// 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_PUBLIC_COMMON_NAVIGATION_NAVIGATION_POLICY_H_
#define THIRD_PARTY_BLINK_PUBLIC_COMMON_NAVIGATION_NAVIGATION_POLICY_H_

#include <bitset>

#include "third_party/blink/public/common/common_export.h"
#include "third_party/blink/public/common/navigation/resource_intercept_policy.h"

// A centralized file for base helper methods and policy decisions about
// navigations.

namespace blink {
// Navigation type that affects the download decision at download-discovery
// time.
enum class NavigationDownloadType {
  kViewSource = 0,
  kInterstitial = 1,

  // The navigation was initiated on a x-origin opener.
  kOpenerCrossOrigin = 2,

  // The navigation was initiated from or occurred in an ad frame without user
  // activation.
  kAdFrameNoGesture = 3,

  // The navigation was initiated from or occurred in an ad frame.
  kAdFrame = 4,

  // The navigation was initiated from or occurred in an iframe with
  // |network::mojom::WebSandboxFlags::kDownloads| flag set.
  kSandbox = 5,

  // The navigation was initiated without user activation.
  kNoGesture = 6,

  // The navigation was initiated from an ad script.
  kAdScript = 7,

  kMaxValue = kAdScript
};

// LINT.IfChange(InputStartPresence)
enum class InputStartPresence {
  kNone = 0,
  kOnlyOld = 1,
  kOnlyNew = 2,
  kBoth = 3,
  kMaxValue = kBoth,
};
// LINT.ThenChange(//tools/metrics/histograms/metadata/navigation/enums.xml:InputStartPresence)

// Stores the navigation types that may be of interest to the download-related
// metrics to be reported at download-discovery time. Also controls how
// navigations behave when they turn into downloads. By default, navigation is
// allowed to become a download.
struct BLINK_COMMON_EXPORT NavigationDownloadPolicy {
  NavigationDownloadPolicy();
  ~NavigationDownloadPolicy();
  NavigationDownloadPolicy(const NavigationDownloadPolicy&);

  // Stores |type| to |observed_types|.
  void SetAllowed(NavigationDownloadType type);

  // Stores |type| to both |observed_types| and |disallowed_types|.
  void SetDisallowed(NavigationDownloadType type);

  // Returns if |observed_types| contains |type|.
  bool IsType(NavigationDownloadType type) const;

  // Get the ResourceInterceptPolicy derived from |disallowed_types|.
  ResourceInterceptPolicy GetResourceInterceptPolicy() const;

  // Returns if download is allowed based on |disallowed_types|.
  bool IsDownloadAllowed() const;

  // Possibly set the impacted types in `observed_types` and `disallowed_types`.
  // The parameter `openee_can_access_opener_origin` only matters if
  // `is_opener_navigation` is true.
  void ApplyDownloadFramePolicy(bool is_opener_navigation,
                                bool has_gesture,
                                bool openee_can_access_opener_origin,
                                bool has_download_sandbox_flag,
                                bool from_ad_frame,
                                bool is_ad_script_in_stack);

  // An alias of a bitset of navigation types.
  using NavigationDownloadTypes =
      std::bitset<static_cast<size_t>(NavigationDownloadType::kMaxValue) + 1>;

  // A bitset of navigation types observed that may be of interest to the
  // download-related metrics to be reported at download-discovery time.
  NavigationDownloadTypes observed_types;

  // A bitset of navigation types observed where if the navigation turns into
  // a download, the download should be dropped.
  NavigationDownloadTypes disallowed_types;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_PUBLIC_COMMON_NAVIGATION_NAVIGATION_POLICY_H_