/* 
  FINAL PROJECT
  this program will implement the "follow me"  1 player game
  it will be used to drive the 8052 chip in order to achieve correct 
  functionality of the game  
  Amin Aun
  xxx-xx-1222
  cs122aao@cs.ucr.edu
*/      

#pragma SMALL DB OE
#include <reg51.h>
#include "io.h"
#include <stdlib.h>

sbit latch0 = P3^2;
sbit latch1 = P3^3;
sbit light0 = P3^7;     
sbit light1 = P3^6;
sbit light2 = P3^5;
sbit light3 = P3^4;
sbit decoder_enable = P0^0; 




//Delay function
void delay() 
{
	int i, j;

	for(i=0; i<1000; i++)
	{
	  for(j=0; j<100; j++)
	  {
	    i = i + 0;
	  }
	}
}

void initialize_latches (  )
{
	decoder_enable = 1;
	light0 = 0;     
	light1 = 0;
	light2 = 0;
	light3 = 0;

 
	latch0 = 0;
	latch1 = 0;     


	
	latch0 = 0;
	latch1 = 1;


	
	latch0 = 1;
	latch1 = 0;

	

	latch0 = 1;
	latch1 = 1;

	decoder_enable = 0;     
}

//this global variable will be used as the seed for the srand function, 
//in order to choose a random seed table every time for every execution of the
//follow me game
int seed;


/* The functions to initialize and control the LCD are assumed to be in the 
file io.c */

/* Function to output the decimal value of the result on the LCD */
void PrintInt(int i) {

	char negative = '0';
	char ch[4];
		     
	//If the answer is a negative number, print out the absolute
	//value and the "-" character
	if ( i < 0 )
	{
	  i = i * -1;
	  negative = '1';
	}   

	//Write code to convert the count to a string value and use the
	//PrintString function provided in io.c 
	
	//devide i by ten to attain the first character in the string
	ch[0] = '0' + (i / 10);

	//mod i by 10 to get the second character in the string
	ch[1] = '0' + (i % 10);
	ch[2] = '\0';

	//ClearScreen ( );    

	if ( negative == '1' )
	{   
	  PrintString ( "-" );
	}

	PrintString (ch);
	delay(); 
}

/* Routine to scan the key pressed */
unsigned char key_scan(int flag)
{
	unsigned char i, j, temp1, temp2;
	unsigned char position;
 
	//set the global variable to 0 for every call of this function so that
	//the timer achieves a different value
	seed = 0;

	while( 1 ) /* keep waiting for a key to be pressed */
	{

	  for(i=0; i<4; i++) 
	  {
	     
	    /* Set each row to 0 */
	    P1 = 0xff & ~(1<<i); 

	    /* Scan each column to see which key was pressed */
	    for (j=4; j<8; j++)
	    {

	      //increment the seed variable as a counter for the amount of 
	      //time that that it takes the user to press the button    
	      seed = seed + 1;

	      //the counter will also be used to determine if the user has not 
	      //pressed a key in a predetermined amount of time
	      if ( seed > 10000 && flag == 0 )
	      {
		return position;
	      }
 
	      //store the value at port 1 into an unsigned register
	      temp1 = P1;
				
	      //do an bitwise AND operation on the complemented value 
	      //from port 1 using
	      //a 1 bit shifted j times, if the value at that bit position 
	      //was set to zero by the pressing of a key, then this XOR
	      //operation will produce a value greater than zero
	      if ( (~temp1 & (1<<j)) > 0 ) 
	      {
		temp1 = i * 4;
		temp2 = j - 4;
		position = temp1 + temp2;
		return position;                                        
	      }
	    }
	  }
	}
}

void main() {


	//this number will be used to lite up one of the led lights 
	unsigned char random_light;

	//this will be used to lite up one of the rows
	unsigned char row;

	//this will be used to lite up one of the coloums
	unsigned char coloum;

	//this number will correspond to the button pressed by the user
	int button_input;       
	int button_input2;
		
	//this will be used to activate the led lights and differnt intervals
	int random_interval;
	
	//this variable will represent the number of points that the user has 
	//scored in playing the game
	int score = 0;  

	//this variable will represent a watchdog timer in that it will count 
	//down a predetermined amount of time until the user has pressed a 
	//button, if the user does not press a button

	/* You can have a conversion table to convert the key position into a
	   valid number which indicates the position of a button */

	int conv_table[] = {

		 0, 1, 2, 3, 
		 4, 5, 6, 7, 
		 8, 9, 10, 11, 
		12, 13, 14, 15 
	};
	

