// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_LINK_HEADER_UTIL_LINK_HEADER_UTIL_H_
#define COMPONENTS_LINK_HEADER_UTIL_LINK_HEADER_UTIL_H_

#include <optional>
#include <string>
#include <unordered_map>
#include <vector>

namespace link_header_util {

using StringIteratorPair =
    std::pair<std::string::const_iterator, std::string::const_iterator>;

// Split a Link: header in its individual values. A single Link: header can
// contain multiple values, which are comma separated. This method splits the
// entire string into iterator pairs for the individual link values.
// This is very similar to what net::HttpUtil::ValuesIterator does, except it
// takes the special syntax of <> enclosed URLs into account.
std::vector<StringIteratorPair> SplitLinkHeader(const std::string& header);

// Parse an individual link header in its URL and parameters. `begin` and `end`
// indicate the string to parse. If it is successfully parsed as a link header
// value this method returns true, sets `url` to the URL part of the link header
// value and adds the parameters from the link header value to `params`. All
// keys of `params` are lower cased.
// If any error occurs parsing, this returns false (but might have also modified
// |url| and/or |params|).
bool ParseLinkHeaderValue(
    std::string::const_iterator begin,
    std::string::const_iterator end,
    std::string* url,
    std::unordered_map<std::string, std::optional<std::string>>* params);

}  // namespace link_header_util

#endif  // COMPONENTS_LINK_HEADER_UTIL_LINK_HEADER_UTIL_H_