// Copyright 2025 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_UI_WEBUI_SIGNIN_SIGNOUT_CONFIRMATION_SIGNOUT_CONFIRMATION_UI_H_
#define CHROME_BROWSER_UI_WEBUI_SIGNIN_SIGNOUT_CONFIRMATION_SIGNOUT_CONFIRMATION_UI_H_

#include "base/functional/callback.h"
#include "base/observer_list.h"
#include "base/observer_list_types.h"
#include "chrome/browser/ui/signin/chrome_signout_confirmation_prompt.h"
#include "chrome/browser/ui/webui/signin/signout_confirmation/signout_confirmation.mojom.h"
#include "chrome/common/webui_url_constants.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/webui_config.h"
#include "content/public/common/url_constants.h"
#include "mojo/public/cpp/bindings/receiver.h"
#include "ui/webui/mojo_web_ui_controller.h"

namespace content {
class WebUI;
}  // namespace content

class BrowserWindowInterface;
class SignoutConfirmationHandler;
class SignoutConfirmationUI;

class SignoutConfirmationUIConfig
    : public content::DefaultWebUIConfig<SignoutConfirmationUI> {
 public:
  SignoutConfirmationUIConfig()
      : DefaultWebUIConfig(content::kChromeUIScheme,
                           chrome::kChromeUISignoutConfirmationHost) {}
};

class SignoutConfirmationUI
    : public ui::MojoWebUIController,
      public signout_confirmation::mojom::PageHandlerFactory {
 public:
  class Observer : public base::CheckedObserver {
   public:
    // Called when the `handler_` is set and ready to be used.
    // TODO(crbug.com/469344442): This method is only used in tests.
    // Once an alternative observer is used for the tests that need this,
    // remove this method (and observer).
    virtual void OnSignoutConfirmationUIHandlerReady() = 0;

    // Called when the SignoutConfirmationUI is being destroyed.
    virtual void OnSignoutConfirmationUIDestroying(
        SignoutConfirmationUI* ui) = 0;
  };

  explicit SignoutConfirmationUI(content::WebUI* web_ui);
  ~SignoutConfirmationUI() override;

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

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

  // Prepares the information to be given to the handler once ready.
  void Initialize(BrowserWindowInterface* browser,
                  ChromeSignoutConfirmationPromptVariant variant,
                  size_t unsynced_data_count,
                  SignoutConfirmationCallback callback);

  // Instantiates the implementor of the
  // `signout_confirmation::mojom::PageHandlerFactory` mojo interface passing
  // the pending receiver that will be internally bound.
  void BindInterface(
      mojo::PendingReceiver<signout_confirmation::mojom::PageHandlerFactory>
          receiver);

  // Returns the instance of this class for the provided `contents` or nullptr
  // if `contents` does not display the signout confirmation UI.
  static SignoutConfirmationUI* GetForTesting(content::WebContents* contents);

  // Simulates accepting the signout confirmation dialog through a direct call
  // to the `handler_`.
  void AcceptDialogForTesting();

  // Simulates cancelling the signout confirmation dialog through a direct call
  // to the `handler_`.
  void CancelDialogForTesting();

  // Simulates cancelling the signout confirmation dialog and triggering a
  // reauth through a direct call to the `handler_`.
  void CancelDialogAndReauthForTesting();

  bool IsHandlerReadyForTesting() { return handler_.get(); }

 private:
  // signout_confirmation::mojom::SignoutConfirmationFactory:
  void CreateSignoutConfirmationHandler(
      mojo::PendingRemote<signout_confirmation::mojom::Page> page,
      mojo::PendingReceiver<signout_confirmation::mojom::PageHandler> receiver)
      override;

  // Callback awaiting `CreateSignoutConfirmationHandler` to create the handlers
  // with all the needed information to display.
  void OnMojoHandlersReady(
      BrowserWindowInterface* browser,
      ChromeSignoutConfirmationPromptVariant variant,
      size_t unsynced_data_count,
      SignoutConfirmationCallback callback,
      mojo::PendingRemote<signout_confirmation::mojom::Page> page,
      mojo::PendingReceiver<signout_confirmation::mojom::PageHandler> receiver);

  // Callback that temporarily holds the information to be passed onto the
  // handler. The callback is called once the mojo handlers are available.
  base::OnceCallback<void(
      mojo::PendingRemote<signout_confirmation::mojom::Page>,
      mojo::PendingReceiver<signout_confirmation::mojom::PageHandler>)>
      initialize_handler_callback_;

  base::ObserverList<Observer> observers_;

  // Handler implementing Mojo interface to communicate with the WebUI.
  std::unique_ptr<SignoutConfirmationHandler> handler_;

  mojo::Receiver<signout_confirmation::mojom::PageHandlerFactory>
      page_factory_receiver_{this};

  WEB_UI_CONTROLLER_TYPE_DECL();
};

#endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_SIGNOUT_CONFIRMATION_SIGNOUT_CONFIRMATION_UI_H_