import 'package:cloud_functions/cloud_functions.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../core/firebase/firebase_providers.dart';
import '../../../core/widgets/app_drawer.dart';
import '../../../l10n/generated/app_localizations.dart';
import '../data/household_providers.dart';
import '../domain/household.dart';

/// Haushalt: Mitglieder mit Rollen, Einladen per Code, Beitreten per Code.
class HouseholdScreen extends ConsumerStatefulWidget {
  const HouseholdScreen({super.key});

  @override
  ConsumerState<HouseholdScreen> createState() => _HouseholdScreenState();
}

class _HouseholdScreenState extends ConsumerState<HouseholdScreen> {
  final _codeController = TextEditingController();
  bool _joining = false;

  @override
  void dispose() {
    _codeController.dispose();
    super.dispose();
  }

  Future<void> _createInvite(HouseholdRole role) async {
    final l10n = AppLocalizations.of(context);
    final householdId = ref.read(householdIdProvider).value;
    if (householdId == null) return;

    final code = await ref
        .read(householdRepositoryProvider)
        .createInvite(householdId: householdId, role: role);
    if (!mounted) return;

    await showDialog<void>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(l10n.inviteCodeTitle),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            SelectableText(
              code,
              style: Theme.of(dialogContext)
                  .textTheme
                  .displaySmall
                  ?.copyWith(letterSpacing: 6, fontWeight: FontWeight.bold),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 12),
            Text(l10n.inviteCodeHint),
          ],
        ),
        actions: [
          TextButton.icon(
            icon: const Icon(Icons.copy),
            label: Text(l10n.copyCode),
            onPressed: () async {
              final messenger = ScaffoldMessenger.of(context);
              await Clipboard.setData(ClipboardData(text: code));
              messenger.showSnackBar(
                SnackBar(content: Text(l10n.codeCopied)),
              );
            },
          ),
          FilledButton(
            onPressed: () => Navigator.pop(dialogContext),
            child: const Text('OK'),
          ),
        ],
      ),
    );
  }

  Future<void> _join() async {
    final l10n = AppLocalizations.of(context);
    final code = _codeController.text.trim();
    if (code.isEmpty) return;

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(l10n.joinWarningTitle),
        content: Text(l10n.joinWarningBody),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(dialogContext, false),
            child: Text(l10n.cancel),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(dialogContext, true),
            child: Text(l10n.joinButton),
          ),
        ],
      ),
    );
    if (confirmed != true || !mounted) return;

    setState(() => _joining = true);
    try {
      final name =
          await ref.read(householdRepositoryProvider).joinHousehold(code);
      if (!mounted) return;
      _codeController.clear();
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(l10n.joinSuccess(name))));
    } on FirebaseFunctionsException catch (e) {
      if (!mounted) return;
      final message = switch (e.code) {
        'not-found' => l10n.joinErrorInvalid,
        'failed-precondition' => l10n.joinErrorUsed,
        _ => l10n.authErrorGeneric,
      };
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(message)));
    } catch (_) {
      if (!mounted) return;
      ScaffoldMessenger.of(context)
        ..hideCurrentSnackBar()
        ..showSnackBar(SnackBar(content: Text(l10n.authErrorGeneric)));
    } finally {
      if (mounted) setState(() => _joining = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    final theme = Theme.of(context);
    final household = ref.watch(householdProvider).value;
    final myRole = ref.watch(myRoleProvider);
    final myUid = ref.watch(authStateProvider).value?.uid;

    return Scaffold(
      appBar: AppBar(title: Text(household?.name ?? l10n.householdTitle)),
      drawer: const AppDrawer(),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Text(l10n.householdMembers, style: theme.textTheme.titleMedium),
          const SizedBox(height: 8),
          if (household != null)
            for (final member in household.members)
              ListTile(
                contentPadding: EdgeInsets.zero,
                leading: CircleAvatar(
                  child: Icon(member.role == HouseholdRole.sitter
                      ? Icons.volunteer_activism
                      : Icons.person),
                ),
                title: Text(
                  member.uid == myUid && member.email.isEmpty
                      ? l10n.meLabel
                      : member.email,
                ),
                subtitle: Text(member.role == HouseholdRole.sitter
                    ? l10n.roleSitter
                    : l10n.roleMember),
                trailing: member.uid == myUid
                    ? Chip(label: Text(l10n.meLabel))
                    : null,
              ),
          if (myRole == HouseholdRole.member) ...[
            const Divider(height: 32),
            Text(l10n.inviteTitle, style: theme.textTheme.titleMedium),
            const SizedBox(height: 4),
            Text(
              l10n.inviteExplanation,
              style: theme.textTheme.bodyMedium
                  ?.copyWith(color: theme.colorScheme.onSurfaceVariant),
            ),
            const SizedBox(height: 12),
            FilledButton.tonalIcon(
              onPressed: () => _createInvite(HouseholdRole.member),
              icon: const Icon(Icons.person_add),
              label: Text(l10n.inviteMember),
            ),
            const SizedBox(height: 8),
            FilledButton.tonalIcon(
              onPressed: () => _createInvite(HouseholdRole.sitter),
              icon: const Icon(Icons.volunteer_activism),
              label: Text(l10n.inviteSitter),
            ),
          ],
          const Divider(height: 32),
          Text(l10n.joinTitle, style: theme.textTheme.titleMedium),
          const SizedBox(height: 12),
          TextField(
            controller: _codeController,
            decoration: InputDecoration(
              labelText: l10n.joinCodeLabel,
              border: const OutlineInputBorder(),
              prefixIcon: const Icon(Icons.key),
            ),
            textCapitalization: TextCapitalization.characters,
            autocorrect: false,
          ),
          const SizedBox(height: 12),
          FilledButton.icon(
            onPressed: _joining ? null : _join,
            icon: _joining
                ? const SizedBox(
                    height: 20,
                    width: 20,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.group_add),
            label: Text(l10n.joinButton),
          ),
        ],
      ),
    );
  }
}