// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_SPECIAL_STORAGE_POLICY_H_
#define CHROME_BROWSER_EXTENSIONS_EXTENSION_SPECIAL_STORAGE_POLICY_H_

#include <map>
#include <memory>
#include <string>

#include "base/synchronization/lock.h"
#include "base/task/sequenced_task_runner.h"
#include "base/thread_annotations.h"
#include "extensions/buildflags/buildflags.h"
#include "extensions/common/extension_set.h"
#include "storage/browser/quota/special_storage_policy.h"
#include "url/gurl.h"
#include "url/origin.h"

static_assert(BUILDFLAG(ENABLE_EXTENSIONS_CORE));

namespace content {
class BrowserContext;
}

namespace content_settings {
class CookieSettings;
}

namespace extensions {
class Extension;
}

// Special rights are granted to 'extensions' and 'applications'. The
// storage subsystems and the browsing data remover query this interface
// to determine which origins have these rights.
class ExtensionSpecialStoragePolicy : public storage::SpecialStoragePolicy {
 public:
  explicit ExtensionSpecialStoragePolicy(
      content_settings::CookieSettings* cookie_settings);

  // storage::SpecialStoragePolicy methods used by storage subsystems and the
  // browsing data remover. These methods are safe to call on any thread.
  bool IsStorageProtected(const GURL& origin) override;
  bool IsStorageUnlimited(const GURL& origin) override;
  bool IsStorageSessionOnly(const GURL& origin) override;
  bool HasIsolatedStorage(const GURL& origin) override;
  bool HasSessionOnlyOrigins() override;
  bool IsStoragePersistent(const GURL& origin) override;

  // Methods used by the ExtensionService to populate this class.
  void GrantRightsForExtension(const extensions::Extension* extension,
                               content::BrowserContext* context);
  void RevokeRightsForExtension(const extensions::Extension* extension,
                                content::BrowserContext* context);
  void RevokeRightsForAllExtensions();

  // Decides whether the storage for `extension`'s web extent needs protection.
  bool NeedsProtection(const extensions::Extension* extension);

  // Returns the set of extensions protecting this origin. The caller does not
  // take ownership of the return value.
  const extensions::ExtensionSet* ExtensionsProtectingOrigin(
      const GURL& origin);

  // Marks an origin as having unlimited storage. This is currently used by web
  // kiosk to give unlimited storage to the kiosk origin.
  void AddOriginWithUnlimitedStorage(const url::Origin& origin);

 protected:
  ~ExtensionSpecialStoragePolicy() override;

 private:
  class SpecialCollection {
   public:
    SpecialCollection();
    ~SpecialCollection();

    bool Contains(const GURL& origin);
    bool GrantsCapabilitiesTo(const GURL& origin);
    const extensions::ExtensionSet* ExtensionsContaining(const GURL& origin);
    bool ContainsExtension(const std::string& extension_id);
    bool Add(const extensions::Extension* extension);
    bool Remove(const extensions::Extension* extension);
    void Clear();

   private:
    void ClearCache();

    extensions::ExtensionSet extensions_;
    std::map<GURL, std::unique_ptr<extensions::ExtensionSet>> cached_results_;
  };

  void NotifyGranted(const GURL& origin, int change_flags);
  void NotifyRevoked(const GURL& origin, int change_flags);
  void NotifyCleared();

  base::Lock lock_;  // Synchronize all access to thread-unsafe data members.

  SpecialCollection protected_apps_ GUARDED_BY_CONTEXT(lock_);
  SpecialCollection unlimited_extensions_ GUARDED_BY_CONTEXT(lock_);
  SpecialCollection file_handler_extensions_ GUARDED_BY_CONTEXT(lock_);
  SpecialCollection isolated_extensions_ GUARDED_BY_CONTEXT(lock_);
  SpecialCollection content_capabilities_unlimited_extensions_
      GUARDED_BY_CONTEXT(lock_);
  std::set<url::Origin> origins_with_unlimited_storage_
      GUARDED_BY_CONTEXT(lock_);

  // GUARDED_BY_CONTEXT() not needed because the data member is thread-safe. The
  // scoped_refptr is immutable, and the CookieSettings instance that it points
  // to supports thread-safe reads.
  const scoped_refptr<content_settings::CookieSettings> cookie_settings_;

  // We live on the IO thread but need to observe CookieSettings from the UI
  // thread. This helper does that.
  class CookieSettingsObserver;
  const std::unique_ptr<CookieSettingsObserver, base::OnTaskRunnerDeleter>
      cookie_settings_observer_;
};

#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SPECIAL_STORAGE_POLICY_H_