/**
 * System Info
 *
 * Gathers system information including CPU, RAM, OS, and Docker status.
 */

import { exec } from 'node:child_process';
import { promisify } from 'node:util';
import * as os from 'node:os';
import type { ISystemInfo } from '../interfaces/gpu.ts';
import { GpuDetector } from './gpu-detector.ts';
import { logger } from '../logger.ts';

const execAsync = promisify(exec);

/**
 * System Info class for gathering system information
 */
export class SystemInfo {
  private gpuDetector: GpuDetector;

  constructor() {
    this.gpuDetector = new GpuDetector();
  }

  /**
   * Get complete system information
   */
  public async getSystemInfo(): Promise<ISystemInfo> {
    const [gpus, dockerVersion, nvidiaContainerVersion, kernelVersion] = await Promise.all([
      this.gpuDetector.detectGpus(),
      this.getDockerVersion(),
      this.getNvidiaContainerVersion(),
      this.getKernelVersion(),
    ]);

    return {
      hostname: os.hostname(),
      cpuModel: this.getCpuModel(),
      cpuCores: os.cpus().length,
      ramTotal: Math.round(os.totalmem() / (1024 * 1024)),
      ramAvailable: Math.round(os.freemem() / (1024 * 1024)),
      os: this.getOsInfo(),
      kernelVersion,
      gpus,
      dockerVersion,
      nvidiaContainerVersion,
    };
  }

  /**
   * Get CPU model name
   */
  private getCpuModel(): string {
    const cpus = os.cpus();
    if (cpus.length > 0) {
      return cpus[0].model;
    }
    return 'Unknown CPU';
  }

  /**
   * Get OS information string
   */
  private getOsInfo(): string {
    const platform = os.platform();
    const release = os.release();

    if (platform === 'linux') {
      return `Linux ${release}`;
    } else if (platform === 'darwin') {
      return `macOS ${release}`;
    }

    return `${platform} ${release}`;
  }

  /**
   * Get kernel version
   */
  private async getKernelVersion(): Promise<string> {
    try {
      const { stdout } = await execAsync('uname -r', { timeout: 5000 });
      return stdout.trim();
    } catch {
      return os.release();
    }
  }

  /**
   * Get Docker version
   */
  private async getDockerVersion(): Promise<string | undefined> {
    try {
      const { stdout } = await execAsync('docker --version', { timeout: 5000 });
      const match = stdout.match(/Docker version (\d+\.\d+\.\d+)/);
      return match ? match[1] : stdout.trim();
    } catch {
      return undefined;
    }
  }

  /**
   * Get NVIDIA Container Toolkit version
   */
  private async getNvidiaContainerVersion(): Promise<string | undefined> {
    try {
      const { stdout } = await execAsync('nvidia-container-cli --version 2>&1 | head -1', { timeout: 5000 });
      const match = stdout.match(/version (\d+\.\d+\.\d+)/);
      return match ? match[1] : undefined;
    } catch {
      return undefined;
    }
  }

  /**
   * Check if Docker is running
   */
  public async isDockerRunning(): Promise<boolean> {
    try {
      await execAsync('docker info', { timeout: 5000 });
      return true;
    } catch {
      return false;
    }
  }

  /**
   * Check if NVIDIA Docker runtime is available
   */
  public async isNvidiaRuntimeAvailable(): Promise<boolean> {
    try {
      const { stdout } = await execAsync('docker info --format "{{.Runtimes}}"', { timeout: 5000 });
      return stdout.includes('nvidia');
    } catch {
      return false;
    }
  }

  /**
   * Check if Podman is available
   */
  public async isPodmanAvailable(): Promise<boolean> {
    try {
      await execAsync('podman --version', { timeout: 5000 });
      return true;
    } catch {
      return false;
    }
  }

  /**
   * Get available disk space in the data directory
   * @param path Directory to check
   * @returns Available space in MB
   */
  public async getAvailableDiskSpace(path: string = '/var/lib'): Promise<number> {
    try {
      const { stdout } = await execAsync(`df -m "${path}" | tail -1 | awk '{print $4}'`, { timeout: 5000 });
      return parseInt(stdout.trim(), 10) || 0;
    } catch {
      return 0;
    }
  }

  /**
   * Get system memory usage
   */
  public getMemoryUsage(): { total: number; used: number; available: number; percent: number } {
    const total = Math.round(os.totalmem() / (1024 * 1024));
    const available = Math.round(os.freemem() / (1024 * 1024));
    const used = total - available;
    const percent = Math.round((used / total) * 100);

    return { total, used, available, percent };
  }

  /**
   * Get system load average
   */
  public getLoadAverage(): { load1: number; load5: number; load15: number } {
    const [load1, load5, load15] = os.loadavg();
    return {
      load1: Math.round(load1 * 100) / 100,
      load5: Math.round(load5 * 100) / 100,
      load15: Math.round(load15 * 100) / 100,
    };
  }

  /**
   * Print system info summary to logger
   */
  public async printSystemInfo(): Promise<void> {
    const info = await this.getSystemInfo();

    logger.logBoxTitle('System Information', 70, 'info');
    logger.logBoxLine(`Hostname: ${info.hostname}`);
    logger.logBoxLine(`OS: ${info.os}`);
    logger.logBoxLine(`Kernel: ${info.kernelVersion}`);
    logger.logBoxLine(`CPU: ${info.cpuModel} (${info.cpuCores} cores)`);
    logger.logBoxLine(`RAM: ${Math.round(info.ramTotal / 1024)} GB total, ${Math.round(info.ramAvailable / 1024)} GB available`);
    logger.logBoxLine('');

    if (info.dockerVersion) {
      logger.logBoxLine(`Docker: v${info.dockerVersion}`);
    } else {
      logger.logBoxLine('Docker: Not installed');
    }

    if (info.nvidiaContainerVersion) {
      logger.logBoxLine(`NVIDIA Container Toolkit: v${info.nvidiaContainerVersion}`);
    }

    logger.logBoxLine('');
    logger.logBoxLine(`GPUs Detected: ${info.gpus.length}`);

    for (const gpu of info.gpus) {
      const vramGb = Math.round(gpu.vram / 1024 * 10) / 10;
      logger.logBoxLine(`  ${gpu.id}: ${gpu.model} (${vramGb} GB)`);
      if (gpu.driverVersion) {
        logger.logBoxLine(`    Driver: ${gpu.driverVersion}`);
      }
      if (gpu.cudaVersion) {
        logger.logBoxLine(`    CUDA: ${gpu.cudaVersion}`);
      }
      if (gpu.rocmVersion) {
        logger.logBoxLine(`    ROCm: ${gpu.rocmVersion}`);
      }
    }

    logger.logBoxEnd();
  }
}