import 'dart:ui';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.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/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.report_outlined),
                      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: Stack(
            children: <Widget>[
              if (Matrix.of(context).wallpaper != null)
                Image.file(
                  Matrix.of(context).wallpaper,
                  width: double.infinity,
                  height: double.infinity,
                  fit: BoxFit.cover,
                ),
              Column(
                children: <Widget>[
                  TombstoneDisplay(controller),
                  Expanded(
                    child: FutureBuilder<bool>(
                      future: controller.getTimeline(),
                      builder: (BuildContext context, snapshot) {
                        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).backgroundColor,
                        child: SafeArea(
                          child: Column(
                            mainAxisSize: MainAxisSize.min,
                            children: [
                              const ConnectionStatusHeader(),
                              ReactionsPicker(controller),
                              ReplyDisplay(controller),
                              ChatInputRow(controller),
                              ChatEmojiPicker(controller),
                            ],
                          ),
                        ),
                      ),
                    ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}