multimedia_flutter/lib/features/series/data/series_exporter_web.dart

import 'dart:convert';
import 'dart:typed_data';
import 'dart:html' as html;

import '../../../core/status.dart';
import 'series_exporter.dart';
import 'package:syncfusion_flutter_xlsio/xlsio.dart' as xlsio;

SeriesExporter getSeriesExporter() => _SeriesExporterWeb();

class _SeriesExporterWeb implements SeriesExporter {
  @override
  Future<String?> chooseSavePath({required bool asXlsx, ItemStatus? filter}) async {
    // Browser decides; we only provide filename.
    return _defaultFilename(filter, asXlsx);
  }

  @override
  Future<String?> exportSeries(
    List<SeriesExportRow> rows, {
    required bool asXlsx,
    ItemStatus? filter,
    String? path,
  }) async {
    final filename = path ?? _defaultFilename(filter, asXlsx);
    final bytes = asXlsx ? _buildXlsxBytes(rows) : _buildCsvBytes(rows);
    _download(bytes, filename);
    return filename;
  }

  Uint8List _buildCsvBytes(List<SeriesExportRow> rows) {
    final rowsWithEpisodes = rows.where((r) => r.episodesBySeason != null).toList();
    final hasEpisodes = rowsWithEpisodes.isNotEmpty;
    final episodeSeasons = <int>{};
    if (hasEpisodes) {
      for (final r in rowsWithEpisodes) {
        episodeSeasons.addAll(r.episodesBySeason!.keys);
      }
    }
    final seasonList = episodeSeasons.toList()..sort();

    final csvRows = <List<String>>[];
    // Header rows
    final baseHeader = ['Titel', 'Jahr', 'Serienstatus', 'Cliffhanger', 'Aufloesung', 'DownloadPfad', 'Staffeln', 'Init', 'Progress', 'Done', 'Episoden Gesamt'];
    final seasonHeader = <String>[]..addAll(baseHeader);
    final epHeader = <String>[]..addAll(baseHeader);
    if (hasEpisodes) {
      for (final s in seasonList) {
        final maxEp = _maxEpForSeason(rowsWithEpisodes, s);
        seasonHeader.add('Season $s');
        for (int ep = 1; ep <= maxEp; ep++) {
          seasonHeader.add('');
          epHeader.add('E$ep');
        }
      }
    }
    csvRows.add(seasonHeader);
    if (hasEpisodes) {
      csvRows.add(epHeader);
    }

    for (final r in rows) {
      final row = [
        r.title,
        r.year?.toString() ?? '',
        r.seriesStatus ?? '',
        r.cliffhanger == null ? '' : (r.cliffhanger! ? 'ja' : 'nein'),
        r.resolution ?? '',
        r.downloadPath ?? '',
        r.seasons.toString(),
        r.episodesInit.toString(),
        r.episodesProgress.toString(),
        r.episodesDone.toString(),
        r.episodesTotal.toString(),
      ];
      if (hasEpisodes) {
        for (final s in seasonList) {
          final eps = r.episodesBySeason?[s] ?? const {};
          final maxEp = _maxEpForSeason(rowsWithEpisodes, s);
          row.add('S$s');
          for (int ep = 1; ep <= maxEp; ep++) {
            row.add(_statusCode(eps[ep]));
          }
        }
      }
      csvRows.add(row);
    }
    final csv = _toCsv(csvRows);
    return Uint8List.fromList(utf8.encode(csv));
  }

  Uint8List _buildXlsxBytes(List<SeriesExportRow> rows) {
    final rowsWithEpisodes = rows.where((r) => r.episodesBySeason != null).toList();
    final hasEpisodes = rowsWithEpisodes.isNotEmpty;
    final episodeSeasons = <int>{};
    if (hasEpisodes) {
      for (final r in rowsWithEpisodes) {
        episodeSeasons.addAll(r.episodesBySeason!.keys);
      }
    }
    final seasonList = episodeSeasons.toList()..sort();

    final wb = xlsio.Workbook();
    final sheet = wb.worksheets[0];
    sheet.name = 'Serien';

    final headers = [
      'Titel',
      'Jahr',
      'Serienstatus',
      'Cliffhanger',
      'Aufloesung',
      'DownloadPfad',
      'Staffeln',
      'Init',
      'Progress',
      'Done',
      'Episoden Gesamt',
    ];
    var col = 1;
    for (final h in headers) {
      sheet.getRangeByIndex(1, col).setText(h);
      col++;
    }
    int headerRowSpan = 1;
    if (hasEpisodes) {
      headerRowSpan = 2;
      int rowSeason = 1;
      int rowEpisode = 2;
      col = headers.length + 1;
      for (final s in seasonList) {
        final maxEp = _maxEpForSeason(rowsWithEpisodes, s);
        sheet.getRangeByIndex(rowSeason, col).setText('Season $s');
        if (maxEp > 1) {
          sheet.getRangeByIndex(rowSeason, col, rowSeason, col + maxEp - 1).merge();
        }
        for (int ep = 1; ep <= maxEp; ep++) {
          sheet.getRangeByIndex(rowEpisode, col + ep - 1).setText('E$ep');
        }
        col += maxEp;
      }
    }

