#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_ARG_LENGTH 1000

#define VERSION "1.0"

// TODO: Check file modification date and only recompile if binary is older.

typedef struct {
  char full_path[MAX_ARG_LENGTH];
  char name[MAX_ARG_LENGTH];
  char exec_name[MAX_ARG_LENGTH];
  char dest_path[MAX_ARG_LENGTH + 6]; // /tmp/ + exec_name + \0
} file_info;

void parse_flags(char argv[][MAX_ARG_LENGTH], file_info* fi) {
  if (strcmp(argv[1], "--version") == 0) {
    printf("cr version: %s\n", VERSION);
    exit(0);
  }

  strncpy(fi->full_path, argv[1], (sizeof(fi->full_path) / sizeof(char)) - 1);
  const char* delim = "/";
  char* first_token = strtok(argv[1], delim);

  if (first_token == NULL) {
    strncpy(fi->name, argv[1], (sizeof(fi->full_path) / sizeof(char)) - 1);
  } else {
    char* prev_token = first_token;
    char* cur_token = first_token;
    while (cur_token != NULL) {
      prev_token = cur_token;
      cur_token = strtok(NULL, delim);
    }

    strncpy(fi->name, prev_token, (sizeof(fi->full_path) / sizeof(char)) - 1);
  }

  strncpy(fi->exec_name, fi->name, sizeof(fi->exec_name) / sizeof(char));
  fi->exec_name[strlen(fi->exec_name) - 2] = '\0';
  strncpy(fi->dest_path, "/tmp/", (sizeof(fi->dest_path) / sizeof(char)) - 1);
  strncat(fi->dest_path, fi->exec_name, (sizeof(fi->dest_path) / sizeof(char)) - 1);
}

int main(int argc, char* argv[]) {
  if (argc < 2) {
    printf("ERROR: Path to C file must be specified.\n");
    return 1;
  }

  file_info fi;
  char argv_copy[argc][MAX_ARG_LENGTH];
  for (int i = 0; i < argc; i++) {
    strncpy(argv_copy[i], argv[i], MAX_ARG_LENGTH);
  }
  parse_flags(argv_copy, &fi);

  const int cmd_max_len = strlen("gcc ") + sizeof(fi.full_path) / sizeof(char) + strlen(" -o ") + sizeof(fi.dest_path) / sizeof(char);
  char cmd[cmd_max_len];
  strcpy(cmd, "gcc ");
  strcat(cmd, fi.full_path);
  strcat(cmd, " -o ");
  strcat(cmd, fi.dest_path);
  strcat(cmd, "\0");

  system(cmd);
  system(fi.dest_path);
  
  return 0;
}