#include <amd64/debug.h>
#include <amd64/io.h>
#include <libk/printf.h>
#include <libk/std.h>
#include <libk/string.h>
#include <sync/spin_lock.h>
#include <sys/debug.h>

/* Port for printing to serial */
/* TODO: Make this configurable */
#define PORT_COM1 0x03F8
/* debugprintf buffer size */
#define BUFFER_SIZE 1024

static spin_lock_t debug_lock = SPIN_LOCK_INIT;

static bool debug_is_init = false;

/* Block until TX buffer is empty */
static bool debug_serial_tx_empty(void) { return (bool)(inb(PORT_COM1 + 5) & 0x20); }

/* Write a single character to serial */
static void debug_serial_write(char x) {
  while (!debug_serial_tx_empty())
    ;
  outb(PORT_COM1, (uint8_t)x);
}

/*
 * Formatted printing to serial. serial_lock ensures that all prints are atomic.
 */
void debugprintf(const char* fmt, ...) {
  if (!debug_is_init)
    return;

  char buffer[BUFFER_SIZE];
  memset(buffer, 0, sizeof(buffer));

  va_list ap;
  va_start(ap, fmt);
  vsnprintf(buffer, sizeof(buffer), fmt, ap);
  va_end(ap);

  buffer[sizeof(buffer) - 1] = '\0';

  const char* p = buffer;

  spin_lock(&debug_lock);

  while (*p) {
    debug_serial_write(*p);
    p++;
  }

  spin_unlock(&debug_lock);
}

void debugprintf_nolock(const char* fmt, ...) {
  if (!debug_is_init)
    return;

  char buffer[BUFFER_SIZE];
  memset(buffer, 0, sizeof(buffer));

  va_list ap;
  va_start(ap, fmt);
  vsnprintf(buffer, sizeof(buffer), fmt, ap);
  va_end(ap);

  buffer[sizeof(buffer) - 1] = '\0';

  const char* p = buffer;

  while (*p) {
    debug_serial_write(*p);
    p++;
  }
}

/* Initialize serial */
void debug_init(void) {
  outb(PORT_COM1 + 1, 0x00);
  outb(PORT_COM1 + 3, 0x80);
  outb(PORT_COM1 + 0, 0x03);
  outb(PORT_COM1 + 1, 0x00);
  outb(PORT_COM1 + 3, 0x03);
  outb(PORT_COM1 + 2, 0xC7);
  outb(PORT_COM1 + 4, 0x0B);

  debug_is_init = true;
}