/**
 * External Data Source Service
 *
 * Import data from external sources into Label Studio
 * Supports:
 * - REST API endpoints
 * - S3/Cloud Storage URLs
 * - Database queries (via Things Factory connections)
 * - CSV/JSON file URLs
 */
declare class ExternalDataSourceConfig {
    sourceType: 'api' | 'url' | 's3' | 'database' | 'csv' | 'json';
    sourceUrl: string;
    authHeader?: string;
    httpMethod?: string;
    requestBody?: string;
    dataPath?: string;
}
declare class ImportFromExternalSourceRequest {
    projectId: number;
    source: ExternalDataSourceConfig;
    fieldMapping?: string;
    imageField?: string;
    autoGeneratePredictions?: boolean;
    limit?: number;
}
declare class ExternalImportResult {
    totalFetched: number;
    tasksImported: number;
    tasksFailed: number;
    taskIds: number[];
    error?: string;
}
declare class DataSourcePreview {
    itemCount: number;
    sampleData: string;
    schema: string;
    error?: string;
}
export declare class ExternalDataSourceService {
    /**
     * Preview external data source before import
     */
    previewExternalDataSource(source: ExternalDataSourceConfig, context: ResolverContext): Promise<DataSourcePreview>;
    /**
     * Import data from external source to Label Studio
     */
    importFromExternalSource(input: ImportFromExternalSourceRequest, context: ResolverContext): Promise<ExternalImportResult>;
    /**
     * Fetch data from external source
     */
    private fetchFromSource;
    /**
     * Fetch from REST API
     */
    private fetchFromApi;
    /**
     * Fetch from URL (JSON file)
     */
    private fetchFromUrl;
    /**
     * Fetch from CSV
     */
    private fetchFromCsv;
    /**
     * Extract data by JSON path (simple implementation)
     */
    private extractDataByPath;
    /**
     * Transform raw data item to Label Studio task format
     */
    private transformToLabelStudioTask;
    /**
     * Detect schema from data item
     */
    private detectSchema;
}
export {};