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

export class BullDipBuyer extends BaseStrategy {
  constructor(config = {}) {
    super('bull-dip-buyer', {
      maxYesPrice: config.maxYesPrice || 45,
      minYesPrice: config.minYesPrice || 15,
      betSize: config.betSize || 2,
      slippage: config.slippage || 3,
      cooldownMs: config.cooldownMs || 20000,
      marketDurationMin: config.marketDurationMin || 15,
      entryWindowMin: config.entryWindowMin || 6,
      ...config
    });

    this._lastTrade = {
      paper: { time: 0, ticker: null },
      live: { time: 0, ticker: null }
    };
  }

  evaluate(state, caller = 'paper') {
    if (!state || !this.enabled || !state.closeTime) return null;

    const track = this._lastTrade[caller] || this._lastTrade.paper;
    const now = Date.now();
    if (now - track.time < this.config.cooldownMs) return null;
    if (state.ticker === track.ticker) return null;

    const closeTs = new Date(state.closeTime).getTime();
    const timeLeftMs = closeTs - now;
    if (!Number.isFinite(timeLeftMs) || timeLeftMs <= 0) return null;

    // Entry gate: only trade in first N minutes of each market cycle.
    // With 15m markets: first 0-6m elapsed => roughly 15m down to 9m remaining.
    const elapsedMin = (this.config.marketDurationMin * 60000 - timeLeftMs) / 60000;
    if (elapsedMin < 0 || elapsedMin > this.config.entryWindowMin) return null;

    const { yesPct } = state;

    if (yesPct <= this.config.maxYesPrice && yesPct >= this.config.minYesPrice) {
      // For live trading, require orderbook data — refuse to trade blind
      if (caller === 'live') {
        const bestAsk = this._getBestYesAsk(state);
        if (bestAsk == null) return null;

        // Verify the actual ask price is within our dip range + slippage
        if (bestAsk > this.config.maxYesPrice + this.config.slippage) return null;

        // Don't let slippage push us above 50¢ — that's not a dip
        if (bestAsk > 50) return null;
      }

      const maxPrice = Math.min(
        yesPct + this.config.slippage,
        this.config.maxYesPrice + this.config.slippage,
        50
      );

      const bestAsk = this._getBestYesAsk(state);
      let reason = `Bullish dip buy (t+${elapsedMin.toFixed(1)}m): Yes @ ${yesPct}¢`;

      if (bestAsk != null) {
        if (bestAsk > maxPrice) return null;
        reason = `Bullish dip buy (t+${elapsedMin.toFixed(1)}m): Yes @ ${yesPct}¢ (ask: ${bestAsk}¢)`;
      }

      const signal = {
        strategy: this.name,
        side: 'yes',
        price: yesPct,
        maxPrice,
        size: this.config.betSize,
        reason,
        ticker: state.ticker
      };

      track.time = now;
      track.ticker = state.ticker;
      return signal;
    }

    return null;
  }

  _getBestYesAsk(state) {
    const ob = state.orderbook;
    if (!ob) return null;

    if (ob.no?.length) {
      const bestNoBid = ob.no[0]?.[0];
      if (bestNoBid != null) return 100 - bestNoBid;
    }
    return null;
  }

  toJSON() {
    return {
      ...super.toJSON(),
      lastTradeTicker: this._lastTrade.live.ticker || this._lastTrade.paper.ticker
    };
  }
}