#!/usr/bin/env node
/**
 * Webhook 告警外发 (v5.3)
 *
 * 支持 Slack / Discord / 企业微信 / 自定义 URL。
 * 集成到 health-check 和 auto-cleanup 的告警管道。
 *
 * 用法:
 *   node webhook-notifier.js --test                      测试 webhook 连通性
 *   node webhook-notifier.js --alert "消息内容"          发送告警
 *   node webhook-notifier.js --level warning "消息"      指定级别 (info/warning/critical)
 *   node webhook-notifier.js --health-report             读取 health-check 并发送摘要
 *
 * 配置:
 *   环境变量 WEBHOOK_URL          主 webhook 地址
 *   环境变量 WEBHOOK_URL_BACKUP   备用 webhook 地址
 *   或 debug/webhook-config.json  本地配置文件
 *
 * 支持的 webhook 类型 (自动检测):
 *   - Slack Incoming Webhook
 *   - Discord Webhook
 *   - 企业微信机器人
 *   - 通用 JSON POST (自定义)
 */

const fs = require('fs');
const path = require('path');
const https = require('https');
const http = require('http');
const { URL } = require('url');

// ─── 路径 ───────────────────────────────────────────
let PATHS;
try {
  PATHS = require('./paths.config.js').PATHS;
} catch {
  const ROOT = __dirname.replace(/[/\\]scripts$/, '');
  PATHS = {
    root: ROOT,
    debugDir: path.join(ROOT, 'debug'),
  };
}

const CONFIG_FILE = path.join(PATHS.debugDir, 'webhook-config.json');
const LOG_FILE = path.join(PATHS.debugDir, 'webhook-log.jsonl');

// ─── 配置加载 ───────────────────────────────────────
function loadConfig() {
  const config = {
    urls: [],
    enabled: true,
    minLevel: 'warning', // 最低告警级别: info < warning < critical
    rateLimitMs: 60000,  // 同一消息最小间隔 (1分钟)
  };

  // 环境变量优先
  if (process.env.WEBHOOK_URL) {
    config.urls.push(process.env.WEBHOOK_URL);
  }
  if (process.env.WEBHOOK_URL_BACKUP) {
    config.urls.push(process.env.WEBHOOK_URL_BACKUP);
  }

  // 本地配置文件补充
  if (fs.existsSync(CONFIG_FILE)) {
    try {
      const local = JSON.parse(fs.readFileSync(CONFIG_FILE, 'utf8'));
      if (local.urls) config.urls.push(...local.urls);
      if (local.enabled !== undefined) config.enabled = local.enabled;
      if (local.minLevel) config.minLevel = local.minLevel;
      if (local.rateLimitMs) config.rateLimitMs = local.rateLimitMs;
    } catch {}
  }

  // 去重
  config.urls = [...new Set(config.urls)];
  return config;
}

// ─── Webhook 类型检测 ───────────────────────────────
function detectWebhookType(url) {
  if (url.includes('hooks.slack.com')) return 'slack';
  if (url.includes('discord.com/api/webhooks') || url.includes('discordapp.com/api/webhooks')) return 'discord';
  if (url.includes('qyapi.weixin.qq.com')) return 'wechat';
  return 'generic';
}

// ─── Payload 格式化 ─────────────────────────────────
const LEVEL_EMOJI = { info: 'ℹ️', warning: '⚠️', critical: '🚨' };
const LEVEL_COLOR = { info: '#36a64f', warning: '#ffa500', critical: '#ff0000' };
const LEVEL_PRIORITY = { info: 0, warning: 1, critical: 2 };

function formatPayload(type, message, level = 'warning', title = 'Bookworm Alert') {
  const emoji = LEVEL_EMOJI[level] || '📢';
  const color = LEVEL_COLOR[level] || '#888';
  const ts = new Date().toISOString().slice(0, 19).replace('T', ' ');
  const text = `${emoji} **${title}** [${level.toUpperCase()}]\n${message}\n_${ts}_`;

  switch (type) {
    case 'slack':
      return {
        attachments: [{
          color,
          title: `${emoji} ${title}`,
          text: message,
          footer: `Bookworm v5.3 | ${ts}`,
          mrkdwn_in: ['text'],
        }],
      };

    case 'discord':
      return {
        embeds: [{
          title: `${emoji} ${title}`,
          description: message,
          color: parseInt(color.replace('#', ''), 16),
          footer: { text: `Bookworm v5.3 | ${ts}` },
        }],
      };

    case 'wechat':
      return {
        msgtype: 'markdown',
        markdown: {
          content: `### ${emoji} ${title}\n> 级别: **${level.toUpperCase()}**\n\n${message}\n\n<font color="comment">${ts}</font>`,
        },
      };

    default: // generic
      return {
        source: 'bookworm-smart-assistant',
        version: 'v5.3',
        level,
        title,
        message,
        timestamp: new Date().toISOString(),
      };
  }
}

