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

// IPC command map for type-safe bridge communication
export type TClientDnsCommands = {
  resolve: {
    params: IResolveParams;
    result: IResolveResult;
  };
  ping: {
    params: Record<string, never>;
    result: { pong: boolean };
  };
};

export interface IResolveParams {
  name: string;
  recordType: string;
  protocol: 'udp' | 'doh';
  serverAddr?: string;
  dohUrl?: string;
  timeoutMs?: number;
}

export interface IClientDnsAnswer {
  name: string;
  type: string;
  ttl: number;
  value: string;
}

export interface IResolveResult {
  answers: IClientDnsAnswer[];
  adFlag: boolean;
  rcode: number;
}

/**
 * Bridge to the Rust DNS client binary via smartrust IPC.
 */
export class RustDnsClientBridge {
  private bridge: InstanceType<typeof plugins.smartrust.RustBridge<TClientDnsCommands>>;
  private spawnPromise: Promise<boolean> | null = null;

  constructor() {
    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-client_${platformSuffix}`));
    }
    // dist_rust/ without suffix (native build)
    localPaths.push(plugins.path.join(packageDir, 'dist_rust', 'rustdns-client'));
    // Local dev build paths
    localPaths.push(plugins.path.join(packageDir, 'rust', 'target', 'release', 'rustdns-client'));
    localPaths.push(plugins.path.join(packageDir, 'rust', 'target', 'debug', 'rustdns-client'));

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

    this.bridge.on('stderr', (line: string) => {
      if (line.trim()) {
        console.log(`[rustdns-client] ${line}`);
      }
    });
  }

  /**
   * Lazily spawn the Rust binary. Only spawns once, caches the promise.
   */
  public async ensureSpawned(): Promise<void> {
    if (!this.spawnPromise) {
      this.spawnPromise = this.bridge.spawn();
    }
    const ok = await this.spawnPromise;
    if (!ok) {
      this.spawnPromise = null;
      throw new Error('Failed to spawn rustdns-client binary');
    }
  }

  /**
   * Resolve a DNS query through the Rust binary.
   */
  public async resolve(
    name: string,
    recordType: string,
    protocol: 'udp' | 'doh',
    serverAddr?: string,
    dohUrl?: string,
    timeoutMs?: number
  ): Promise<IResolveResult> {
    await this.ensureSpawned();
    const params: IResolveParams = {
      name,
      recordType,
      protocol,
    };
    if (serverAddr) params.serverAddr = serverAddr;
    if (dohUrl) params.dohUrl = dohUrl;
    if (timeoutMs) params.timeoutMs = timeoutMs;
    return this.bridge.sendCommand('resolve', params);
  }

  /**
   * Ping the Rust binary for health check.
   */
  public async ping(): Promise<boolean> {
    await this.ensureSpawned();
    const result = await this.bridge.sendCommand('ping', {} as Record<string, never>);
    return result.pong;
  }

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

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

/**
 * Get the tsrust platform suffix for the current platform.
 */
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;
}