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

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

// 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__)) {
    if (fork() == 0) {
      char* args[] = {"gcc", __FILE__, "-o", argv[0], NULL};
      print_cmd(args);
      execvp(args[0], args);
      return 0;
    } else {
      wait(NULL);
      print_cmd(argv);
      execvp(argv[0], argv);
    }
  }

  if (fork() == 0) {
    char* args[] = {"mkdir", "-p", "output", NULL};
    print_cmd(args);
    execvp(args[0], args);
    return 0;
  } else {
    wait(NULL);
  }

  if (argc > 1) {
    if (strcmp(argv[1], "test") == 0) {
      printf("Test mode\n");
      if (fork() == 0) {
        char* args[] = {"gcc", "generate/find_tests.c", "-o", "output/find_tests.o", NULL};
        print_cmd(args);
        execvp(args[0], args);
        return 0;
      } else {
        wait(NULL);
      }
      if (fork() == 0) {
        char* args[] = {"./output/find_tests.o", NULL};
        print_cmd(args);
        execvp(args[0], args);
        return 0;
      } else {
        wait(NULL);
      }
      printf("\n");
      if (fork() == 0) {
        char* args[] = {"gcc", "tests/main.c", "-o", "output/test.o", NULL};
        print_cmd(args);
        execvp(args[0], args);
        return 0;
      } else {
        wait(NULL);
      }

      char* args[] = {"./output/test.o", NULL};
      print_cmd(args);
      execvp(args[0], args);
      return 0;
    }
    if (strcmp(argv[1], "server") == 0) {
      printf("Server mode\n");
      if (fork() == 0) {
        char* args[] = {"gcc", "src/server.c", "-lcrypto", "-o", "output/server.o", NULL};
        print_cmd(args);
        execvp(args[0], args);
        return 0;
      } else {
        wait(NULL);
      }

      char* args[] = {"./output/server.o", "./output/main.o", NULL};
      print_cmd(args);
      execvp(args[0], args);
      return 0;
    }
  }

  if (fork() == 0) {
    char* args[] = {"gcc", "src/main.c", "-o", "output/main.o", NULL};
    print_cmd(args);
    execvp(args[0], args);
    return 0;
  } else {
    wait(NULL);
  }

  char* args[] = {"./output/main.o", NULL};
  print_cmd(args);
  execvp(args[0], args);
  return 0;
}