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

const execAsync = promisify(exec);

export interface DiskInfo { mount: string; total: string; used: string; free: string; percent: number }
export interface ProcessInfo { pid: number; cpu: string; mem: string; name: string; command: string }
export interface ServerInfo {
  name: string; role: string; hostname: string;
  cpu: { model: string; cores: number; usagePercent: number };
  memory: { total: string; used: string; free: string; percent: number };
  disks: DiskInfo[];
  uptime: string;
  processes: ProcessInfo[];
  network: { publicIp: string; privateIp: string; domains: string[] };
}

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

// Map raw process commands to friendly names
const PROCESS_ALIASES: Record<string, string> = {
  'mysqld': 'MySQL 8.0',
  'redis-server': 'Redis 7',
  'qdrant': 'Qdrant',
  'nginx': 'Nginx',
  'gitea': 'Gitea',
  'node dist/src/main.js': 'NestJS API',
  'node dist/main.js': 'NestJS API',
  'act_runner': 'Gitea Runner',
  'zhixi-worker': 'RAG Worker',
  'python3': 'Python Worker',
  'docker': 'Docker Daemon',
  'containerd': 'containerd',
  'hermes': 'Hermes Agent',
  'certbot': 'Certbot',
};

function friendlyName(cmd: string): string {
  for (const [pattern, name] of Object.entries(PROCESS_ALIASES)) {
    if (cmd.includes(pattern)) return name;
  }
  // Trim common paths
  return cmd.replace(/^\/usr\/bin\//, '').replace(/^\/opt\/.*?\//, '').replace(/^\/usr\/lib\//, '').slice(0, 30);
}

async function getDisks(mounts: string[]): Promise<DiskInfo[]> {
  const results: DiskInfo[] = [];
  for (const m of mounts) {
    try {
      const { stdout } = await execAsync(`df -h ${m} | tail -1 | awk '{print $2,$3,$4,$5}'`);
      const parts = stdout.trim().split(/\s+/);
      results.push({ mount: m, total: parts[0] || '-', used: parts[1] || '-', free: parts[2] || '-', percent: parseInt(parts[3]) || 0 });
    } catch { results.push({ mount: m, total: '-', used: '-', free: '-', percent: 0 }) }
  }
  return results;
}

async function getProcesses(): Promise<ProcessInfo[]> {
  try {
    const { stdout } = await execAsync("ps aux --sort=-%mem --no-headers | head -10 | awk '{print $2,$3,$4,$11}'");
    return stdout.trim().split('\n').filter(Boolean).map(line => {
      const [pid, cpu, mem, ...cmd] = line.trim().split(/\s+/);
      const command = (cmd || []).join(' ');
      return { pid: parseInt(pid), cpu: cpu + '%', mem: mem + '%', name: friendlyName(command), command };
    });
  } catch { return [] }
}

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

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

    const [disks, processes] = await Promise.all([
      getDisks(['/', '/data']),
      getProcesses(),
    ]);

    const nets = os.networkInterfaces();
    const privateIp = Object.values(nets).flat().find(n => n?.family === 'IPv4' && !n.internal)?.address || '172.21.0.4';
    const d = Math.floor(os.uptime() / 86400);
    const h = Math.floor((os.uptime() % 86400) / 3600);
    const m = Math.floor((os.uptime() % 3600) / 60);

    return {
      name: '蜂驰云 8核32G', role: '生产核心', 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) },
      disks, uptime: `${d}d ${h}h ${m}m`, processes,
      network: { publicIp: '120.53.227.155', privateIp, domains: ['api.longde.cloud', 'admin.longde.cloud'] },
    };
  }

  async getRemoteMetrics(): Promise<ServerInfo | null> {
    try {
      const base = `ssh -o StrictHostKeyChecking=no -o ConnectTimeout=5 -i ${SSH_KEY_PATH} ubuntu@${REMOTE_HOST}`;

      const execSSH = (cmd: string) => execAsync(`${base} "${cmd.replace(/"/g, '\\"')}"`, { timeout: 5000 }).then(r => r.stdout.trim()).catch(() => '');

      const [hostname, privateIp, load, cores, memRaw, diskRoot, diskData, uptimeStr] = await Promise.all([
        execSSH('hostname'),
        execSSH("hostname -I | awk '{print $1}'"),
        execSSH("cat /proc/loadavg | awk '{print $1}'"),
        execSSH('cat /proc/cpuinfo | grep processor | wc -l'),
        execSSH("free -m | grep Mem | awk '{print $2,$3,$4}'"),
        execSSH("df -h / | tail -1 | awk '{print $2,$3,$4,$5}'"),
        execSSH("df -h /data 2>/dev/null | tail -1 | awk '{print $2,$3,$4,$5}'"),
        execSSH("uptime -p | sed 's/up //'"),
      ]);

      // Get remote process list
      let processes: ProcessInfo[] = [];
      try {
        const procRaw = await execAsync(`${base} "ps aux --sort=-%mem --no-headers | head -10 | awk '{print \\$2,\\$3,\\$4,\\$11}'"`, { timeout: 5000 });
        processes = procRaw.stdout.trim().split('\n').filter(Boolean).map(line => {
          const [pid, cpu, mem, ...cmd] = line.trim().split(/\s+/);
          const command = (cmd || []).join(' ');
          return { pid: parseInt(pid), cpu: cpu + '%', mem: mem + '%', name: friendlyName(command), command };
        });
      } catch {}

      const load1 = parseFloat(load) || 0;
      const cpuCores = parseInt(cores) || 4;
      const cpuUsage = Math.min(100, Math.round((load1 / cpuCores) * 100));

      const memParts = memRaw.split(/\s+/);
      const memPer = memParts[0] && memParts[1] ? Math.round((parseInt(memParts[1]) / parseInt(memParts[0])) * 100) : 0;

      const rootParts = diskRoot.split(/\s+/);
      const dataParts = diskData.split(/\s+/);
      const disks: DiskInfo[] = [
        { mount: '/', total: rootParts[0] || '-', used: rootParts[1] || '-', free: rootParts[2] || '-', percent: parseInt(rootParts[3]) || 0 },
      ];
      if (dataParts.length >= 3) {
        disks.push({ mount: '/data', total: dataParts[0], used: dataParts[1], free: dataParts[2], percent: parseInt(dataParts[3]) || 0 });
      }

      return {
        name: '轻量云 4核4G', role: '工具/辅助', hostname: hostname || 'remote',
        cpu: { model: 'Intel Xeon (Lighthouse)', cores: cpuCores, usagePercent: cpuUsage },
        memory: { total: memParts[0] ? (parseInt(memParts[0]) / 1024).toFixed(1) + 'G' : '-', used: memParts[1] ? (parseInt(memParts[1]) / 1024).toFixed(1) + 'G' : '-', free: memParts[2] ? (parseInt(memParts[2]) / 1024).toFixed(1) + 'G' : '-', percent: memPer },
        disks, uptime: uptimeStr || '-', processes,
        network: { publicIp: '81.70.187.179', privateIp: privateIp || '10.2.0.7', domains: ['longde.cloud', 'git.longde.cloud'] },
      };
    } 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 = [local];
    if (remote) servers.push(remote);
    return { servers };
  }
}