import 'package:flutter/material.dart';

import '../data/hub_endpoint.dart';
import '../data/hub_repository.dart';
import '../data/repository.dart';
import '../theme/lawheatmap_tokens.dart';
import '../widgets/lawheatmap_card.dart';

/// Hub connection + settings. Read-only summary at the top, then
/// an editable form for endpoint host/port/secure/token, then a
/// "Verbinden / Test"-button. Changes are persisted via
/// HubSettings and take effect on the next app start (Phase 0
/// keeps the running repository to avoid mid-session swap
/// headaches).
class HubStatusPage extends StatefulWidget {
  const HubStatusPage({super.key, required this.repository});

  final EvaluationRepository repository;

  @override
  State<HubStatusPage> createState() => _HubStatusPageState();
}

class _HubStatusPageState extends State<HubStatusPage> {
  HubSettings? _settings;
  late final TextEditingController _hostCtl;
  late final TextEditingController _portCtl;
  late final TextEditingController _tokenCtl;
  bool _secure = false;
  bool _useHub = false;
  String? _probeMessage;
  bool _probing = false;

  @override
  void initState() {
    super.initState();
    _hostCtl = TextEditingController();
    _portCtl = TextEditingController();
    _tokenCtl = TextEditingController();
    HubSettings.load().then((s) {
      setState(() {
        _settings = s;
        _hostCtl.text = s.host;
        _portCtl.text = s.port.toString();
        _tokenCtl.text = s.authToken ?? '';
        _secure = s.secure;
        _useHub = s.useHub;
      });
    });
  }

  @override
  void dispose() {
    _hostCtl.dispose();
    _portCtl.dispose();
    _tokenCtl.dispose();
    super.dispose();
  }

  HubSettings _formSettings() => HubSettings(
        host: _hostCtl.text.trim().isEmpty
            ? HubSettings.defaultHost
            : _hostCtl.text.trim(),
        port: int.tryParse(_portCtl.text.trim()) ??
            HubSettings.defaultPort,
        secure: _secure,
        authToken:
            _tokenCtl.text.trim().isEmpty ? null : _tokenCtl.text.trim(),
        useHub: _useHub,
      );

  Future<void> _save() async {
    final s = _formSettings();
    await s.save();
    if (!mounted) return;
    setState(() => _settings = s);
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(
        content: Text('Einstellungen gespeichert. '
            'Beim nächsten Start wird die App den Hub verwenden, '
            'wenn der Schalter „Hub nutzen" aktiv ist.'),
      ),
    );
  }

