#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <time.h>
#include <string.h>

#define GLOBAL_INCLUDE "-Iinclude/"

#define CC "gcc", "-fsanitize=address", "-g", GLOBAL_INCLUDE

#define ENGINE_O "output/engine.o"
#define UCI_O "output/uci.o"
#define IPC_O "output/ipc.o"

#define MAIN_O "output/main.o"

int status;

#define RUN_CMD(...) do { \
  if (fork() == 0) { \
    char* args[] = __VA_ARGS__; \
    print_cmd(args); \
    execvp(args[0], args); \
    return 0; \
  } else { \
    wait(&status); \
  } \
} while (0);

void print_cmd(char** args) {
  int i = 0;
  while (args[i] != NULL) {
    printf("%s ", args[i++]);
  }
  printf("\n");
}

int clean_mode(int run_mode);
int test_mode(int run_mode);
int uci_mode(int run_mode);

// https://github.com/tsoding/nob.h/blob/0a08926d8094fc4ae678155c5d73ae21d1f96f3f/nob.h#L2413
int needs_rebuild(char* bin_file, char* source_file) {
  struct stat statbuf = {0};
  if (stat(bin_file, &statbuf) < 0) {
    if (errno == ENOENT) return 1;
    return -1;
  }
  time_t output_path_time = statbuf.st_mtime;

  if (stat(source_file, &statbuf) < 0) {
    fprintf(stderr, "could not stat %s: %s", source_file, strerror(errno));
    return -1;
  }

  time_t input_path_time = statbuf.st_mtime;
  return input_path_time > output_path_time;
}

int main(int argc, char** argv) {
  if (needs_rebuild(argv[0], __FILE__)) {
    RUN_CMD({CC, __FILE__, "-o", argv[0], NULL});
    if (status != 0) {
      // cc error
      return 0;
    }
    print_cmd(argv);
    execvp(argv[0], argv);
  }

  RUN_CMD({"mkdir", "-p", "output", NULL});

  if (argc <= 1) return 1;
  int run_mode = argc == 3;

  if (strcmp(argv[1], "test") == 0) {
    return test_mode(run_mode);
  }
  if (strcmp(argv[1], "clean") == 0) {
    return clean_mode(run_mode);
  }
  return uci_mode(run_mode);
}

int clean_mode(int _) {
  char* args[] = {"rm", "-r", "output", NULL};
  print_cmd(args);
  execvp(args[0], args);
  return 0;
}

int test_mode(int run_mode) {
  if (run_mode) {
    char* args[] = {"./output/test.o", NULL};
    print_cmd(args);
    execvp(args[0], args);
  }

  RUN_CMD({CC, "tests/find_tests.c", "-o", "output/find_tests.o", NULL});
  RUN_CMD({"./output/find_tests.o", NULL});
  printf("\n");
  RUN_CMD({CC, "tests/main.c", "-o", "output/test.o", NULL});
  return status != 0;
}

int uci_mode(int run_mode) {
  if (run_mode) {
    char* args[] = {MAIN_O, NULL};
    print_cmd(args);
    execvp(args[0], args);
  }

  RUN_CMD({CC, "-c", "src/ipc.c", "-o", IPC_O, NULL});
  RUN_CMD({CC, "-c", "src/engine.c", "-o", ENGINE_O, NULL});
  RUN_CMD({CC, "-c", "src/uci.c", "-o", UCI_O, NULL});
  RUN_CMD({CC, "src/main.c", UCI_O, ENGINE_O, IPC_O, "-o", MAIN_O, NULL});
  return status != 0;
}