// 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.

#include "components/javascript_dialogs/app_modal_dialog_queue.h"

#include "base/no_destructor.h"
#include "components/javascript_dialogs/app_modal_dialog_controller.h"

namespace javascript_dialogs {

// static
AppModalDialogQueue* AppModalDialogQueue::GetInstance() {
  static base::NoDestructor<AppModalDialogQueue> instance;
  return instance.get();
}

void AppModalDialogQueue::CancelAllDialogs() {
  shutting_down_ = true;
  InvalidateAndClearQueuedDialogs();
}

void AppModalDialogQueue::ResetForTesting() {
  active_dialog_ = nullptr;
  shutting_down_ = false;
  InvalidateAndClearQueuedDialogs();
}

void AppModalDialogQueue::InvalidateAndClearQueuedDialogs() {
  while (!app_modal_dialog_queue_.empty()) {
    app_modal_dialog_queue_.front()->Invalidate();
    app_modal_dialog_queue_.pop_front();
  }
}

void AppModalDialogQueue::AddDialog(
    std::unique_ptr<AppModalDialogController> dialog) {
  if (shutting_down_) {
    dialog->Invalidate();
    return;
  }

  if (!active_dialog_) {
    ShowModalDialog(std::move(dialog));
    return;
  }

  app_modal_dialog_queue_.push_back(std::move(dialog));
}

void AppModalDialogQueue::ShowNextDialog() {
  if (shutting_down_) {
    active_dialog_ = nullptr;
    InvalidateAndClearQueuedDialogs();
    return;
  }

  std::unique_ptr<AppModalDialogController> dialog = GetNextDialog();
  if (dialog) {
    ShowModalDialog(std::move(dialog));
  } else {
    active_dialog_ = nullptr;
  }
}

void AppModalDialogQueue::ActivateModalDialog() {
  if (showing_modal_dialog_) {
    // As part of showing a modal dialog we may end up back in this method
    // (showing a dialog activates the WebContents, which can trigger a call
    // to ActivateModalDialog). We ignore such a request as after the call to
    // activate the tab contents the dialog is shown.
    return;
  }

  if (active_dialog_) {
    active_dialog_->ActivateModalDialog();
  }
}

bool AppModalDialogQueue::HasActiveDialog() const {
  return !!active_dialog_;
}

AppModalDialogQueue::AppModalDialogQueue() = default;

AppModalDialogQueue::~AppModalDialogQueue() = default;

void AppModalDialogQueue::ShowModalDialog(
    std::unique_ptr<AppModalDialogController> dialog) {
  // Be sure and set the active_dialog_ field first, otherwise if
  // ShowModalDialog triggers a call back to the queue they'll get the old
  // dialog. Also, if the dialog calls `ShowNextDialog()` before returning, that
  // would write nullptr into `active_dialog_` and this function would then undo
  // that.
  active_dialog_ = dialog.get();
  showing_modal_dialog_ = true;
  active_dialog_->ShowModalDialog(std::move(dialog));
  showing_modal_dialog_ = false;
}

std::unique_ptr<AppModalDialogController> AppModalDialogQueue::GetNextDialog() {
  while (!app_modal_dialog_queue_.empty()) {
    std::unique_ptr<AppModalDialogController> dialog =
        std::move(app_modal_dialog_queue_.front());
    app_modal_dialog_queue_.pop_front();
    if (dialog->IsValid()) {
      return dialog;
    }
  }
  return nullptr;
}

}  // namespace javascript_dialogs