?using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Media;
using System.IO;

namespace ChinaBlock
{
    class GameField
    {
        public const int width = 20;           //場景的寬，以方塊個數為單位
        public const int height = 30;
        public const int SquareSize = 15;      //每個四分之一小方塊的邊長
        public static Color BackColor;         //場景的背景色
        public static System.IntPtr winHandle; //場景的handle
        public static Color[] BlockForeColor ={ Color.Blue, Color.Beige, Color.DarkKhaki, Color.DarkMagenta, Color.DarkOliveGreen, Color.DarkOrange, Color.DarkRed };
        public static Color[] BlockBackColor ={ Color.LightCyan, Color.DarkSeaGreen, Color.Beige, Color.Beige, Color.Beige, Color.Beige, Color.Beige };
        public static bool isChanged=false; //設置是否被更改的標志位
        public static SoundPlayer sound = new SoundPlayer();

        public static Square[,] arriveBlock = new Square[width, height]; //保存已經不能再下落了的方塊
        public static int[] arrBitBlock=new int[height];  //位數組：當某個位置有方塊時，該行的該位為1
        private const int bitEmpty = 0x0;      //0000 0000 0000 0000 0000
        private const int bitFull = 0xFFFFF;   //1111 1111 1111 1111 1111

        /*檢測是否為空*/
        public static bool isEmpty(int x, int y)
        {
            //先檢測是否越界
            if (y < 0 || y >= height)
                return false;
            if (x < 0 || x >= width)
                return false;
            //然后檢測是否為空
            if ((arrBitBlock[y] & (1 << x)) != 0)
                return false;
            else
                return true;
        }
        /*將方塊停住*/
        public static void stopSquare(Square sq, int x, int y)
        {
            arriveBlock[x, y] = sq;
            arrBitBlock[y]=arrBitBlock[y]|(1<<x);
        }
        /*檢測行是否滿 
         * 返回：成功消除的行數和  （方便統計分數）
         */
        public static int CheckLines()
        {
            //從最下面一行往上檢測，當某行為空或到頂時結束
            int lineFullCount = 0;
            int y = height - 1;
            while (y >= 0 && arrBitBlock[y] != bitEmpty)
            {
                if (arrBitBlock[y] == bitFull)
                {
                    lineFullCount++; //消除一行記分
                    arrBitBlock[y] = bitEmpty;//消除該行的block
                    PlaySound("FinishOneLine");  //播放聲音
                    for (int x = 0; x < width; x++) //消除該行的block
                        arriveBlock[x, y] = null;
                    //將該行之上的block下移，如果到頂則不執行
                    for (int i = y; i - 1 >= 0; i--)
                    {
                        for (int x = 0; x < width; x++)
                        {
                            if ((arrBitBlock[i - 1] & (1 << x)) != 0) //如果上方有block
                            {
                                arriveBlock[x, i - 1].location = new Point(arriveBlock[x,i-1].location.X,arriveBlock[x,i-1].location.Y+SquareSize);
                                arriveBlock[x, i] = arriveBlock[x, i - 1];
                            }
                        }
                        arrBitBlock[i] = arrBitBlock[i - 1];
                    } 
                }
                else  //當消除一行后指針不下移，當沒有消除的時候指針才下移
                   y--;
             }//while循環結束
            return lineFullCount;
        }
        /*播放聲音*/
        public static void PlaySound(string soundstr)
        {
            switch (soundstr)
            {
                case "FinishOneLine": //消除一行的聲音
                    if (!File.Exists("FinishOneLine.wav")) return;
                    sound.SoundLocation = "FinishOneLine.wav";
                    break;
                case "CanNotDo": //當無法操作時
                    if (!File.Exists("CanNotDo.wav")) return;
                    sound.SoundLocation = "CanNotDo.wav";
                    break;
            }
            sound.Play();
        }
        /*重畫*/
        public static void Redraw()
        { 
            for(int y=height-1;y>=0;y--)
                if(arrBitBlock[y]!=bitEmpty)
                    for(int x=0;x<width;x++)
                        if ((arrBitBlock[y] & (1 << x)) != 0)
                            arriveBlock[x, y].Draw(winHandle);  
        }
        
        //結束
    }
}