import 'dart:convert';

import 'package:chain_client_sdk/chain_client_sdk.dart' as chain;
import 'package:flutter/services.dart' show rootBundle;

import 'hub_endpoint.dart';
import 'live_inputs.dart';
import 'models.dart';
import 'repository.dart';

/// Live `EvaluationRepository` backed by a Ch∆In hub over gRPC.
///
/// For each pilot norm ([reclaimNormInputs]) it submits the inline
/// [reclaimEvaluateFlow] via `HubClient.submit` and maps the returned
/// `outputs` to an [Evaluation]. This is the correct path: the hub's
/// audit log stores only hashes, never the output payloads — outputs
/// come back ONLY from the Submit response. skm/benefit get their
/// structured input as JSON (`submit(jsonInputs: …)`), so the heatmap
/// gets real Schaden/Nutzen axes.
///
/// Sort order matches MockRepository: highest €/Jahr first. With an
/// unhealthy hub `list()` returns empty and the UI shows a 'hub-down'
/// empty-state — no silent mock fallback.
class HubRepository implements EvaluationRepository {
  HubRepository._(this._client, this.settings, this._healthy);

  final chain.HubClient _client;
  final HubSettings settings;
  final bool _healthy;

  static Future<HubRepository> connect(HubSettings settings) async {
    final endpoint = chain.HubEndpoint(
      host: settings.host,
      port: settings.port,
      secure: settings.secure,
    );
    final client = chain.HubClient(
      endpoint: endpoint,
      authToken: settings.authToken,
    );
    // The probe must NEVER throw out of connect(): main() awaits
    // this before runApp(), so any uncaught error here leaves the
    // app on a blank page. A timeout maps to false; so does any
    // transport error (e.g. a gRPC-web call against a plain-gRPC
    // hub, or a refused connection) — the app then comes up in
    // 'hub-down' state and shows the empty-state hint.
    bool ok;
    try {
      ok = await client.healthy().timeout(
            const Duration(seconds: 4),
            onTimeout: () => false,
          );
    } catch (_) {
      ok = false;
    }
    return HubRepository._(client, settings, ok);
  }

  bool get isHealthy => _healthy;

  chain.HubClient get client => _client;

  @override
  Future<List<Evaluation>> list() async {
    if (!_healthy) return const [];
    final evals = <Evaluation>[];
    for (final input in reclaimNormInputs) {
      try {
        final eval = await _evaluate(input);
        if (eval != null) evals.add(eval);
      } catch (_) {
        // One norm failing must not blank the whole heatmap.
      }
    }
    evals.sort((a, b) => b.skmEurPerYear.compareTo(a.skmEurPerYear));
    return evals;
  }

  @override
  Future<Evaluation?> byEli(String eli) async {
    final all = await list();
    for (final e in all) {
      if (e.norm.eli == eli) return e;
    }
    return null;
  }

  @override
  String get mode => _healthy ? 'hub-live' : 'hub-down';

  @override
  String get hubLabel => '${settings.url}'
      '${_healthy ? '' : ' — Verbindung gestört'}';

  /// Run one norm through the flow and assemble its [Evaluation].
  Future<Evaluation?> _evaluate(NormLiveInput input) async {
    final asset = await rootBundle.load(input.assetPath);
    final content = asset.buffer.asUint8List(
      asset.offsetInBytes,
      asset.lengthInBytes,
    );

    final resp = await _client.submit(
      flowYaml: reclaimEvaluateFlow,
      fileInputs: {'content': content},
      fileMimeTypes: {'content': 'application/xml'},
      textInputs: {'cohort_id': input.cohortId},
      jsonInputs: {'duties': input.duties, 'ratings': input.ratings},
    );

    final out = _decodeOutputs(resp);
    final normJson = out['norm'];
    if (normJson == null) return null;

    final skm = out['skm'];
    final benefit = out['benefit'];
    final frust = out['frust'];
    final cohort = out['cohort'];

    final norm = Norm(
      eli: (normJson['eli'] as String?) ?? 'eli/unknown',
      title: (normJson['title'] as String?) ?? '(ohne Titel)',
      jurabk: (normJson['jurabk'] as String?) ?? '',
      paragraph: (normJson['paragraph'] as String?) ?? '',
      // Geltungsbereich/Freshness can't be derived from the bund
      // adapter for EU/Berlin norms — take the curated override.
      jurisdiction: input.jurisdiction,
      freshness: input.freshness,
      supersededNote: input.supersededNote,
      standDate: DateTime.now(),
      sourceUrl: (normJson['source_url'] as String?) ?? '',
      sourceSha256: (normJson['source_sha256'] as String?) ?? '',
      paragraphs: _parseParagraphs(normJson['paragraphs']),
    );