  Future<void> _probe() async {
    setState(() {
      _probing = true;
      _probeMessage = null;
    });
    try {
      final hub = await HubRepository.connect(_formSettings());
      setState(() {
        _probeMessage = hub.isHealthy
            ? 'Verbindung erfolgreich (healthy=true).'
            : 'Hub nicht erreichbar oder antwortet nicht SERVING.';
      });
    } catch (e) {
      setState(() => _probeMessage = 'Fehler: $e');
    } finally {
      if (mounted) setState(() => _probing = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final t = Theme.of(context).textTheme;
    final repo = widget.repository;
    final s = _settings;
    return SingleChildScrollView(
      padding: const EdgeInsets.all(LawHeatmapSpace.xl),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text('Ch∆In Hub', style: t.displaySmall),
          const SizedBox(height: LawHeatmapSpace.xs),
          Text(
            'Status der Verbindung und Konfiguration des lokalen Hubs.',
            style: t.bodyLarge?.copyWith(color: LawHeatmapColors.mute),
          ),
          const SizedBox(height: LawHeatmapSpace.lg),
          LawHeatmapCard(
            accent: true,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _row('Aktiver Modus', repo.mode.toUpperCase(), t),
                _row('Datenquelle', repo.hubLabel, t),
                _row(
                  'gRPC-Endpunkt',
                  s == null ? '…' : s.url,
                  t,
                ),
                _row(
                  'Hub-Nutzung beim Start',
                  s == null ? '…' : (s.useHub ? 'ja' : 'nein'),
                  t,
                ),
                _row('Audit-DB', '~/.chain/chain.db (Hub-seitig)', t),
                _row('Hash-Tag', 'CHAIN-EVENT-V3', t),
              ],
            ),
          ),
          const SizedBox(height: LawHeatmapSpace.lg),
          LawHeatmapCard(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text('Verbindung konfigurieren',
                    style: t.headlineSmall),
                const SizedBox(height: LawHeatmapSpace.sm),
                Text(
                  '`chain serve` läuft standardmäßig auf '
                  '127.0.0.1:50051 ohne Auth. '
                  'Bei aktiver Auth den Bearer-Token aus '
                  '~/.chain/hub-auth-token hier eintragen.',
                  style: t.labelSmall
                      ?.copyWith(color: LawHeatmapColors.mute),
                ),
                const SizedBox(height: LawHeatmapSpace.lg),
                Row(children: [
                  Expanded(
                    flex: 3,
                    child: TextField(
                      controller: _hostCtl,
                      decoration: const InputDecoration(
                        labelText: 'Host',
                        hintText: '127.0.0.1',
                      ),
                    ),
                  ),
                  const SizedBox(width: LawHeatmapSpace.md),
                  Expanded(
                    child: TextField(
                      controller: _portCtl,
                      decoration: const InputDecoration(
                        labelText: 'Port',
                        hintText: '50051',
                      ),
                      keyboardType: TextInputType.number,
                    ),
                  ),
                ]),
                const SizedBox(height: LawHeatmapSpace.md),
                TextField(
                  controller: _tokenCtl,
                  decoration: const InputDecoration(
                    labelText: 'Auth-Token (optional)',
                  ),
                  obscureText: true,
                ),
                const SizedBox(height: LawHeatmapSpace.md),
                Row(children: [
                  Switch(
                    value: _secure,
                    onChanged: (v) => setState(() => _secure = v),
                  ),
                  const SizedBox(width: LawHeatmapSpace.sm),
                  const Text('TLS (https)'),
                  const SizedBox(width: LawHeatmapSpace.xl),
                  Switch(
                    value: _useHub,
                    onChanged: (v) => setState(() => _useHub = v),
                  ),
                  const SizedBox(width: LawHeatmapSpace.sm),
                  const Text('Hub beim Start nutzen'),
                ]),
                const SizedBox(height: LawHeatmapSpace.lg),
                Row(children: [
                  FilledButton.icon(
                    onPressed: _probing ? null : _probe,
                    icon: _probing
                        ? const SizedBox(
                            width: 14,
                            height: 14,
                            child: CircularProgressIndicator(
                              strokeWidth: 2,
                            ),
                          )
                        : const Icon(Icons.bolt_outlined),
                    label: const Text('Verbindung testen'),
                  ),
                  const SizedBox(width: LawHeatmapSpace.md),
                  OutlinedButton.icon(
                    onPressed: _save,
                    icon: const Icon(Icons.save_outlined),
                    label: const Text('Speichern'),
                  ),
                ]),
                if (_probeMessage != null) ...[
                  const SizedBox(height: LawHeatmapSpace.md),
                  Text(_probeMessage!,
                      style: t.labelLarge?.copyWith(
                        color: LawHeatmapColors.signal,
                      )),
                ],
              ],
            ),
          ),
          const SizedBox(height: LawHeatmapSpace.lg),
          LawHeatmapCard(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text('Geplanter Live-Flow', style: t.headlineSmall),
                const SizedBox(height: LawHeatmapSpace.sm),
                Text(
                  '1. `chain serve` auf localhost:50051 starten.\n'
                  '2. Module installieren (`chain install`).\n'
                  '3. Flow ausführen:\n'
                  '   chain run flows/durchstich-gewo-14.yaml \\\n'
                  '     --input norm_url=https://www.gesetze-im-internet.de/gewo/__14.xml \\\n'
                  '     --input cohort_id=berlin-kmu\n'
                  '4. `chain admin approvals list` → '
                  'Juristen-Gate freigeben.\n'
                  '5. App neu starten — Hub-Modus aktiv, '
                  'flow.completed-Events werden in '
                  'Evaluation-Objekte übersetzt.',
                  style: t.bodyLarge?.copyWith(
                    height: 1.6,
                    fontFamily: LawHeatmapTypography.mono,
                    fontSize: 12,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _row(String label, String value, TextTheme t) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        children: [
          SizedBox(
            width: 200,
            child: Text(label,
                style: t.labelLarge
                    ?.copyWith(color: LawHeatmapColors.mute)),
          ),
          Expanded(
            child: Text(value,
                style: t.bodyLarge
                    ?.copyWith(fontFamily: LawHeatmapTypography.mono)),
          ),
        ],
      ),
    );
  }
}