/**
 * Benchmark Auto-Evolver — 红皇后效应
 *
 * 种群变强时自动提高 Benchmark 难度:
 *   通过率 > 90% → difficulty +1
 *   通过率 < 20% → difficulty -1
 *   30%-80% → 保持（健康压力区间）
 *
 * Per-skill: 只调整该 Run 关联 Skill 的 Benchmark。
 */
const evolutionQueries = require('../queries').evolutionQueries;

/**
 * 评估并调整单个 Benchmark 的难度
 */
async function evolveBenchmark(benchmarkId, runId) {
  const evaluations = await evolutionQueries.getEvaluationsByRun(runId, {});
  const benchEvals = evaluations.filter(e => e.benchmark_id === benchmarkId);

  if (benchEvals.length < 3) {
    return { action: 'skip', reason: '评估数据不足 (<3)' };
  }

  const passCount = benchEvals.filter(e => e.overall_score >= 0.7).length;
  const passRate = passCount / benchEvals.length;

  const run = await evolutionQueries.getRun(runId);
  const benchmarks = await evolutionQueries.getBenchmarks(run?.skill_name);
  const benchmark = benchmarks.find(b => b.id === benchmarkId);
  if (!benchmark) return { action: 'skip', reason: 'Benchmark not found' };

  const currentDifficulty = benchmark.difficulty || 3;
  const currentThreshold = benchmark.pass_threshold || 0.7;

  let newDifficulty = currentDifficulty;
  let newThreshold = currentThreshold;
  let action = 'maintain';

  if (passRate > 0.9) {
    newDifficulty = Math.min(5, currentDifficulty + 1);
    newThreshold = Math.min(0.95, currentThreshold + 0.05);
    action = 'increase';
  } else if (passRate < 0.2) {
    newDifficulty = Math.max(1, currentDifficulty - 1);
    newThreshold = Math.max(0.3, currentThreshold - 0.05);
    action = 'decrease';
  }

  if (action !== 'maintain') {
    await evolutionQueries.upsertBenchmark({
      ...benchmark,
      difficulty: newDifficulty,
      passThreshold: newThreshold,
    });
  }

  return {
    benchmarkId, action,
    passRate: parseFloat(passRate.toFixed(2)),
    evaluationCount: benchEvals.length,
    difficulty: { from: currentDifficulty, to: newDifficulty },
    threshold: { from: currentThreshold, to: newThreshold },
  };
}

/**
 * 自进化该 Run 关联 Skill 的所有 Benchmark
 */
async function evolveAllBenchmarks(runId) {
  const run = await evolutionQueries.getRun(runId);
  const skillName = run?.skill_name;
  const benchmarks = await evolutionQueries.getBenchmarks(skillName);

  console.log(`🔄 自进化 ${benchmarks.length} 个 Benchmark [${skillName || '?'}]\n`);

  const results = [];
  for (const benchmark of benchmarks) {
    const result = await evolveBenchmark(benchmark.id, runId);
    results.push(result);

    if (result.action === 'increase') {
      console.log(`  📈 ${benchmark.id}: 难度 ${result.difficulty.from} → ${result.difficulty.to} (通过率 ${(result.passRate * 100).toFixed(0)}%)`);
    } else if (result.action === 'decrease') {
      console.log(`  📉 ${benchmark.id}: 难度 ${result.difficulty.from} → ${result.difficulty.to} (通过率 ${(result.passRate * 100).toFixed(0)}%)`);
    } else if (result.action === 'skip') {
      console.log(`  ⏭️  ${benchmark.id}: ${result.reason}`);
    }
  }

  const adjusted = results.filter(r => r.action !== 'maintain' && r.action !== 'skip');
  console.log(`\n✅ Benchmark 自进化完成: ${adjusted.length}/${benchmarks.length} 调整`);
  return results;
}

module.exports = { evolveBenchmark, evolveAllBenchmarks };