    for (var i = 0; i < rows.length; i++) {
      final r = rows[i];
      final row = i + headerRowSpan + 1;
      sheet.getRangeByIndex(row, 1).setText(r.title);
      if (r.year != null) sheet.getRangeByIndex(row, 2).setNumber(r.year!.toDouble());
      sheet.getRangeByIndex(row, 3).setText(r.seriesStatus ?? '');
      sheet.getRangeByIndex(row, 4).setText(r.cliffhanger == null ? '' : (r.cliffhanger! ? 'ja' : 'nein'));
      sheet.getRangeByIndex(row, 5).setText(r.resolution ?? '');
      sheet.getRangeByIndex(row, 6).setText(r.downloadPath ?? '');
      sheet.getRangeByIndex(row, 7).setNumber(r.seasons.toDouble());
      sheet.getRangeByIndex(row, 8).setNumber(r.episodesInit.toDouble());
      sheet.getRangeByIndex(row, 9).setNumber(r.episodesProgress.toDouble());
      sheet.getRangeByIndex(row, 10).setNumber(r.episodesDone.toDouble());
      sheet.getRangeByIndex(row, 11).setNumber(r.episodesTotal.toDouble());
      if (hasEpisodes) {
        var colOffset = headers.length + 1;
        final epsBySeason = r.episodesBySeason ?? const {};
        for (final s in seasonList) {
          final eps = epsBySeason[s] ?? const {};
          final maxEp = _maxEpForSeason(rowsWithEpisodes, s);
          for (int ep = 1; ep <= maxEp; ep++) {
            sheet.getRangeByIndex(row, colOffset + ep - 1).setText(_statusCode(eps[ep]));
          }
          colOffset += maxEp;
        }
      }
    }

    final bytes = wb.saveAsStream();
    wb.dispose();
    return Uint8List.fromList(bytes);
  }

  void _download(Uint8List bytes, String filename) {
    final blob = html.Blob([bytes]);
    final url = html.Url.createObjectUrlFromBlob(blob);
    final anchor = html.AnchorElement(href: url)
      ..download = filename
      ..style.display = 'none';
    html.document.body?.append(anchor);
    anchor.click();
    anchor.remove();
    html.Url.revokeObjectUrl(url);
  }

  String _defaultFilename(ItemStatus? filter, bool asXlsx) {
    final safeFilter = (filter?.name ?? 'alle').replaceAll(RegExp(r'[^A-Za-z0-9_-]'), '_');
    final ts = DateTime.now();
    String two(int v) => v.toString().padLeft(2, '0');
    final stamp = '${ts.year}${two(ts.month)}${two(ts.day)}_${two(ts.hour)}${two(ts.minute)}${two(ts.second)}';
    return 'series_${safeFilter}_$stamp.${asXlsx ? 'xlsx' : 'csv'}';
  }

  int _maxEpForSeason(List<SeriesExportRow> rows, int season) {
    var maxEp = 0;
    for (final r in rows) {
      final eps = r.episodesBySeason?[season];
      if (eps != null && eps.isNotEmpty) {
        final m = eps.keys.reduce((a, b) => a > b ? a : b);
        if (m > maxEp) maxEp = m;
      }
    }
    return maxEp;
  }

  String _statusCode(ItemStatus? st) {
    switch (st) {
      case ItemStatus.Init:
        return 'I';
      case ItemStatus.Progress:
        return 'P';
      case ItemStatus.Done:
        return 'D';
      default:
        return '';
    }
  }

  String _toCsv(List<List<String>> rows) {
    final buffer = StringBuffer();
    for (var i = 0; i < rows.length; i++) {
      final row = rows[i];
      for (var j = 0; j < row.length; j++) {
        buffer.write(_escape(row[j]));
        if (j < row.length - 1) buffer.write(',');
      }
      if (i < rows.length - 1) buffer.writeln();
    }
    return buffer.toString();
  }

  String _escape(String v) {
    final needsQuotes = v.contains(',') || v.contains('"') || v.contains('\n') || v.contains('\r');
    final escaped = v.replaceAll('"', '""');
    return needsQuotes ? '"$escaped"' : escaped;
  }
}