// Copyright 2016 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

//  Utility functions used by the image decoders.

//

#include "./imageio_util.h"

#if defined(_WIN32)

#include <fcntl.h>   // for _O_BINARY

#include <io.h>      // for _setmode()

#endif

#include <stdlib.h>

#include <string.h>

// -----------------------------------------------------------------------------

// File I/O

FILE* ImgIoUtilSetBinaryMode(FILE* file) {

#if defined(_WIN32)

  if (_setmode(_fileno(file), _O_BINARY) == -1) {

    fprintf(stderr, "Failed to reopen file in O_BINARY mode.\n");

    return NULL;

  }

#endif

  return file;

}

int ImgIoUtilReadFromStdin(const uint8_t** data, size_t* data_size) {

  static const size_t kBlockSize = 16384;  // default initial size

  size_t max_size = 0;

  size_t size = 0;

  uint8_t* input = NULL;

  if (data == NULL || data_size == NULL) return 0;

  *data = NULL;

  *data_size = 0;

  if (!ImgIoUtilSetBinaryMode(stdin)) return 0;

  while (!feof(stdin)) {

    // We double the buffer size each time and read as much as possible.

    const size_t extra_size = (max_size == 0) ? kBlockSize : max_size;

    // we allocate one extra byte for the \0 terminator

    void* const new_data = realloc(input, max_size + extra_size + 1);

    if (new_data == NULL) goto Error;

    input = (uint8_t*)new_data;

    max_size += extra_size;

    size += fread(input + size, 1, extra_size, stdin);

    if (size < max_size) break;

  }

  if (ferror(stdin)) goto Error;

  if (input != NULL) input[size] = '\0';  // convenient 0-terminator

  *data = input;

  *data_size = size;

  return 1;

 Error:

  free(input);

  fprintf(stderr, "Could not read from stdin\n");

  return 0;

}

int ImgIoUtilReadFile(const char* const file_name,

                      const uint8_t** data, size_t* data_size) {

  int ok;

  uint8_t* file_data;

  size_t file_size;

  FILE* in;

  const int from_stdin = (file_name == NULL) || !strcmp(file_name, "-");

  if (from_stdin) return ImgIoUtilReadFromStdin(data, data_size);

  if (data == NULL || data_size == NULL) return 0;

  *data = NULL;

  *data_size = 0;

  in = fopen(file_name, "rb");

  if (in == NULL) {

    fprintf(stderr, "cannot open input file '%s'\n", file_name);

    return 0;

  }

  fseek(in, 0, SEEK_END);

  file_size = ftell(in);

  fseek(in, 0, SEEK_SET);

  // we allocate one extra byte for the \0 terminator

  file_data = (uint8_t*)malloc(file_size + 1);

  if (file_data == NULL) {

    fclose(in);

    fprintf(stderr, "memory allocation failure when reading file %s\n",

            file_name);

    return 0;

  }

  ok = (fread(file_data, file_size, 1, in) == 1);

  fclose(in);

  if (!ok) {

    fprintf(stderr, "Could not read %d bytes of data from file %s\n",

            (int)file_size, file_name);

    free(file_data);

    return 0;

  }

  file_data[file_size] = '\0';  // convenient 0-terminator

  *data = file_data;

  *data_size = file_size;

  return 1;

}

// -----------------------------------------------------------------------------

int ImgIoUtilWriteFile(const char* const file_name,

                       const uint8_t* data, size_t data_size) {

  int ok;

  FILE* out;

  const int to_stdout = (file_name == NULL) || !strcmp(file_name, "-");

  if (data == NULL) {

    return 0;

  }

  out = to_stdout ? ImgIoUtilSetBinaryMode(stdout) : fopen(file_name, "wb");

  if (out == NULL) {

    fprintf(stderr, "Error! Cannot open output file '%s'\n", file_name);

    return 0;

  }

  ok = (fwrite(data, data_size, 1, out) == 1);

  if (out != stdout) fclose(out);

  return ok;

}

// -----------------------------------------------------------------------------

void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,

                        uint8_t* dst, int dst_stride, int width, int height) {

  while (height-- > 0) {

    memcpy(dst, src, width * sizeof(*dst));

    src += src_stride;

    dst += dst_stride;

  }

}

// -----------------------------------------------------------------------------

int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {

  const uint64_t total_size = nmemb * size;

  int ok = (total_size == (size_t)total_size);

#if defined(WEBP_MAX_IMAGE_SIZE)

  ok = ok && (total_size <= (uint64_t)WEBP_MAX_IMAGE_SIZE);

#endif

  return ok;

}

// -----------------------------------------------------------------------------