import type { Row } from '../types.ts';

// The rows of a GSF seed CSV (an app's or a PBC's data/*.csv): a header line,
// then one record per line; a value is bare or double-quoted ("" is a quote
// inside one). Values stay strings — a table's declared fields convert them
// when the rows are stored, as GSF's loader does. An empty cell is left out of
// its row (null), since SendTable sets only the non-empty cells
// (SendTableOperation.createRecord, genesis-db, GSF v8.15.29).
export function parseSeedCsv(text: string): Row[] {
  const records: string[][] = [];
  let record: string[] = [];
  let field = '';
  let quoted = false;
  const endRecord = () => {
    record.push(field);
    if (record.some((value) => value !== '')) records.push(record);
    record = [];
    field = '';
  };
  for (let i = 0; i < text.length; i += 1) {
    const char = text[i];
    if (quoted) {
      if (char === '"' && text[i + 1] === '"') {
        field += '"';
        i += 1;
      } else if (char === '"') {
        quoted = false;
      } else {
        field += char;
      }
    } else if (char === '"') {
      quoted = true;
    } else if (char === ',') {
      record.push(field);
      field = '';
    } else if (char === '\n' || char === '\r') {
      if (char === '\r' && text[i + 1] === '\n') i += 1;
      endRecord();
    } else {
      field += char;
    }
  }
  endRecord();
  const [header = [], ...rows] = records;
  return rows.map((values) =>
    Object.fromEntries(
      header.flatMap((name, i) => (values[i] ? [[name.trim(), values[i]] as const] : [])),
    ),
  );
}