import 'dart:convert';

import '../../domain/catalog/catalog_item.dart';
import '../../domain/catalog/display_category.dart';
import '../db/app_database.dart';

/// 3 source (Protocols / BreakProtocols / DietPatterns) → 단일 `List<CatalogItem>`.
///
/// 본 이슈 (#226) 의 핵심 변환 한 점. 본 함수는 fn-catalog_repository.md 의 알고리즘대로.
class CatalogRepository {
  CatalogRepository(this._db);

  final AppDatabase _db;

  /// 47 항목 (protocols 34 + break 8 + diet 5) 을 displayCategory 기준 정렬해 반환.
  Future<List<CatalogItem>> all() async {
    final protocolRows = await _db.select(_db.protocols).get();
    final breakRows = await _db.select(_db.breakProtocols).get();
    final dietRows = await _db.select(_db.dietPatterns).get();

    final items = <CatalogItem>[];

    for (final p in protocolRows) {
      final dc = DisplayCategory.fromProtocolCategory(p.category);
      if (dc == null) {
        throw StateError(
            'unknown protocol category "${p.category}" for id=${p.id}');
      }
      items.add(ProtocolCatalogItem(
        id: p.id,
        title: p.title,
        titleEn: p.titleEn,
        summary: _summary(p.what, fallback: p.title),
        displayCategory: dc,
        evidenceStrength: p.evidenceStrength,
        referenceIds: _decodeIds(p.referenceIdsJson),
        what: p.what,
        whenText: p.whenText,
        dose: p.dose,
        why: p.why,
        how: _decodeList(p.howJson),
        checkText: p.checkText,
        caution: p.caution,
        defaultAnchor: _decodeAnchor(p.defaultAnchorJson),
        minDoseForStart: p.minDoseForStart,
        sourceDoc: p.sourceDoc,
      ));
    }

    for (final b in breakRows) {
      items.add(BreakCatalogItem(
        id: b.id,
        title: b.title,
        titleEn: null,
        summary: _summary(b.hubermanSummary, fallback: b.title),
        evidenceStrength: null,
        referenceIds: _decodeIds(b.referenceIdsJson),
        breakCategory: b.category,
        hubermanSummary: b.hubermanSummary,
        phases: _decodeList(b.phasesJson),
        defaultCommonFrames: _decodeList(b.defaultCommonFramesJson),
        tools: _decodeList(b.toolsJson),
        medicalWarning: b.medicalWarning,
      ));
    }

    for (final d in dietRows) {
      items.add(DietCatalogItem(
        id: d.id,
        title: d.name,
        titleEn: null,
        summary: _summary(d.core, fallback: d.name),
        evidenceStrength: d.evidenceStrength,
        referenceIds: _decodeIds(d.referenceIdsJson),
        name: d.name,
        core: d.core,
        strengths: _decodeList(d.strengthsJson),
        weaknesses: _decodeList(d.weaknessesJson),
        koreanContextFit: d.koreanContextFit,
        starterLevers: _decodeList(d.starterLeversJson),
        medicalWarning: d.medicalWarning,
        linkedProtocolIds: _decodeIds(d.linkedProtocolIdsJson),
      ));
    }

    items.sort((a, b) {
      final c = a.displayCategory.index - b.displayCategory.index;
      return c != 0 ? c : a.id.compareTo(b.id);
    });

    return items;
  }

  /// 단건 조회. Preview 화면 진입 시.
  Future<CatalogItem?> byId(String id) async {
    final all_ = await all();
    for (final item in all_) {
      if (item.id == id) return item;
    }
    return null;
  }

  /// reference id 리스트 → References 테이블 매칭. 미매칭 항목은 결과에서 누락.
  Future<List<ReferenceRow>> referencesByIds(List<String> ids) async {
    if (ids.isEmpty) return const [];
    return (_db.select(_db.references)..where((t) => t.id.isIn(ids))).get();
  }
}

/// `what` 의 첫 문장을 추출. 비어있으면 `fallback` 사용. 60자 초과 시 절단.
String _summary(String what, {required String fallback, int max = 60}) {
  final firstSentence = what.split(RegExp(r'[.!?。！？]')).first.trim();
  final s = firstSentence.isEmpty ? fallback : firstSentence;
  return s.length <= max ? s : '${s.substring(0, max - 1)}…';
}

List<String> _decodeIds(String? jsonStr) {
  if (jsonStr == null) return const [];
  final decoded = jsonDecode(jsonStr);
  return decoded is List ? decoded.cast<String>() : const [];
}

List<String> _decodeList(String? jsonStr) {
  if (jsonStr == null) return const [];
  final decoded = jsonDecode(jsonStr);
  return decoded is List ? decoded.map((e) => e.toString()).toList() : const [];
}

Map<String, dynamic>? _decodeAnchor(String? jsonStr) {
  if (jsonStr == null) return null;
  final decoded = jsonDecode(jsonStr);
  return decoded is Map<String, dynamic> ? decoded : null;
}