#include "src/mapserver.h"

#include "src/mapshape.h"

#include "cpl_vsi.h"

#include <stdlib.h>

#include <string.h>

#include <stdbool.h>

extern int LLVMFuzzerTestOneInput(GByte *data, size_t size);

extern int LLVMFuzzerInitialize(int *argc, char ***argv);

static void *msMemmem(const void *haystack, size_t haystack_len,

                      const void *const needle, const size_t needle_len) {

  if (haystack_len == 0)

    return NULL;

  if (needle_len == 0)

    return NULL;

  for (const char *h = (const char *)haystack; haystack_len >= needle_len;

       ++h, --haystack_len) {

    if (!memcmp(h, needle, needle_len)) {

      return (void *)h;

    }

  }

  return NULL;

}

static VSILFILE *SegmentFile(const char *filename, GByte **data_p,

                             size_t *size_p) {

  GByte *data = *data_p;

  size_t size = *size_p;

  GByte *separator = (GByte *)msMemmem(data, size, "deadbeef", 8);

  if (separator != NULL) {

    size = separator - data;

    *data_p = separator + 8;

    *size_p -= size + 8;

  } else {

    *size_p = 0;

  }

  return VSIFileFromMemBuffer(filename, data, size, false);

}

int LLVMFuzzerInitialize(int *argc, char ***argv) {

  (void)argc;

  (void)argv;

  return 0;

}

int LLVMFuzzerTestOneInput(GByte *data, size_t size) {

  /* this fuzzer expects three files concatenated, separated by the

     string "deadbeef"; you can generate such a file by typing:

     { cat foo.shp; echo -n "deadbeef"; cat foo.shx; echo -n "deadbeef"; cat

     foo.dbf; } >/tmp/corpus/start

     then run the fuzzer:

     ./build/fuzzer/fuzzer /tmp/corpus

  */

  VSILFILE *shp = SegmentFile("/vsimem/foo.shp", &data, &size);

  VSILFILE *shx = SegmentFile("/vsimem/foo.shx", &data, &size);

  VSILFILE *dbf = SegmentFile("/vsimem/foo.dbf", &data, &size);

  shapefileObj file;

  errorObj *ms_error = msGetErrorObj();

  if (msShapefileOpenVirtualFile(&file, "/vsimem/foo.shp", shp, shx, dbf,

                                 false) == 0) {

    if (file.numshapes > 100 * 1000) {

      VSIStatBufL sStat;

      if (VSIStatL("/vsimem/foo.shx", &sStat) == 0 && sStat.st_size >= 100 &&

          file.numshapes > (int)(sStat.st_size - 100) / 8) {

        file.numshapes = (int)(sStat.st_size - 100) / 8;

      }

    }

    for (int i = 0; i < file.numshapes; ++i) {

      shapeObj shape;

      msInitShape(&shape);

      msSHPReadShape(file.hSHP, i, &shape);

      msFreeShape(&shape);

      // Give up as soon an error is triggered to avoid too long processing

      // time.

      if (ms_error->code != MS_NOERR)

        break;

    }

    msShapefileClose(&file);

  }

  msResetErrorList();

  VSIUnlink("/vsimem/foo.shp");

  VSIUnlink("/vsimem/foo.shx");

  VSIUnlink("/vsimem/foo.dbf");

  return EXIT_SUCCESS;

}