import { Asset } from './Asset';
import type { EtfData, EtfMetrics } from '../types/models.model';

export class Etf extends Asset {
  metrics: EtfMetrics;

  constructor(data: EtfData) {
    super(data);
    // Preserve null for missing fields — coercing to 0 would auto-fail gates
    // in EtfScorer for data Yahoo simply didn't return.
    const num = (v: unknown): number | null => {
      if (v == null) return null;
      const f = parseFloat(String(v));
      return Number.isFinite(f) ? f : null;
    };
    this.metrics = {
      expenseRatio: num(data.expenseRatio),
      totalAssets: num(data.totalAssets),
      yield: num(data.yield),
      volume: num(data.volume),
      fiveYearReturn: num(data.fiveYearReturn),
    };
  }

  getDisplayMetrics(): Record<string, string> {
    const m = this.metrics;
    const fmt = (v: number | null, dec: number, suffix = '') =>
      v != null ? `${v.toFixed(dec)}${suffix}` : '—';
    return {
      Ticker: this.ticker,
      Type: 'ETF',
      Price: this.formatCurrency(this.currentPrice),
      'Exp Ratio%': fmt(m.expenseRatio, 2, '%'),
      'Yield%': fmt(m.yield, 2, '%'),
      AUM: m.totalAssets != null ? this.formatLargeNumber(m.totalAssets) : '—',
      '5Y Return%': fmt(m.fiveYearReturn, 1, '%'),
    };
  }
}