// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_CLIENT_HINTS_PREFERENCES_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_CLIENT_HINTS_PREFERENCES_H_

#include "services/metrics/public/cpp/ukm_source_id.h"
#include "services/network/public/cpp/client_hints.h"
#include "third_party/blink/public/common/client_hints/enabled_client_hints.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"

namespace ukm {
class UkmRecorder;
}  // namespace ukm

namespace blink {

class KURL;

// TODO (tbansal): Remove PLATFORM_EXPORT, and pass WebClientHintsType
// everywhere.
class PLATFORM_EXPORT ClientHintsPreferences {
  DISALLOW_NEW();

 public:
  class Context {
   public:
    virtual ukm::SourceId GetUkmSourceId() = 0;
    virtual ukm::UkmRecorder* GetUkmRecorder() = 0;
    virtual void CountClientHints(network::mojom::WebClientHintsType) = 0;

   protected:
    virtual ~Context() = default;
  };

  ClientHintsPreferences();

  void UpdateFrom(const ClientHintsPreferences&);
  void CombineWith(const ClientHintsPreferences&);

  // Parses <meta http-equiv="accept-ch"> or <meta name="accept-ch"> value
  // `header_value`, and updates `this` to enable the requested client hints.
  // `url` is the URL of the page. `context` may be null. `is_http_equiv` is
  // true if 'accept-ch' is an 'http-equiv' attribute and not 'name'.
  // `is_doc_preloader` is true if the document preloader and `is_sync_parser`
  // is true if the synchronous parser created the element.
  // Returns true if `this` is modified.
  bool UpdateFromMetaCH(const String& header_value,
                        const KURL& url,
                        Context* context,
                        network::MetaCHType type,
                        bool is_doc_preloader,
                        bool is_sync_parser);

  bool ShouldSend(network::mojom::WebClientHintsType type) const;
  void SetShouldSend(network::mojom::WebClientHintsType type);

  // Returns true if client hints are allowed for the provided KURL. Client
  // hints are allowed only on HTTP URLs that belong to secure contexts.
  static bool IsClientHintsAllowed(const KURL&);

  EnabledClientHints GetEnabledClientHints() const;

 private:
  EnabledClientHints enabled_hints_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_LOADER_FETCH_CLIENT_HINTS_PREFERENCES_H_