export interface KisRealtimeStockTick {
  symbol: string; // 종목코드
  time: string; // 체결시간
  currentPrice: number; // 현재가
  sign: string; // 전일대비부호 (1:상한, 2:상승, 3:보합, 4:하한, 5:하락)
  change: number; // 전일대비
  changeRate: number; // 전일대비율
  accumulatedVolume: number; // 누적거래량
}

const STOCK_realtime_TR_ID = "H0STCNT0";

// H0STCNT0 Output format indices based on typical KIS Realtime API
// Format: MKSC_SHRN_ISCD^STCK_CNTG_HOUR^STCK_PRPR^PRDY_VRSS_SIGN^PRDY_VRSS^PRDY_CTRT^...
const STOCK_FIELD_INDEX = {
  symbol: 0, // MKSC_SHRN_ISCD
  time: 1, // STCK_CNTG_HOUR
  currentPrice: 2, // STCK_PRPR
  sign: 3, // PRDY_VRSS_SIGN
  change: 4, // PRDY_VRSS
  changeRate: 5, // PRDY_CTRT
  accumulatedVolume: 12, // ACML_VOL (Usually at index 12 or similar, need to be careful here)
} as const;

export function parseKisRealtimeStockTick(
  raw: string,
): KisRealtimeStockTick | null {
  // Format: 0|H0STCNT0|001|SYMBOL^TIME^PRICE^SIGN^CHANGE^...
  if (!/^([01])\|/.test(raw)) return null;

  const parts = raw.split("|");
  if (parts.length < 4) return null;

  // Check TR ID
  if (parts[1] !== STOCK_realtime_TR_ID) {
    return null;
  }

  const values = parts[3].split("^");
  if (values.length < 6) return null; // Ensure minimum fields exist

  const symbol = values[STOCK_FIELD_INDEX.symbol];
  const currentPrice = parseFloat(values[STOCK_FIELD_INDEX.currentPrice]);
  const sign = values[STOCK_FIELD_INDEX.sign];
  const changeRaw = parseFloat(values[STOCK_FIELD_INDEX.change]);
  const changeRateRaw = parseFloat(values[STOCK_FIELD_INDEX.changeRate]);

  // Adjust sign for negative values if necessary
  const isNegative = sign === "5" || sign === "4"; // 5: 하락, 4: 하한

  const change = isNegative ? -Math.abs(changeRaw) : Math.abs(changeRaw);
  const changeRate = isNegative
    ? -Math.abs(changeRateRaw)
    : Math.abs(changeRateRaw);

  // Validate numeric values
  if (isNaN(currentPrice)) return null;

  return {
    symbol,
    time: values[STOCK_FIELD_INDEX.time],
    currentPrice,
    sign,
    change,
    changeRate,
    accumulatedVolume:
      parseFloat(values[STOCK_FIELD_INDEX.accumulatedVolume]) || 0,
  };
}