// Copyright 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Provides shared functions used by the internals of the parser and
// canonicalizer for file URLs. Do not use outside of these modules.

#ifndef GOOGLEURL_SRC_URL_FILE_H__
#define GOOGLEURL_SRC_URL_FILE_H__

#include "url_parse_internal.h"

namespace url_parse {

#ifdef WIN32

// We allow both "c:" and "c|" as drive identifiers.
inline bool IsWindowsDriveSeparator(char16 ch) {
  return ch == ':' || ch == '|';
}
inline bool IsWindowsDriveLetter(char16 ch) {
  return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
}

#endif  // WIN32

// Returns the index of the next slash in the input after the given index, or
// spec_len if the end of the input is reached.
template<typename CHAR>
inline int FindNextSlash(const CHAR* spec, int begin_index, int spec_len) {
  int idx = begin_index;
  while (idx < spec_len && !IsURLSlash(spec[idx]))
    idx++;
  return idx;
}

#ifdef WIN32

// Returns true if the start_offset in the given spec looks like it begins a
// drive spec, for example "c:". This function explicitly handles start_offset
// values that are equal to or larger than the spec_len to simplify callers.
//
// If this returns true, the spec is guaranteed to have a valid drive letter
// plus a colon starting at |start_offset|.
template<typename CHAR>
inline bool DoesBeginWindowsDriveSpec(const CHAR* spec, int start_offset,
                                      int spec_len) {
  int remaining_len = spec_len - start_offset;
  if (remaining_len < 2)
    return false;  // Not enough room.
  if (!IsWindowsDriveLetter(spec[start_offset]))
    return false;  // Doesn't start with a valid drive letter.
  if (!IsWindowsDriveSeparator(spec[start_offset + 1]))
    return false;  // Isn't followed with a drive separator.
  return true;
}

// Returns true if the start_offset in the given text looks like it begins a
// UNC path, for example "\\". This function explicitly handles start_offset
// values that are equal to or larger than the spec_len to simplify callers.
//
// When strict_slashes is set, this function will only accept backslashes as is
// standard for Windows. Otherwise, it will accept forward slashes as well
// which we use for a lot of URL handling.
template<typename CHAR>
inline bool DoesBeginUNCPath(const CHAR* text,
                             int start_offset,
                             int len,
                             bool strict_slashes) {
  int remaining_len = len - start_offset;
  if (remaining_len < 2)
    return false;

  if (strict_slashes)
    return text[start_offset] == '\\' && text[start_offset + 1] == '\\';
  return IsURLSlash(text[start_offset]) && IsURLSlash(text[start_offset + 1]);
}

#endif  // WIN32

}  // namespace url_parse

#endif  // GOOGLEURL_SRC_URL_FILE_H__