#include <stdio.h>
#include <port_io.h>

#include <drivers/ps2_keyboard.h>


/*
PS/2 Controller IO Ports

The PS/2 Controller itself uses 2 IO ports (IO ports 0x60 and 0x64). Like many IO ports, reads and writes may access different internal registers.

Historical note: The PC-XT PPI had used port 0x61 to reset the keyboard interrupt request signal (among other unrelated functions). Port 0x61 has no keyboard related functions on AT and PS/2 compatibles.
IO Port  Access Type  Purpose
0x60 	 Read/Write   Data Port
0x64 	 Read 	     Status Register
0x64 	 Write 	     Command Register
*/

#define PS2_DATA_PORT   0x60
#define PS2_STATUS_PORT 0x64

#define KEYBOARD_IRQ    33

/*extern void register_interrupt_handler(int irq, void (*handler)(void));*/

static const char scancode_map[128] = {
    0,  27, '1','2','3','4','5','6','7','8','9','0','-','=','\b', /* Backspace */
    '\t', /* Tab */
    'q','w','e','r','t','y','u','i','o','p','[',']','\n', /* Enter */
    0, /* Control */
    'a','s','d','f','g','h','j','k','l',';','\'','`',
    0, /* Left shift */
    '\\','z','x','c','v','b','n','m',',','.','/',
    0, /* Right shift */
    '*',
    0, /* Alt */
    ' ', /* Spacebar */
    0, /* Caps lock */
    /* The rest are function and control keys */
};

static bool shift_pressed = false;

void keyboard_handler(isr_stack_t* regs)
{
  (void)regs; /* Only here to dismiss the "Unused parameter" warnings */
  printd("PS/2 Keyboard handler fired!\n");

  uint8_t scancode = inb(PS2_DATA_PORT);

  /* Handle shift press/release */
  if (scancode == 0x2A || scancode == 0x36)
  {
    shift_pressed = true;
    return;
  }
  else if (scancode == 0xAA || scancode == 0xB6)
  {
    shift_pressed = false;
    return;
  }

  if (scancode & 0x80)
  {
    /* Key release event, ignore for now */
  }
  else
  {
    char c = scancode_map[scancode];
    if (shift_pressed && c >= 'a' && c <= 'z') 
    {
      c -= 32; /* Convert to uppercase */
    }

    if (c)
    {
      /* Do something with the keypress (e.g., print or buffer) */
      printf("Char: %c", c);
    }
  }
  
  outb(0x20, 0x20); /* Acknowledge PIC */
}

void test_handler(isr_stack_t* r) {
    printf("IRQ1 fired!\n");
}


void keyboard_init(void)
{
  outb(0x21, inb(0x21) & ~0x02);
  
  register_interrupt_handler(KEYBOARD_IRQ, test_handler);

  /* Enable keyboard (controller-specific, often optional if already working) */
  //outb(0x64, 0xAE);
}