/**
 * Docker Manager
 *
 * Handles Docker installation, configuration, and management.
 */

import { exec } from 'node:child_process';
import { promisify } from 'node:util';
import * as fs from 'node:fs';
import { logger } from '../logger.ts';
import { DOCKER, TIMING } from '../constants.ts';

const execAsync = promisify(exec);

/**
 * Docker installation result
 */
export interface IDockerInstallResult {
  success: boolean;
  version?: string;
  error?: string;
}

/**
 * Docker status information
 */
export interface IDockerStatus {
  installed: boolean;
  running: boolean;
  version?: string;
  runtimes: string[];
  hasNvidiaRuntime: boolean;
  networkExists: boolean;
  storageDriver?: string;
  rootDir?: string;
}

/**
 * Docker Manager class
 */
export class DockerManager {
  private networkName: string;

  constructor(networkName: string = DOCKER.DEFAULT_NETWORK) {
    this.networkName = networkName;
  }

  /**
   * Check if Docker is installed
   */
  public async isInstalled(): Promise<boolean> {
    try {
      const { stdout } = await execAsync('docker --version', { timeout: 5000 });
      return stdout.includes('Docker');
    } catch {
      return false;
    }
  }

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

  /**
   * Get Docker version
   */
  public async getVersion(): 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] : undefined;
    } catch {
      return undefined;
    }
  }

  /**
   * Get full Docker status
   */
  public async getStatus(): Promise<IDockerStatus> {
    const status: IDockerStatus = {
      installed: false,
      running: false,
      runtimes: [],
      hasNvidiaRuntime: false,
      networkExists: false,
    };

    // Check installation
    status.installed = await this.isInstalled();
    if (!status.installed) {
      return status;
    }

    status.version = await this.getVersion();

    // Check if running
    status.running = await this.isRunning();
    if (!status.running) {
      return status;
    }

    // Get detailed info
    try {
      const { stdout } = await execAsync('docker info --format json', {
        timeout: TIMING.DOCKER_COMMAND_TIMEOUT_MS,
      });

      const info = JSON.parse(stdout);

      // Get runtimes
      if (info.Runtimes) {
        status.runtimes = Object.keys(info.Runtimes);
        status.hasNvidiaRuntime = status.runtimes.includes('nvidia');
      }

      status.storageDriver = info.Driver;
      status.rootDir = info.DockerRootDir;
    } catch {
      // Try alternative method for runtimes
      try {
        const { stdout } = await execAsync('docker info 2>/dev/null | grep -i "runtimes"', {
          timeout: 5000,
        });
        status.hasNvidiaRuntime = stdout.toLowerCase().includes('nvidia');
      } catch {
        // Ignore
      }
    }

    // Check network exists
    status.networkExists = await this.networkExists();

    return status;
  }

  /**
   * Install Docker on the system
   */
  public async install(): Promise<IDockerInstallResult> {
    try {
      // Check if already installed
      if (await this.isInstalled()) {
        return {
          success: true,
          version: await this.getVersion(),
        };
      }

      // Detect distribution
      const distro = await this.getLinuxDistro();
      logger.info(`Installing Docker on ${distro.id}...`);

      if (distro.id === 'ubuntu' || distro.id === 'debian') {
        await this.installOnDebian();
      } else if (
        distro.id === 'fedora' ||
        distro.id === 'rhel' ||
        distro.id === 'centos' ||
        distro.id === 'rocky' ||
        distro.id === 'almalinux'
      ) {
        await this.installOnRhel();
      } else {
        // Use convenience script as fallback
        await this.installWithScript();
      }

      // Start Docker service
      await this.startService();

      // Verify installation
      const version = await this.getVersion();
      if (version) {
        logger.success(`Docker ${version} installed successfully`);
        return { success: true, version };
      }

      return { success: false, error: 'Installation completed but Docker not found' };
    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : String(error),
      };
    }
  }

  /**
   * Install Docker on Debian/Ubuntu
   */
  private async installOnDebian(): Promise<void> {
    // Remove old versions
    await execAsync(
      'apt-get remove -y docker docker-engine docker.io containerd runc || true',
      { timeout: 60000 },
    );

