import GRPCClient from "./GRPCClient";
import IClientBinding from "../../../interfaces/Client/IClientBinding";
import { KeyValueType } from "../../../types/KeyValue.type";
/**
 * gRPC-based output bindings building block implementation.
 *
 * Output bindings invoke external systems through the Dapr sidecar.
 * This implementation uses gRPC for efficient communication with binding connectors.
 *
 * Supported binding types include databases, message queues, webhooks, and more.
 * Bindings allow sending data to external systems without maintaining direct connections.
 *
 * @implements {IClientBinding}
 * @see {@link https://docs.dapr.io/reference/api/bindings_api/} Dapr Bindings API
 * @see {@link DaprClient.binding} for unified API
 *
 * @internal
 */
export default class GRPCClientBinding implements IClientBinding {
    /**
     * Reference to the underlying gRPC client.
     */
    client: GRPCClient;
    /**
     * Creates a gRPC output binding building block.
     *
     * @param client - The gRPC client instance
     */
    constructor(client: GRPCClient);
    /**
     * Sends a request to an output binding.
     *
     * Invokes the named binding with the specified operation and data.
     * The binding connector determines how the operation is interpreted
     * (e.g., "create" for databases, "send" for message queues).
     *
     * @param bindingName - Name of the binding to invoke
     * @param operation - Binding-specific operation identifier
     * @param data - Data to send (automatically serialized)
     * @param metadata - Optional metadata key-value pairs (default: {})
     *
     * @returns Promise resolving to response object with data and metadata
     *
     * @throws Rejects if binding does not exist, operation fails, or gRPC call fails
     *
     * @example
     * ```typescript
     * // Send data to a database binding
     * const response = await client.binding.send(
     *   "mydb",
     *   "create",
     *   { id: 1, name: "Alice", city: "San Francisco" },
     *   { table: "users" }
     * );
     * // response: { data: ..., metadata: { table: "users" }, operation: "create" }
     *
     * // Send message to a message queue binding
     * await client.binding.send(
     *   "mqbinding",
     *   "send",
     *   { message: "Hello World" }
     * );
     * ```
     *
     * @see {@link https://docs.dapr.io/reference/api/bindings_api/#invoking-output-bindings}
     */
    send(bindingName: string, operation: string, data: any, metadata?: KeyValueType): Promise<object>;
}