4
	{
		// ============= Fields ==============//
		public Vector2 upperLeft;
		public Vector2 upperRight;
		public Vector2 lowerLeft;
		public Vector2 lowerRight;
		// ============ Static Properties =========== //
		public static Corner4 Default {
			get {
				return new Corner4(new Vector2(-0.5f, 0.5f), new Vector2(0.5f, 0.5f), 
					new Vector2(-0.5f, -0.5f), new Vector2(0.5f, -0.5f));
			}
		}
		public static Vector2 DefaultValue(Corner4Pos pos)
        {
			switch(pos) {
				case Corner4Pos.UpperLeft:
					return new Vector2(-0.5f, 0.5f);
				case Corner4Pos.UpperRight:
					return new Vector2(0.5f, 0.5f);
				case Corner4Pos.LowerLeft:
					return new Vector2(-0.5f, -0.5f);
				case Corner4Pos.LowerRight:
					return new Vector2(0.5f, -0.5f);
				default:
					throw new System.IndexOutOfRangeException("Invalid Corner4 index!");
			}
		}
		//========= Indexer============//
		public Vector2 this[int index] {
			get => this[(Corner4Pos)index];
			set => this[(Corner4Pos)index] = value;
        }
		public Vector2 this[Corner4Pos pos] {
			get {
				switch(pos) {
					case Corner4Pos.UpperLeft:
						return upperLeft;
					case Corner4Pos.UpperRight:
						return upperRight;
					case Corner4Pos.LowerLeft:
						return lowerLeft;
					case Corner4Pos.LowerRight:
						return lowerRight;
					default:
						throw new System.IndexOutOfRangeException("Invalid Corner4 index!");
				}
			}
			set {
                switch(pos) {
                    case Corner4Pos.UpperLeft:
						upperLeft = value;
                        break;
                    case Corner4Pos.UpperRight:
						upperRight = value;
                        break;
					case Corner4Pos.LowerLeft:
						lowerLeft = value;
						break;
					case Corner4Pos.LowerRight:
						lowerRight = value;
                        break;
					default:
						throw new System.IndexOutOfRangeException("Invalid Corner4 index!");
				}
            }
        }

		public Corner4(Vector2 upperLeft, Vector2 upperRight, Vector2 lowerLeft, Vector2 lowerRight)
        {
			this.upperLeft = upperLeft;
			this.upperRight = upperRight;
			this.lowerLeft = lowerLeft;
			this.lowerRight = lowerRight;
        }
		public void Set(Vector2 upperLeft, Vector2 upperRight, Vector2 lowerLeft, Vector2 lowerRight)
		{
			this.upperLeft = upperLeft;
			this.upperRight = upperRight;
			this.lowerLeft = lowerLeft;
			this.lowerRight = lowerRight;
		}
		public void ResetToDefault()
		{
			for(int i = 0; i < 4; i++) {
				this[i] = DefaultValue((Corner4Pos)i);
			}
		}
		public void ResetToDefault(Corner4Pos pos)
        {
			this[(int)pos] = DefaultValue(pos);
		}
		//====== Operators========//
		public override string ToString()
		{
			return string.Format("ul:{0}, ur:{1}, ll:{2}, lr:{3}", upperLeft, upperRight, lowerLeft, lowerRight);
		}
		public static Corner4 operator *(Corner4 a, float d)
		{
			return new Corner4(a.upperLeft * d, a.upperRight * d, a.lowerLeft * d, a.lowerRight * d);
		}
		public static Corner4 operator /(Corner4 a, float d)
		{
			return new Corner4(a.upperLeft / d, a.upperRight / d, a.lowerLeft / d, a.lowerRight / d);
		}
		public static Corner4 operator +(Corner4 a, Corner4 b)
		{
			return new Corner4(a.upperLeft + b.upperLeft, a.upperRight + b.upperRight, a.lowerLeft + b.lowerLeft, a.lowerRight + b.lowerRight);
		}
		public static Corner4 operator -(Corner4 a, Corner4 b)
		{
			return new Corner4(a.upperLeft - b.upperLeft, a.upperRight - b.upperRight, a.lowerLeft - b.lowerLeft, a.lowerRight - b.lowerRight);
		}
	}
}