// SPDX-FileCopyrightText: 2017 Konstantinos Sideris <siderisk@auth.gr>
// SPDX-FileCopyrightText: 2021 Nheko Contributors
//
// SPDX-License-Identifier: GPL-3.0-or-later

#pragma once

#include <atomic>
#include <optional>
#include <stack>
#include <variant>

#include <mtx/common.hpp>
#include <mtx/events.hpp>
#include <mtx/events/encrypted.hpp>
#include <mtx/events/member.hpp>
#include <mtx/events/presence.hpp>
#include <mtx/secret_storage.hpp>

#include <QHBoxLayout>
#include <QMap>
#include <QPoint>
#include <QTimer>
#include <QWidget>

#include "CacheCryptoStructs.h"
#include "CacheStructs.h"
#include "notifications/Manager.h"

class OverlayModal;
class TimelineViewManager;
class UserSettings;
class NotificationsManager;
class TimelineModel;
class CallManager;

constexpr int CONSENSUS_TIMEOUT      = 1000;
constexpr int SHOW_CONTENT_TIMEOUT   = 3000;
constexpr int TYPING_REFRESH_TIMEOUT = 10000;

namespace mtx::requests {
struct CreateRoom;
}
namespace mtx::responses {
struct Notifications;
struct Sync;
struct Timeline;
struct Rooms;
}

using SecretsToDecrypt = std::map<std::string, mtx::secret_storage::AesHmacSha2EncryptedData>;

class ChatPage : public QWidget
{
    Q_OBJECT

public:
    ChatPage(QSharedPointer<UserSettings> userSettings, QWidget *parent = nullptr);

    // Initialize all the components of the UI.
    void bootstrap(QString userid, QString homeserver, QString token);

    static ChatPage *instance() { return instance_; }

    QSharedPointer<UserSettings> userSettings() { return userSettings_; }
    CallManager *callManager() { return callManager_; }
    TimelineViewManager *timelineManager() { return view_manager_; }
    void deleteConfigs();

    void initiateLogout();

    QString status() const;
    void setStatus(const QString &status);

    mtx::presence::PresenceState currentPresence() const;

    // TODO(Nico): Get rid of this!
    QString currentRoom() const;

public slots:
    bool handleMatrixUri(const QByteArray &uri);
    bool handleMatrixUri(const QUrl &uri);

    void startChat(QString userid);
    void leaveRoom(const QString &room_id);
    void createRoom(const mtx::requests::CreateRoom &req);
    void joinRoom(const QString &room);
    void joinRoomVia(const std::string &room_id,
                     const std::vector<std::string> &via,
                     bool promptForConfirmation = true);

    void inviteUser(QString userid, QString reason);
    void kickUser(QString userid, QString reason);
    void banUser(QString userid, QString reason);
    void unbanUser(QString userid, QString reason);

    void receivedSessionKey(const std::string &room_id, const std::string &session_id);
    void decryptDownloadedSecrets(mtx::secret_storage::AesHmacSha2KeyDescription keyDesc,
                                  const SecretsToDecrypt &secrets);
signals:
    void connectionLost();
    void connectionRestored();

    void notificationsRetrieved(const mtx::responses::Notifications &);
    void highlightedNotifsRetrieved(const mtx::responses::Notifications &, const QPoint widgetPos);

    void contentLoaded();
    void closing();
    void changeWindowTitle(const int);
    void unreadMessages(int count);
    void showNotification(const QString &msg);
    void showLoginPage(const QString &msg);
    void showUserSettingsPage();
    void showOverlayProgressBar();

    void ownProfileOk();
    void setUserDisplayName(const QString &name);
    void setUserAvatar(const QString &avatar);
    void loggedOut();

    void trySyncCb();
    void tryDelayedSyncCb();
    void tryInitialSyncCb();
    void newSyncResponse(const mtx::responses::Sync &res, const std::string &prev_batch_token);
    void leftRoom(const QString &room_id);
    void newRoom(const QString &room_id);
    void changeToRoom(const QString &room_id);

