#!/usr/bin/env node
'use strict';
/**
 * Phase 1 · T1.4 补丁 — /mcp-prune 命令
 *
 * 产出:
 *   1. scripts/mcp-prune.js    — 剪枝分析 CLI (纯只读 + 生成 plan)
 *   2. skills/mcp-prune/SKILL.md — 触发器 /mcp-prune
 *
 * 安全设计:
 *   - 默认只报告 (read-only)
 *   - --plan: 生成 mcp-prune-plan-<date>.json
 *   - --confirm: 输出用户手动 apply 的指令，不自动修改 .claude.json
 *   - 永远不修改用户核心配置
 *
 * 幂等:
 *   - sentinel: PHASE1_T1_4_MCP_PRUNE_2026_04_24
 *   - 已存在且一致则跳过
 *
 * 回滚:
 *   - 删除 scripts/mcp-prune.js + skills/mcp-prune/ 目录
 */

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

const CLAUDE_ROOT = path.join(__dirname, '..', '..');
const SENTINEL = 'PHASE1_T1_4_MCP_PRUNE_2026_04_24';

const SCRIPT_TARGET = path.join(CLAUDE_ROOT, 'scripts', 'mcp-prune.js');
const SKILL_DIR = path.join(CLAUDE_ROOT, 'skills', 'mcp-prune');
const SKILL_TARGET = path.join(SKILL_DIR, 'SKILL.md');

const SCRIPT_CONTENT = `#!/usr/bin/env node
'use strict';
/**
 * /mcp-prune — MCP 剪枝分析工具 (Phase 1 · T1.4)
 * sentinel: ${SENTINEL}
 *
 * 职责:
 *   - 基于 mcp-usage-tracker 的数据识别低频 MCP
 *   - 交叉 mcp-critical-allowlist.json 保护救命 MCP
 *   - 生成剪枝 plan 文件 (JSON)
 *   - 输出用户手动 apply 的指令
 *
 * 用法:
 *   node scripts/mcp-prune.js            # 默认: 只报告
 *   node scripts/mcp-prune.js --days 30  # 用 30 天窗口
 *   node scripts/mcp-prune.js --plan     # 写入 mcp-prune-plan-<date>.json
 *   node scripts/mcp-prune.js --confirm  # 输出用户 apply 的完整步骤
 *
 * 安全:
 *   - 永不修改 ~/.claude.json (用户核心配置)
 *   - 永不自动删除 MCP
 *   - --confirm 只打印操作指南，用户自行执行
 */

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

const HOME = process.env.USERPROFILE || process.env.HOME || os.homedir();
const CLAUDE_ROOT = process.env.CLAUDE_HOME ||
  (fs.existsSync(path.join(HOME, '.claude')) ? path.join(HOME, '.claude') : HOME);
const TRACKER_PATH = path.join(CLAUDE_ROOT, 'scripts', 'mcp-usage-tracker.js');
const ALLOWLIST_FILE = path.join(CLAUDE_ROOT, 'mcp-critical-allowlist.json');
const GLOBAL_CONFIG = path.join(HOME, '.claude.json');

function parseArgs(argv) {
  const args = { days: 30, plan: false, confirm: false };
  for (let i = 2; i < argv.length; i++) {
    const a = argv[i];
    if (a === '--days' && argv[i + 1]) { args.days = parseInt(argv[++i], 10) || 30; }
    else if (a === '--plan') { args.plan = true; }
    else if (a === '--confirm') { args.confirm = true; }
    else if (a === '-h' || a === '--help') { args.help = true; }
  }
  return args;
}

function safeReadJson(file, fallback) {
  try { return JSON.parse(fs.readFileSync(file, 'utf8')); }
  catch { return fallback; }
}

function runAnalysis(days) {
  const tracker = require(TRACKER_PATH);
  const allowlist = safeReadJson(ALLOWLIST_FILE, { critical: [] });
  const criticalSet = new Set((allowlist.critical || []).map(c => c.name));
  const cfg = safeReadJson(GLOBAL_CONFIG, { mcpServers: {} });
  const allServers = Object.keys(cfg.mcpServers || {});

  const events = tracker.collectMcpEvents(days);
  const stats = tracker.aggregate(events, allServers);
  const candidates = tracker.identifyPruneCandidates(stats, criticalSet);

