// Copyright 2014 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.

#ifndef COMPONENTS_AUTOCOMPLETE_URL_PREFIX_H_
#define COMPONENTS_AUTOCOMPLETE_URL_PREFIX_H_

#include <vector>

#include "base/strings/string16.h"

struct URLPrefix;
typedef std::vector<URLPrefix> URLPrefixes;

// A URL prefix; combinations of schemes and (least significant) domain labels
// that may be inferred from certain URL-like input strings.
struct URLPrefix {
  URLPrefix(const base::string16& prefix, size_t num_components);

  // Returns a vector of URL prefixes sorted by descending number of components.
  static const URLPrefixes& GetURLPrefixes();

  // Returns if the argument is a valid URL prefix.
  static bool IsURLPrefix(const base::string16& prefix);

  // Returns the URL prefix of |text| with the most components, or NULL.
  // |prefix_suffix| (which may be empty) is appended to every attempted prefix,
  // which is useful for finding the innermost match of user input in a URL.
  // Performs case insensitive string comparison.
  static const URLPrefix* BestURLPrefix(const base::string16& text,
                                        const base::string16& prefix_suffix);

  // A helper function for BestURLPrefix().  Returns true if |text| starts
  // with |prefix| which is then followed by |prefix_suffix|.
  // Performs case insensitive string comparison.
  static bool PrefixMatch(const URLPrefix& prefix,
                          const base::string16& text,
                          const base::string16& prefix_suffix);

  // Sees if |text| is inlineable against either |input| or |fixed_up_input|,
  // returning the appropriate inline autocomplete offset or
  // base::string16::npos if |text| is not inlineable.
  // |allow_www_prefix_without_scheme| says whether to consider an input such
  // as "foo" to be allowed to match against text "www.foo.com".  This is
  // needed because sometimes the string we're matching against here can come
  // from a match's fill_into_edit, which can start with "www." without having
  // a protocol at the beginning, and we want to allow these matches to be
  // inlineable.  ("www." is not otherwise on the default prefix list.)
  static size_t GetInlineAutocompleteOffset(
      const base::string16& input,
      const base::string16& fixed_up_input,
      const bool allow_www_prefix_without_scheme,
      const base::string16& text);

  base::string16 prefix;

  // The number of URL components (scheme, domain label, etc.) in the prefix.
  // For example, "http://foo.com" and "www.bar.com" each have one component,
  // while "ftp://ftp.ftp.com" has two, and "mysite.com" has none.
  size_t num_components;
};

#endif  // COMPONENTS_AUTOCOMPLETE_URL_PREFIX_H_