// ─── HTTP POST ──────────────────────────────────────
function httpPost(url, payload) {
  return new Promise((resolve, reject) => {
    const parsed = new URL(url);
    const data = JSON.stringify(payload);
    const mod = parsed.protocol === 'https:' ? https : http;

    const req = mod.request({
      hostname: parsed.hostname,
      port: parsed.port,
      path: parsed.pathname + parsed.search,
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Content-Length': Buffer.byteLength(data),
        'User-Agent': 'Bookworm-Webhook/5.3',
      },
      timeout: 10000,
    }, (res) => {
      let body = '';
      res.on('data', (c) => body += c);
      res.on('end', () => {
        if (res.statusCode >= 200 && res.statusCode < 300) {
          resolve({ ok: true, status: res.statusCode, body });
        } else {
          resolve({ ok: false, status: res.statusCode, body });
        }
      });
    });

    req.on('error', (e) => reject(e));
    req.on('timeout', () => { req.destroy(); reject(new Error('timeout')); });
    req.write(data);
    req.end();
  });
}

// ─── 速率限制 ────────────────────────────────────────
function checkRateLimit(message, rateLimitMs) {
  if (!fs.existsSync(LOG_FILE)) return true;
  try {
    const lines = fs.readFileSync(LOG_FILE, 'utf8').trim().split('\n').slice(-20);
    const now = Date.now();
    for (const line of lines.reverse()) {
      const entry = JSON.parse(line);
      if (entry.message === message && (now - new Date(entry.ts).getTime()) < rateLimitMs) {
        return false; // 重复消息，限流
      }
    }
  } catch {}
  return true;
}

function logSend(message, level, results) {
  try {
    if (!fs.existsSync(PATHS.debugDir)) fs.mkdirSync(PATHS.debugDir, { recursive: true });
    const entry = {
      ts: new Date().toISOString(),
      level,
      message: message.slice(0, 200),
      results: results.map(r => ({ url: r.url.replace(/\/[^/]{20,}/, '/***'), ok: r.ok, status: r.status })),
    };
    fs.appendFileSync(LOG_FILE, JSON.stringify(entry) + '\n');
  } catch {}
}

// ─── 核心发送函数 ────────────────────────────────────
/**
 * 发送告警到所有已配置的 webhook
 * @param {string} message - 告警消息
 * @param {object} [options] - 选项
 * @param {string} [options.level='warning'] - 告警级别
 * @param {string} [options.title='Bookworm Alert'] - 标题
 * @param {boolean} [options.force=false] - 跳过级别过滤和速率限制
 * @returns {Promise<{sent: number, failed: number, skipped: string|null}>}
 */
async function sendAlert(message, options = {}) {
  const { level = 'warning', title = 'Bookworm Alert', force = false } = options;
  const config = loadConfig();

  // 未配置
  if (config.urls.length === 0) {
    return { sent: 0, failed: 0, skipped: 'no webhook URLs configured' };
  }

  // 禁用
  if (!config.enabled && !force) {
    return { sent: 0, failed: 0, skipped: 'webhooks disabled' };
  }

  // 级别过滤
  if (!force && LEVEL_PRIORITY[level] < LEVEL_PRIORITY[config.minLevel]) {
    return { sent: 0, failed: 0, skipped: `level ${level} below minLevel ${config.minLevel}` };
  }

  // 速率限制
  if (!force && !checkRateLimit(message, config.rateLimitMs)) {
    return { sent: 0, failed: 0, skipped: 'rate limited (duplicate message)' };
  }

  let sent = 0, failed = 0;
  const results = [];

  for (const url of config.urls) {
    const type = detectWebhookType(url);
    const payload = formatPayload(type, message, level, title);
    try {
      const result = await httpPost(url, payload);
      results.push({ url, ...result });
      if (result.ok) sent++;
      else failed++;
    } catch (e) {
      results.push({ url, ok: false, status: 0, body: e.message });
      failed++;
    }
  }

  logSend(message, level, results);
  return { sent, failed, skipped: null, results };
}