	InitIO();

	while (1)
	{       

		if ( score < -99 )
		{
			ClearScreen ( );
			button_input2 = conv_table[key_scan(0)];
			button_input = button_input2;
			do 
			{
				GotoXY ( 0, 0 );
				PrintString ("GAME OVE");
				GotoXY (1, 0 );
				PrintString ( "R :-(" );
				delay ( );
				ClearScreen ( );
				PrintString("Press to");
				GotoXY ( 1, 0 );
				PrintString(" play ");
				button_input = conv_table[key_scan(0)];
			} while ( button_input == button_input2 );                               
		}

		if ( score > 99 )
		{
			ClearScreen ( );
			button_input2 = conv_table[key_scan(0)];
			button_input = button_input2;
			do 
			{
				GotoXY ( 0, 0 );
				PrintString ("YOU WIN!!!");
				GotoXY (1, 0 );
				PrintString ( "R :-)" );
				delay ( );
				ClearScreen ( );
				PrintString("Press to");
				GotoXY ( 1, 0 );
				PrintString(" play ");
				button_input = conv_table[key_scan(0)];
			} while ( button_input == button_input2 );                              
		}

		score = 0;
		//set all lights low
		initialize_latches (  );
		
		ClearScreen ( );
		delay ( );
		PrintString("Press to");
		GotoXY ( 1, 0 );
		PrintString(" start");
	
		//wait for user to press a button
		button_input = conv_table[key_scan(1)]; 
		ClearScreen ( );
	
		//now take the variable counter which was set inside key_scan and 
		//use it as a seed value to select a random seed table
		srand( seed );          

		while( score >= -99 && score <= 99 ) 
		{                                                      
			ClearScreen ( );
			PrintString ("SCORE: " );
			GotoXY ( 1, 0 );
			PrintInt ( score );
			delay ( );      

		
			//make a timer that waits a random amount of time in order to 
			//light up the an led at different intervals
			random_interval = rand ( ) % 1000;
		
			for ( ; random_interval != 0; random_interval-- );
						
			//set the led
			random_light = rand() % 16; 

			//ClearScreen ( );
			//PrintString ("position" );
			//GotoXY ( 1, 0 );
			//PrintInt ( random_light );            

			row = random_light/4;
			coloum = random_light%4;

			switch (coloum)
			{       
				case 0:
					light0 = 1;     
					light1 = 0;
					light2 = 0;
					light3 = 0;
					break;
				case 1:
					light0 = 0;     
					light1 = 1;
					light2 = 0;
					light3 = 0;
					break;
				case 2:
					light0 = 0;     
					light1 = 0;
					light2 = 1;
					light3 = 0;
					break;
				case 3:
					light0 = 0;     
					light1 = 0;
					light2 = 0;
					light3 = 1;
					break;
				default:
					light0 = 0;     
					light1 = 0;
					light2 = 0;
					light3 = 0;
					break;
			}

			switch ( row )
			{
				case 0:
					latch0 = 0;
					latch1 = 0;
				
					decoder_enable = 1;
	
					delay ( );
					decoder_enable = 0;
					break;
				case 1:
					latch0 = 1;
					latch1 = 0;
			
					decoder_enable = 1;
	
					delay ( );
					decoder_enable = 0;
					break;
				case 2:
					latch0 = 0;
					latch1 = 1;
	
					decoder_enable = 1;

					delay ( );
					decoder_enable = 0;
					break;
				case 3:
					latch0 = 1;
					latch1 = 1;
	
					decoder_enable = 1;                             

					delay ( );
					decoder_enable = 0;
					break;
				default:
					latch0 = 0;
					latch1 = 0;
	
					decoder_enable = 1;

					delay ( );
					decoder_enable = 0;
					break;
			}



	
			//wait for user to press a button
			button_input = conv_table[key_scan(0)];
					
			//set lights low 
			light0 = 0;     
			light1 = 0;
			light2 = 0;
			light3 = 0;
			decoder_enable = 1;
			delay ( );
			decoder_enable = 0;

			//if the user pressed the wrong button then notify the user 
			//that they have
			//lost one point 
			if ( random_light != button_input && seed < 1000 )  
			{
				ClearScreen ( );
				PrintString  ( "WRONG BU" );
				GotoXY (1, 0 );
				PrintString ( "TON: -1" );
				score--;
			}       


			//if the user has not pressed the button in the specified 
			//amount of time
			//notify the user that they have lost five points
			else if ( seed >= 1000 )
			{       
				ClearScreen ( );
				PrintString  ( "TOO SLOW" );
				GotoXY (1, 0 );
				PrintString ( " MINUS 5" );
				score = score - 5;
			}
	
			//if the button corresponds to the correct light pressed, then 
			//notify the user that they have earned a point 
			else if ( random_light == button_input ) 
			{
				ClearScreen ( );
				PrintString ("HIT!!! P" );
				GotoXY (1, 0 );
				PrintString ( "LUS 1" );                       
				score++;
			}       
		

			delay ( );                                                              
	       }
	}
}