// Parser CSV minimo (RFC4180: campos entre comillas, comillas escapadas
// como "", comas y saltos de linea dentro de campos citados) -- se evita
// sumar una dependencia nueva (papaparse/csv-parse) para un formato que
// nosotros mismos controlamos via la plantilla descargable.
export function parseCsv(text: string): string[][] {
  const rows: string[][] = [];
  let row: string[] = [];
  let field = "";
  let inQuotes = false;
  let i = 0;
  const normalized = text.replace(/\r\n/g, "\n").replace(/\r/g, "\n");

  while (i < normalized.length) {
    const char = normalized[i];
    if (inQuotes) {
      if (char === '"') {
        if (normalized[i + 1] === '"') {
          field += '"';
          i += 2;
          continue;
        }
        inQuotes = false;
        i += 1;
        continue;
      }
      field += char;
      i += 1;
      continue;
    }
    if (char === '"') {
      inQuotes = true;
      i += 1;
      continue;
    }
    if (char === ",") {
      row.push(field);
      field = "";
      i += 1;
      continue;
    }
    if (char === "\n") {
      row.push(field);
      rows.push(row);
      row = [];
      field = "";
      i += 1;
      continue;
    }
    field += char;
    i += 1;
  }
  if (field.length > 0 || row.length > 0) {
    row.push(field);
    rows.push(row);
  }
  return rows.filter((r) => r.some((cell) => cell.trim().length > 0));
}

export function csvRowsToObjects(rows: string[][]): Record<string, string>[] {
  const [header, ...body] = rows;
  if (!header) return [];
  const keys = header.map((h) => h.trim().toLowerCase());
  return body.map((cols) => {
    const obj: Record<string, string> = {};
    keys.forEach((key, index) => {
      obj[key] = (cols[index] ?? "").trim();
    });
    return obj;
  });
}