import 'package:collection/collection.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_linkify/flutter_linkify.dart';

import '../../../api/marianumconnect/queries/get_capabilities/guardian_child.dart';
import '../../../api/marianumconnect/queries/parent_letters/parent_letter_models.dart';
import '../../../extensions/date_time.dart';
import '../../../notification/notification_tasks.dart';
import '../../../state/app/infrastructure/loadable_state/loadable_state.dart';
import '../../../state/app/infrastructure/loadable_state/view/loadable_state_consumer.dart';
import '../../../state/app/infrastructure/utility_widgets/bloc_module.dart';
import '../../../state/app/modules/capabilities/bloc/capabilities_cubit.dart';
import '../../../state/app/modules/parent_letters/bloc/parent_letter_bloc.dart';
import '../../../state/app/modules/parent_letters/bloc/parent_letter_state.dart';
import '../../../state/app/modules/parent_letters/bloc/parent_letters_bloc.dart';
import '../../../utils/url_opener.dart';
import 'parent_letter_form_policy.dart';
import 'widgets/parent_letter_attachments.dart';
import 'widgets/parent_letter_response_card.dart';
import 'widgets/parent_letter_thread.dart';

class ParentLetterView extends StatelessWidget {
  final String id;

  const ParentLetterView({required this.id, super.key});

  @override
  Widget build(
    BuildContext context,
  ) => BlocModule<ParentLetterBloc, LoadableState<ParentLetterState>>(
    create: (context) =>
        ParentLetterBloc(id, inbox: context.read<ParentLettersBloc>()),
    autoRebuild: true,
    onInitialisation: (_, _) =>
        NotificationTasks.clearParentLetterNotification(id),
    child: (context, bloc, state) {
      final letter = state.data?.letter;
      return Scaffold(
        appBar: AppBar(title: const Text('Elternbrief')),
        body: Column(
          children: [
            Expanded(
              child: LoadableStateConsumer<ParentLetterBloc, ParentLetterState>(
                isReady: (state) => state.letter != null,
                child: (state, loading) => _LetterBody(
                  letter: state.letter!,
                  children: context.watch<CapabilitiesCubit>().state.children,
                  bloc: bloc,
                ),
              ),
            ),
            if (letter != null && letter.content.thread.enabled)
              ParentLetterThreadInput(
                recipientName: letter.summary.sender.displayName,
                onSend: bloc.sendThreadMessage,
              ),
          ],
        ),
      );
    },
  );
}

class _LetterBody extends StatelessWidget {
  final ParentLetterDetail letter;
  final List<GuardianChild> children;
  final ParentLetterBloc bloc;

  const _LetterBody({
    required this.letter,
    required this.children,
    required this.bloc,
  });

  String _childName(String childId) =>
      children.firstWhereOrNull((child) => child.id == childId)?.displayName ??
      'dein Kind';

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final summary = letter.summary;
    final content = letter.content;
    final editedAt = summary.editedAt;
    return ListView(
      physics: const AlwaysScrollableScrollPhysics(),
      padding: const EdgeInsets.only(bottom: 16),
      children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(16, 16, 16, 0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(summary.subject, style: theme.textTheme.titleLarge),
              const SizedBox(height: 4),
              Text(
                [
                  summary.sender.displayName,
                  summary.sentAt.formatDateTime(),
                  if (editedAt != null)
                    'bearbeitet am ${editedAt.formatDateTime()}',
                ].join(' · '),
                style: theme.textTheme.bodySmall,
              ),
              if (children.length > 1)
                Text(
                  'Betrifft: ${summary.childIds.map(_childName).join(', ')}',
                  style: theme.textTheme.bodySmall,
                ),
              const SizedBox(height: 16),
              SelectableLinkify(
                text: content.body,
                onOpen: UrlOpener.onOpen,
                options: const LinkifyOptions(humanize: false),
                style: theme.textTheme.bodyLarge,
              ),
            ],
          ),
        ),
        if (content.attachments.isNotEmpty) ...[
          const SizedBox(height: 8),
          ParentLetterAttachments(
            letterId: summary.id,
            attachments: content.attachments,
            load: bloc.loadAttachment,
          ),
        ],
        const SizedBox(height: 8),
        for (final child in content.children)
          if (ParentLetterFormPolicy.resolve(
                request: content.request,
                child: child,
              )
              case final policy?)
            ParentLetterResponseCard(
              key: ValueKey((child.childId, child.response)),
              childName: _childName(child.childId),
              child: child,
              policy: policy,
              deadline: content.request?.deadline,
              onSubmit: (answers, signaturePng) => bloc.submitResponse(
                childId: child.childId,
                answers: answers,
                signaturePng: signaturePng,
              ),
            ),
        if (content.thread.messages.isNotEmpty) ...[
          const Padding(
            padding: EdgeInsets.fromLTRB(16, 12, 16, 4),
            child: Text(
              'Nachrichten',
              style: TextStyle(fontWeight: FontWeight.w600),
            ),
          ),
          ParentLetterThreadMessages(content.thread.messages),
        ],
      ],
    );
  }
}