// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/filters/file_data_source.h"

#include <algorithm>

#include "base/logging.h"

namespace media {

FileDataSource::FileDataSource()
    : force_read_errors_(false),
      force_streaming_(false) {
}

bool FileDataSource::Initialize(const base::FilePath& file_path) {
  DCHECK(!file_.IsValid());

  if (!file_.Initialize(file_path))
    return false;

  UpdateHostBytes();
  return true;
}

bool FileDataSource::InitializeFromPlatformFile(
    const base::PlatformFile& file) {
  DCHECK(!file_.IsValid());

  if (!file_.Initialize(file))
    return false;

  UpdateHostBytes();
  return true;
}

void FileDataSource::set_host(DataSourceHost* host) {
  DataSource::set_host(host);
  UpdateHostBytes();
}

void FileDataSource::Stop(const base::Closure& callback) {
  callback.Run();
}

void FileDataSource::Read(int64 position, int size, uint8* data,
                          const DataSource::ReadCB& read_cb) {
  if (force_read_errors_ || !file_.IsValid()) {
    read_cb.Run(kReadError);
    return;
  }

  int64 file_size = file_.length();

  CHECK_GE(file_size, 0);
  CHECK_GE(position, 0);
  CHECK_GE(size, 0);

  // Cap position and size within bounds.
  position = std::min(position, file_size);
  int64 clamped_size = std::min(static_cast<int64>(size), file_size - position);

  memcpy(data, file_.data() + position, clamped_size);
  read_cb.Run(clamped_size);
}

bool FileDataSource::GetSize(int64* size_out) {
  *size_out = file_.length();
  return true;
}

bool FileDataSource::IsStreaming() {
  return force_streaming_;
}

void FileDataSource::SetBitrate(int bitrate) {}

FileDataSource::~FileDataSource() {}

void FileDataSource::UpdateHostBytes() {
  if (host() && file_.IsValid()) {
    host()->SetTotalBytes(file_.length());
    host()->AddBufferedByteRange(0, file_.length());
  }
}

}  // namespace media