#!/usr/bin/env node
/**
 * P0-3 Patch: Skill 三层分层
 * 基于 actual-skills.jsonl 频率 + criticality 维度, 给 skills-index.json 每个 skill 追加:
 *   - tier: 1 (常驻 ~20) / 2 (按需 ~30) / 3 (归档 ~45)
 *   - criticality: "HIGH" / "MEDIUM" / "LOW"
 * 幂等: 检查首个 skill 是否已有 tier 字段
 */
'use strict';
const fs = require('fs');
const path = require('path');

const CLAUDE_ROOT = path.resolve(__dirname, '..', '..');
const INDEX_PATH = path.join(CLAUDE_ROOT, 'skills-index.json');
const ACTUAL_PATH = path.join(CLAUDE_ROOT, 'debug', 'actual-skills.jsonl');

// --- Criticality 定义 ---
const CRITICALITY_HIGH = new Set([
  'security-expert', 'guardian', 'zero-defect-guardian', 'review',
  'debugger-expert', 'developer-expert', 'project-audit-expert',
]);

const TIER1_ESSENTIAL = new Set([
  'frontend-expert', 'backend-builder', 'qa', 'prompt-optimizer',
  'mobile-expert', 'architect-expert',
]);

const TIER2_USEFUL = new Set([
  'cloud-architect', 'database-tuning-expert', 'notification-system-expert',
  'finance-advisor', 'sre-expert', 'data-analyst-expert', 'vue-expert',
  'nextjs-developer', 'python-pro', 'typescript-pro', 'rust-engineer',
  'golang-pro', 'swift-expert', 'flutter-expert', 'terraform-engineer',
  'kubernetes-specialist', 'graphql-architect', 'websocket-engineer',
  'angular-architect', 'cloud-native-expert',
]);

const TIER1_FREQ_THRESHOLD = 3;

// --- 频率统计 ---
function countFrequency() {
  const counts = {};
  try {
    const lines = fs.readFileSync(ACTUAL_PATH, 'utf8').trim().split('\n');
    for (const line of lines) {
      try {
        const obj = JSON.parse(line);
        const skill = obj.actualSkill;
        if (skill) counts[skill] = (counts[skill] || 0) + 1;
      } catch {}
    }
  } catch {}
  return counts;
}

// --- 分层逻辑 ---
function assignTier(name, freq) {
  const isHigh = CRITICALITY_HIGH.has(name);
  const isEssential = TIER1_ESSENTIAL.has(name);
  const criticality = isHigh ? 'HIGH' : (isEssential || TIER2_USEFUL.has(name) || freq >= 2) ? 'MEDIUM' : 'LOW';

  let tier;
  if (freq >= TIER1_FREQ_THRESHOLD || isHigh || isEssential) {
    tier = 1;
  } else if (freq >= 1 || TIER2_USEFUL.has(name) || criticality === 'MEDIUM') {
    tier = 2;
  } else {
    tier = 3;
  }
  return { tier, criticality };
}

// --- Execute ---
if (!fs.existsSync(INDEX_PATH)) {
  process.stderr.write('[FAIL] skills-index.json not found\n');
  process.exit(1);
}

const index = JSON.parse(fs.readFileSync(INDEX_PATH, 'utf8'));

// 幂等检查
if (index.skills[0] && typeof index.skills[0].tier === 'number') {
  process.stderr.write('[SKIP] skills-index.json already has tier field\n');
  process.exit(0);
}

const freq = countFrequency();
const tierCounts = { 1: 0, 2: 0, 3: 0 };

for (const skill of index.skills) {
  const f = freq[skill.name] || 0;
  const { tier, criticality } = assignTier(skill.name, f);
  skill.tier = tier;
  skill.criticality = criticality;
  skill.callCount30d = f;
  tierCounts[tier]++;
}

// 备份
fs.writeFileSync(INDEX_PATH + '.bak-p03.' + Date.now(), fs.readFileSync(INDEX_PATH));

// 原子写
const tmp = INDEX_PATH + '.tmp.' + process.pid;
fs.writeFileSync(tmp, JSON.stringify(index, null, 2), 'utf8');
fs.renameSync(tmp, INDEX_PATH);

process.stderr.write('[DONE] skills-index.json tiered: T1=' + tierCounts[1] + ' T2=' + tierCounts[2] + ' T3=' + tierCounts[3] + '\n');