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

async function fetchWithRetry(url, options = {}, retries = 3, backoff = 2000) {
  for (let i = 0; i < retries; i++) {
    try {
      const response = await fetch(url, options);
      if (response.ok) return response;
      if (response.status >= 500) {
        throw new Error(`HTTP ${response.status}: ${response.statusText}`);
      }
      return response;
    } catch (err) {
      if (i === retries - 1) throw err;
      console.warn(`Fetch to ${url} failed (attempt ${i + 1}/${retries}): ${err.message}. Retrying in ${backoff}ms...`);
      await new Promise(resolve => setTimeout(resolve, backoff));
    }
  }
}

async function checkStatus() {
  try {
    // 1. Fetch status page HTML
    const htmlResponse = await fetchWithRetry('https://uptime.ginnoir.com/status/default');
    if (!htmlResponse.ok) {
      throw new Error(`Failed to fetch status page: ${htmlResponse.statusText}`);
    }
    const html = await htmlResponse.text();

    // Extract window.preloadData = ...;
    const preloadRegex = /window\.preloadData\s*=\s*({.*?});/s;
    const match = html.match(preloadRegex);
    if (!match) {
      throw new Error("Could not find window.preloadData in HTML");
    }

    let preloadData;
    try {
      preloadData = new Function(`return ${match[1]};`)();
    } catch (e) {
      throw new Error(`Failed to parse preloadData: ${e.message}`);
    }

    const monitors = [];
    if (preloadData && preloadData.publicGroupList) {
      for (const group of preloadData.publicGroupList) {
        if (group.monitorList) {
          monitors.push(...group.monitorList);
        }
      }
    }

    // 2. Fetch heartbeat JSON
    const heartbeatResponse = await fetchWithRetry('https://uptime.ginnoir.com/api/status-page/heartbeat/default');
    if (!heartbeatResponse.ok) {
      throw new Error(`Failed to fetch heartbeat: ${heartbeatResponse.statusText}`);
    }
    const heartbeats = await heartbeatResponse.json();

    // 3. Map status and print summary
    const monitorMap = {};
    for (const monitor of monitors) {
      monitorMap[monitor.id] = {
        name: monitor.name,
        type: monitor.type,
        status: 'UNKNOWN',
        ping: null,
        lastCheck: null,
        msg: ''
      };
    }

    const heartbeatList = heartbeats.heartbeatList || {};
    for (const id in heartbeatList) {
      const list = heartbeatList[id];
      if (list && list.length > 0) {
        const latest = list[list.length - 1];
        if (monitorMap[id]) {
          monitorMap[id].status = latest.status === 1 ? 'UP' : 'DOWN';
          monitorMap[id].ping = latest.ping;
          monitorMap[id].lastCheck = latest.time;
          monitorMap[id].msg = latest.msg || '';
        }
      }
    }

    // Generate summary
    const monitorValues = Object.values(monitorMap);
    const total = monitorValues.length;
    const up = monitorValues.filter(m => m.status === 'UP').length;
    const down = monitorValues.filter(m => m.status === 'DOWN').length;
    const unknown = monitorValues.filter(m => m.status === 'UNKNOWN').length;

    let summaryMd = `### Uptime Status Summary (Checked at ${new Date().toLocaleString()})\n\n`;
    
    if (down > 0) {
      summaryMd += `⚠️ **Status: Degraded (${down}/${total} services DOWN)**\n\n`;
    } else if (up === total) {
      summaryMd += `✅ **Status: Healthy (All ${total} services UP)**\n\n`;
    } else {
      summaryMd += `ℹ️ **Status: Mixed (UP: ${up}, DOWN: ${down}, UNKNOWN: ${unknown})**\n\n`;
    }

    if (down > 0) {
      summaryMd += `#### 🚨 DOWN Services:\n`;
      monitorValues.filter(m => m.status === 'DOWN').forEach(m => {
        summaryMd += `- **${m.name}** (${m.type}) - ${m.msg || 'No message'} (Last checked: ${m.lastCheck})\n`;
      });
      summaryMd += `\n`;
    }

    summaryMd += `#### 📋 Service Statuses:\n`;
    summaryMd += `| Service | Status | Latency (ms) | Last Check |\n`;
    summaryMd += `| :--- | :---: | :---: | :--- |\n`;
    
    // Sort services by name
    monitorValues.sort((a, b) => a.name.localeCompare(b.name));
    
    for (const m of monitorValues) {
      const statusIcon = m.status === 'UP' ? '🟢 UP' : m.status === 'DOWN' ? '🔴 DOWN' : '⚪ UNKNOWN';
      const pingText = m.ping !== null ? `${m.ping} ms` : 'N/A';
      summaryMd += `| ${m.name} | ${statusIcon} | ${pingText} | ${m.lastCheck || 'N/A'} |\n`;
    }

    console.log(summaryMd);
  } catch (error) {
    console.error(`Error checking status: ${error.message}`);
    process.exit(1);
  }
}

checkStatus();