// 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_COMMANDS_COMMAND_SERVICE_H_
#define CHROME_BROWSER_EXTENSIONS_COMMANDS_COMMAND_SERVICE_H_

#include <string>

#include "base/memory/raw_ptr.h"
#include "base/observer_list.h"
#include "base/scoped_observation.h"
#include "extensions/browser/browser_context_keyed_api_factory.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_registry_observer.h"
#include "extensions/buildflags/buildflags.h"
#include "extensions/common/api/extension_action/action_info.h"
#include "extensions/common/command.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_id.h"
#include "ui/base/accelerators/command.h"

static_assert(BUILDFLAG(ENABLE_EXTENSIONS_CORE));

class Profile;

namespace content {
class BrowserContext;
}

namespace ui {
class Accelerator;
}

namespace user_prefs {
class PrefRegistrySyncable;
}

namespace extensions {

// This service keeps track of preferences related to extension commands
// (assigning initial keybindings on install and removing them on deletion
// and answers questions related to which commands are active.
class CommandService : public BrowserContextKeyedAPI,
                       public ExtensionRegistryObserver {
 public:
  // An enum specifying which extension commands to fetch. There are effectively
  // four options: all, active, suggested, and inactive. Only the first two
  // appear in the enum since there isn't currently a need for 'inactive' yet or
  // 'suggested'.
  //
  // 'inactive' means no key is bound. It might be because 1) a key wasn't
  // specified (suggested) or 2) it was not granted (key already taken).
  //
  // 'suggested' covers developer-assigned keys that may or may not have been
  // granted. Reasons for not granting include permission denied/key already
  // taken.
  //
  // ACTIVE means developer-assigned keys that were granted or user-assigned
  // keys.
  //
  // ACTIVE_OR_USER_MODIFIED means ACTIVE plus keys explicitly cleared by the
  // user.
  //
  // ALL is all of the above.
  enum QueryType {
    ALL,
    ACTIVE,
    ACTIVE_OR_USER_MODIFIED,
  };

  // An enum specifying whether the command is global in scope or not. Global
  // commands -- unlike regular commands -- have a global keyboard hook
  // associated with them (and therefore work when Chrome doesn't have focus).
  enum CommandScope {
    REGULAR,    // Regular (non-globally scoped) command.
    GLOBAL,     // Global command (works when Chrome doesn't have focus)
    ANY_SCOPE,  // All commands, regardless of scope (used when querying).
  };

  class Observer {
   public:
    // Called when an extension command is added.
    virtual void OnExtensionCommandAdded(const ExtensionId& extension_id,
                                         const std::string& command_name) {}

    // Called when an extension command is removed.
    virtual void OnExtensionCommandRemoved(const ExtensionId& extension_id,
                                           const std::string& command_name) {}

    // Called when the CommandService is being destroyed.
    virtual void OnCommandServiceDestroying() {}

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

  // Register prefs for keybinding.
  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);

  // Constructs a CommandService object for the given profile.
  explicit CommandService(content::BrowserContext* context);

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

  ~CommandService() override;

  // BrowserContextKeyedAPI implementation.
  static BrowserContextKeyedAPIFactory<CommandService>* GetFactoryInstance();

  // Convenience method to get the CommandService for a profile.
  static CommandService* Get(content::BrowserContext* context);

  // Gets the command (if any) for the specified `action_type` of an extension
  // given its `extension_id`. The function consults the master list to see if
  // the command is active. Returns false if the command is not active and
  // `type` requested is ACTIVE. `command` contains the command found and
  // `active` (if not null) contains whether `command` is active.
  bool GetExtensionActionCommand(const ExtensionId& extension_id,
                                 ActionInfo::Type action_type,
                                 QueryType type,
                                 Command* command,
                                 bool* active) const;

  // Gets the active named commands (if any) for the extension with
  // `extension_id`. The function consults the master list to see if the
  // commands are active. Returns an empty map if the extension has no named
  // commands of the right `scope` or no such active named commands when `type`
  // requested is ACTIVE.
  bool GetNamedCommands(const ExtensionId& extension_id,
                        QueryType type,
                        CommandScope scope,
                        ui::CommandMap* command_map) const;

  // Records a keybinding `accelerator` as active for an extension with id
  // `extension_id` and command with the name `command_name`. If
  // `allow_overrides` is false, the keybinding must be free for the change to
  // be recorded (as determined by the master list in `user_prefs`). If
  // `allow_overwrites` is true, any previously recorded keybinding for this
  // `accelerator` will be overwritten. If `global` is true, the command will
  // be registered as a global command (be active even when Chrome does not have
  // focus. Returns true if the change was successfully recorded.
  bool AddKeybindingPref(const ui::Accelerator& accelerator,
                         const ExtensionId& extension_id,
                         const std::string& command_name,
                         bool allow_overrides,
                         bool global);

