import 'package:flutter/material.dart';

import '../api.dart';
import '../main.dart';
import '../theme.dart';
import 'admin_screen.dart';
import 'chat_screen.dart';
import 'files_screen.dart';
import 'verantwortliche_register_screen.dart';
import 'wahl_screen.dart';

class HomeScreen extends StatelessWidget {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final state = AppScope.of(context);
    final id = state.identity!;
    final kcId = id.kcId;

    final needsVerantwRegistration = id.kind == SessionKind.user &&
        !id.isLeitungsteam &&
        id.memberships.isEmpty;

    final tiles = <Widget>[
      if (id.isLeitungsteam)
        _NavTile(
          icon: Icons.admin_panel_settings,
          title: 'Verwaltung',
          subtitle: 'KCs, Gemeinden, Onboarding-Freigaben',
          onTap: () => _open(context, const AdminScreen()),
        ),
      if (needsVerantwRegistration)
        _NavTile(
          icon: Icons.how_to_reg,
          title: 'Als Verantwortliche/r registrieren',
          subtitle: 'KC-Code eingeben, Gemeinde wählen, Freigabe abwarten',
          onTap: () => _open(context, const VerantwortlicheRegisterScreen()),
        ),
      if (id.kind == SessionKind.guest)
        _NavTile(
          icon: Icons.how_to_vote,
          title: 'Workshop-Wahl',
          subtitle: 'Deine Wünsche abgeben',
          onTap: () => _open(context, const WahlScreen()),
        ),
      if (kcId != null)
        _NavTile(
          icon: Icons.folder_shared,
          title: 'Dateien',
          subtitle: 'Freigegebene Dateien ansehen',
          onTap: () => _open(context, FilesScreen(kcId: kcId)),
        ),
      if (kcId != null)
        _NavTile(
          icon: Icons.forum,
          title: 'Chat',
          subtitle: 'Kanäle, Verlauf & Live-Nachrichten',
          onTap: () => _open(context, ChatScreen(kcId: kcId)),
        ),
    ];

    return Scaffold(
      appBar: AppBar(
        title: const Text('KC-App'),
        actions: [
          IconButton(
            tooltip: 'Abmelden',
            onPressed: state.logout,
            icon: const Icon(Icons.logout),
          ),
        ],
      ),
      body: SafeArea(
        child: Center(
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 560),
            child: ListView(
              padding: const EdgeInsets.all(20),
              children: [
                _IdentityCard(id: id),
                const SizedBox(height: 16),
                ...tiles,
                if (tiles.isEmpty)
                  const Padding(
                    padding: EdgeInsets.only(top: 24),
                    child: Text(
                      'Für diesen Account gibt es hier noch keine Ansichten. '
                      'Sobald dir eine Gemeinde/ein KC zugeordnet ist, erscheinen '
                      'Dateien und Chat.',
                    ),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void _open(BuildContext context, Widget screen) {
    Navigator.of(context).push(MaterialPageRoute(builder: (_) => screen));
  }
}

class _IdentityCard extends StatelessWidget {
  const _IdentityCard({required this.id});
  final Identity id;

  @override
  Widget build(BuildContext context) {
    final lines = <String>[
      if (id.email != null) id.email!,
      if (id.isLeitungsteam)
        'Leitungsteam-Rechte gelten KC-übergreifend.'
      else if (id.memberships.length > 1)
        '${id.memberships.length} Zuordnungen',
    ];
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Row(
          children: [
            Container(
              width: 48,
              height: 48,
              decoration: BoxDecoration(
                gradient: const LinearGradient(
                  colors: [KcColors.blue, KcColors.teal],
                  begin: Alignment.topLeft,
                  end: Alignment.bottomRight,
                ),
                shape: BoxShape.circle,
              ),
              child: const Icon(Icons.person, color: Colors.white),
            ),
            const SizedBox(width: 14),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(id.roleLabel, style: Theme.of(context).textTheme.titleMedium),
                  for (final l in lines) ...[
                    const SizedBox(height: 2),
                    Text(l, style: Theme.of(context).textTheme.bodySmall),
                  ],
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _NavTile extends StatelessWidget {
  const _NavTile({
    required this.icon,
    required this.title,
    required this.subtitle,
    required this.onTap,
  });
  final IconData icon;
  final String title;
  final String subtitle;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.only(bottom: 12),
      child: InkWell(
        borderRadius: BorderRadius.circular(20),
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Row(
            children: [
              Container(
                width: 44,
                height: 44,
                decoration: BoxDecoration(
                  color: KcColors.blue.withValues(alpha: 0.1),
                  borderRadius: BorderRadius.circular(12),
                ),
                child: Icon(icon, color: KcColors.blue),
              ),
              const SizedBox(width: 14),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(title, style: Theme.of(context).textTheme.titleMedium),
                    const SizedBox(height: 2),
                    Text(subtitle, style: Theme.of(context).textTheme.bodySmall),
                  ],
                ),
              ),
              Icon(Icons.chevron_right, color: KcColors.slate.withValues(alpha: 0.6)),
            ],
          ),
        ),
      ),
    );
  }
}