// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_
#define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_

#include <map>
#include <optional>
#include <string>

#include "base/memory/raw_ptr.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/task/sequenced_task_runner.h"
#include "base/thread_annotations.h"
#include "components/services/storage/public/mojom/local_storage_control.mojom.h"
#include "components/services/storage/public/mojom/session_storage_control.mojom.h"
#include "components/services/storage/public/mojom/storage_usage_info.mojom.h"
#include "content/browser/security/cpsp/child_process_security_policy_impl.h"
#include "content/common/content_export.h"
#include "content/public/browser/dom_storage_context.h"
#include "mojo/public/cpp/bindings/message.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "storage/browser/quota/storage_policy_observer.h"
#include "third_party/blink/public/common/tokens/tokens.h"
#include "third_party/blink/public/mojom/dom_storage/session_storage_namespace.mojom.h"
#include "third_party/blink/public/mojom/dom_storage/storage_area.mojom.h"

namespace blink {
class StorageKey;
}  // namespace blink

namespace storage {
class SpecialStoragePolicy;
}  // namespace storage

namespace content {

class SessionStorageNamespaceImpl;
class StoragePartitionImpl;

// This is owned by Storage Partition and encapsulates all its dom storage
// state.
// Can only be accessed on the UI thread, except for the AddNamespace and
// RemoveNamespace methods.
class CONTENT_EXPORT DOMStorageContextWrapper
    : public DOMStorageContext,
      public base::RefCountedThreadSafe<DOMStorageContextWrapper> {
 public:
  // Option for PurgeMemory.
  enum PurgeOption {
    // Determines if purging is required based on the usage and the platform.
    PURGE_IF_NEEDED,

    // Purge unopened areas only.
    PURGE_UNOPENED,

    // Purge aggressively, i.e. discard cache even for areas that have
    // non-zero open count.
    PURGE_AGGRESSIVE,
  };

  static scoped_refptr<DOMStorageContextWrapper> Create(
      StoragePartitionImpl* partition,
      scoped_refptr<storage::SpecialStoragePolicy> special_storage_policy);

  DOMStorageContextWrapper() = delete;

  explicit DOMStorageContextWrapper(StoragePartitionImpl* partition);

  DOMStorageContextWrapper(const DOMStorageContextWrapper&) = delete;
  DOMStorageContextWrapper& operator=(const DOMStorageContextWrapper&) = delete;

  storage::mojom::SessionStorageControl* GetSessionStorageControl();
  storage::mojom::LocalStorageControl* GetLocalStorageControl();

  void PerformLocalStorageCleanup(base::OnceClosure callback);
  void PerformSessionStorageCleanup(base::OnceClosure callback);

  using GetSessionStorageUsageCallback =
      base::OnceCallback<void(const std::vector<SessionStorageUsageInfo>&)>;
  void GetSessionStorageUsage(GetSessionStorageUsageCallback callback);

  // DOMStorageContext implementation.
  void GetLocalStorageUsage(GetLocalStorageUsageCallback callback) override;
  void DeleteLocalStorage(const blink::StorageKey& storage_key,
                          base::OnceClosure callback) override;
  void DeleteSessionStorage(const SessionStorageUsageInfo& usage_info,
                            base::OnceClosure callback) override;
  scoped_refptr<SessionStorageNamespace> RecreateSessionStorage(
      const std::string& namespace_id) override;
  void StartScavengingUnusedSessionStorage() override;
  bool scavenging_started_for_testing() const {
    return scavenging_started_for_testing_;
  }

  // Used by content settings to alter the behavior around
  // what data to keep and what data to discard at shutdown.
  // The policy is not so straight forward to describe, see
  // the implementation for details.
  void SetForceKeepSessionState();