/**
 * 从 health-check JSON 输出生成告警消息
 * @returns {Promise<{sent: number, message: string}>}
 */
async function sendHealthReport() {
  const { execSync } = require('child_process');
  try {
    const output = execSync(
      `node "${path.join(PATHS.root, 'scripts', 'health-check.js')}" --json`,
      { encoding: 'utf8', timeout: 30000, cwd: PATHS.root }
    );
    const report = JSON.parse(output);

    // 仅在非 HEALTHY 时发送
    if (report.overallStatus === 'HEALTHY' && report.overallScore >= 90) {
      return { sent: 0, message: 'System healthy, no alert needed' };
    }

    const failDims = (report.dimensions || [])
      .filter(d => d.status === 'FAIL' || d.status === 'WARN')
      .map(d => `${d.id} ${d.name}: ${d.score}/100 (${d.detail})`)
      .join('\n');

    const message = `健康评分: ${report.overallScore}/100 (${report.overallStatus})\n\n问题维度:\n${failDims || '无'}`;
    const level = report.overallScore < 60 ? 'critical' : 'warning';

    const result = await sendAlert(message, {
      level,
      title: 'Bookworm 健康检查告警',
    });
    return { ...result, message };
  } catch (e) {
    return { sent: 0, message: `健康检查执行失败: ${e.message}` };
  }
}

// ─── CLI ─────────────────────────────────────────────
async function main() {
  const args = process.argv.slice(2);

  if (args.includes('--test')) {
    console.log('=== Webhook 连通性测试 ===');
    const config = loadConfig();
    if (config.urls.length === 0) {
      console.log('未配置 webhook URL。');
      console.log('设置方式:');
      console.log('  1. 环境变量: export WEBHOOK_URL="https://hooks.slack.com/..."');
      console.log(`  2. 配置文件: ${CONFIG_FILE}`);
      console.log('     {"urls": ["https://hooks.slack.com/..."], "enabled": true}');
      return;
    }
    console.log(`已配置 ${config.urls.length} 个 webhook:`);
    for (const url of config.urls) {
      const type = detectWebhookType(url);
      const masked = url.replace(/\/[^/]{20,}/, '/***');
      console.log(`  [${type}] ${masked}`);
    }
    const result = await sendAlert('Bookworm webhook 测试消息 - 请忽略', {
      level: 'info',
      title: 'Webhook 连通性测试',
      force: true,
    });
    console.log(`\n结果: ${result.sent} 成功, ${result.failed} 失败`);
    if (result.results) {
      for (const r of result.results) {
        console.log(`  ${r.ok ? '✓' : '✗'} ${r.url.replace(/\/[^/]{20,}/, '/***')} (HTTP ${r.status})`);
      }
    }
    return;
  }

  if (args.includes('--health-report')) {
    const result = await sendHealthReport();
    console.log(result.message);
    if (result.sent > 0) console.log(`已发送 ${result.sent} 条告警`);
    return;
  }

  if (args.includes('--alert')) {
    const alertIdx = args.indexOf('--alert');
    const levelIdx = args.indexOf('--level');
    const level = levelIdx >= 0 ? args[levelIdx + 1] : 'warning';
    const message = args.filter((a, i) =>
      !a.startsWith('--') &&
      !(levelIdx >= 0 && i === levelIdx + 1)
    ).join(' ') || args[alertIdx + 1];

    if (!message) {
      console.error('Usage: --alert "消息内容" [--level warning]');
      process.exit(1);
    }

    const result = await sendAlert(message, { level });
    if (result.skipped) {
      console.log(`跳过: ${result.skipped}`);
    } else {
      console.log(`已发送: ${result.sent} 成功, ${result.failed} 失败`);
    }
    return;
  }

  // 默认: 显示帮助
  console.log('Bookworm Webhook Notifier v5.3');
  console.log('');
  console.log('用法:');
  console.log('  --test                      测试 webhook 连通性');
  console.log('  --alert "消息"              发送告警');
  console.log('  --level info|warning|critical  指定级别 (默认 warning)');
  console.log('  --health-report             发送健康检查报告');
  console.log('');
  console.log('配置:');
  console.log('  WEBHOOK_URL=...             环境变量');
  console.log(`  ${CONFIG_FILE}  本地配置`);
}

// ─── 导出 ─────────────────────────────────────────────
if (typeof module !== 'undefined') {
  module.exports = {
    loadConfig,
    detectWebhookType,
    formatPayload,
    sendAlert,
    sendHealthReport,
    checkRateLimit,
    httpPost,
    LEVEL_PRIORITY,
  };
}

if (require.main === module) {
  main().catch(e => {
    console.error(e.message);
    process.exit(1);
  });
}