// Copyright 2021 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_SIDE_PANEL_SIDE_PANEL_ENTRY_H_
#define CHROME_BROWSER_UI_SIDE_PANEL_SIDE_PANEL_ENTRY_H_

#include <memory>
#include <optional>
#include <string>

#include "base/containers/enum_set.h"
#include "base/functional/callback.h"
#include "base/functional/callback_forward.h"
#include "base/observer_list.h"
#include "base/time/time.h"
#include "chrome/browser/ui/side_panel/side_panel_entry_id.h"
#include "chrome/browser/ui/side_panel/side_panel_entry_key.h"
#include "chrome/browser/ui/side_panel/side_panel_enums.h"
#include "chrome/browser/ui/side_panel/side_panel_native_view.h"
#include "extensions/common/extension_id.h"
#include "ui/base/class_property.h"
#include "ui/base/models/image_model.h"
#include "ui/base/models/menu_model.h"
#include "url/gurl.h"

class SidePanelEntryScope;
class SidePanelEntryObserver;
enum class SidePanelEntryHideReason;

// This class represents an entry inside the side panel. These are owned by
// a SidePanelRegistry (either a per-tab or a per-window registry).
class SidePanelEntry final : public ui::PropertyHandler {
 public:

  // The default and minimum acceptable side panel content width.
  static constexpr int kSidePanelDefaultContentWidth = 360;
  using CreateContentCallback =
      base::RepeatingCallback<SidePanelNativeView(SidePanelEntryScope&)>;
  using Id = SidePanelEntryId;
  using Key = SidePanelEntryKey;

  // If adding a callback to provide a URL to the 'Open in New Tab' button, you
  // must also add a relevant entry in actions.xml because a user action is
  // logged on button click.
  SidePanelEntry(Key key,
                 CreateContentCallback create_content_callback,
                 base::RepeatingCallback<GURL()> open_in_new_tab_url_callback,
                 base::RepeatingCallback<std::unique_ptr<ui::MenuModel>()>
                     more_info_callback,
                 base::RepeatingCallback<int()> default_content_width_callback);

  // This constructor should be primarily used for features that want a
  // non-kContent SidePanelType.
  SidePanelEntry(SidePanelType type,
                 Key key,
                 CreateContentCallback create_content_callback,
                 base::RepeatingCallback<int()> default_content_width_callback);

  // This constructor is primarily used for extensions. Extensions don't have
  // `Open in New Tab` functionality. Other side panels can use this if nothing
  // custom is needed (we call the other constructor passing
  // base::NullCallback()).
  SidePanelEntry(Key key,
                 CreateContentCallback create_content_callback,
                 base::RepeatingCallback<int()> default_content_width_callback);
  SidePanelEntry(const SidePanelEntry&) = delete;
  SidePanelEntry& operator=(const SidePanelEntry&) = delete;
  ~SidePanelEntry() override;

  // Creates the content to be shown inside the side panel when this entry is
  // shown.
  SidePanelNativeView GetContent();
  void CacheView(SidePanelNativeView view);
  void ClearCachedView();
  SidePanelNativeView& CachedView() { return content_view_; }

  // Called when the entry has been shown/hidden in the side panel.
  void OnEntryShown();
  void OnEntryWillHide(SidePanelEntryHideReason reason);
  void OnEntryHideCancelled();
  void OnEntryHidden();
#if BUILDFLAG(IS_ANDROID)
  // TODO(crbug.com/496962614): compile OnEntryHiddenWithReason() into all
  // platforms.
  void OnEntryHiddenWithReason(SidePanelEntryHideReason reason);
#endif

  SidePanelType type() const { return type_; }
  const Key& key() const { return key_; }

  void set_last_open_trigger(std::optional<SidePanelOpenTrigger> trigger) {
    last_open_trigger_ = trigger;
  }

  std::optional<SidePanelOpenTrigger> last_open_trigger() const {
    return last_open_trigger_;
  }

  // Sets whether a button will be shown ephemerally in the toolbar when the
  // entry is showing in the side panel. Note, even if this is false the button
  // would still be seen if pinned.
  void set_should_show_ephemerally_in_toolbar(
      bool should_show_ephemerally_in_toolbar) {
    should_show_ephemerally_in_toolbar_ = should_show_ephemerally_in_toolbar;
  }

  bool should_show_ephemerally_in_toolbar() const {
    return should_show_ephemerally_in_toolbar_;
  }

