#include "cpu.h"
#include "ram.h"
#include "rom.h"

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#define MACHINE_SPEED_HZ 1e6 // 1 MHz;

static struct termios orig_termios;
static struct timespec sleepTime;

void restore_terminal(void) { tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios); }

void set_nonblocking_input(void) {
  struct termios raw;

  tcgetattr(STDIN_FILENO, &orig_termios);
  atexit(restore_terminal);

  raw = orig_termios;
  raw.c_lflag &= ~(ICANON | ECHO); // disable line buffering and echo
  raw.c_cc[VMIN] = 0;              // don't block waiting for input
  raw.c_cc[VTIME] = 0;
  tcsetattr(STDIN_FILENO, TCSANOW, &raw);

  // make stdin reads non-blocking too
  int flags = fcntl(STDIN_FILENO, F_GETFL, 0);
  fcntl(STDIN_FILENO, F_SETFL, flags | O_NONBLOCK);
}

int main(void) {
  uint8_t *ram = NULL;
  CPU cpu;

  set_nonblocking_input();

  initRom(rom);

  if (createRAM(&ram) != 0) {
    printf("Could not create RAM\n");
    return 1;
  }

  /* DEBUG */

  //FILE *fp = fopen("/Users/Kili2/Documents/Projekte/6502pc/6502_65C02_functional_tests/6502_functional_test.bin", "rb");
  //FILE *fp = fopen("/Users/Kili2/Documents/Projekte/6502pc/6502_65C02_functional_tests/6502_decimal_test.bin", "rb");
  FILE *fp = fopen("/mnt/c/Users/llego/source/repos/6502PC/6502_65C02_functional_tests/6502_functional_test.bin", "rb");
  //FILE *fp = fopen("/mnt/c/Users/llego/source/repos/6502PC/6502_65C02_functional_tests/6502_decimal_test.bin", "rb");
  if (!fp) {
    perror("fopen");
    return 1;
  }

  fread(ram, 1, RAM_SIZE, fp);
  if (ferror(fp)) {
    perror("fread");
    fclose(fp);
    return 1;
  }

  fclose(fp);

  /* DEBUG END*/

  initCPU(&cpu);
  resetCPU(&cpu, rom);

  while (1) {
    uint8_t sleep = runCycle(&cpu, ram, rom);
    if (sleep == 1) {
      printf("opcode missing: 0x%X\n", ram[cpu.ProgrammeCounter - 1]);
      return 1;
    }
    sleepTime.tv_sec = 0;
    sleepTime.tv_nsec = sleep * (1000 / MACHINE_SPEED_HZ);
    nanosleep(&sleepTime, NULL);
  }

  destroyRAM(ram);

  return 0;
}