  // Removes all keybindings for a given extension by its `extension_id`.
  // `command_name` is optional and if specified, causes only the command with
  // the name `command_name` to be removed.
  void RemoveKeybindingPrefs(const ExtensionId& extension_id,
                             const std::string& command_name);

  // Update the keybinding prefs (for a command with a matching `extension_id`
  // and `command_name`) to `keystroke`. If the command had another key assigned
  // that key assignment will be removed.
  void UpdateKeybindingPrefs(const ExtensionId& extension_id,
                             const std::string& command_name,
                             const std::string& keystroke);

  // Set the scope of the keybinding. If `global` is true, the keybinding works
  // even when Chrome does not have focus. If the scope requested is already
  // set, the function returns false, otherwise true.
  bool SetScope(const ExtensionId& extension_id,
                const std::string& command_name,
                bool global);

  // Finds the command with the name `command_name` within an extension with id
  // `extension_id` . Returns an empty Command object (with keycode
  // VKEY_UNKNOWN) if the command is not found.
  Command FindCommandByName(const ExtensionId& extension_id,
                            const std::string& command) const;

  void AddObserver(Observer* observer);
  void RemoveObserver(Observer* observer);

  // Retrieves an extension with `extension_id` if it is enabled or disabled.
  const Extension* GetExtensionInEnabledOrDisabledExtensions(
      const ExtensionId& extension_id) const;

  // True if we are upgrading the extension from MV2->MV3.
  bool IsUpgradeFromMV2ToMV3(const Extension* extension,
                             const std::string& existing_command_name) const;

  void UpdateKeybindingsForTest(const Extension* extension) {
    UpdateKeybindings(extension);
  }

 private:
  friend class BrowserContextKeyedAPIFactory<CommandService>;

  // BrowserContextKeyedAPI implementation.
  static const char* service_name() {
    return "CommandService";
  }
  static const bool kServiceRedirectedInIncognito = true;

  // ExtensionRegistryObserver.
  void OnExtensionWillBeInstalled(content::BrowserContext* browser_context,
                                  const Extension* extension,
                                  bool is_update,
                                  const std::string& old_name) override;
  void OnExtensionUninstalled(content::BrowserContext* browser_context,
                              const Extension* extension,
                              extensions::UninstallReason reason) override;

  // Updates keybindings for a given `extension`'s page action, browser action
  // and named commands. Assigns new keybindings and removes relinquished
  // keybindings if not changed by the user. In the case of adding keybindings,
  // if the suggested keybinding is free, it will be taken by this extension. If
  // not, the keybinding request is ignored.
  void UpdateKeybindings(const Extension* extension);

  // On update, removes keybindings that the extension previously suggested but
  // now no longer does, as long as the user has not modified them. If a user
  // has modified an action command, transfer it to the new action command if
  // we're upgrading (MV2->MV3) before relinquishing.
  void RemoveRelinquishedKeybindings(const Extension* extension);

  // Assigns keybindings that the extension suggests, as long as they are not
  // already assigned.
  void AssignKeybindings(const Extension* extension);

  // Checks if `extension` is permitted to automatically assign the
  // `accelerator` key.
  bool CanAutoAssign(const ui::Command& command, const Extension* extension);

  // Updates the record of `extension`'s most recent suggested command shortcut
  // keys in the preferences.
  void UpdateExtensionSuggestedCommandPrefs(const Extension* extension);

  // Remove suggested key command prefs that apply to commands that have been
  // removed.
  void RemoveDefunctExtensionSuggestedCommandPrefs(const Extension* extension);

  // Returns true if the user modified a command's shortcut key from the
  // `extension`-suggested value.
  bool IsCommandShortcutUserModified(const Extension* extension,
                                     const std::string& command_name) const;

  // A weak pointer to the profile we are associated with. Not owned by us.
  raw_ptr<Profile> profile_;

  base::ScopedObservation<ExtensionRegistry, ExtensionRegistryObserver>
      extension_registry_observation_{this};

  base::ObserverList<Observer>::Unchecked observers_;
};

template <>
void
    BrowserContextKeyedAPIFactory<CommandService>::DeclareFactoryDependencies();

}  //  namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_COMMANDS_COMMAND_SERVICE_H_