import { ColumnType } from "./ts-rs/ColumnType.ts";
import { ViewConfig } from "./ts-rs/ViewConfig.ts";
import { ViewWindow } from "./ts-rs/ViewWindow.ts";
import type * as perspective from "../../dist/wasm/perspective-js.js";
/**
 * VirtualServer API for implementing custom data sources in JavaScript/WASM.
 *
 * The VirtualServer pattern allows you to create custom data sources that
 * integrate with Perspective's protocol. This is useful for:
 * - Connecting to external databases (DuckDB, PostgreSQL, etc.)
 * - Streaming data from APIs or message queues
 * - Implementing custom aggregation or transformation logic
 * - Creating data adapters without copying data into Perspective tables
 *
 * @module virtual_server
 */
export interface ServerFeatures {
    expressions?: boolean;
}
/**
 * Handler interface that you implement to provide custom data sources.
 *
 * All methods will be called by the VirtualServer when handling protocol
 * messages from Perspective clients. Methods can return values directly or
 * return Promises for asynchronous operations (e.g., database queries).
 */
export interface VirtualServerHandler {
    getHostedTables(): string[] | Promise<string[]>;
    tableSchema(tableId: string): Record<string, ColumnType> | Promise<Record<string, ColumnType>>;
    tableSize(tableId: string): number | Promise<number>;
    tableMakeView(tableId: string, viewId: string, config: ViewConfig): void | Promise<void>;
    viewDelete(viewId: string): void | Promise<void>;
    viewGetData(viewId: string, config: ViewConfig, schema: Record<string, ColumnType>, viewport: ViewWindow, dataSlice: perspective.VirtualDataSlice): void | Promise<void>;
    viewSchema?(viewId: string, config?: ViewConfig): Record<string, ColumnType> | Promise<Record<string, ColumnType>>;
    viewSize?(viewId: string): number | Promise<number>;
    tableValidateExpression?(tableId: string, expression: string): ColumnType | Promise<ColumnType>;
    viewGetMinMax?(viewId: string, columnName: string, config: ViewConfig): {
        min: any;
        max: any;
    } | Promise<{
        min: any;
        max: any;
    }>;
    getFeatures?(): ServerFeatures | Promise<ServerFeatures>;
    makeTable?(tableId: string, data: string | Uint8Array): void | Promise<void>;
}
export declare function createMessageHandler(mod: typeof perspective, handler: VirtualServerHandler): MessagePort;