import { Injectable, Logger } from '@nestjs/common';
import * as os from 'os';
import { exec } from 'child_process';
import { promisify } from 'util';

const execAsync = promisify(exec);

interface ServerMetrics {
  hostname: string;
  cpu: { model: string; cores: number; usagePercent: number };
  memory: { total: string; used: string; free: string; percent: number };
  disk: { total: string; used: string; free: string; percent: number };
  uptime: string;
  processes: { pid: number; cpu: string; mem: string; command: string }[];
  network: { ip: string };
}

const SSH_KEY_PATH = process.env.SSH_KEY_PATH || '/home/ubuntu/.ssh/wangdl.pem';
const REMOTE_HOST = '10.2.0.7';

@Injectable()
export class AdminServersService {
  private readonly logger = new Logger(AdminServersService.name);

  async getLocalMetrics(): Promise<ServerMetrics> {
    const cpus = os.cpus();
    const totalMem = os.totalmem();
    const freeMem = os.freemem();
    const usedMem = totalMem - freeMem;
    const loadAvg = os.loadavg();
    const cpuUsage = Math.min(100, Math.round((loadAvg[0] / cpus.length) * 100));

    let disk = { total: '-', used: '-', free: '-', percent: 0 };
    try {
      const { stdout } = await execAsync("df -h / | tail -1 | awk '{print $2,$3,$4,$5}'");
      const parts = stdout.trim().split(/\s+/);
      disk = { total: parts[0] || '-', used: parts[1] || '-', free: parts[2] || '-', percent: parseInt(parts[3]) || 0 };
    } catch {}

    let processes: ServerMetrics['processes'] = [];
    try {
      const { stdout } = await execAsync("ps aux --sort=-%mem --no-headers | head -8 | awk '{print $2,$3,$4,$11}'");
      processes = stdout.trim().split('\n').filter(Boolean).map(line => {
        const [pid, cpu, mem, ...cmd] = line.trim().split(/\s+/);
        return { pid: parseInt(pid), cpu: cpu + '%', mem: mem + '%', command: (cmd || []).join(' ').slice(0, 50) };
      });
    } catch {}

    const nets = os.networkInterfaces();
    const ip = Object.values(nets).flat().find(n => n?.family === 'IPv4' && !n.internal)?.address || 'unknown';
    const d = Math.floor(os.uptime() / 86400);
    const h = Math.floor((os.uptime() % 86400) / 3600);
    const m = Math.floor((os.uptime() % 3600) / 60);

    return {
      hostname: os.hostname(),
      cpu: { model: cpus[0]?.model || '', cores: cpus.length, usagePercent: cpuUsage },
      memory: { total: (totalMem / 1e9).toFixed(1) + 'G', used: (usedMem / 1e9).toFixed(1) + 'G', free: (freeMem / 1e9).toFixed(1) + 'G', percent: Math.round((usedMem / totalMem) * 100) },
      disk, uptime: `${d}d ${h}h ${m}m`, processes,
      network: { ip },
    };
  }

  async getRemoteMetrics(): Promise<ServerMetrics | null> {
    try {
      const base = `ssh -o StrictHostKeyChecking=no -o ConnectTimeout=5 -i ${SSH_KEY_PATH} ubuntu@${REMOTE_HOST}`;
      const cmds = [
        `${base} hostname`,
        `${base} "hostname -I | awk '{print \\$1}'"`,
        `${base} "cat /proc/loadavg | awk '{print \\$1}'"`,
        `${base} "cat /proc/cpuinfo | grep processor | wc -l"`,
        `${base} "free -m | grep Mem | awk '{print \\$2,\\$3,\\$4}'"`,
        `${base} "df -h / | tail -1 | awk '{print \\$2,\\$3,\\$4,\\$5}'"`,
        `${base} "uptime -p | sed 's/up //'"`,
        `${base} "ps aux --sort=-%mem --no-headers | head -6 | awk '{print \\$2,\\$3,\\$4,\\$11}'"`,
      ];

      const results = await Promise.all(cmds.map(c => execAsync(c, { timeout: 5000 }).then(r => r.stdout.trim()).catch(() => '')));

      const hostname = results[0] || 'remote';
      const ip = results[1] || '10.2.0.7';
      const load1 = parseFloat(results[2]) || 0;
      const cores = parseInt(results[3]) || 4;
      const cpuUsage = Math.min(100, Math.round((load1 / cores) * 100));

      const memParts = results[4].split(/\s+/);
      const memTotal = memParts[0] ? (parseInt(memParts[0]) / 1024).toFixed(1) + 'G' : '-';
      const memUsed = memParts[1] ? (parseInt(memParts[1]) / 1024).toFixed(1) + 'G' : '-';
      const memFree = memParts[2] ? (parseInt(memParts[2]) / 1024).toFixed(1) + 'G' : '-';
      const memPercent = memParts[0] && memParts[1] ? Math.round((parseInt(memParts[1]) / parseInt(memParts[0])) * 100) : 0;

      const diskParts = results[5].split(/\s+/);
      const diskPercent = parseInt(diskParts[3]) || 0;

      const processes = results[7].split('\n').filter(Boolean).map(line => {
        const [pid, cpu, mem, ...cmd] = line.trim().split(/\s+/);
        return { pid: parseInt(pid), cpu: cpu + '%', mem: mem + '%', command: (cmd || []).join(' ').slice(0, 50) };
      });

      return {
        hostname, cpu: { model: 'Intel Xeon (Lighthouse)', cores, usagePercent: cpuUsage },
        memory: { total: memTotal, used: memUsed, free: memFree, percent: memPercent },
        disk: { total: diskParts[0] || '-', used: diskParts[1] || '-', free: diskParts[2] || '-', percent: diskPercent },
        uptime: results[6] || '-', processes,
        network: { ip },
      };
    } catch (err: any) {
      this.logger.warn('Remote metrics failed: ' + err.message);
      return null;
    }
  }

  async getAllMetrics() {
    const [local, remote] = await Promise.all([this.getLocalMetrics(), this.getRemoteMetrics()]);
    const servers = [
      { name: '蜂驰云 8核32G', role: '生产核心', ...local },
    ];
    if (remote) servers.push({ name: '轻量云 4核4G', role: '工具/辅助', ...remote });
    return { servers };
  }
}