'use strict';

const INTERFERENCE_TYPES = new Set(['COE', 'P2P', 'P3P']);
const DIRECTION_TYPES     = new Set(['UL', 'DL', 'BI']);

/**
 * Parse a TC_WIFI_*.ini filename and its parent directory name into tags.
 * Returns an object with all tag fields plus id and file_id.
 */
function parseFilename(filename, parentDir) {
  // Strip prefix and extension → full derived ID used as primary key
  const base = filename.replace(/^TC_WIFI_/, '').replace(/\.ini$/, '');
  const id = base;
  const segments = base.split('_');

  // Interference: first segment, fixed enum
  const interference = INTERFERENCE_TYPES.has(segments[0]) ? segments[0] : null;

  // File ID: segment matching R<digit><ALNUM>+
  const file_id = segments.find(s => /^R\d+[A-Z0-9]+$/i.test(s)) || null;

  // Device: segment matching CGW<digits>q
  const device = segments.find(s => /^CGW\d+$/.test(s)) || null;

  // Test Point: segment starting with TPT
  const test_point = segments.find(s => /^TPT\w+$/.test(s)) || null;

  // RSSI: segment matching RSSI<digits>
  const rssi = segments.find(s => /^RSSI\d+$/.test(s)) || null;

  // Station: segment matching STA<digits>
  const station = segments.find(s => /^STA\d+$/.test(s)) || null;

  // Band: segment matching <digit>GHZ
  const band = segments.find(s => /^\dGHZ$/.test(s)) || null;

  // Channel: segment matching CH<digits>
  const channel = segments.find(s => /^CH\d+$/.test(s)) || null;

  // Bandwidth: segment matching BW<digits>
  const bandwidth = segments.find(s => /^BW\d+$/.test(s)) || null;

  // Direction: last segment, fixed enum
  const lastSeg = segments[segments.length - 1];
  const direction = DIRECTION_TYPES.has(lastSeg) ? lastSeg : null;

  // Rotation from parent directory name: ROT<digits>
  const rotation = parentDir
    ? (parentDir.split('_').find(s => /^ROT\d+$/.test(s)) || null)
    : null;

  return { id, file_id, interference, device, test_point, rssi, station, band, channel, bandwidth, direction, rotation };
}

/**
 * Extract a timestamp from a result log filename.
 * Matches YYYY-MM-DD-HH-MM or YYYY-MM-DD-HH-MM-SS at the end of the name.
 * Returns an ISO-ish string (e.g. "2026-05-16T07:30:14") or null.
 */
function parseTimestamp(filename) {
  const match = filename.match(/(\d{4}-\d{2}-\d{2}-\d{2}-\d{2}(?:-\d{2})?)(?:\.\w+)?$/);
  if (!match) return null;
  const parts = match[1].split('-');
  const [year, month, day, hour, minute, second = '00'] = parts;
  return `${year}-${month}-${day}T${hour}:${minute}:${second}`;
}

/**
 * Convert an elapsed time string "H:MM:SS.ffffff" to total seconds.
 */
function parseElapsedTime(timeStr) {
  const match = timeStr.match(/^(\d+):(\d{2}):(\d{2})\.(\d+)$/);
  if (!match) return null;
  const [, h, m, s, frac] = match;
  return parseInt(h) * 3600 + parseInt(m) * 60 + parseInt(s) + parseFloat(`0.${frac}`);
}

module.exports = { parseFilename, parseTimestamp, parseElapsedTime };