#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mruby.h"
#include "mruby/irep.h"
#include "mruby/dump.h"

struct strip_args {
  mrb_bool lvar;
};


static void
irep_remove_lv(mrb_state *mrb, mrb_irep *irep)
{
  size_t i;

  if (irep->lv) {
    mrb_free(mrb, irep->lv);
    irep->lv = NULL;
  }

  for (i = 0; i < irep->rlen; ++i) {
    irep_remove_lv(mrb, irep->reps[i]);
  }
}

static void
print_usage(const char *f)
{
  printf("Usage: %s [options] irepfiles\n", f);
  printf("options:\n");
  printf("  -l, --lvar   remove LVAR section too.\n");
}

static int
parse_args(int argc, char **argv, struct strip_args *args)
{
  static const struct strip_args initial_args = {0};
  int i;

  *args = initial_args;

  for (i = 1; i < argc; ++i) {
    size_t const len = strlen(argv[i]);
    if (len >= 2 && argv[i][0] == '-') {
      switch(argv[i][1]) {
      case 'l':
        args->lvar = TRUE;
        break;
      case '-':
        if (strncmp((*argv) + 2, "lvar", len) == 0) {
          args->lvar = TRUE;
          break;
        }
      default:
        return -1;
      }
    } else {
      break;
    }
  }

  return i;
}

int
main(int argc, char **argv)
{
  struct strip_args args;
  int args_result, i, dump_result;
  FILE **files;
  mrb_irep **ireps;
  mrb_state *mrb;

  if (argc <= 1) {
    printf("no files to strip\n");
    print_usage(argv[0]);
    return EXIT_FAILURE;
  }

  args_result = parse_args(argc, argv, &args);
  if (args_result < 0) {
    print_usage(argv[0]);
    return EXIT_FAILURE;
  }

  files = (FILE**)malloc(sizeof(FILE*) * argc);
  for (i = args_result; i < argc; ++i) {
    files[i] = fopen(argv[i], "rb");

    if (!files[i]) {
      fprintf(stderr, "can't open file %s\n", argv[i]);
      return EXIT_FAILURE;
    }
  }

  mrb = mrb_open();

  ireps = (mrb_irep**)malloc(sizeof(mrb_irep*) * argc);
  for (i = args_result; i < argc; ++i) {
    ireps[i] = mrb_read_irep_file(mrb, files[i]);
    if (!ireps[i]) {
      fprintf(stderr, "can't read irep file %s\n", argv[i]);
      return EXIT_FAILURE;
    }
    fclose(files[i]);
    files[i] = fopen(argv[i], "wb");
    if (!ireps[i]) {
      fprintf(stderr, "can't reopen irep file %s\n", argv[i]);
      return EXIT_FAILURE;
    }
  }

  for (i = args_result; i < argc; ++i) {
    /* clear lv if --lvar is enabled */
    if (args.lvar) {
      irep_remove_lv(mrb, ireps[i]);
    }

    /* debug flag must be alway false */
    dump_result = mrb_dump_irep_binary(mrb, ireps[i], FALSE, files[i]);
    if (dump_result != MRB_DUMP_OK) {
      fprintf(stderr, "error occur when dumping %s", argv[i]);
      return EXIT_FAILURE;
    }
  }

  mrb_close(mrb);
  return EXIT_SUCCESS;
}