#include "keyboard.h"

uint8_t scan_code=0;            // make code or break code
int keyboard_id = KEYBOARD_IRQ; 	// KEYBOARD_IRQ is defined in interrupt.h in .minix-src folder
uint32_t cnt = 0;									// counter of sys_inb calls

int (util_sys_inb)(int port, uint8_t *value) { //transform 8 bit into 32 bit

  uint32_t new_val;                           //initializing 32 bit variable

  if(sys_inb(port,&new_val)!=0){              //verifies if there is an error
      printf("Error in util_sys_inb\n");
      return 1;
  }
  *value=new_val & 0xFF;                      //dereferencing "value"
  #ifdef LAB3
  cnt++;
  #endif

  return 0;
}

void (kbc_ih)(void){
  uint8_t status_reg;

  if(util_sys_inb(STATUS_REG,&status_reg)!=0){ //checks if there is an error
    return;
  }
  if(((status_reg & STAT_REG_OBF)==0) ||((status_reg&(STAT_REG_PAR|STAT_REG_TIMEOUT))!=0)|| ((status_reg&STAT_REG_AUX)!=0)){ //checks if there is a parity or timeout error (mask -> 0xC0, bit 7 and 6 set), checks if output buffer is empty and checks if there is data coming from the mouse
    return;
  }
  util_sys_inb(OUTPUT_BUF,&scan_code);

}


int (kbc_subscribe_int)(uint8_t *bit_no) {    //similar function to that of timer_subscribe_int
    *bit_no = BIT(keyboard_id);
    if(sys_irqsetpolicy(KEYBOARD_IRQ,(IRQ_REENABLE|IRQ_EXCLUSIVE),&keyboard_id)==1){      //operation to subscribe int
        printf("Error subscribing int\n");
        return 1;
    }
  return 0;
}

int (kbc_unsubscribe_int)() {           //similar function to that of timer_unsubscribe_int
  if(sys_irqrmpolicy(&keyboard_id)==1){
      printf("Error unsubscribing int\n");
      return 1;
  }
  return 0;
}

int (enable_interrupt)()
{
  uint8_t command;

  if(sys_outb(STATUS_REG,READ_COMMAND)!=0){
    printf("Error writing read-command\n");
    return 1;
  }

  if(util_sys_inb(OUTPUT_BUF, &command)!=0){
    printf("Error reading output buffer\n");
    return 1;
  }

  command = command | INT_ENABLE;

  if(sys_outb(STATUS_REG,OUTPUT_BUF)!=0){
    printf("Error writing output buffer\n");
    return 1;
  }

  if(sys_outb(OUTPUT_BUF,command)!=0){
    printf("Error writing new buffer status\n");
    return 1;
  }

  return 0;
}