module FPGA_FINAL(
	input CLK, reset, 
	output reg [0:27] led,
	input left, right,
	input throw,
	output testLED
);

	reg [7:0]blockFirst =  8'b11111111;
	reg [7:0]blockSecond = 8'b11111111;

	reg [2:0]plat_position; // 板子位置
	reg [2:0]ball_position;	// 球  位置
	reg [2:0]ball_y_position; // 球 y 座標
	
	reg upPosition;
	integer horizonPosition;

	reg handsOn; 				// bool，紀錄球現在丟出去了沒

	
	initial
	begin
		// 歸零，重製 8x8 LED
		led[0:23] = 23'b11111111111111111111;
		led[27] = 1;
		led[24:26] = 3'b000;
		
		plat_position = 3'b010;		// 預設在 x=2 的位置
		ball_position = 3'b011;		// 預設在 x=3 的位置
		ball_y_position = 3'b010;	// 預設在 y=1 的位置
		handsOn = 1;					// 預設為 為丟出狀態
		
		upPosition = 1;				// 預設為 向上
		horizonPosition = 0;			// 預設為 正中間方向
	end
	
	

	// 開始所有除頻器
	divfreq F(CLK, divclk);
	buttondivfreq BT(CLK, buttonclk);

	
	
	integer ballTime;
	// 判斷 所有操作
	always @(posedge buttonclk)
	begin
		
		
		if(reset)
		begin
			blockFirst =  8'b11111111;
			blockSecond = 8'b11111111;
			
			plat_position <= 3'b010;		// 預設在 x=2 的位置
			ball_position <= 3'b011;		// 預設在 x=3 的位置
			ball_y_position <= 3'b010;	// 預設在 y=1 的位置
			handsOn = 1;				// 預設為 為丟出狀態
			
			upPosition = 1;				// 預設為 向上
			horizonPosition = 0;		// 預設為 正中間方向
		end


		// 判斷 向左
		if(left)
			if(plat_position>0)
			begin
				plat_position <= plat_position-1;
				if(handsOn==1)ball_position <= ball_position-1;
			end
		
		// 判斷 向右
		if(right)
			if(plat_position<5)
			begin
				plat_position <= plat_position+1;
				if(handsOn==1)ball_position <= ball_position+1;
			end
				
		// 判斷 丟出球
		if(throw)
			if(handsOn)
			begin
				handsOn = 0;
			end
			
	

			
		
		// 下方操作球的運行
		// 除頻用
		if(ballTime<2)
			ballTime <= ballTime+1;
		else
		//開始判斷球的行進
		begin
			ballTime <= 0;
			if(handsOn==0)	// 如果是丟出去的狀態才移動
			begin
				// 先判斷垂直方向
				if(upPosition)
					if(ball_y_position<7)	// 還沒到頂端
						ball_y_position <= ball_y_position+1;
					else
					begin
						ball_y_position <= ball_y_position-1;	// 到頂端就開始往下
						upPosition = 0;
					end
				else
					if(ball_y_position>1)
						ball_y_position <= ball_y_position-1;

				

				// 判斷水平方向
				if(horizonPosition==1)
					if(ball_position<7)
						ball_position <= ball_position+1;	// 範圍內右移
					else
					begin
						horizonPosition = -1;				// 超過範圍就轉向左邊
						ball_position <= ball_position-1;
					end
				else if(horizonPosition==-1)
					if(ball_position>0)
						ball_position <= ball_position-1;	// 範圍內左移
					else
					begin
						horizonPosition = 1;					// 超過範圍就轉向右邊
						ball_position <= ball_position+1;
					end
					
				// 判斷特殊狀況(碰到板子)
				if(ball_y_position==1)
					if(ball_position==plat_position)
					begin
						if(horizonPosition==0) horizonPosition = -1;
						else ball_y_position <= ball_y_position+1;
						upPosition = 1;
					end 
					else if(ball_position==plat_position+1)
					begin
						upPosition = 1;
						ball_y_position <= ball_y_position+1;
					end
					else if(ball_position==plat_position+2)
					begin
						if(horizonPosition==0) horizonPosition = 1;
						else ball_y_position <= ball_y_position+1;
						upPosition = 1;
					end
					else if(ball_position==plat_position-1 && horizonPosition==1)
					begin
						horizonPosition = -1;
						ball_position <= ball_position-1;
						ball_y_position <= ball_y_position+1;
						upPosition = 1;
					end
					else if(ball_position==plat_position+3 && horizonPosition==-1)
					begin
						horizonPosition = 1;
						ball_position <= ball_position+1;
						ball_y_position <= ball_y_position+1;
						upPosition = 1;
					end
					else
					begin
						horizonPosition = 0;
						ball_y_position <= ball_y_position-1;
					end




				// // 判斷特殊狀態
				if(ball_y_position==6)
					if(blockSecond[ball_position]==1)
					begin
						blockSecond[ball_position] = 0;

						if(upPosition) upPosition = 0;
						else upPosition = 1;
						
						if(ball_position==0) horizonPosition = 1;
						if(ball_position==7) horizonPosition = -1;

						ball_position <= ball_position + horizonPosition;
						if(upPosition) ball_y_position <= ball_y_position +1;
						else ball_y_position <= ball_y_position -1;
					end
				
			end
		end
	end
	
	
	// 顯示用
	always @(posedge divclk)
	begin
		reg [0:2]row;
		
		// 跑 0~7 行
		if(row>=7)
			row <= 3'b000;
		else
			row <= row + 1'b1;
		
		// 設定這次要畫第 n 行
		led[24:26] = row;
		
		// 開始畫板子 ( R )
		if(row==plat_position || row==plat_position+1 || row==plat_position+2)
			led[0:7] = 8'b11111110;
		else
			led[0:7] = 8'b11111111;
			
			
		// 開始畫球 ( G )
		if(handsOn)
			if(row==plat_position+1)		// 放在正中間
				led[8:15] = 8'b11111101;
			else
				led[8:15] = 8'b11111111;
		else
			if(row==ball_position)
			begin
				reg [7:0] map;
				case(ball_y_position)
					3'b000: map = 8'b11111110 ;
					3'b001: map = 8'b11111101 ;
					3'b010: map = 8'b11111011 ;
					3'b011: map = 8'b11110111 ;
					3'b100: map = 8'b11101111 ;
					3'b101: map = 8'b11011111 ;
					3'b110: map = 8'b10111111 ;
					3'b111: map = 8'b01111111 ; 
				endcase
				led[8:15] = map;
			end
			else
				led[8:15] = 8'b11111111;
		
		//開始畫磚塊
		led[16:23] = {~blockFirst[row], ~blockSecond[row], 6'b111111};
	end
endmodule


// 顯示用的除頻器
module divfreq(input CLK, output reg CLK_div);
	reg[24:0] Count;
	always @(posedge CLK)
	begin
		if(Count>25000)
			begin
				Count <= 25'b0;
				CLK_div <= ~CLK_div;
			end
		else
			Count <= Count + 1'b1;
	end
endmodule


// 按鈕用的除頻器
module buttondivfreq(input CLK, output reg CLK_div);
	reg[24:0] Count;
	always @(posedge CLK)
	begin
		if(Count>2500000)			// 20 Hz
			begin
				Count <= 25'b0;
				CLK_div <= ~CLK_div;
			end
		else
			Count <= Count + 1'b1;
	end
endmodule