// Copyright (c) 2010 The Chromium Embedded Framework 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 "include/wrapper/cef_byte_read_handler.h"

#include <algorithm>
#include <cstdio>
#include <cstdlib>

CefByteReadHandler::CefByteReadHandler(const unsigned char* bytes,
                                       size_t size,
                                       CefRefPtr<CefBaseRefCounted> source)
    : bytes_(bytes), size_(size), offset_(0), source_(source) {}

size_t CefByteReadHandler::Read(void* ptr, size_t size, size_t n) {
  base::AutoLock lock_scope(lock_);
  size_t s = static_cast<size_t>(size_ - offset_) / size;
  size_t ret = std::min(n, s);
  memcpy(ptr, bytes_ + offset_, ret * size);
  offset_ += ret * size;
  return ret;
}

int CefByteReadHandler::Seek(int64 offset, int whence) {
  int rv = -1L;
  base::AutoLock lock_scope(lock_);
  switch (whence) {
    case SEEK_CUR:
      if (offset_ + offset > size_ || offset_ + offset < 0)
        break;
      offset_ += offset;
      rv = 0;
      break;
    case SEEK_END: {
#if defined(OS_WIN)
      int64 offset_abs = _abs64(offset);
#else
      int64 offset_abs = std::abs(offset);
#endif
      if (offset_abs > size_)
        break;
      offset_ = size_ - offset_abs;
      rv = 0;
      break;
    }
    case SEEK_SET:
      if (offset > size_ || offset < 0)
        break;
      offset_ = offset;
      rv = 0;
      break;
  }

  return rv;
}

int64 CefByteReadHandler::Tell() {
  base::AutoLock lock_scope(lock_);
  return offset_;
}

int CefByteReadHandler::Eof() {
  base::AutoLock lock_scope(lock_);
  return (offset_ >= size_);
}