import { StreamChunk } from '../../../types.js';
import { AbortInfo, AfterToolCallInfo, BeforeToolCallDecision, ChatMiddleware, ChatMiddlewareConfig, ChatMiddlewareContext, ErrorInfo, FinishInfo, IterationInfo, ToolCallHookContext, ToolPhaseCompleteInfo, UsageInfo } from './types.js';
/**
 * Internal middleware runner that manages composed execution of middleware hooks.
 * Created once per chat() invocation.
 */
export declare class MiddlewareRunner {
    private readonly middlewares;
    constructor(middlewares: ReadonlyArray<ChatMiddleware>);
    get hasMiddleware(): boolean;
    /**
     * Pipe config through all middleware onConfig hooks in order.
     * Each middleware receives the merged config from previous middleware.
     * Partial returns are shallow-merged with the current config.
     */
    runOnConfig(ctx: ChatMiddlewareContext, config: ChatMiddlewareConfig): Promise<ChatMiddlewareConfig>;
    /**
     * Call onStart on all middleware in order.
     */
    runOnStart(ctx: ChatMiddlewareContext): Promise<void>;
    /**
     * Pipe a single chunk through all middleware onChunk hooks in order.
     * Returns the resulting chunks (0..N) to yield to the consumer.
     *
     * - void: pass through unchanged
     * - chunk: replace with this chunk
     * - chunk[]: expand to multiple chunks
     * - null: drop the chunk entirely
     */
    runOnChunk(ctx: ChatMiddlewareContext, chunk: StreamChunk): Promise<Array<StreamChunk>>;
    /**
     * Run onBeforeToolCall through middleware in order.
     * Returns the first non-void decision, or undefined to continue normally.
     */
    runOnBeforeToolCall(ctx: ChatMiddlewareContext, hookCtx: ToolCallHookContext): Promise<BeforeToolCallDecision>;
    /**
     * Run onAfterToolCall on all middleware in order.
     */
    runOnAfterToolCall(ctx: ChatMiddlewareContext, info: AfterToolCallInfo): Promise<void>;
    /**
     * Run onUsage on all middleware in order.
     */
    runOnUsage(ctx: ChatMiddlewareContext, usage: UsageInfo): Promise<void>;
    /**
     * Run onFinish on all middleware in order.
     */
    runOnFinish(ctx: ChatMiddlewareContext, info: FinishInfo): Promise<void>;
    /**
     * Run onAbort on all middleware in order.
     */
    runOnAbort(ctx: ChatMiddlewareContext, info: AbortInfo): Promise<void>;
    /**
     * Run onError on all middleware in order.
     */
    runOnError(ctx: ChatMiddlewareContext, info: ErrorInfo): Promise<void>;
    /**
     * Run onIteration on all middleware in order.
     * Called at the start of each agent loop iteration.
     */
    runOnIteration(ctx: ChatMiddlewareContext, info: IterationInfo): Promise<void>;
    /**
     * Run onToolPhaseComplete on all middleware in order.
     * Called after all tool calls in an iteration have been processed.
     */
    runOnToolPhaseComplete(ctx: ChatMiddlewareContext, info: ToolPhaseCompleteInfo): Promise<void>;
}