// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_
#define CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_

#include <memory>
#include <set>
#include <string>

#include "base/macros.h"
#include "base/scoped_observer.h"
#include "content/public/browser/web_contents_observer.h"
#include "extensions/browser/extension_registry_observer.h"
#include "extensions/common/extension_set.h"
#include "extensions/common/url_pattern_set.h"

class Profile;

namespace content {
class WebContents;
}

namespace extensions {

class Extension;
class ExtensionRegistry;

// Responsible for granting and revoking tab-specific permissions to extensions
// with the activeTab or tabCapture permission.
class ActiveTabPermissionGranter
    : public content::WebContentsObserver,
      public extensions::ExtensionRegistryObserver {
 public:
  // Platform specific delegate.
  class Delegate {
   public:
    virtual ~Delegate() {}
    // Platform specific check whether the activeTab permission is allowed.
    virtual bool ShouldGrantActiveTabOrPrompt(
        const Extension* extension,
        content::WebContents* web_contents) = 0;
  };

  ActiveTabPermissionGranter(content::WebContents* web_contents,
                             int tab_id,
                             Profile* profile);
  ~ActiveTabPermissionGranter() override;

  // Platform specific delegate should be set during startup.
  static void SetPlatformDelegate(std::unique_ptr<Delegate> delegate);

  // If |extension| has the activeTab or tabCapture permission, grants
  // tab-specific permissions to it until the next page navigation or refresh.
  void GrantIfRequested(const Extension* extension);

  // Clears tab-specific permissions for all extensions. Used only for testing.
  void RevokeForTesting();

 private:
  // content::WebContentsObserver implementation.
  void DidFinishNavigation(
      content::NavigationHandle* navigation_handle) override;
  void WebContentsDestroyed() override;

  // extensions::ExtensionRegistryObserver implementation.
  void OnExtensionUnloaded(content::BrowserContext* browser_context,
                           const Extension* extension,
                           UnloadedExtensionReason reason) override;

  // Clears any tab-specific permissions for all extensions on |tab_id_| and
  // notifies renderers.
  void ClearActiveExtensionsAndNotify();

  // The tab ID for this tab.
  int tab_id_;

  // Extensions with the activeTab permission that have been granted
  // tab-specific permissions until the next navigation/refresh.
  ExtensionSet granted_extensions_;

  // Listen to extension unloaded notifications.
  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
      extension_registry_observer_;

  DISALLOW_COPY_AND_ASSIGN(ActiveTabPermissionGranter);
};

}  // namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_ACTIVE_TAB_PERMISSION_GRANTER_H_