    void initializeViews(const mtx::responses::Rooms &rooms);
    void initializeEmptyViews();
    void initializeMentions(const QMap<QString, mtx::responses::Notifications> &notifs);
    void syncUI(const mtx::responses::Rooms &rooms);
    void dropToLoginPageCb(const QString &msg);

    void notifyMessage(const QString &roomid,
                       const QString &eventid,
                       const QString &roomname,
                       const QString &sender,
                       const QString &message,
                       const QImage &icon);

    void retrievedPresence(const QString &statusMsg, mtx::presence::PresenceState state);
    void themeChanged();
    void decryptSidebarChanged();
    void chatFocusChanged(const bool focused);

    //! Signals for device verificaiton
    void receivedDeviceVerificationAccept(const mtx::events::msg::KeyVerificationAccept &message);
    void receivedDeviceVerificationRequest(const mtx::events::msg::KeyVerificationRequest &message,
                                           std::string sender);
    void receivedRoomDeviceVerificationRequest(
      const mtx::events::RoomEvent<mtx::events::msg::KeyVerificationRequest> &message,
      TimelineModel *model);
    void receivedDeviceVerificationCancel(const mtx::events::msg::KeyVerificationCancel &message);
    void receivedDeviceVerificationKey(const mtx::events::msg::KeyVerificationKey &message);
    void receivedDeviceVerificationMac(const mtx::events::msg::KeyVerificationMac &message);
    void receivedDeviceVerificationStart(const mtx::events::msg::KeyVerificationStart &message,
                                         std::string sender);
    void receivedDeviceVerificationReady(const mtx::events::msg::KeyVerificationReady &message);
    void receivedDeviceVerificationDone(const mtx::events::msg::KeyVerificationDone &message);

    void downloadedSecrets(mtx::secret_storage::AesHmacSha2KeyDescription keyDesc,
                           const SecretsToDecrypt &secrets);

private slots:
    void logout();
    void removeRoom(const QString &room_id);
    void changeRoom(const QString &room_id);
    void dropToLoginPage(const QString &msg);

    void handleSyncResponse(const mtx::responses::Sync &res, const std::string &prev_batch_token);

private:
    static ChatPage *instance_;

    void startInitialSync();
    void tryInitialSync();
    void trySync();
    void verifyOneTimeKeyCountAfterStartup();
    void ensureOneTimeKeyCount(const std::map<std::string, uint16_t> &counts);
    void getProfileInfo();
    void getBackupVersion();

    //! Check if the given room is currently open.
    bool isRoomActive(const QString &room_id);

    using UserID      = QString;
    using Membership  = mtx::events::StateEvent<mtx::events::state::Member>;
    using Memberships = std::map<std::string, Membership>;

    void loadStateFromCache();
    void resetUI();

    template<class Collection>
    Memberships getMemberships(const std::vector<Collection> &events) const;

    //! Send desktop notification for the received messages.
    void sendNotifications(const mtx::responses::Notifications &);

    template<typename T>
    void connectCallMessage();

    QHBoxLayout *topLayout_;

    TimelineViewManager *view_manager_;

    QTimer connectivityTimer_;
    std::atomic_bool isConnected_;

    // Global user settings.
    QSharedPointer<UserSettings> userSettings_;

    NotificationsManager notificationsManager;
    CallManager *callManager_;
};

template<class Collection>
std::map<std::string, mtx::events::StateEvent<mtx::events::state::Member>>
ChatPage::getMemberships(const std::vector<Collection> &collection) const
{
    std::map<std::string, mtx::events::StateEvent<mtx::events::state::Member>> memberships;

    using Member = mtx::events::StateEvent<mtx::events::state::Member>;

    for (const auto &event : collection) {
        if (auto member = std::get_if<Member>(event)) {
            memberships.emplace(member->state_key, *member);
        }
    }

    return memberships;
}