    // Install prerequisites
    await execAsync('apt-get update', { timeout: 120000 });
    await execAsync(
      'DEBIAN_FRONTEND=noninteractive apt-get install -y ca-certificates curl gnupg',
      { timeout: 120000 },
    );

    // Add Docker's official GPG key
    await execAsync('install -m 0755 -d /etc/apt/keyrings');

    const distro = await this.getLinuxDistro();
    const isUbuntu = distro.id === 'ubuntu';

    if (isUbuntu) {
      await execAsync(
        'curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg',
      );
      await execAsync('chmod a+r /etc/apt/keyrings/docker.gpg');

      // Get Ubuntu codename
      const { stdout: codename } = await execAsync('lsb_release -cs');
      await execAsync(
        `echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu ${codename.trim()} stable" > /etc/apt/sources.list.d/docker.list`,
      );
    } else {
      await execAsync(
        'curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg',
      );
      await execAsync('chmod a+r /etc/apt/keyrings/docker.gpg');

      const { stdout: codename } = await execAsync('lsb_release -cs');
      await execAsync(
        `echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian ${codename.trim()} stable" > /etc/apt/sources.list.d/docker.list`,
      );
    }

    // Install Docker
    await execAsync('apt-get update', { timeout: 120000 });
    await execAsync(
      'DEBIAN_FRONTEND=noninteractive apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin',
      { timeout: 300000 },
    );
  }

  /**
   * Install Docker on RHEL/Fedora/CentOS
   */
  private async installOnRhel(): Promise<void> {
    const distro = await this.getLinuxDistro();
    const isFedora = distro.id === 'fedora';

    // Remove old versions
    await execAsync(
      'dnf remove -y docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine || true',
      { timeout: 60000 },
    );

    // Install prerequisites
    await execAsync('dnf install -y dnf-plugins-core', { timeout: 120000 });

    // Add Docker repository
    const repoUrl = isFedora
      ? 'https://download.docker.com/linux/fedora/docker-ce.repo'
      : 'https://download.docker.com/linux/centos/docker-ce.repo';

    await execAsync(`dnf config-manager --add-repo ${repoUrl}`);

    // Install Docker
    await execAsync(
      'dnf install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin',
      { timeout: 300000 },
    );
  }

  /**
   * Install Docker using convenience script
   */
  private async installWithScript(): Promise<void> {
    logger.info('Installing Docker using convenience script...');
    await execAsync('curl -fsSL https://get.docker.com | sh', {
      timeout: 600000, // 10 minutes
    });
  }

  /**
   * Start Docker service
   */
  public async startService(): Promise<void> {
    try {
      await execAsync('systemctl start docker');
      await execAsync('systemctl enable docker');
      logger.success('Docker service started and enabled');
    } catch (error) {
      logger.warn(`Could not start Docker service: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

  /**
   * Stop Docker service
   */
  public async stopService(): Promise<void> {
    try {
      await execAsync('systemctl stop docker');
      logger.success('Docker service stopped');
    } catch (error) {
      logger.warn(`Could not stop Docker service: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

  /**
   * Restart Docker service
   */
  public async restartService(): Promise<void> {
    try {
      await execAsync('systemctl restart docker');
      logger.success('Docker service restarted');
    } catch (error) {
      logger.warn(`Could not restart Docker service: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

  /**
   * Check if ModelGrid network exists
   */
  public async networkExists(): Promise<boolean> {
    try {
      await execAsync(`docker network inspect ${this.networkName}`, { timeout: 5000 });
      return true;
    } catch {
      return false;
    }
  }

