import 'package:flutter/material.dart';

import 'package:desktop_drop/desktop_drop.dart';
import 'package:flutter_gen/gen_l10n/l10n.dart';
import 'package:future_loading_dialog/future_loading_dialog.dart';
import 'package:matrix/matrix.dart';
import 'package:scroll_to_index/scroll_to_index.dart';
import 'package:swipe_to_action/swipe_to_action.dart';
import 'package:vrouter/vrouter.dart';

import 'package:fluffychat/config/app_config.dart';
import 'package:fluffychat/config/themes.dart';
import 'package:fluffychat/pages/chat/chat.dart';
import 'package:fluffychat/pages/chat/chat_app_bar_title.dart';
import 'package:fluffychat/pages/chat/reactions_picker.dart';
import 'package:fluffychat/pages/chat/reply_display.dart';
import 'package:fluffychat/pages/chat/seen_by_row.dart';
import 'package:fluffychat/pages/chat/tombstone_display.dart';
import 'package:fluffychat/pages/chat/typing_indicators.dart';
import 'package:fluffychat/pages/user_bottom_sheet/user_bottom_sheet.dart';
import 'package:fluffychat/utils/platform_infos.dart';
import 'package:fluffychat/utils/sentry_controller.dart';
import 'package:fluffychat/widgets/chat_settings_popup_menu.dart';
import 'package:fluffychat/widgets/connection_status_header.dart';
import 'package:fluffychat/widgets/matrix.dart';
import 'package:fluffychat/widgets/unread_badge_back_button.dart';
import '../../utils/stream_extension.dart';
import 'chat_emoji_picker.dart';
import 'chat_input_row.dart';
import 'events/message.dart';

enum _EventContextAction { info, report }

class ChatView extends StatelessWidget {
  final ChatController controller;

  const ChatView(this.controller, {Key key}) : super(key: key);

  List<Widget> _appBarActions(BuildContext context) => controller.selectMode
      ? [
          if (controller.canEditSelectedEvents)
            IconButton(
              icon: const Icon(Icons.edit_outlined),
              tooltip: L10n.of(context).edit,
              onPressed: controller.editSelectedEventAction,
            ),
          IconButton(
            icon: const Icon(Icons.copy_outlined),
            tooltip: L10n.of(context).copy,
            onPressed: controller.copyEventsAction,
          ),
          if (controller.canRedactSelectedEvents)
            IconButton(
              icon: const Icon(Icons.delete_outlined),
              tooltip: L10n.of(context).redactMessage,
              onPressed: controller.redactEventsAction,
            ),
          if (controller.selectedEvents.length == 1)
            PopupMenuButton<_EventContextAction>(
              onSelected: (action) {
                switch (action) {
                  case _EventContextAction.info:
                    controller.showEventInfo();
                    controller.clearSelectedEvents();
                    break;
                  case _EventContextAction.report:
                    controller.reportEventAction();
                    break;
                }
              },
              itemBuilder: (context) => [
                PopupMenuItem(
                  value: _EventContextAction.info,
                  child: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      const Icon(Icons.info_outlined),
                      const SizedBox(width: 12),
                      Text(L10n.of(context).messageInfo),
                    ],
                  ),
                ),
                PopupMenuItem(
                  value: _EventContextAction.report,
                  child: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      const Icon(
                        Icons.shield_outlined,
                        color: Colors.red,
                      ),
                      const SizedBox(width: 12),
                      Text(L10n.of(context).reportMessage),
                    ],
                  ),
                ),
              ],
            ),
        ]
      : [
          ChatSettingsPopupMenu(controller.room, !controller.room.isDirectChat),
        ];

  @override
  Widget build(BuildContext context) {
    controller.matrix ??= Matrix.of(context);
    final client = controller.matrix.client;
    controller.sendingClient ??= client;
    controller.room = controller.sendingClient.getRoomById(controller.roomId);
    if (controller.room == null) {
      return Scaffold(
        appBar: AppBar(
          title: Text(L10n.of(context).oopsSomethingWentWrong),
        ),
        body: Center(
          child: Text(L10n.of(context).youAreNoLongerParticipatingInThisChat),
        ),
      );
    }

