@thuantan2060/technicalindicators/lib/candlestick/DownsideTasukiGap.js

Techincal Indicators written in javascript

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = exports.DEFAULT_DOWNSIDE_TASUKI_GAP_CONFIG = void 0;
exports.downsidetasukigap = downsidetasukigap;
var _CandlestickFinder = _interopRequireWildcard(require("./CandlestickFinder"));
function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function (e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, default: e }; if (null === e || "object" != typeof e && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (const t in e) "default" !== t && {}.hasOwnProperty.call(e, t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, t)) && (i.get || i.set) ? o(f, t, i) : f[t] = e[t]); return f; })(e, t); }
/**
 * Configuration interface for DownsideTasukiGap pattern.
 * Only requires scale parameter since this pattern uses direct price comparisons.
 */

/**
 * Default configuration for DownsideTasukiGap pattern.
 */
const DEFAULT_DOWNSIDE_TASUKI_GAP_CONFIG = exports.DEFAULT_DOWNSIDE_TASUKI_GAP_CONFIG = {
  ..._CandlestickFinder.DEFAULT_CANDLESTICK_CONFIG
};
class DownsideTasukiGap extends _CandlestickFinder.default {
  constructor(config) {
    const finalConfig = {
      ...DEFAULT_DOWNSIDE_TASUKI_GAP_CONFIG,
      ...config
    };
    super(finalConfig);
    this.requiredCount = 3;
    this.name = 'DownsideTasukiGap';
  }
  logic(data) {
    // Based on ascending chronological order: [day1, day2, day3]
    // [0]=oldest (day 1), [1]=middle (day 2), [2]=most recent (day 3)
    let firstdaysOpen = data.open[0]; // Day 1 (oldest) - first bearish candle
    let firstdaysClose = data.close[0];
    let firstdaysHigh = data.high[0];
    let firstdaysLow = data.low[0];
    let seconddaysOpen = data.open[1]; // Day 2 (middle) - second bearish candle with gap
    let seconddaysClose = data.close[1];
    let seconddaysHigh = data.high[1];
    let seconddaysLow = data.low[1];
    let thirddaysOpen = data.open[2]; // Day 3 (most recent) - bullish candle filling gap
    let thirddaysClose = data.close[2];
    let thirddaysHigh = data.high[2];
    let thirddaysLow = data.low[2];

    // Basic OHLC validation for all three days
    if (!this.validateOHLC(firstdaysOpen, firstdaysHigh, firstdaysLow, firstdaysClose) || !this.validateOHLC(seconddaysOpen, seconddaysHigh, seconddaysLow, seconddaysClose) || !this.validateOHLC(thirddaysOpen, thirddaysHigh, thirddaysLow, thirddaysClose)) {
      return false;
    }

    // Pattern requirements:
    // 1. Day 1 and Day 2 must be bearish
    let isFirstBearish = firstdaysClose < firstdaysOpen;
    let isSecondBearish = seconddaysClose < seconddaysOpen;

    // 2. Day 3 must be bullish
    let isThirdBullish = thirddaysClose > thirddaysOpen;

    // 3. There must be a gap down between Day 1 and Day 2
    let isGapDown = seconddaysHigh < firstdaysLow;

    // 4. Day 3 must open within Day 2's body
    let day3OpensInDay2Body = thirddaysOpen > Math.min(seconddaysOpen, seconddaysClose) && thirddaysOpen < Math.max(seconddaysOpen, seconddaysClose);

    // 5. Day 3 must close within the gap (between Day 1 low and Day 2 high)
    let day3ClosesInGap = thirddaysClose > seconddaysHigh && thirddaysClose < firstdaysLow;

    // 6. Day 3 must NOT fully close the gap (i.e., Day 3 close should not reach Day 1 low)
    let gapNotFullyClosed = thirddaysClose < firstdaysLow;
    return isFirstBearish && isSecondBearish && isThirdBullish && isGapDown && day3OpensInDay2Body && day3ClosesInGap && gapNotFullyClosed;
  }
}

/**
 * Detects DownsideTasukiGap candlestick pattern in the provided stock data.
 *
 * A DownsideTasukiGap is a three-candle continuation pattern that occurs during a downtrend.
 * It consists of:
 * 1. A bearish candle
 * 2. A second bearish candle that gaps down from the first
 * 3. A bullish candle that opens within the second candle's body and closes within the gap
 *
 * This pattern suggests that the downtrend will continue despite the temporary bullish reversal.
 *
 * @param data - Stock data containing OHLC values for at least 3 periods
 * @param config - Configuration object for pattern detection
 * @param config.scale - Scale parameter for approximateEqual function precision (default: 0.001)
 * @returns True if DownsideTasukiGap pattern is detected, false otherwise
 *
 * @example
 * ```typescript
 * // Using default configuration
 * const hasDownsideTasukiGapPattern = downsidetasukigap(stockData);
 *
 * // Using custom configuration
 * const hasDownsideTasukiGapPattern = downsidetasukigap(stockData, {
 *   scale: 0.002
 * });
 *
 * // Backward compatibility with scale parameter
 * const hasDownsideTasukiGapPattern = downsidetasukigap(stockData, { scale: 0.002 });
 * ```
 */
exports.default = DownsideTasukiGap;
function downsidetasukigap(data, config = DEFAULT_DOWNSIDE_TASUKI_GAP_CONFIG) {
  return new DownsideTasukiGap(config).hasPattern(data);
}
//# sourceMappingURL=DownsideTasukiGap.js.map