import { EdgeData, DataSource, DataAdapterConfig, GraphData, NodeId, NodeData, PaginationOptions, PaginatedResult, DataFilter, ContentData } from '@inferagraph/core/data';

type FileType = 'csv' | 'tsv' | 'markdown';
interface FileDataSourceConfigBase {
    /** Which file format to load */
    type: FileType;
    /** File path (csv/tsv) or folder path (markdown) */
    path: string;
    /** Host-supplied relationships */
    edges: EdgeData[];
    /** Column / frontmatter key for the node id (default 'id') */
    idField?: string;
}
interface CsvLikeConfig extends FileDataSourceConfigBase {
    type: 'csv' | 'tsv';
    /** First row contains column names (default true) */
    hasHeader?: boolean;
    /** Required when hasHeader=false; length must equal first row's field count */
    columns?: string[];
    /** Host-chosen columns exposed via getContent for template injection */
    contentFields?: string[];
}
interface MarkdownConfig extends FileDataSourceConfigBase {
    type: 'markdown';
    /** Required keys; each .md file must contain EXACTLY these keys (no more, no less) */
    frontmatter: string[];
}
type FileDataSourceConfig = CsvLikeConfig | MarkdownConfig;

/**
 * DataSource that loads nodes from delimited files (CSV/TSV) or a folder
 * of Markdown files with frontmatter. Edges are host-supplied via config.
 *
 * After parsing, an internal {@link StaticDataAdapter} handles all graph
 * traversal/search/filter operations. `getContent` is handled directly:
 *
 * - markdown: returns the body of the source .md file with `contentType: 'markdown'`
 * - csv/tsv with `contentFields`: returns selected columns as `metadata` with
 *   `content: ''` and `contentType: 'fields'`
 * - csv/tsv without `contentFields`: returns `undefined`
 */
declare class FileDataSource extends DataSource {
    readonly name = "file";
    private readonly config;
    private readonly idField;
    private adapter;
    private connected;
    private contentByNodeId;
    private csvRowsById;
    constructor(config: FileDataSourceConfig);
    connect(): Promise<void>;
    disconnect(): Promise<void>;
    isConnected(): boolean;
    getInitialView(config?: DataAdapterConfig): Promise<GraphData>;
    getNode(id: NodeId): Promise<NodeData | undefined>;
    getNeighbors(nodeId: NodeId, depth?: number): Promise<GraphData>;
    findPath(fromId: NodeId, toId: NodeId): Promise<GraphData>;
    search(query: string, pagination?: PaginationOptions): Promise<PaginatedResult<NodeData>>;
    filter(filter: DataFilter, pagination?: PaginationOptions): Promise<PaginatedResult<NodeData>>;
    getContent(nodeId: NodeId): Promise<ContentData | undefined>;
    private loadCsvLike;
    private loadMarkdown;
    private requireAdapter;
    private ensureConnected;
}

/**
 * Factory for {@link FileDataSource}. Preferred entry point for hosts; the
 * class export remains available as an escape hatch for advanced subclassing.
 */
declare function fileDataSource(config: FileDataSourceConfig): FileDataSource;

export { type CsvLikeConfig, FileDataSource, type FileDataSourceConfig, type FileDataSourceConfigBase, type FileType, type MarkdownConfig, fileDataSource };