import type { SourceExtractor } from '../domain/source-extraction';

function safeId(value: string): string {
  return value.replace(/[^a-zA-Z0-9_-]/g, '-');
}

export const genericTableSourceExtractor: SourceExtractor = {
  id: 'generic-table-source-extractor',
  version: '1.0.0',
  fallback: true,
  detect(document) {
    const count = document.tables.length;
    return count
      ? { score: 0.1, evidence: [`${count} kompatible Tabellenansicht(en) vorhanden.`] }
      : { score: 0, evidence: [] };
  },
  extract(document) {
    const candidates = document.tables.flatMap(table => {
      const header = table.headerCandidates[0];
      return table.rows
        .filter(row => row.index !== header?.rowIndex && row.cells.some(cell => cell.decodedValue.trim()))
        .map(row => ({
          version: 1 as const,
          id: `candidate-${safeId(table.id)}-${row.index}`,
          source: { fileName: document.file.name, tableIndex: table.index, rowIndex: row.index },
          fields: row.cells.map(cell => ({
            key: `column-${cell.source.columnIndex ?? 0}`,
            label: header?.headers[cell.source.columnIndex ?? 0] || `Spalte ${(cell.source.columnIndex ?? 0) + 1}`,
            originalValue: cell.rawValue,
            decodedValue: cell.decodedValue,
            source: { ...cell.source, fileName: document.file.name }
          }))
        }));
    });
    return { version: 1, candidates, diagnostics: [] };
  }
};