  // Called when the BrowserContext/Profile is going away.
  void Shutdown();

  void Flush();

  void OpenLocalStorage(
      const blink::StorageKey& storage_key,
      std::optional<blink::LocalFrameToken> local_frame_token,
      mojo::PendingReceiver<blink::mojom::StorageArea> receiver,
      ChildProcessSecurityPolicyImpl::Handle security_policy_handle,
      mojo::ReportBadMessageCallback bad_message_callback);
  void BindNamespace(
      const std::string& namespace_id,
      mojo::ReportBadMessageCallback bad_message_callback,
      mojo::PendingReceiver<blink::mojom::SessionStorageNamespace> receiver);
  void BindStorageArea(
      const blink::StorageKey& storage_key,
      std::optional<blink::LocalFrameToken> local_frame_token,
      const std::string& namespace_id,
      mojo::PendingReceiver<blink::mojom::StorageArea> receiver,
      ChildProcessSecurityPolicyImpl::Handle security_policy_handle,
      mojo::ReportBadMessageCallback bad_message_callback);

  // Pushes information about known Session Storage namespaces down to the
  // Storage Service instance after a crash. This in turn allows renderer
  // clients to re-establish working connections.
  void OnSessionStorageDisconnected();
  // Resets LocalStorage related StorageAreas after disconnection.
  void OnLocalStorageDisconnected();

 private:
  friend class DOMStorageContextWrapperTest;
  friend class base::RefCountedThreadSafe<DOMStorageContextWrapper>;
  friend class SessionStorageNamespaceImpl;  // For MaybeGetExistingNamespace()

  ~DOMStorageContextWrapper() override;

  void MaybeBindSessionStorageControl(bool clear_on_open);
  void MaybeBindLocalStorageControl();
  scoped_refptr<SessionStorageNamespaceImpl> MaybeGetExistingNamespace(
      const std::string& namespace_id) const;

  // Note: can be called on multiple threads, protected by a mutex.
  void AddNamespace(const std::string& namespace_id,
                    SessionStorageNamespaceImpl* session_namespace);

  // Note: can be called on multiple threads, protected by a mutex.
  void RemoveNamespace(const std::string& namespace_id);

  void PurgeMemory(PurgeOption purge_option);

  void OnStartupUsageRetrieved(
      std::vector<storage::mojom::StorageUsageInfoPtr> usage);
  void ApplyPolicyUpdates(
      std::vector<storage::mojom::StoragePolicyUpdatePtr> policy_updates);

  enum class StorageType {
    kLocalStorage,
    kSessionStorage,
  };
  bool IsRequestValid(
      const StorageType type,
      const blink::StorageKey& storage_key,
      std::optional<blink::LocalFrameToken> local_frame_token,
      ChildProcessSecurityPolicyImpl::Handle security_policy_handle,
      mojo::ReportBadMessageCallback bad_message_callback);

  // Since the tab restore code keeps a reference to the session namespaces
  // of recently closed tabs (see sessions::ContentPlatformSpecificTabData and
  // sessions::TabRestoreService), a SessionStorageNamespaceImpl can outlive the
  // destruction of the browser window. A session restore can also happen
  // without the browser context being shutdown or destroyed in between. The
  // design of SessionStorageNamespaceImpl assumes there is only one object per
  // namespace. A session restore creates new objects for all tabs while the
  // Profile wasn't destructed. This map allows the restored session to re-use
  // the SessionStorageNamespaceImpl objects that are still alive thanks to the
  // sessions component.
  std::map<std::string, raw_ptr<SessionStorageNamespaceImpl, CtnExperimental>>
      alive_namespaces_ GUARDED_BY(alive_namespaces_lock_);
  mutable base::Lock alive_namespaces_lock_;

  // Unowned reference to our owning partition. This is always valid until it's
  // reset to null if/when the partition is destroyed. May also be null in
  // tests.
  raw_ptr<StoragePartitionImpl> partition_;

  // Connections to the partition's Session and Local Storage control interfaces
  // within the Storage Service.
  mojo::Remote<storage::mojom::SessionStorageControl> session_storage_control_;
  mojo::Remote<storage::mojom::LocalStorageControl> local_storage_control_;

  std::optional<storage::StoragePolicyObserver> storage_policy_observer_;
  bool scavenging_started_for_testing_ = false;
};

}  // namespace content

#endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_