  return { stats, candidates, criticalSet, allServers, cfg, days, events };
}

function report(result) {
  console.log('');
  console.log('═══════════════════════════════════════════════════════════');
  console.log('  /mcp-prune — 剪枝分析 · ' + result.days + '天窗口');
  console.log('═══════════════════════════════════════════════════════════');
  console.log('');
  console.log('总 MCP 数:           ' + result.allServers.length);
  console.log('★critical (永不剪枝): ' + result.criticalSet.size);
  console.log('活跃 MCP (>0 调用):   ' + Object.values(result.stats).filter(s => s.totalCalls > 0).length);
  console.log('剪枝候选 (0 调用):   ' + result.candidates.length);
  console.log('');

  if (result.candidates.length === 0) {
    console.log('✅ 没有剪枝候选。所有 MCP 都在最近 ' + result.days + ' 天被使用或在 critical 清单。');
    return;
  }

  console.log('剪枝候选清单:');
  console.log('─'.repeat(60));
  for (const c of result.candidates) {
    console.log('  - ' + c.server.padEnd(24) + '  ' + c.reason);
  }
  console.log('');

  const estTokens = result.candidates.length * 200;
  console.log('预估节省 (tokens/cold start): ≈ ' + estTokens + ' tokens');
  console.log('  (每 MCP schema 均值 200 tokens × ' + result.candidates.length + ')');
}

function writePlan(result, planFile) {
  const plan = {
    schema_version: 1,
    generated: new Date().toISOString(),
    tool: 'mcp-prune',
    windowDays: result.days,
    totalMcps: result.allServers.length,
    critical: Array.from(result.criticalSet),
    candidates: result.candidates.map(c => ({
      server: c.server,
      reason: c.reason,
      recommendedAction: 'REMOVE from ~/.claude.json mcpServers (manual)',
      backupHint: 'cp ~/.claude.json ~/.claude.json.bak-before-prune-' + new Date().toISOString().slice(0, 10)
    })),
    note: '此 plan 仅供参考，mcp-prune 绝不自动修改 .claude.json。用户需人工 apply。'
  };

  const tmp = planFile + '.tmp';
  fs.writeFileSync(tmp, JSON.stringify(plan, null, 2), 'utf8');
  fs.renameSync(tmp, planFile);
  console.log('');
  console.log('✅ Plan 写入: ' + planFile);
  return plan;
}

function printApplyInstructions(plan) {
  console.log('');
  console.log('═══════════════════════════════════════════════════════════');
  console.log('  用户 Apply 步骤 (请人工执行)');
  console.log('═══════════════════════════════════════════════════════════');
  console.log('');
  console.log('1. 备份原配置:');
  console.log('   Copy-Item ~/.claude.json ~/.claude.json.bak-$(Get-Date -Format yyyy-MM-dd)');
  console.log('');
  console.log('2. 用编辑器打开 ~/.claude.json，在 mcpServers 下删除以下键:');
  for (const c of plan.candidates) {
    console.log('     • ' + c.server);
  }
  console.log('');
  console.log('3. 重启 Claude Code 使改动生效');
  console.log('');
  console.log('4. 若需恢复某个 MCP, 从备份文件找回对应 JSON 片段即可');
  console.log('');
  console.log('⚠ 本工具不会自动修改 .claude.json — 这是故意设计的安全边界。');
}

function main() {
  const args = parseArgs(process.argv);
  if (args.help) {
    console.log('用法: node scripts/mcp-prune.js [--days N] [--plan] [--confirm]');
    console.log('  默认:     只报告');
    console.log('  --plan:   生成 mcp-prune-plan-<date>.json');
    console.log('  --confirm: 打印用户手动 apply 的完整步骤');
    process.exit(0);
  }

  if (!fs.existsSync(TRACKER_PATH)) {
    console.error('错误: mcp-usage-tracker.js 不存在，需先完成 Phase 1 T1.1');
    process.exit(2);
  }

  const result = runAnalysis(args.days);
  report(result);

  if (result.candidates.length === 0) {
    process.exit(0);
  }

  if (args.plan || args.confirm) {
    const planFile = path.join(CLAUDE_ROOT, 'mcp-prune-plan-' + new Date().toISOString().slice(0, 10) + '.json');
    const plan = writePlan(result, planFile);

    if (args.confirm) {
      printApplyInstructions(plan);
    }
  } else {
    console.log('');
    console.log('提示: 运行 \\'--plan\\' 生成 plan 文件, \\'--confirm\\' 查看完整 apply 步骤');
  }

  process.exit(0);
}

if (require.main === module) main();
`;

const SKILL_CONTENT = `---
name: mcp-prune
version: 1.0.0
description: |
  MCP 剪枝分析工具 (Phase 1 · T1.4)。基于 mcp-usage-tracker 的使用率数据，
  识别最近 N 天零调用且非 critical 的 MCP 候选，生成剪枝 plan 文件。
  绝不自动修改 ~/.claude.json，用户需人工 apply。
  触发词: "mcp-prune", "剪枝 MCP", "MCP 剪枝", "清理 MCP", "精简 MCP",
  "disable unused MCP", "prune MCP servers"。
maturity: stable
allowed-tools:
  - Bash
  - Read
---