    final skmEur = _asDouble(skm?['total_eur_per_year']);
    final tierLowest = _parseTier(skm?['tier_lowest']);

    return Evaluation(
      norm: norm,
      skmEurPerYear: skmEur,
      benefitScore: _asDouble(benefit?['total']),
      affectedCount: _asInt(cohort?['count']),
      frustScore: _asDouble(frust?['composite_frust']),
      tierLowest: tierLowest,
      duties: _parseDuties(out['duties']),
      sources: _liveSources(cohort),
      auditEventId: _invocationId(resp),
      reviewedBy: input.reviewedBy,
      reviewedAt: input.reviewedAt,
      notes: 'Live aus Hub-Flow reclaim-evaluate.'
          '${input.supersededNote != null ? '\n${input.supersededNote}' : ''}',
      componentSummary: _componentSummary(skm, cohort),
    );
  }

  /// Decode `SubmitResponse.outputs` into plain Dart maps. Each output
  /// Payload serializes (proto3-json) as `{json: {value: "<jsonstr>"}}`
  /// (module `with_json`) or `{text: "…"}`; we json-decode the inner
  /// string.
  Map<String, Map<String, dynamic>> _decodeOutputs(chain.SubmitResponse r) {
    final out = <String, Map<String, dynamic>>{};
    final j = r.toProto3Json();
    if (j is! Map) return out;
    final outputs = j['outputs'];
    if (outputs is! Map) return out;
    for (final entry in outputs.entries) {
      final v = entry.value;
      String? raw;
      if (v is Map) {
        final js = v['json'];
        if (js is Map && js['value'] is String) {
          raw = js['value'] as String;
        } else if (v['text'] is String) {
          raw = v['text'] as String;
        }
      }
      if (raw == null) continue;
      try {
        final decoded = jsonDecode(raw);
        if (decoded is Map<String, dynamic>) out[entry.key] = decoded;
      } catch (_) {}
    }
    return out;
  }

  static String _invocationId(chain.SubmitResponse r) {
    try {
      final j = r.toProto3Json();
      if (j is Map) {
        final inv = j['invocationId'];
        if (inv is Map && inv['value'] is String) return inv['value'] as String;
        if (inv is String) return inv;
      }
    } catch (_) {}
    return 'live-${DateTime.now().millisecondsSinceEpoch}';
  }

  static List<Source> _liveSources(Map<String, dynamic>? cohort) {
    final out = <Source>[];
    final label = cohort?['source'] as String?;
    if (label != null && label.isNotEmpty) {
      out.add(Source(
        label: label,
        url: '',
        tier: _parseTier(cohort?['tier']),
      ));
    }
    return out;
  }

  static List<String> _componentSummary(
    Map<String, dynamic>? skm,
    Map<String, dynamic>? cohort,
  ) {
    final lines = <String>[];
    final items = skm?['items'];
    if (items is List && items.isNotEmpty) {
      final first = items.first;
      if (first is Map && first['formula'] is String) {
        lines.add('SKM · ${first['formula']}');
      }
    }
    final src = cohort?['source'] as String?;
    if (src != null && src.isNotEmpty) {
      lines.add('P · ${_parseTier(cohort?['tier']).short} — $src');
    }
    return lines;
  }

  static double _asDouble(dynamic v) {
    if (v is num) return v.toDouble();
    if (v is String) return double.tryParse(v) ?? 0.0;
    return 0.0;
  }

  static int _asInt(dynamic v) {
    if (v is num) return v.toInt();
    if (v is String) return int.tryParse(v) ?? 0;
    return 0;
  }

  static EvidenceTier _parseTier(dynamic v) {
    final s = (v as String?)?.toUpperCase() ?? 'T4';
    return switch (s) {
      'T1' => EvidenceTier.t1,
      'T2' => EvidenceTier.t2,
      'T3' => EvidenceTier.t3,
      _ => EvidenceTier.t4,
    };
  }

  static List<NormParagraph> _parseParagraphs(dynamic v) {
    if (v is! List) return const [];
    return v.whereType<Map<String, dynamic>>().map((p) {
      return NormParagraph(
        number: (p['number'] as String?) ?? '',
        text: (p['text'] as String?) ?? '',
      );
    }).toList();
  }

  static List<Duty> _parseDuties(Map<String, dynamic>? v) {
    final inner = v?['duties'];
    if (inner is! List) return const [];
    return inner.whereType<Map<String, dynamic>>().map((d) {
      return Duty(
        modality: (d['modality'] as String?) ?? '?',
        addressee: (d['addressee'] as String?) ?? '',
        action: (d['action'] as String?) ?? '',
        frequency: (d['frequency'] as String?) ?? '',
        sourceNorm: (d['source_norm'] as String?) ?? '',
        authority: d['authority'] as String?,
        consequence: d['consequence'] as String?,
      );
    }).toList();
  }
}