#!/usr/bin/env node
/**
 * P0-1 Patch: 可观测性指标
 * - prompt-dispatcher.js: 追加 metrics.emit('route', ...) 含路由延迟/置信度/技能
 * - agent-claim-observer.js: 追加 model/duration_ms 字段 + metrics.emit('agent', ...)
 * 幂等: sentinel [P0-1] METRICS_EMIT_v1
 */
'use strict';
const fs = require('fs');
const path = require('path');

const HOOKS = path.resolve(__dirname, '..', '..', 'hooks');
const SENTINEL = '[P0-1] METRICS_EMIT_v1';

function patchFile(name, fn) {
  const fp = path.join(HOOKS, name);
  if (!fs.existsSync(fp)) { console.log('[SKIP] ' + name + ' — not found'); return false; }
  const src = fs.readFileSync(fp, 'utf8');
  if (src.includes(SENTINEL)) { console.log('[SKIP] ' + name + ' — already patched'); return false; }
  fs.writeFileSync(fp + '.bak-p01.' + Date.now(), src);
  const out = fn(src);
  const tmp = fp + '.tmp.' + process.pid;
  fs.writeFileSync(tmp, out, 'utf8');
  fs.renameSync(tmp, fp);
  console.log('[DONE] ' + name);
  return true;
}

// --- prompt-dispatcher.js ---
function patchDispatcher(src) {
  const marker = "require('fs').appendFileSync(timingPath, entry);";
  if (!src.includes(marker)) throw new Error('marker not found in prompt-dispatcher.js');

  const lines = [
    '',
    '        // ' + SENTINEL,
    "        try {",
    "          const metrics = require('./lib/metrics.js');",
    "          let ri = {};",
    "          try {",
    "            const parsed = JSON.parse(stdout || '{}');",
    "            const ctx = (parsed.hookSpecificOutput && parsed.hookSpecificOutput.additionalContext) || '';",
    "            const cm = ctx.match(/\\u7f6e\\u4fe1\\u5ea6\\s+(\\d+)%/);",
    "            const sm = ctx.match(/\\u4e3b\\u8def\\u7531:\\s+(\\S+)/);",
    "            ri = { confidence: cm ? +cm[1] : null, skill: sm ? sm[1] : null };",
    "          } catch {}",
    "          metrics.emit('route', Object.assign({ hook: 'prompt-dispatcher', elapsed_ms: elapsed }, ri));",
    "        } catch {}",
  ];
  return src.replace(marker, marker + lines.join('\n'));
}

// --- agent-claim-observer.js ---
function patchObserver(src) {
  // 1. 追加字段到 record 对象
  const fieldMarker = '        text_length: text.length,';
  if (!src.includes(fieldMarker)) throw new Error('field marker not found in agent-claim-observer.js');

  const newFields = [
    '        text_length: text.length,',
    '        // ' + SENTINEL,
    "        model: (input.tool_input && input.tool_input.model) || '',",
    "        tool_name: (input.tool_input && input.tool_input.name) || 'Agent',",
    "        duration_ms: (input.tool_response && input.tool_response.duration_ms) || null,",
  ].join('\n');
  let result = src.replace(fieldMarker, newFields);

  // 2. 追加 metrics emit
  const appendMarker = "fs.appendFileSync(LOG_FILE, JSON.stringify(record) + '\\n');";
  if (!result.includes(appendMarker)) throw new Error('append marker not found');

  result = result.replace(
    appendMarker,
    appendMarker + "\n      // " + SENTINEL + " — 指标发射\n      try { require('./lib/metrics.js').emit('agent', record); } catch {}"
  );
  return result;
}

// --- Execute ---
let count = 0;
if (patchFile('prompt-dispatcher.js', patchDispatcher)) count++;
if (patchFile('agent-claim-observer.js', patchObserver)) count++;
console.log('\nP0-1 Metrics: ' + count + '/2 files patched');