/**
 * OpenAI Chat Completions API format conversion layer.
 *
 * Provides a request parser (OpenAI -> NeuroLink), a response serializer
 * (NeuroLink -> OpenAI), a streaming SSE state machine, and an error
 * envelope helper.  Together they allow NeuroLink to act as a
 * drop-in OpenAI API proxy.
 *
 * Reference: https://platform.openai.com/docs/api-reference/chat/create
 */
import type { ClaudeRequest, ClaudeResponse, InternalResult, OpenAICompletionRequest, OpenAICompletionResponse, OpenAIErrorResponse, ParsedOpenAIRequest, StreamLifecycleState } from "../types/index.js";
/** Generate a unique chat completion ID in the OpenAI format. */
export declare function generateChatCompletionId(): string;
/** Generate an OpenAI-format tool call ID (`call_` + random chars). */
export declare function generateOpenAIToolCallId(): string;
/**
 * Parse an incoming OpenAI Chat Completions request into an intermediate
 * representation consumable by NeuroLink's generate/stream pipeline.
 *
 * Handles:
 * - System prompt extraction from system messages
 * - Message flattening (text + image parts)
 * - Tool definition conversion
 * - tool_choice mapping
 * - top_p, temperature, max_tokens pass-through
 */
export declare function parseOpenAIRequest(body: OpenAICompletionRequest): ParsedOpenAIRequest;
/**
 * Serialize a NeuroLink GenerateResult into an OpenAI Chat Completions response.
 */
export declare function serializeOpenAIResponse(result: InternalResult, requestModel: string): OpenAICompletionResponse;
/**
 * Build an OpenAI-compatible error envelope.
 */
export declare function buildOpenAIError(status: number, message: string): OpenAIErrorResponse;
/**
 * Format a single OpenAI SSE frame.
 * OpenAI uses only `data:` lines (no `event:` prefix unlike Claude).
 */
export declare function formatOpenAISSE(data: unknown): string;
/**
 * Stateful SSE serializer that emits a well-formed OpenAI streaming response.
 *
 * Tracks lifecycle state (`idle` -> `streaming` -> `done`) and the current
 * tool call index for multi-tool streaming.
 *
 * Usage:
 * ```ts
 * const sse = new OpenAIStreamSerializer(requestModel);
 *
 * // Start the stream
 * yield* sse.start();
 *
 * // Text deltas
 * for await (const chunk of textStream) {
 *   yield* sse.pushDelta(chunk);
 * }
 *
 * // Tool use
 * yield* sse.pushToolUse(toolId, toolName, toolInput);
 *
 * // Finalize
 * yield* sse.finish("stop", usage);
 * ```
 */
export declare class OpenAIStreamSerializer {
    private state;
    private readonly id;
    private readonly model;
    private started;
    private toolCallIndex;
    constructor(model: string);
    /** Current lifecycle state (exposed for testing). */
    getState(): StreamLifecycleState;
    private makeChunk;
    /**
     * Emit the opening frame with `role: "assistant"`.
     */
    start(): Generator<string>;
    /**
     * Push a text content delta.
     */
    pushDelta(text: string): Generator<string>;
    /**
     * Push the start of a tool call (id, name, empty arguments).
     */
    pushToolCallStart(id: string, name: string): Generator<string>;
    /**
     * Push an arguments delta for the current tool call.
     */
    pushToolCallArgDelta(index: number, argsChunk: string): Generator<string>;
    /**
     * Push a complete tool use: emits tool call start followed by chunked
     * argument deltas (~100 chars per chunk).
     */
    pushToolUse(id: string, name: string, input: unknown): Generator<string>;
    /**
     * Finalize the stream: emit finish_reason chunk, then `data: [DONE]`.
     */
    finish(finishReason?: string, usage?: {
        input: number;
        output: number;
        total: number;
    }): Generator<string>;
    /**
     * Emit an error event.  Transitions to terminal ERROR state.
     */
    emitError(message: string): Generator<string>;
}
/**
 * Convert an OpenAI Chat Completions request to a Claude Messages API request.
 *
 * Used by the OpenAI proxy endpoint to internally loopback requests targeting
 * Claude models through the proxy's native /v1/messages passthrough path,
 * so they benefit from OAuth account rotation, retry, SSE interception, etc.
 */
export declare function convertOpenAIToClaudeRequest(openai: OpenAICompletionRequest): ClaudeRequest;
/**
 * Convert a non-streaming Claude Messages response to an OpenAI Chat
 * Completions response by bridging through {@link InternalResult}.
 */
export declare function convertClaudeToOpenAIResponse(claude: ClaudeResponse, requestModel: string): OpenAICompletionResponse;
/**
 * Create a TransformStream that parses Claude Messages API SSE events from
 * the upstream response and re-emits them as OpenAI Chat Completions SSE
 * frames.
 *
 * Handles the canonical Claude SSE event types:
 *  - message_start       -> emits the opening `role: "assistant"` chunk
 *  - content_block_start -> text block: no-op; tool_use block: emit tool call start
 *  - content_block_delta -> text_delta: emit content delta;
 *                           input_json_delta: emit tool call argument delta
 *  - content_block_stop  -> no-op
 *  - message_delta       -> captures stop_reason and output token usage
 *  - message_stop        -> emits the final `finish_reason` chunk + `[DONE]`
 */
export declare function createClaudeToOpenAIStreamTransform(requestModel: string): TransformStream<Uint8Array, Uint8Array>;