// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ASH_QUICK_INSERT_QUICK_INSERT_INSERT_MEDIA_REQUEST_H_
#define ASH_QUICK_INSERT_QUICK_INSERT_INSERT_MEDIA_REQUEST_H_

#include <optional>
#include <string>
#include <variant>

#include "ash/ash_export.h"
#include "ash/quick_insert/quick_insert_insert_media.h"
#include "ash/quick_insert/quick_insert_rich_media.h"
#include "base/functional/callback_forward.h"
#include "base/scoped_observation.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "ui/base/ime/input_method_observer.h"

namespace ui {
class InputMethod;
class TextInputClient;
}  // namespace ui

namespace ash {

struct QuickInsertWebPasteTarget;

// Inserts rich media such as text and images into an input field.
class ASH_EXPORT QuickInsertInsertMediaRequest
    : public ui::InputMethodObserver {
 public:
  enum class Result {
    kSuccess,
    // There was no compatible input field to insert in during the timeout.
    kTimeout,
    // The insertion failed because the input field was incompatible.
    kUnsupported,
    // The media was not found.
    kNotFound,
  };

  using OnCompleteCallback = base::OnceCallback<void(Result)>;

  // Creates a request to insert `data` in the next focused input field.
  // If there's no focus change within `insert_timeout`, then this
  // request is cancelled. If this request is destroyed before insertion could
  // happen, the request is cancelled.
  // If `on_complete_callback` is valid, it is called when the insert
  // completed successfully, or when there is an error, such as no insertion
  // happened before the timeout.
  explicit QuickInsertInsertMediaRequest(
      ui::InputMethod* input_method,
      const QuickInsertRichMedia& media,
      base::TimeDelta insert_timeout,
      base::OnceCallback<std::optional<QuickInsertWebPasteTarget>()>
          get_web_paste_target = {},
      OnCompleteCallback on_complete_callback = {});
  ~QuickInsertInsertMediaRequest() override;

  // ui::InputMethodObserver:
  void OnFocus() override {}
  void OnBlur() override {}
  void OnCaretBoundsChanged(const ui::TextInputClient* client) override {}
  void OnTextInputStateChanged(const ui::TextInputClient* client) override;
  void OnInputMethodDestroyed(const ui::InputMethod* input_method) override;

 private:
  // Cancels the insertion if it's still pending.
  // Does nothing if the insertion has already happened.
  void CancelPendingInsert();

  std::optional<QuickInsertRichMedia> media_to_insert_;
  base::OnceCallback<std::optional<QuickInsertWebPasteTarget>()>
      get_web_paste_target_;
  base::ScopedObservation<ui::InputMethod, ui::InputMethodObserver>
      observation_{this};
  base::OneShotTimer insert_timeout_timer_;
  // This is guaranteed to be non-null before the insertion is complete (even if
  // a null callback is passed in the constructor), and null afterwards.
  OnCompleteCallback on_complete_callback_;
};

}  // namespace ash

#endif  // ASH_QUICK_INSERT_QUICK_INSERT_INSERT_MEDIA_REQUEST_H_