  // Whether the header should be visible when the entry is shown.
  void set_should_show_header(bool should_show_header) {
    should_show_header_ = should_show_header;
  }
  bool should_show_header() const { return should_show_header_; }

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

  // Gets the 'Open in New Tab' URL. Returns an empty GURL if this function is
  // unavailable for the current side panel entry.
  GURL GetOpenInNewTabURL() const;

  // Gets the menu model for the more info menu if the current side panel entry
  // has one, otherwise null.
  std::unique_ptr<ui::MenuModel> GetMoreInfoMenuModel() const;

  // Returns whether the side panel entry has a defined callback for getting the
  // open new tab button URL.
  bool SupportsNewTabButton();

  // Returns whether the side panel entry has a defined callback for the more
  // info button.
  bool SupportsMoreInfoButton();

  // Resets the `entry_show_triggered_timestamp_` so we don't track metrics
  // incorrectly.
  void ResetLoadTimestamp();

  void set_scope(SidePanelEntryScope* scope) { scope_ = scope; }

  base::WeakPtr<SidePanelEntry> GetWeakPtr() {
    return weak_factory_.GetWeakPtr();
  }

  // Gets the default content width for this entry, if one is specified.
  int GetDefaultContentWidth() const;

  // Allows tests to override the default width for an existing entry.
  void SetDefaultContentWidthForTesting(int width) {
    default_content_width_ = width;
  }

 private:
  const SidePanelType type_;
  const Key key_;
  SidePanelNativeView content_view_;

  // Whether a button will be shown ephemerally in the toolbar when the entry is
  // showing in the side panel. Note, even if this is false the button would
  // still be seen if pinned.
  bool should_show_ephemerally_in_toolbar_ = true;

  // Whether the side panel header will be visible when this entry is showing.
  bool should_show_header_ = true;

  // Scope of this entry, will outlive the entry and its content.
  raw_ptr<SidePanelEntryScope> scope_ = nullptr;

  CreateContentCallback create_content_callback_;

  // If this returns an empty GURL, the 'Open in New Tab' button is hidden.
  base::RepeatingCallback<GURL()> open_in_new_tab_url_callback_;

  // If this returns null, the more info button is hidden.
  base::RepeatingCallback<std::unique_ptr<ui::MenuModel>()> more_info_callback_;

  // When specified sets the default starting width for this entry. However, if
  // the user manually changes the size of the side panel that preference is
  // used instead (prefs::kSidePanelIdToWidth). If nothing is specified, then
  // the default minimum content width of the side panel is used.
  base::RepeatingCallback<int()> default_content_width_callback_;

  // Timestamp of when the side panel was triggered to be shown.
  base::TimeTicks entry_show_triggered_timestamp_;

  base::TimeTicks entry_shown_timestamp_;

  base::ObserverList<
      SidePanelEntryObserver,
      /*check_empty=*/false,
      /*reentrancy=*/
      base::ObserverListReentrancyPolicy::kAllowReentrancyUntriaged>
      observers_;

  // The last trigger that caused this side panel entry to be shown. This is
  // used for metrics.
  std::optional<SidePanelOpenTrigger> last_open_trigger_;

  // The default minimum content width for the side panel that can be overridden
  // for testing. This is used if the default_content_width_callback_ is not
  // set. However, if the user manually changes the size of the side panel that
  // preference is used instead (prefs::kSidePanelIdToWidth).
  int default_content_width_ = kSidePanelDefaultContentWidth;

  base::WeakPtrFactory<SidePanelEntry> weak_factory_{this};
};

#if BUILDFLAG(IS_ANDROID)
// Title is retrieve from SidePanelHelper::GetActionItem() on non-Android.
extern const ui::ClassProperty<std::u16string*>* const kSidePanelTitleKey;
#else
extern const ui::ClassProperty<bool>* const
    kShouldShowTitleInSidePanelHeaderKey;
#endif

#endif  // CHROME_BROWSER_UI_SIDE_PANEL_SIDE_PANEL_ENTRY_H_