#include "keyboard.h"
#include <stdlib.h>

/*
 * https://wiki.osdev.org/%228042%22_PS/2_Controller
 * https://wiki.osdev.org/PS/2_Keyboard
 */

constexpr uint8_t comm_enable_first_ps2 = 0xae;
constexpr uint8_t comm_read_ctrl_config = 0x20;
constexpr uint8_t comm_write_ctrl_config = 0x60;

constexpr uint8_t dat_enable_scanning = 0xf4;

Keyboard::Keyboard() : InterruptHandler(0x01) {
  // eat all previous keystrikes
  while (commstatport.read() & 0x1) {
    [[maybe_unused]] auto _c = dataport.read();
  }
  commstatport.write(comm_enable_first_ps2);
  commstatport.write(comm_read_ctrl_config);
  const uint8_t conf = (dataport.read() | 1) & ~0x10;
  commstatport.write(comm_write_ctrl_config);
  dataport.write(conf);
  dataport.write(dat_enable_scanning);
}

cpu_state_t* Keyboard::trigger(cpu_state_t* cpu) {
  const auto key = dataport.read();

  if (key < 0x80) {
    switch (key) {
      case 0x04:
        printk('3');
        break;
      case 0x05:
        printk('4');
        break;
      case 0x06:
        printk('5');
        break;
      case 0x07:
        printk('6');
        break;
      case 0x08:
        printk('7');
        break;
      case 0x09:
        printk('8');
        break;
      case 0x0A:
        printk('9');
        break;
      case 0x0B:
        printk('0');
        break;

      case 0x10:
        printk('q');
        break;
      case 0x11:
        printk('w');
        break;
      case 0x12:
        printk('e');
        break;
      case 0x13:
        printk('r');
        break;
      case 0x14:
        printk('t');
        break;
      case 0x15:
        printk('y');
        break;
      case 0x16:
        printk('u');
        break;
      case 0x17:
        printk('i');
        break;
      case 0x18:
        printk('o');
        break;
      case 0x19:
        printk('p');
        break;

      case 0x1E:
        printk('a');
        break;
      case 0x1F:
        printk('s');
        break;
      case 0x20:
        printk('d');
        break;
      case 0x21:
        printk('f');
        break;
      case 0x22:
        printk('g');
        break;
      case 0x23:
        printk('h');
        break;
      case 0x24:
        printk('j');
        break;
      case 0x25:
        printk('k');
        break;
      case 0x26:
        printk('l');
        break;

      case 0x2C:
        printk('z');
        break;
      case 0x2D:
        printk('x');
        break;
      case 0x2E:
        printk('c');
        break;
      case 0x2F:
        printk('v');
        break;
      case 0x30:
        printk('b');
        break;
      case 0x31:
        printk('n');
        break;
      case 0x32:
        printk('m');
        break;
      case 0x33:
        printk(',');
        break;
      case 0x34:
        printk('.');
        break;
      case 0x35:
        printk('/');
        break;

      case 0x1C:
        printk('\n');
        break;
      case 0x39:
        printk(' ');
        break;

      default:
        printk("keyboard interrupt: ", uhex{key}, "\n");
        break;
    }
  }

  return cpu;
}