/**
 * Zoe Core — StreamManager
 *
 * Shared streaming queue management for text deltas, step results,
 * and SSE conversion. Eliminates duplication between SDK's streamText()
 * and agent's chatStream().
 *
 * Pattern: push-based queues with resolver-based backpressure.
 * Producers call enqueueText/enqueueStep; consumers iterate via
 * textStream/stepsStream async iterables.
 */
import type { StepResult, Usage } from "./types.js";
export declare class StreamManager {
    private textQueue;
    private stepQueue;
    private eventQueue;
    private textDone;
    private stepsDone;
    private eventsDone;
    private textResolver;
    private stepResolver;
    private eventResolver;
    private textResolve;
    private usageResolve;
    private finishResolve;
    readonly fullText: Promise<string>;
    readonly usage: Promise<Usage>;
    readonly finishReason: Promise<string>;
    constructor();
    /** Enqueue a text delta and wake any waiting consumer. */
    enqueueText(delta: string): void;
    /** Enqueue a step result and wake any waiting consumer. */
    enqueueStep(step: StepResult): void;
    /** Resolve the fullText promise. */
    resolveText(text: string): void;
    /** Resolve the usage promise. */
    resolveUsage(usage: Usage): void;
    /** Resolve the finishReason promise. */
    resolveFinish(reason: string): void;
    /** Signal completion: set done flags and wake any waiting consumers. */
    complete(): void;
    /** Async iterable of text deltas. */
    get textStream(): AsyncIterable<string>;
    /** Async iterable of step results. */
    get stepsStream(): AsyncIterable<StepResult>;
    /**
     * Returns a ReadableStream that pipes text deltas and tool events as SSE.
     *
     * Events emitted:
     *  - `text`        — { delta: string }
     *  - `tool_call`   — { callId, name, args }
     *  - `tool_result` — { callId, output, success }
     *  - `done`        — { usage: { totalTokens, cost }, finishReason }
     */
    toSSEStream(): ReadableStream;
    /** Returns a Web API Response wrapping the SSE stream. */
    toResponse(): Response;
}