# /mcp-prune — MCP 剪枝分析

基于 \`scripts/mcp-usage-tracker.js\` 产出的使用率数据，识别并报告低频 MCP
候选。**绝不自动修改** \`~/.claude.json\` — 用户必须人工 apply。

## 安全边界

| 能力 | 默认 | --plan | --confirm |
|------|------|--------|-----------|
| 只读分析 | ✅ | ✅ | ✅ |
| 生成 plan 文件 | — | ✅ | ✅ |
| 修改 .claude.json | ❌ | ❌ | ❌ (永远不自动改) |
| 打印 apply 指令 | — | — | ✅ |

## 执行

\`\`\`bash
# 报告模式 (默认 30 天窗口)
node ~/.claude/scripts/mcp-prune.js

# 7 天窗口 (更激进)
node ~/.claude/scripts/mcp-prune.js --days 7

# 写入 plan 文件
node ~/.claude/scripts/mcp-prune.js --plan

# 打印用户 apply 步骤
node ~/.claude/scripts/mcp-prune.js --confirm
\`\`\`

## 剪枝逻辑

- 候选条件: 窗口内 0 调用 **AND** 不在 \`~/.claude/mcp-critical-allowlist.json\` 中
- 豁免: critical 清单永远保留
- 数据源:
  - 使用率: \`~/.claude/debug/activity-*.jsonl\` (event=='mcp')
  - 白名单: \`~/.claude/mcp-critical-allowlist.json\`
  - 配置: \`~/.claude.json\` (只读)

## 输出

- 报告到 stdout
- --plan 时写入 \`~/.claude/mcp-prune-plan-<date>.json\`
- --confirm 追加 apply 指令 (PowerShell + 编辑 .claude.json 指引)

## 关联

- 依赖: \`scripts/mcp-usage-tracker.js\` (Phase 1 · T1.1)
- 依赖: \`mcp-critical-allowlist.json\` (Phase 1 · T1.5)
- 消费方: 用户手动 apply plan

## sentinel

${SENTINEL}
`;

function writeIfDifferent(target, content, label) {
  if (fs.existsSync(target)) {
    const current = fs.readFileSync(target, 'utf8');
    if (current === content) {
      console.log('[patch-phase1-T1.4] ' + label + ' 已一致，跳过');
      return 'skipped';
    }
    const bak = target + '.bak.phase1-t1.4';
    fs.copyFileSync(target, bak);
    console.log('[patch-phase1-T1.4] 已备份:', bak);
  }
  const tmp = target + '.tmp.js';
  fs.writeFileSync(tmp, content, 'utf8');
  if (target.endsWith('.js')) {
    try {
      const { execFileSync } = require('child_process');
      execFileSync(process.execPath, ['--check', tmp], { stdio: 'pipe' });
    } catch (e) {
      try { fs.unlinkSync(tmp); } catch {}
      console.error('[patch-phase1-T1.4] ' + label + ' 语法检查失败:',
        (e.stderr || e.message || '').toString().slice(0, 500));
      process.exit(3);
    }
  }
  fs.renameSync(tmp, target);
  console.log('[patch-phase1-T1.4] 已写入 ' + label + ':', target);
  return 'written';
}

function main() {
  // 确保 skill 目录存在
  if (!fs.existsSync(SKILL_DIR)) {
    fs.mkdirSync(SKILL_DIR, { recursive: true });
    console.log('[patch-phase1-T1.4] 已创建 skill 目录:', SKILL_DIR);
  }

  const r1 = writeIfDifferent(SCRIPT_TARGET, SCRIPT_CONTENT, 'script');
  const r2 = writeIfDifferent(SKILL_TARGET, SKILL_CONTENT, 'SKILL.md');

  console.log('');
  console.log('[patch-phase1-T1.4] sentinel:', SENTINEL);
  console.log('[patch-phase1-T1.4] script:', r1);
  console.log('[patch-phase1-T1.4] skill:', r2);
  console.log('[patch-phase1-T1.4] 完成。');
  console.log('');
  console.log('验证:');
  console.log('  node scripts/mcp-prune.js --days 30');
  process.exit(0);
}

main();