KalBot/lib/strategies/sniper-reversal.js

import { BaseStrategy } from './base.js';

export class SniperReversalStrategy extends BaseStrategy {
  constructor(config = {}) {
    super('sniper-reversal', {
      triggerPct: config.triggerPct || 95, // Bet against a 95% favorite
      minsLeft: config.minsLeft || 3,      // Only in the last 3 minutes
      betSize: config.betSize || 1,        // Cheap lotto tickets
      cooldownMs: config.cooldownMs || 60000,
      ...config
    });
    
    this.lastTradeTime = 0;
    this.lastTradeTicker = null;
  }

  evaluate(state) {
    if (!state || !this.enabled || !state.closeTime) return null;

    const now = Date.now();
    if (now - this.lastTradeTime < this.config.cooldownMs) return null;
    if (state.ticker === this.lastTradeTicker) return null;

    const timeLeftMs = new Date(state.closeTime).getTime() - now;
    const minsLeft = timeLeftMs / 60000;

    // Only strike in the final minutes
    if (minsLeft > this.config.minsLeft || minsLeft <= 0) return null;

    const { yesPct, noPct } = state;
    const trigger = this.config.triggerPct;

    let signal = null;

    if (yesPct >= trigger && noPct > 0) {
      signal = {
        strategy: this.name,
        side: 'no',
        price: noPct,
        size: this.config.betSize,
        reason: `Buzzer beater No at ${noPct}¢ (Yes is ${yesPct}%) with ${minsLeft.toFixed(1)}m left`,
        ticker: state.ticker
      };
    } else if (noPct >= trigger && yesPct > 0) {
      signal = {
        strategy: this.name,
        side: 'yes',
        price: yesPct,
        size: this.config.betSize,
        reason: `Buzzer beater Yes at ${yesPct}¢ (No is ${noPct}%) with ${minsLeft.toFixed(1)}m left`,
        ticker: state.ticker
      };
    }

    if (signal) {
      this.lastTradeTime = now;
      this.lastTradeTicker = state.ticker;
    }

    return signal;
  }
}