    if (controller.room.membership == Membership.invite) {
      showFutureLoadingDialog(
          context: context, future: () => controller.room.join());
    }
    final bottomSheetPadding = FluffyThemes.isColumnMode(context) ? 16.0 : 8.0;
    final horizontalPadding = FluffyThemes.isColumnMode(context) ? 8.0 : 0.0;

    return VWidgetGuard(
      onSystemPop: (redirector) async {
        if (controller.selectedEvents.isNotEmpty) {
          controller.clearSelectedEvents();
          redirector.stopRedirection();
        }
      },
      child: StreamBuilder(
        stream: controller.room.onUpdate.stream
            .rateLimit(const Duration(milliseconds: 250)),
        builder: (context, snapshot) => Scaffold(
          appBar: AppBar(
            actionsIconTheme: IconThemeData(
              color: controller.selectedEvents.isEmpty
                  ? null
                  : Theme.of(context).colorScheme.primary,
            ),
            leading: controller.selectMode
                ? IconButton(
                    icon: const Icon(Icons.close),
                    onPressed: controller.clearSelectedEvents,
                    tooltip: L10n.of(context).close,
                    color: Theme.of(context).colorScheme.primary,
                  )
                : UnreadBadgeBackButton(roomId: controller.roomId),
            titleSpacing: 0,
            title: ChatAppBarTitle(controller),
            actions: _appBarActions(context),
          ),
          floatingActionButton: controller.showScrollDownButton
              ? Padding(
                  padding: const EdgeInsets.only(bottom: 56.0),
                  child: FloatingActionButton(
                    onPressed: controller.scrollDown,
                    foregroundColor:
                        Theme.of(context).textTheme.bodyText2.color,
                    backgroundColor: Theme.of(context).scaffoldBackgroundColor,
                    mini: true,
                    child: Icon(Icons.arrow_downward_outlined,
                        color: Theme.of(context).primaryColor),
                  ),
                )
              : null,
          backgroundColor: Theme.of(context).colorScheme.surface,
          body: DropTarget(
            onDragDone: controller.onDragDone,
            onDragEntered: controller.onDragEntered,
            onDragExited: controller.onDragExited,
            child: Stack(
              children: <Widget>[
                if (Matrix.of(context).wallpaper != null)
                  Image.file(
                    Matrix.of(context).wallpaper,
                    width: double.infinity,
                    height: double.infinity,
                    fit: BoxFit.cover,
                  ),
                SafeArea(
                  child: Column(
                    children: <Widget>[
                      TombstoneDisplay(controller),
                      Expanded(
                        child: FutureBuilder<bool>(
                          future: controller.getTimeline(),
                          builder: (BuildContext context, snapshot) {
                            if (snapshot.hasError) {
                              SentryController.captureException(
                                snapshot.error,
                                StackTrace.current,
                              );
                            }
                            if (controller.timeline == null) {
                              return const Center(
                                child: CircularProgressIndicator.adaptive(
                                    strokeWidth: 2),
                              );
                            }

