import { GenerateResponseChunkData, Role } from '../model-types.js';
import { Part, ToolRequestPart } from '../parts.js';
import '@genkit-ai/core';

/**
 * Copyright 2024 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/** A function that parses a {@link GenerateResponseChunk} into a typed output value. */
type ChunkParser<T = unknown> = (chunk: GenerateResponseChunk<T>) => T;
/**
 * Represents a single chunk of a streaming model response. Provides convenience
 * accessors for extracting text, media, tool requests, and accumulated output
 * from the chunk and all preceding chunks in the stream.
 */
declare class GenerateResponseChunk<T = unknown> implements GenerateResponseChunkData {
    /** The index of the message this chunk corresponds to, starting with `0` for the first model response of the generation. */
    index: number;
    /** The role of the message this chunk corresponds to. Will always be `model` or `tool`. */
    role: Role;
    /** The content generated in this chunk. */
    content: Part[];
    /** Custom model-specific data for this chunk. */
    custom?: unknown;
    /** Accumulated chunks for partial output extraction. */
    previousChunks?: GenerateResponseChunkData[];
    /** The parser to be used to parse `output` from this chunk. */
    parser?: ChunkParser<T>;
    constructor(data: GenerateResponseChunkData, options: {
        previousChunks?: GenerateResponseChunkData[];
        role: Role;
        index: number;
        parser?: ChunkParser<T>;
    });
    /**
     * Concatenates all `text` parts present in the chunk with no delimiter.
     * @returns A string of all concatenated text parts.
     */
    get text(): string;
    /**
     * Concatenates all `reasoning` parts present in the chunk with no delimiter.
     * @returns A string of all concatenated reasoning parts.
     */
    get reasoning(): string;
    /**
     * Concatenates all `text` parts of all chunks from the response thus far.
     * @returns A string of all concatenated chunk text content.
     */
    get accumulatedText(): string;
    /**
     * Concatenates all `text` parts of all preceding chunks.
     */
    get previousText(): string;
    /**
     * Returns the first media part detected in the chunk. Useful for extracting
     * (for example) an image from a generation expected to create one.
     * @returns The first detected `media` part in the chunk.
     */
    get media(): {
        url: string;
        contentType?: string;
    } | null;
    /**
     * Returns the first detected `data` part of a chunk.
     * @returns The first `data` part detected in the chunk (if any).
     */
    get data(): T | null;
    /**
     * Returns all tool request found in this chunk.
     * @returns Array of all tool request found in this chunk.
     */
    get toolRequests(): ToolRequestPart[];
    /**
     * Parses the chunk into the desired output format using the parser associated
     * with the generate request, or falls back to naive JSON parsing otherwise.
     */
    get output(): T | null;
    toJSON(): GenerateResponseChunkData;
}

export { type ChunkParser, GenerateResponseChunk };