import { test } from 'node:test';
import assert from 'node:assert/strict';
import { EtfScorer } from '../server/scorers/EtfScorer';
import type { EtfMetrics } from '../server/types';

const rules = {
  gates: { maxExpenseRatio: 0.5 },
  weights: { yield: 2, lowCost: 3 },
  thresholds: { minYield: 1.5, maxExpense: 0.1, minVolume: 500000 },
};

// Helper to build minimal EtfMetrics fixtures (totalAssets/fiveYearReturn unused by scorer).
const etf = (partial: Partial<EtfMetrics>): EtfMetrics => ({
  totalAssets: 0,
  fiveYearReturn: 0,
  volume: 0,
  yield: 0,
  expenseRatio: 0,
  ...partial,
});

test('rejects ETF with expense ratio above gate', () => {
  const result = EtfScorer.score(etf({ expenseRatio: 0.8, yield: 2.0 }), rules);
  assert.equal(result.label, '🔴 REJECT');
});

test('efficient label for low-cost, high-yield ETF', () => {
  const result = EtfScorer.score(etf({ expenseRatio: 0.03, yield: 2.0, volume: 1000000 }), rules);
  assert.equal(result.label, '🟢 Efficient');
});

test('neutral when yield is below threshold', () => {
  const result = EtfScorer.score(etf({ expenseRatio: 0.03, yield: 0.4, volume: 1000000 }), rules);
  assert.equal(result.label, '🟡 Neutral');
});

test('audit breakdown includes cost, yield, vol keys', () => {
  const result = EtfScorer.score(etf({ expenseRatio: 0.03, yield: 2.0, volume: 1000000 }), rules);
  assert(result.audit.breakdown!.cost != null);
  assert(result.audit.breakdown!.yield != null);
  assert(result.audit.breakdown!.vol != null);
});

test('penalises ETF with volume below liquidity floor', () => {
  const result = EtfScorer.score(etf({ expenseRatio: 0.03, yield: 2.0, volume: 100000 }), rules);
  assert(result.audit.breakdown!.vol < 0, 'low-volume ETF should receive negative vol score');
});

test('scores 5Y return when threshold configured', () => {
  const rulesWithReturn = {
    ...rules,
    weights: { ...rules.weights, fiveYearReturn: 2 },
    thresholds: { ...rules.thresholds, minFiveYearReturn: 8.0 },
  };
  const good = EtfScorer.score(
    etf({ expenseRatio: 0.03, yield: 2.0, volume: 1000000, fiveYearReturn: 10 }),
    rulesWithReturn,
  );
  const poor = EtfScorer.score(
    etf({ expenseRatio: 0.03, yield: 2.0, volume: 1000000, fiveYearReturn: 5 }),
    rulesWithReturn,
  );
  assert(good.audit.breakdown!.fiveYearReturn > 0, 'strong 5Y return should score positively');
  assert(poor.audit.breakdown!.fiveYearReturn < 0, 'weak 5Y return should score negatively');
});