/* Copyright (c) 2026 Juhapekka Piiroinen <jp@1337.fi>
 * All Rights Reserved.
 * AmoosedWeb project: https://amoosed.com
 */
#include <AmoosedWeb/PreviewC.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* Usage: native-c-memory ORIGIN VIRTUAL_RESOURCE_PATH
 * The caller chooses a trusted HTTPS origin. Loopback HTTP is accepted for
 * development. The example reads a public resource and never prints its bytes. */
static void clear_bytes(uint8_t* bytes, size_t length) {
  volatile uint8_t* current = bytes;
  while (length--) *current++ = 0;
}

int main(int argc, char** argv) {
  if (argc != 3) {
    fprintf(stderr, "Usage: native-c-memory ORIGIN VIRTUAL_RESOURCE_PATH\n");
    return 2;
  }
  uint64_t capabilities = 0;
  const uint64_t needed = AMW_PREVIEW_CAP_HOSTED_INDEX |
                          AMW_PREVIEW_CAP_MEMORY_READ;
  if (amw_preview_abi_revision() != AMW_PREVIEW_ABI_REVISION ||
      amw_preview_capabilities(&capabilities) != AMW_PREVIEW_OK ||
      (capabilities & needed) != needed) {
    fprintf(stderr, "This library lacks the required preview ABI capabilities\n");
    return 1;
  }

  char error[256] = {0};
  amw_preview_site* site = NULL;
  int32_t status = amw_preview_site_open_hosted(argv[1], (uint64_t)strlen(argv[1]),
                                                 &site, error, sizeof(error));
  if (status != AMW_PREVIEW_OK) {
    fprintf(stderr, "Index open failed (%" PRId32 "): %s\n", status, error);
    return 1;
  }

  uint64_t indexed_length = 0;
  status = amw_preview_site_read_memory(site, argv[2], (uint64_t)strlen(argv[2]),
                                         NULL, 0, NULL, 0, &indexed_length,
                                         error, sizeof(error));
  if (status != AMW_PREVIEW_OK || indexed_length > AMW_PREVIEW_MEMORY_LIMIT ||
      indexed_length > SIZE_MAX) {
    fprintf(stderr, "Size query failed (%" PRId32 "): %s\n", status, error);
    amw_preview_site_release(site);
    return 1;
  }
  /* A non-NULL buffer and positive capacity also handle a zero-length file. */
  const size_t capacity = indexed_length ? (size_t)indexed_length : 1u;
  uint8_t* bytes = (uint8_t*)malloc(capacity);
  if (!bytes) {
    fprintf(stderr, "Cannot allocate the bounded output buffer\n");
    amw_preview_site_release(site);
    return 1;
  }
  memset(bytes, 0xa5, capacity);
  uint64_t verified_length = 0;
  status = amw_preview_site_read_memory(site, argv[2], (uint64_t)strlen(argv[2]),
                                         NULL, 0, bytes, (uint64_t)capacity,
                                         &verified_length, error, sizeof(error));
  if (status != AMW_PREVIEW_OK || verified_length != indexed_length) {
    fprintf(stderr, "Verified read failed (%" PRId32 "): %s\n", status, error);
    clear_bytes(bytes, capacity);
    free(bytes);
    amw_preview_site_release(site);
    return 1;
  }
  /* Application code may use bytes[0..verified_length) only after success.
   * The library leaves this buffer unchanged if verification fails. */
  printf("Verified %" PRIu64 " bytes in caller memory\n", verified_length);
  clear_bytes(bytes, capacity);
  free(bytes);
  amw_preview_site_release(site);
  return 0;
}