/* Copyright 2013 Google Inc. All Rights Reserved.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

/* Functions for streaming input and output. */

#include <string.h>
#ifndef _WIN32
#include <unistd.h>
#endif
#include "./streams.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

int BrotliMemInputFunction(void* data, uint8_t* buf, size_t count) {
  BrotliMemInput* input = (BrotliMemInput*)data;
  if (input->pos > input->length) {
    return -1;
  }
  if (input->pos + count > input->length) {
    count = input->length - input->pos;
  }
  memcpy(buf, input->buffer + input->pos, count);
  input->pos += count;
  return (int)count;
}

BrotliInput BrotliInitMemInput(const uint8_t* buffer, size_t length,
                               BrotliMemInput* mem_input) {
  BrotliInput input;
  mem_input->buffer = buffer;
  mem_input->length = length;
  mem_input->pos = 0;
  input.cb_ = &BrotliMemInputFunction;
  input.data_ = mem_input;
  return input;
}

int BrotliMemOutputFunction(void* data, const uint8_t* buf, size_t count) {
  BrotliMemOutput* output = (BrotliMemOutput*)data;
  size_t limit = output->length - output->pos;
  if (count > limit) {
    count = limit;
  }
  memcpy(output->buffer + output->pos, buf, count);
  output->pos += count;
  return (int)count;
}

BrotliOutput BrotliInitMemOutput(uint8_t* buffer, size_t length,
                                 BrotliMemOutput* mem_output) {
  BrotliOutput output;
  mem_output->buffer = buffer;
  mem_output->length = length;
  mem_output->pos = 0;
  output.cb_ = &BrotliMemOutputFunction;
  output.data_ = mem_output;
  return output;
}

int BrotliFileInputFunction(void* data, uint8_t* buf, size_t count) {
  return (int)fread(buf, 1, count, (FILE*)data);
}

BrotliInput BrotliFileInput(FILE* f) {
  BrotliInput in;
  in.cb_ = BrotliFileInputFunction;
  in.data_ = f;
  return in;
}

int BrotliFileOutputFunction(void* data, const uint8_t* buf, size_t count) {
  return (int)fwrite(buf, 1, count, (FILE*)data);
}

BrotliOutput BrotliFileOutput(FILE* f) {
  BrotliOutput out;
  out.cb_ = BrotliFileOutputFunction;
  out.data_ = f;
  return out;
}

int BrotliNullOutputFunction(void* data , const uint8_t* buf, size_t count) {
  BROTLI_UNUSED(data);
  BROTLI_UNUSED(buf);
  return (int)count;
}

BrotliOutput BrotliNullOutput() {
  BrotliOutput out;
  out.cb_ = BrotliNullOutputFunction;
  out.data_ = NULL;
  return out;
}

#if defined(__cplusplus) || defined(c_plusplus)
}    /* extern "C" */
#endif