#!/usr/bin/env node
/**
 * _observer-summary.js (v6.6-rc2 附件, 下划线前缀避开 baseline 保护)
 * P0 观察期数据摘要 · 读 debug/agent-returns.jsonl 出统计
 *
 * 用法:
 *   node scripts/patches/_observer-summary.js           # 人类可读
 *   node scripts/patches/_observer-summary.js --json    # 机器可读
 *
 * 阈值: P1 开工门槛 = 业务样本 >= 100 条 (原规划)
 * 业务样本 = 排除 session_id 以 'smoke-' / 'test-' 开头的冒烟记录
 */
'use strict';

const fs = require('fs');
const path = require('path');

const CLAUDE_ROOT = path.resolve(__dirname, '..', '..');
const LOG_FILE = path.join(CLAUDE_ROOT, 'debug', 'agent-returns.jsonl');
const THRESHOLD = 100;
const AS_JSON = process.argv.includes('--json');

function pct(part, whole) {
  return whole === 0 ? '0.0%' : (part / whole * 100).toFixed(1) + '%';
}

function percentile(sorted, p) {
  if (sorted.length === 0) return 0;
  const idx = Math.min(sorted.length - 1, Math.max(0, Math.floor(sorted.length * p)));
  return sorted[idx];
}

function readRecords() {
  if (!fs.existsSync(LOG_FILE)) return [];
  const raw = fs.readFileSync(LOG_FILE, 'utf8');
  const records = [];
  for (const line of raw.split(/\r?\n/)) {
    if (!line.trim()) continue;
    try { records.push(JSON.parse(line)); } catch {}
  }
  return records;
}

function isSmoke(r) {
  const sid = (r.session_id || '').toLowerCase();
  return sid.startsWith('smoke-') || sid.startsWith('test-') || sid.includes('smoke');
}

function summarize(records) {
  const total = records.length;
  const smokes = records.filter(isSmoke);
  const business = records.filter(r => !isSmoke(r));

  const agentTypes = {};
  const traceIdSet = new Set();
  const lengths = [];
  let tsMin = null, tsMax = null;

  for (const r of business) {
    const t = r.agent_type || '(empty)';
    agentTypes[t] = (agentTypes[t] || 0) + 1;
    if (r.traceId) traceIdSet.add(r.traceId);
    if (typeof r.text_length === 'number') lengths.push(r.text_length);
    const ts = r.ts;
    if (ts) {
      if (!tsMin || ts < tsMin) tsMin = ts;
      if (!tsMax || ts > tsMax) tsMax = ts;
    }
  }
  lengths.sort((a, b) => a - b);

  return {
    total_records: total,
    smoke_records: smokes.length,
    business_records: business.length,
    unique_traceIds: traceIdSet.size,
    agent_type_distribution: agentTypes,
    text_length_stats: lengths.length === 0 ? null : {
      min: lengths[0],
      max: lengths[lengths.length - 1],
      avg: +(lengths.reduce((a, b) => a + b, 0) / lengths.length).toFixed(1),
      p50: percentile(lengths, 0.50),
      p90: percentile(lengths, 0.90),
    },
    time_span: { from: tsMin, to: tsMax },
    threshold: THRESHOLD,
    progress: pct(business.length, THRESHOLD),
    p1_eligible: business.length >= THRESHOLD,
  };
}

function renderHuman(s) {
  const lines = [];
  lines.push('=== v6.6-rc2 P0 观察期摘要 ===');
  lines.push('');
  lines.push('总条数     : ' + s.total_records + '  (冒烟 ' + s.smoke_records + ' + 业务 ' + s.business_records + ')');
  lines.push('唯一 trace : ' + s.unique_traceIds);
  lines.push('时间跨度   : ' + (s.time_span.from || '-') + '  ~  ' + (s.time_span.to || '-'));
  lines.push('');
  lines.push('agent_type 分布:');
  const dist = s.agent_type_distribution;
  const keys = Object.keys(dist).sort((a, b) => dist[b] - dist[a]);
  if (keys.length === 0) lines.push('  (空)');
  for (const k of keys) lines.push('  ' + k.padEnd(24) + dist[k]);
  lines.push('');
  if (s.text_length_stats) {
    const t = s.text_length_stats;
    lines.push('text_length: min=' + t.min + ' max=' + t.max + ' avg=' + t.avg + ' p50=' + t.p50 + ' p90=' + t.p90);
  } else {
    lines.push('text_length: (无业务样本)');
  }
  lines.push('');
  lines.push('P1 开工门槛: ' + s.business_records + ' / ' + s.threshold + '  (' + s.progress + ')');
  lines.push('P1 可开工 : ' + (s.p1_eligible ? 'YES' : 'NO · 继续观察'));
  return lines.join('\n');
}

function main() {
  const records = readRecords();
  const s = summarize(records);
  if (AS_JSON) {
    process.stdout.write(JSON.stringify(s, null, 2));
  } else {
    process.stdout.write(renderHuman(s) + '\n');
  }
}

main();