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

namespace BF
{
    [ExecuteInEditMode]
    public class BFHorizontalOrVerticalLayout : BFLayoutBase
    {
        [SerializeField] 
        protected float spacing = 0;
        public float Spaceing
        {
            get { return spacing; }
            set { SetProperty(ref spacing, value); }
        }

        [SerializeField] 
        protected bool verticalOrHorizontal = true;

        public bool VerticalOrHorizontal
        {
            get { return verticalOrHorizontal; }
            set { SetProperty(ref verticalOrHorizontal, value); }
        }

        private float verticalSize = 0f;
        private float horizontalSize = 0f;

        public void Update()
        {
            if (!isDirty)
            {
                return;
            }

            RefreshLayout();
        }

        public void RefreshLayout()
        {
            CalculateLayoutInput();

            if (verticalOrHorizontal)
            {
                CalChildPosVertical();
            }
            else
            {
                CalChildPosHorizontal();
            }
            isDirty = false;
        }

        protected void CalculateLayoutInput()
        {
            RectChildren.Clear();
            var toIgnoreList = new List<Component>();

            for (var i = 0; i < RectTransform.childCount; i++)
            {
                var rect = (RectTransform)RectTransform.GetChild(i);
                if (rect != null && rect.gameObject.activeSelf)
                {
                    RectChildren.Add(rect);
                }
            }

            toIgnoreList = null;
        }

        protected void CalChildPosVertical()
        {
            verticalSize = 0f;
            var rectSizeX = RectTransform.sizeDelta.x;
            var rectSizeY = RectTransform.sizeDelta.y;

            var tmpVec2 = Vector2.zero;
            for (var i = 0; i < RectChildren.Count; ++i)
            {
                tmpVec2 = RectChildren[i].sizeDelta * RectChildren[i].localScale;
                verticalSize += tmpVec2.y + Spaceing;
                horizontalSize = Mathf.Max(horizontalSize, tmpVec2.x);
            }

            verticalSize -= Spaceing;

            //align参数
            var horizontalAlign = (int)ChildAlignment % 3;
            var verticalAlign = (int)ChildAlignment / 3;
            
            var horMiddlePos = 0f;
            horMiddlePos += (rectSizeX - Right - Left) / 2 + Left;
            
            //垂直开始位置
            var verStartPos = 0f;
            
            if (verticalAlign == 0) //upper
            {
                verStartPos += Top;
            }
            else if (verticalAlign == 1) //middle
            {
                if (verticalSize + Top + Bottom > rectSizeY)
                {
                    verStartPos += Top;
                }
                else
                {
                    verStartPos += (rectSizeY - verticalSize) / 2;
                }
            }
            else if (verticalAlign == 2) //lower
            {
                if (verticalSize + Top + Bottom > rectSizeY)
                {
                    verStartPos += Top;
                }
                else
                {
                    verStartPos += rectSizeY - verticalSize - Bottom;
                }
            }
            
            for (var i = 0; i < RectChildren.Count; ++i)
            {
                //设置水平位置
                var rect = RectChildren[i];
                
                if (horizontalAlign == 0) //left
                {
                    SetChildAlongAxis(rect, 0, Left);
                }
                else if (horizontalAlign == 1) //center
                {
                    SetChildAlongAxis(rect, 0, horMiddlePos - rect.sizeDelta.x * rect.localScale.x / 2);
                }
                else if (horizontalAlign == 2) //right
                {
                    SetChildAlongAxis(rect, 0, rectSizeX - Right - rect.sizeDelta.x * rect.localScale.x);
                }

                //设置垂直位置   
                SetChildAlongAxis(rect, 1, verStartPos);
                verStartPos += rect.sizeDelta.y * rect.localScale.y + spacing;
            }
        }
        
        protected void CalChildPosHorizontal()
        {
            horizontalSize = 0f;
            var rectSizeX = RectTransform.sizeDelta.x;
            var rectSizeY = RectTransform.sizeDelta.y;
            
            var tmpVec2 = Vector2.zero;
            for (var i = 0; i < RectChildren.Count; ++i)
            {
                tmpVec2 = RectChildren[i].sizeDelta * RectChildren[i].localScale;
                horizontalSize += tmpVec2.x + Spaceing;
                verticalSize = Mathf.Max(verticalSize, tmpVec2.y);
            }

            horizontalSize -= Spaceing;

            //align参数
            var horizontalAlign = (int)ChildAlignment % 3;
            var verticalAlign = (int)ChildAlignment / 3;
            
            var verMiddlePos = 0f;
            verMiddlePos += (rectSizeY - Top - Bottom) / 2 + Top;
            
            //水平开始位置
            var horStartPos = 0f;

            if (horizontalAlign == 0) //left
            {
                horStartPos += Left;
            }
            else if (horizontalAlign == 1) //middle
            {
                if (horizontalSize + Left + Right > rectSizeX)
                {
                    horStartPos += Left;
                }
                else
                {
                    horStartPos += (rectSizeX - horizontalSize) / 2;
                }
            }
            else if (horizontalAlign == 2) //right
            {
                if (horStartPos + Left + Right > rectSizeX)
                {
                    horStartPos += Left;
                }
                else
                {
                    horStartPos += rectSizeX - horizontalSize - Right;
                }
            }
            
            for (var i = 0; i < RectChildren.Count; ++i)
            {
                //设置垂直位置
                var rect = RectChildren[i];
                
                if (verticalAlign == 0) //upper
                {
                    SetChildAlongAxis(rect, 1, Top);
                }
                else if (verticalAlign == 1) //center
                {
                    SetChildAlongAxis(rect, 1, verMiddlePos - rect.sizeDelta.y * rect.localScale.y / 2, rect.sizeDelta.y);
                }
                else if (verticalAlign == 2) //lower
                {
                    SetChildAlongAxis(rect, 1, rectSizeY - Bottom - rect.sizeDelta.y * rect.localScale.y, rect.sizeDelta.y);
                }

                //设置水平位置   
                SetChildAlongAxis(rect, 0, horStartPos);
                horStartPos += rect.sizeDelta.x * rect.localScale.x + spacing;
            }
        }

        public float GetVerticalSize()
        {
            return verticalSize + Top + Bottom;
        }
        
        public float GetHorizontalSize()
        {
            return horizontalSize + Left + Right;
        }
    }
}