// lib/features/igel/data/export_service.dart
import 'dart:convert';
import 'dart:typed_data';

import 'package:file_saver/file_saver.dart';
import 'package:intl/intl.dart';

import '../../igel/data/igel_repository.dart';
import '../../messwerte/data/messwerte_repository.dart';
import '../../messwerte/domain/messwert.dart';

class IgelExportService {
  final IgelRepository igelRepo;
  final MesswerteRepository messRepo;

  IgelExportService({
    required this.igelRepo,
    required this.messRepo,
  });

  String _fmtDate(DateTime? d) =>
      d == null ? '' : DateFormat('yyyy-MM-dd').format(d);

  String _fmtDateTime(DateTime? d) =>
      d == null ? '' : DateFormat('yyyy-MM-dd HH:mm').format(d);

  String _csvEscape(String? v, {String delimiter = ';'}) {
    final s = v ?? '';
    final needsQuote =
        s.contains(delimiter) || s.contains('\n') || s.contains('"');
    final escaped = s.replaceAll('"', '""');
    return needsQuote ? '"$escaped"' : escaped;
  }

  /// Erzeugt eine *denormalisierte* CSV:
  /// Jede Zeile = 1 Messwert + zugehörige Igel-Stammdaten.
  /// Hat ein Igel *keine* Messwerte, gibt es *trotzdem eine Zeile* mit leeren Messwert-Spalten.
  Future<void> exportDenormalizedCsv() async {
    // Immer frisch laden
    final igelList = await igelRepo.list();

    const sep = ';';
    final sb = StringBuffer();

    // Kopfzeile – nur Felder, die deine Models wirklich haben
    sb.writeln([
      // Igel
      'igel_id',
      'igel_name',
      'igel_gender',
      'igel_feature',
      'igel_note',
      'igel_rescued_at',
      'igel_location',
      'igel_marking',
      'igel_finder',
      'igel_phone',
      'igel_email',
      'igel_admission_reason',
      'igel_animal_condition',
      'igel_released_at',
      'igel_release_location',
      // Messwert
      'messwert_id',
      'messwert_datum',
      'messwert_gewicht',
      'messwert_behandlung',
      'messwert_bemerkung',
    ].join(sep));

    for (final ig in igelList) {
      List<Messwert> mw = [];
      try {
        mw = await messRepo.list(ig.id);
      } catch (_) {
        mw = [];
      }

      if (mw.isEmpty) {
        // Igel ohne Messwerte → eine Zeile mit leeren Messwert-Spalten
        sb.writeln([
          ig.id,
          _csvEscape(ig.name, delimiter: sep),
          _csvEscape(ig.gender, delimiter: sep),
          _csvEscape(ig.feature, delimiter: sep),
          _csvEscape(ig.note, delimiter: sep),
          _fmtDate(ig.rescuedAt),
          _csvEscape(ig.location, delimiter: sep),
          _csvEscape(ig.marking, delimiter: sep),
          _csvEscape(ig.finder, delimiter: sep),
          _csvEscape(ig.phone, delimiter: sep),
          _csvEscape(ig.email, delimiter: sep),
          _csvEscape(ig.admissionReason, delimiter: sep),
          _csvEscape(ig.animalCondition, delimiter: sep),
          _fmtDate(ig.releasedAt),
          _csvEscape(ig.releaseLocation, delimiter: sep),

          // Messwert-Spalten leer
          '',
          '',
          '',
          '',
          '',
        ].join(sep));
        continue;
      }

      for (final m in mw) {
        sb.writeln([
          ig.id,
          _csvEscape(ig.name, delimiter: sep),
          _csvEscape(ig.gender, delimiter: sep),
          _csvEscape(ig.feature, delimiter: sep),
          _csvEscape(ig.note, delimiter: sep),
          _fmtDate(ig.rescuedAt),
          _csvEscape(ig.location, delimiter: sep),
          _csvEscape(ig.marking, delimiter: sep),
          _csvEscape(ig.finder, delimiter: sep),
          _csvEscape(ig.phone, delimiter: sep),
          _csvEscape(ig.email, delimiter: sep),
          _csvEscape(ig.admissionReason, delimiter: sep),
          _csvEscape(ig.animalCondition, delimiter: sep),
          _fmtDate(ig.releasedAt),
          _csvEscape(ig.releaseLocation, delimiter: sep),
          m.id,
          _fmtDateTime(m.datum),
          m.gewicht,
          _csvEscape(m.behandlung, delimiter: sep),
          _csvEscape(m.bemerkung, delimiter: sep),
        ].join(sep));
      }
    }

    final bytes =
        Uint8List.fromList(const Utf8Encoder().convert(sb.toString()));
    final filename =
        'igel_export_denorm_${DateFormat('yyyyMMdd_HHmmss').format(DateTime.now())}';

    await FileSaver.instance.saveFile(
      name: filename,
      bytes: bytes,
      ext: 'csv',
      mimeType: MimeType.csv,
    );
  }
}