                            // create a map of eventId --> index to greatly improve performance of
                            // ListView's findChildIndexCallback
                            final thisEventsKeyMap = <String, int>{};
                            for (var i = 0;
                                i < controller.filteredEvents.length;
                                i++) {
                              thisEventsKeyMap[
                                  controller.filteredEvents[i].eventId] = i;
                            }
                            return ListView.custom(
                              padding: EdgeInsets.only(
                                top: 16,
                                bottom: 4,
                                left: horizontalPadding,
                                right: horizontalPadding,
                              ),
                              reverse: true,
                              controller: controller.scrollController,
                              keyboardDismissBehavior: PlatformInfos.isIOS
                                  ? ScrollViewKeyboardDismissBehavior.onDrag
                                  : ScrollViewKeyboardDismissBehavior.manual,
                              childrenDelegate: SliverChildBuilderDelegate(
                                (BuildContext context, int i) {
                                  return i ==
                                          controller.filteredEvents.length + 1
                                      ? controller.timeline.isRequestingHistory
                                          ? const Center(
                                              child: CircularProgressIndicator
                                                  .adaptive(strokeWidth: 2),
                                            )
                                          : controller.canLoadMore
                                              ? Center(
                                                  child: OutlinedButton(
                                                    style: OutlinedButton
                                                        .styleFrom(
                                                      backgroundColor: Theme.of(
                                                              context)
                                                          .scaffoldBackgroundColor,
                                                    ),
                                                    onPressed: controller
                                                        .requestHistory,
                                                    child: Text(L10n.of(context)
                                                        .loadMore),
                                                  ),
                                                )
                                              : Container()
                                      : i == 0
                                          ? Column(
                                              mainAxisSize: MainAxisSize.min,
                                              children: [
                                                SeenByRow(controller),
                                                TypingIndicators(controller),
                                              ],
                                            )
                                          : AutoScrollTag(
                                              key: ValueKey(controller
                                                  .filteredEvents[i - 1]
                                                  .eventId),
                                              index: i - 1,
                                              controller:
                                                  controller.scrollController,
                                              child: Swipeable(
                                                key: ValueKey(controller
                                                    .filteredEvents[i - 1]
                                                    .eventId),
                                                background: const Padding(
                                                  padding: EdgeInsets.symmetric(
                                                      horizontal: 12.0),
                                                  child: Center(
                                                    child: Icon(
                                                        Icons.reply_outlined),
                                                  ),
                                                ),
                                                direction:
                                                    SwipeDirection.endToStart,
                                                onSwipe: (direction) =>
                                                    controller.replyAction(
                                                        replyTo: controller
                                                                .filteredEvents[
                                                            i - 1]),
                                                child: Message(
                                                    controller
                                                        .filteredEvents[i - 1],
                                                    onInfoTab: controller
                                                        .showEventInfo,
                                                    onAvatarTab: (Event event) =>
                                                        showModalBottomSheet(
                                                          context: context,
                                                          builder: (c) =>
                                                              UserBottomSheet(
                                                            user: event.sender,
                                                            outerContext:
                                                                context,
                                                            onMention: () => controller
                                                                    .sendController
                                                                    .text +=
                                                                '${event.sender.mention} ',
                                                          ),
                                                        ),
                                                    unfold: controller.unfold,
                                                    onSelect: controller
                                                        .onSelectMessage,
                                                    scrollToEventId:
                                                        (String eventId) =>
                                                            controller.scrollToEventId(
                                                                eventId),
                                                    longPressSelect: controller
                                                        .selectedEvents.isEmpty,
                                                    selected: controller
                                                        .selectedEvents
                                                        .any((e) =>
                                                            e.eventId ==
                                                            controller
                                                                .filteredEvents[i - 1]
                                                                .eventId),
                                                    timeline: controller.timeline,
                                                    nextEvent: i < controller.filteredEvents.length ? controller.filteredEvents[i] : null),
                                              ),
                                            );
                                },
                                childCount:
                                    controller.filteredEvents.length + 2,
                                findChildIndexCallback: (key) =>
                                    controller.findChildIndexCallback(
                                        key, thisEventsKeyMap),
                              ),
                            );
                          },
                        ),
                      ),
                      if (controller.room.canSendDefaultMessages &&
                          controller.room.membership == Membership.join)
                        Container(
                          margin: EdgeInsets.only(
                            bottom: bottomSheetPadding,
                            left: bottomSheetPadding,
                            right: bottomSheetPadding,
                          ),
                          constraints: const BoxConstraints(
                              maxWidth: FluffyThemes.columnWidth * 2.5),
                          alignment: Alignment.center,
                          child: Material(
                            borderRadius: const BorderRadius.only(
                              bottomLeft:
                                  Radius.circular(AppConfig.borderRadius),
                              bottomRight:
                                  Radius.circular(AppConfig.borderRadius),
                            ),
                            elevation: 6,
                            shadowColor: Theme.of(context)
                                .secondaryHeaderColor
                                .withAlpha(100),
                            clipBehavior: Clip.hardEdge,
                            color:
                                Theme.of(context).appBarTheme.backgroundColor,
                            child: Column(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                const ConnectionStatusHeader(),
                                ReactionsPicker(controller),
                                ReplyDisplay(controller),
                                ChatInputRow(controller),
                                ChatEmojiPicker(controller),
                              ],
                            ),
                          ),
                        ),
                    ],
                  ),
                ),
                if (controller.dragging)
                  Container(
                    color: Theme.of(context)
                        .scaffoldBackgroundColor
                        .withOpacity(0.9),
                    alignment: Alignment.center,
                    child: const Icon(
                      Icons.upload_outlined,
                      size: 100,
                    ),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}