  /**
   * Create the ModelGrid Docker network
   */
  public async createNetwork(): Promise<boolean> {
    try {
      if (await this.networkExists()) {
        logger.dim(`Network '${this.networkName}' already exists`);
        return true;
      }

      await execAsync(`docker network create ${this.networkName}`, {
        timeout: TIMING.DOCKER_COMMAND_TIMEOUT_MS,
      });
      logger.success(`Created Docker network '${this.networkName}'`);
      return true;
    } catch (error) {
      logger.error(`Failed to create network: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Remove the ModelGrid Docker network
   */
  public async removeNetwork(): Promise<boolean> {
    try {
      if (!await this.networkExists()) {
        return true;
      }

      await execAsync(`docker network rm ${this.networkName}`, {
        timeout: TIMING.DOCKER_COMMAND_TIMEOUT_MS,
      });
      logger.success(`Removed Docker network '${this.networkName}'`);
      return true;
    } catch (error) {
      logger.error(`Failed to remove network: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Pull a Docker image
   */
  public async pullImage(image: string): Promise<boolean> {
    try {
      logger.info(`Pulling image: ${image}`);
      await execAsync(`docker pull ${image}`, {
        timeout: 600000, // 10 minutes for large images
      });
      logger.success(`Pulled image: ${image}`);
      return true;
    } catch (error) {
      logger.error(`Failed to pull image: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Check if an image exists locally
   */
  public async imageExists(image: string): Promise<boolean> {
    try {
      await execAsync(`docker image inspect ${image}`, { timeout: 5000 });
      return true;
    } catch {
      return false;
    }
  }

  /**
   * List running containers
   */
  public async listContainers(all: boolean = false): Promise<string[]> {
    try {
      const flag = all ? '-a' : '';
      const { stdout } = await execAsync(
        `docker ps ${flag} --format "{{.ID}}"`,
        { timeout: 5000 },
      );
      return stdout.trim().split('\n').filter((id) => id);
    } catch {
      return [];
    }
  }

  /**
   * Get container by name
   */
  public async getContainerByName(name: string): Promise<string | null> {
    try {
      const { stdout } = await execAsync(
        `docker ps -a --filter "name=${name}" --format "{{.ID}}"`,
        { timeout: 5000 },
      );
      const id = stdout.trim();
      return id || null;
    } catch {
      return null;
    }
  }

  /**
   * Add user to docker group
   */
  public async addUserToDockerGroup(username?: string): Promise<boolean> {
    try {
      const user = username || process.env.SUDO_USER || process.env.USER || '';
      if (!user) {
        logger.warn('Could not determine username for docker group');
        return false;
      }

      await execAsync(`usermod -aG docker ${user}`);
      logger.success(`Added user '${user}' to docker group`);
      logger.info('Log out and log back in for the change to take effect');
      return true;
    } catch (error) {
      logger.error(`Failed to add user to docker group: ${error instanceof Error ? error.message : String(error)}`);
      return false;
    }
  }

  /**
   * Get Linux distribution info
   */
  private async getLinuxDistro(): Promise<{ id: string; version: string }> {
    try {
      const content = await fs.promises.readFile('/etc/os-release', 'utf8');
      const idMatch = content.match(/^ID=["']?(\w+)["']?$/m);
      const versionMatch = content.match(/^VERSION_ID=["']?([\d.]+)["']?$/m);

      return {
        id: idMatch ? idMatch[1].toLowerCase() : 'unknown',
        version: versionMatch ? versionMatch[1] : '',
      };
    } catch {
      return { id: 'unknown', version: '' };
    }
  }

  /**
   * Print Docker status
   */
  public async printStatus(): Promise<void> {
    const status = await this.getStatus();

    const lines: string[] = [];
    lines.push(`Installed: ${status.installed ? 'Yes' : 'No'}`);

    if (status.installed) {
      lines.push(`Version: ${status.version || 'Unknown'}`);
      lines.push(`Running: ${status.running ? 'Yes' : 'No'}`);

      if (status.running) {
        lines.push(`NVIDIA Runtime: ${status.hasNvidiaRuntime ? 'Yes' : 'No'}`);
        lines.push(`ModelGrid Network: ${status.networkExists ? 'Yes' : 'No'}`);
        if (status.storageDriver) {
          lines.push(`Storage Driver: ${status.storageDriver}`);
        }
      }
    }

    logger.logBox(
      'Docker Status',
      lines,
      50,
      status.installed && status.running ? 'success' : status.installed ? 'warning' : 'error',
    );
  }
}