#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vm/fzl_vm.h>

typedef struct
{
  char *filepath;
  bool help;
  bool debug;
} run_args_t;

void print_hint()
{
  printf("Usage: fz [flags] <file path>\n");
  printf("Flags:\n");
  printf("\t-h\t--help\tprint usage information\n");
}

// Parse passed arguments and build args setup structure
run_args_t *parse_args(int argc, char **argv)
{
  if (argc < 2)
  {
    print_hint();
    return NULL;
  }

  run_args_t *args = malloc(sizeof(run_args_t));
  args->filepath   = NULL;
  args->help       = false;
  args->debug      = false;

  for (int i = 0; i < argc; i++)
  {
    if (argv[i][0] != '-')
      continue;

    if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0)
    {
      args->help = true;
      return args;
    }
    else if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--debug") == 0)
      args->debug = true;
    else
    {
      printf("Error: unknown flag '%s'.\n", argv[i]);
      printf("Use 'fz --help' to read the usage\n");
      free(args);
      return NULL;
    }
  }

  if (argv[argc - 1][0] == '-')
  {
    printf("Error: last argument MUST be a file path\n");
    printf("Use 'fz --help' for help\n");
    free(args);
    return NULL;
  }

  args->filepath = argv[argc - 1];

  return args;
}

int main(int argc, char **argv)
{
  run_args_t *args = parse_args(argc, argv);
  if (!args)
    return -1;
  else if (args->help)
  {
    print_hint();
    free(args);
    return 0;
  }

  fzl_vm_t *vm = fzl_mkvm(args->filepath);
  if (!vm)
  {
    printf("Error: %s\n", fzl_vm_geterror());
    free(args);
    return -1;
  }

  if (args->debug)
    fzl_vm_print_ops(vm);
  else
  {
    int result = fzl_vm_run(vm);
    if (result != 0)
    {
      char *err = fzl_vm_geterror();
      if (err && err[0])
        printf("Error: %s\n", err);

      free(args);
      fzl_freevm(vm);
      return -1;
    }
  }

  free(args);
  fzl_freevm(vm);

  return 0;
}