// global variables declaration

char i = 0 , m = 0 , error = 0 ;
const int number[]={'y','y',3,2,1,'x',6,5,4,'x',9,8,7,'x','x',0 ,'y'} ;
char temp[6] ;
char temp2[6] ;
char attempts = 0 ;
unsigned cnt ;


void interrupt()
{
     cnt++;
     intcon = 0x20 ;
}

                                // subroutines
void tone1()
{
     sound_play ( 659, 250 ) ;
}
void tone2()
{
     sound_play ( 698, 250 ) ;
}
void Tone3()
{
     sound_play ( 784, 250 ) ;
}
void melody()
{
           cnt = 0 ; tmr0 = 0 ;
           while( cnt < 36621 && keypad_read()!= 16 )   // 5-minute alarm until long press on *
           {
                     tone1(); tone2(); tone3(); tone3();
                     tone1(); tone2(); tone3(); tone3();
                     tone1(); tone2(); tone3();
                     tone1(); tone2(); tone3(); tone3();
                     tone1(); tone2(); tone3();
                     tone3(); tone3(); tone2(); tone2(); tone1();
           }


          stop_alarm : portc.f3 = 0 ;
}


void set_new_pass()
{
     lcd_cmd(lcd_clear) ;
     lcd_out(1,1,"ENTER NEW PASS:") ;
     lcd_cmd(lcd_second_row) ;
     i = 0 ;
     while(portc.f2==0) {}
     get_new_pass :

     if(portc.f2==0)                  // if CANCEL button is pressed
     {

            if(i!=0)
            {
                    while(portc.f2==0) {}
                    if(eeprom_read(i-1)!=temp2[i-1] && error>0 ) error-- ;
                    lcd_out(2,i," ") ;
                    lcd_cmd(lcd_move_cursor_left);
                    i-- ;
                    goto get_new_pass ;
            }
            else goto end_sub ;
     }

     m = 0 ;
     m = keypad_released() ;
     while(m==0 || m==14 ||m==16) goto get_new_pass ;
     lcd_chr_cp('*') ;
     temp[i] = number[m] ;
     i++ ;
     if(i==6) goto confirm_new_pass ;
     goto get_new_pass ;

     confirm_new_pass:
     while(keypad_released() !=14 && portc.f2==1) {}
     if(portc.f2==0) goto get_new_pass ;

     for(i=0;i<6;i++)
     {
                     eeprom_write(i,temp[i]) ;
                     delay_ms(20) ;
     }

    lcd_cmd(lcd_clear) ;
    lcd_out(1,3,"NEW PASS HAS" ) ;
    lcd_out(2,4,"BEEN ADDED") ;
    delay_ms(2000) ;
    end_sub :
    lcd_cmd(lcd_clear) ;


}
void check_old_pass()
{

     start2:
     m = 0 ; i = 0 ; error = 0 ;
     lcd_cmd(lcd_clear) ;
     lcd_out(1,1,"ENTER OLD PASS:") ;
     lcd_cmd(lcd_second_row) ;
     wait2 :
     if(portc.f2==0)                  // if CANCEL button is pressed
     {
            if(i!=0)
            {
                  while(portc.f2==0) {}
                  if(eeprom_read(i-1) != temp2[i-1])
                  {
                              if(error>0) error-- ;
                  }
                  lcd_out(2,i," ") ;
                  lcd_cmd(lcd_move_cursor_left);
                  i-- ;
                  goto wait2 ;
            }
            else goto end_sub ;
     }
     m = keypad_released() ;
     while(m==0 || m==14 || m==16) goto wait2 ;
     lcd_chr_cp('*') ;
     temp2[i] = number[m] ;
     if(eeprom_read(i)!=temp2[i]) error++ ;
     i++ ;
     if(i==6)
     {
                     while(keypad_released()!=14 && portc.f2==1) {}
                     if(portc.f2==0) goto wait2 ;
                     goto compare2 ;
     }
     goto wait2 ;
     compare2:
     if(error!=0)
     {
                     lcd_cmd(lcd_clear) ;
                     lcd_out(1,4,"INVALID!!") ;
                     while(keypad_released()==0) {}
                     goto start2 ;
     }

      else set_new_pass() ;
      end_sub:
      lcd_cmd(lcd_clear) ;
}



                           // main program

void main()
{


     trisb = 0 ; portb = 0 ;
     trisd = 0 ; portd = 0 ;
     trisc.f0 = trisc.f1 = 0 ; portc = 0 ;
     trisc.f2 =1 ;
     trisc.f3 = 0 ;

     option_reg = 0x84;       // Assign prescaler to TMR0
     intcon = 0xA0;           // Enable TMRO interrupt


                      // lcd initialization
     lcd_init(&portb) ;
     lcd_cmd(lcd_cursor_off) ;

                        // keypad initialization
     keypad_init(&portd) ;

                         // sound play initialization
     sound_init(&portc,0) ;

     while(1)
     {
             start :
             if(eeprom_read(0) != 0xff) goto get_current_pass ;
             set_new_pass() ;

             get_current_pass :

             i = 0 ;
             error = 0 ;           // reset error flag
             lcd_cmd(lcd_clear) ;
             lcd_out(1,4,"ENTER PASS:") ;

             lcd_cmd(lcd_second_row) ;


             wait :
             m = 0 ;
             edit:
             if(portc.f2==0)               // if CANCEL button is pressed
             {

                    cnt = 0 ;
                    tmr0 = 0 ;

                    while(portc.f2==0)
                    {
                            if(cnt>=367)
                            {
                                    set_new_pass() ;
                                    goto start ;
                            }
                    }
                            if(i!=0)
                            {
                                    while(portc.f2==0) {}
                                    if(eeprom_read(i-1)!=temp2[i-1] && error>0 ) error-- ;
                                    lcd_out(2,i," ") ;
                                    lcd_cmd(lcd_move_cursor_left);
                                    i-- ;
                                    goto wait ;
                            }

             }

             m = keypad_released() ;
             while(m==0 || m==14) goto wait ;

             if(m==16)
             {
                            check_old_pass() ;
                            goto get_current_pass ;
             }

             lcd_chr_cp('*') ;
             temp2[i] = number[m] ;

             if(eeprom_read(i)!=temp2[i]) error++ ;
             i++ ;
             if(i==6)
             {
                             while(keypad_released()!=14 && portc.f2==1) {}
                             if(portc.f2==0) goto edit ;
                             goto compare ;
             }
             goto wait ;

             compare :
             for(i=0;i<6;i++)
             {
                             if(temp2[i]!=eeprom_read(i)) error++ ;
             }

             if(error!=0)
             {
                             lcd_cmd(lcd_clear) ;
                             lcd_out(1,3,"INVALID PASS") ;
                             error = 0 ;
                             attempts++ ;
                             if(attempts>=3)
                             {
                                            lcd_out( 2,6,"ALARM" ) ;
                                            portc.f3 = 1 ;
                                            melody() ;
                                            goto get_current_pass ;
                             }
                             while(keypad_released()==0) {}
                             goto get_current_pass ;
             }

             else
             {
                             lcd_cmd(lcd_clear) ;
                             lcd_out(1,7,"OPEN") ;
                             portc.f1 = 1 ; delay_ms(5000) ;
                             portc.f1 = 0 ;
                             attempts = 0 ;
            }
}
}