import 'dart:async';
import 'dart:math';

import 'package:flutter/material.dart';

import 'package:go_router/go_router.dart';
import 'package:matrix/matrix.dart';

import 'package:fluffychat/config/app_config.dart';
import 'package:fluffychat/l10n/l10n.dart';
import 'package:fluffychat/pangea/bot/utils/bot_name.dart';
import 'package:fluffychat/pangea/course_creation/course_info_chip_widget.dart';
import 'package:fluffychat/pangea/course_plans/courses/course_plan_builder.dart';
import 'package:fluffychat/pangea/course_plans/courses/course_plan_room_extension.dart';
import 'package:fluffychat/pangea/events/constants/pangea_event_types.dart';
import 'package:fluffychat/widgets/avatar.dart';
import 'package:fluffychat/widgets/future_loading_dialog.dart';
import 'package:fluffychat/widgets/matrix.dart';

class CourseInvitePage extends StatefulWidget {
  final String courseId;
  final Completer<String>? courseCreationCompleter;

  const CourseInvitePage(
    this.courseId, {
    super.key,
    this.courseCreationCompleter,
  });

  @override
  CourseInvitePageController createState() => CourseInvitePageController();
}

class CourseInvitePageController extends State<CourseInvitePage>
    with CoursePlanProvider {
  @override
  void initState() {
    super.initState();
    loadCourse(widget.courseId);
  }

  @override
  void didUpdateWidget(covariant CourseInvitePage oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.courseId != widget.courseId) {
      loadCourse(widget.courseId);
    }
  }

  Future<String> getSpaceId() async {
    if (widget.courseCreationCompleter == null) {
      throw Exception("No course creation completer provided");
    }
    final spaceId = await widget.courseCreationCompleter!.future;
    final room = Matrix.of(context).client.getRoomById(spaceId);
    if (room == null || room.coursePlan == null) {
      await Matrix.of(context).client.onRoomState.stream.firstWhere((event) {
        return event.roomId == spaceId &&
            event.state.type == PangeaEventTypes.coursePlan;
      }).timeout(
        const Duration(seconds: 10),
      );
    }
    return spaceId;
  }

  @override
  Widget build(BuildContext context) {
    const avatarSize = 44.0;

    final theme = Theme.of(context);
    final client = Matrix.of(context).client;

    return Scaffold(
      body: SafeArea(
        child: Center(
          child: Container(
            padding: const EdgeInsets.all(20.0),
            constraints: const BoxConstraints(
              maxWidth: 750,
            ),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                course != null
                    ? Container(
                        decoration: BoxDecoration(
                          border: Border.all(color: AppConfig.gold),
                          borderRadius: BorderRadius.circular(12),
                        ),
                        padding: const EdgeInsets.all(16.0),
                        child: Column(
                          spacing: 16.0,
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Row(
                              spacing: 10.0,
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: [
                                const Icon(
                                  Icons.map_outlined,
                                  size: 40.0,
                                ),
                                Flexible(
                                  child: Text(
                                    course!.title,
                                    style: theme.textTheme.titleLarge?.copyWith(
                                      fontWeight: FontWeight.bold,
                                    ),
                                    overflow: TextOverflow.ellipsis,
                                  ),
                                ),
                              ],
                            ),
                            CourseInfoChips(
                              widget.courseId,
                              fontSize: 12.0,
                              iconSize: 12.0,
                            ),
                          ],
                        ),
                      )
                    : loadingCourse
                        ? const CircularProgressIndicator.adaptive()
                        : const SizedBox(),
                Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: Column(
                    spacing: 16.0,
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      LayoutBuilder(
                        builder: (context, constraints) {
                          const avatarSpace = avatarSize + 8.0;
                          final availableSpace = constraints.maxWidth - 24.0;

                          final visibleAvatars = min(
                            3,
                            (availableSpace / avatarSpace).floor() - 2,
                          );

                          return Row(
                            spacing: 8.0,
                            mainAxisSize: MainAxisSize.min,
                            children: [
                              FutureBuilder(
                                future:
                                    client.getProfileFromUserId(client.userID!),
                                builder: (context, snapshot) {
                                  return Avatar(
                                    size: avatarSize,
                                    mxContent: snapshot.data?.avatarUrl,
                                    name: snapshot.data?.displayName ??
                                        client.userID!.localpart,
                                    userId: client.userID!,
                                  );
                                },
                              ),
                              Avatar(
                                userId: BotName.byEnvironment,
                                size: avatarSize,
                              ),
                              ...List.generate(visibleAvatars, (index) {
                                return CircleAvatar(
                                  radius: avatarSize / 2,
                                  backgroundColor: AppConfig.gold.withAlpha(80),
                                  child: const Icon(
                                    Icons.question_mark,
                                    size: 20.0,
                                  ),
                                );
                              }),
                              const Icon(
                                Icons.more_horiz,
                                size: 24.0,
                              ),
                            ],
                          );
                        },
                      ),
                      Text(
                        L10n.of(context).courseStartDesc,
                        style: theme.textTheme.titleMedium,
                      ),
                    ],
                  ),
                ),
                Column(
                  spacing: 24.0,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    ElevatedButton(
                      onPressed: () async {
                        final resp = await showFutureLoadingDialog(
                          context: context,
                          future: getSpaceId,
                        );
                        if (mounted && !resp.isError) {
                          context.go("/rooms/spaces/${resp.result}/invite");
                        }
                      },
                      style: ElevatedButton.styleFrom(
                        backgroundColor: theme.colorScheme.primaryContainer,
                        foregroundColor: theme.colorScheme.onPrimaryContainer,
                      ),
                      child: Row(
                        spacing: 8.0,
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          const Icon(Icons.upload_file),
                          Text(L10n.of(context).inviteYourFriends),
                        ],
                      ),
                    ),
                    ElevatedButton(
                      onPressed: () async {
                        final resp = await showFutureLoadingDialog(
                          context: context,
                          future: getSpaceId,
                        );
                        if (mounted && !resp.isError) {
                          context.go("/rooms/spaces/${resp.result}");
                        }
                      },
                      style: ElevatedButton.styleFrom(
                        backgroundColor: theme.colorScheme.primaryContainer,
                        foregroundColor: theme.colorScheme.onPrimaryContainer,
                      ),
                      child: Row(
                        spacing: 8.0,
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          Text(L10n.of(context).playWithAI),
                        ],
                      ),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}