import * as plugins from './plugins.js';

// IPC command map for type-safe bridge communication
export type TDnsCommands = {
  start: {
    params: { config: IRustDnsConfig };
    result: Record<string, never>;
  };
  stop: {
    params: Record<string, never>;
    result: Record<string, never>;
  };
  dnsQueryResult: {
    params: {
      correlationId: string;
      answers: IIpcDnsAnswer[];
      answered: boolean;
    };
    result: { resolved: boolean };
  };
  updateCerts: {
    params: { httpsKey: string; httpsCert: string };
    result: Record<string, never>;
  };
  processPacket: {
    params: { packet: string }; // base64-encoded DNS packet
    result: { packet: string }; // base64-encoded DNS response
  };
  ping: {
    params: Record<string, never>;
    result: { pong: boolean };
  };
};

export interface IRustDnsConfig {
  udpPort: number;
  httpsPort: number;
  udpBindInterface: string;
  httpsBindInterface: string;
  httpsKey: string;
  httpsCert: string;
  dnssecZone: string;
  dnssecAlgorithm: string;
  primaryNameserver: string;
  enableLocalhostHandling: boolean;
  manualUdpMode: boolean;
  manualHttpsMode: boolean;
}

export interface IIpcDnsQuestion {
  name: string;
  type: string;
  class: string;
}

export interface IIpcDnsAnswer {
  name: string;
  type: string;
  class: string;
  ttl: number;
  data: any;
}

export interface IDnsQueryEvent {
  correlationId: string;
  questions: IIpcDnsQuestion[];
  dnssecRequested: boolean;
}

/**
 * Bridge to the Rust DNS binary via smartrust IPC.
 */
export class RustDnsBridge extends plugins.events.EventEmitter {
  private bridge: InstanceType<typeof plugins.smartrust.RustBridge<TDnsCommands>>;

  constructor() {
    super();

    const packageDir = plugins.path.resolve(
      plugins.path.dirname(new URL(import.meta.url).pathname),
      '..'
    );

    // Determine platform suffix for dist_rust binaries (matches tsrust naming)
    const platformSuffix = getPlatformSuffix();
    const localPaths: string[] = [];

    // dist_rust/ candidates (tsrust cross-compiled output, platform-specific)
    if (platformSuffix) {
      localPaths.push(plugins.path.join(packageDir, 'dist_rust', `rustdns_${platformSuffix}`));
    }
    // dist_rust/ without suffix (native build)
    localPaths.push(plugins.path.join(packageDir, 'dist_rust', 'rustdns'));
    // Local dev build paths
    localPaths.push(plugins.path.join(packageDir, 'rust', 'target', 'release', 'rustdns'));
    localPaths.push(plugins.path.join(packageDir, 'rust', 'target', 'debug', 'rustdns'));

    this.bridge = new plugins.smartrust.RustBridge<TDnsCommands>({
      binaryName: 'rustdns',
      cliArgs: ['--management'],
      requestTimeoutMs: 30_000,
      readyTimeoutMs: 10_000,
      localPaths,
      searchSystemPath: false,
    });

    // Forward events from inner bridge
    this.bridge.on('management:dnsQuery', (data: IDnsQueryEvent) => {
      this.emit('dnsQuery', data);
    });

    this.bridge.on('management:started', () => {
      this.emit('started');
    });

    this.bridge.on('management:stopped', () => {
      this.emit('stopped');
    });

    this.bridge.on('management:error', (data: { message: string }) => {
      this.emit('error', new Error(data.message));
    });

    this.bridge.on('stderr', (line: string) => {
      // Forward Rust tracing output as debug logs
      if (line.trim()) {
        console.log(`[rustdns] ${line}`);
      }
    });
  }

  /**
   * Spawn the Rust binary and wait for readiness.
   */
  public async spawn(): Promise<boolean> {
    return this.bridge.spawn();
  }

  /**
   * Start the DNS server with given config.
   */
  public async startServer(config: IRustDnsConfig): Promise<void> {
    await this.bridge.sendCommand('start', { config });
  }

  /**
   * Stop the DNS server.
   */
  public async stopServer(): Promise<void> {
    await this.bridge.sendCommand('stop', {});
  }

  /**
   * Send a DNS query result back to Rust.
   */
  public async sendQueryResult(
    correlationId: string,
    answers: IIpcDnsAnswer[],
    answered: boolean
  ): Promise<void> {
    await this.bridge.sendCommand('dnsQueryResult', {
      correlationId,
      answers,
      answered,
    });
  }

  /**
   * Update TLS certificates.
   */
  public async updateCerts(httpsKey: string, httpsCert: string): Promise<void> {
    await this.bridge.sendCommand('updateCerts', { httpsKey, httpsCert });
  }

  /**
   * Process a raw DNS packet via IPC (for manual/passthrough mode).
   * Returns the DNS response as a Buffer.
   */
  public async processPacket(packet: Buffer): Promise<Buffer> {
    const result = await this.bridge.sendCommand('processPacket', {
      packet: packet.toString('base64'),
    });
    return Buffer.from(result.packet, 'base64');
  }

  /**
   * Ping the Rust binary for health check.
   */
  public async ping(): Promise<boolean> {
    const result = await this.bridge.sendCommand('ping', {});
    return result.pong;
  }

  /**
   * Kill the Rust process.
   */
  public kill(): void {
    this.bridge.kill();
  }

  /**
   * Whether the bridge is running.
   */
  public get running(): boolean {
    return this.bridge.running;
  }
}

/**
 * Get the tsrust platform suffix for the current platform.
 * Matches the naming convention used by @git.zone/tsrust.
 */
function getPlatformSuffix(): string | null {
  const platform = process.platform;
  const arch = process.arch;

  const platformMap: Record<string, string> = {
    'linux': 'linux',
    'darwin': 'macos',
    'win32': 'windows',
  };

  const archMap: Record<string, string> = {
    'x64': 'amd64',
    'arm64': 'arm64',
  };

  const p = platformMap[platform];
  const a = archMap[arch];

  if (p && a) {
    return `${p}_${a}`;
  }

  return null;
}