/**
 * @license
 * Copyright 2025 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.
 */
/**
 * The subset of the Prompt API
 * (see {@link https://github.com/webmachinelearning/prompt-api#full-api-surface-in-web-idl }
 * required for hybrid functionality.
 *
 * @internal
 */
export interface LanguageModel extends EventTarget {
    create(options?: LanguageModelCreateOptions): Promise<LanguageModel>;
    availability(options?: LanguageModelCreateCoreOptions): Promise<Availability>;
    prompt(input: LanguageModelPrompt, options?: LanguageModelPromptOptions): Promise<string>;
    promptStreaming(input: LanguageModelPrompt, options?: LanguageModelPromptOptions): ReadableStream;
    measureInputUsage(input: LanguageModelPrompt, options?: LanguageModelPromptOptions): Promise<number>;
    destroy(): undefined;
}
/**
 * @internal
 */
export declare enum Availability {
    'UNAVAILABLE' = "unavailable",
    'DOWNLOADABLE' = "downloadable",
    'DOWNLOADING' = "downloading",
    'AVAILABLE' = "available"
}
/**
 * Configures the creation of an on-device language model session.
 * @beta
 */
export interface LanguageModelCreateCoreOptions {
    topK?: number;
    temperature?: number;
    expectedInputs?: LanguageModelExpected[];
}
/**
 * Configures the creation of an on-device language model session.
 * @beta
 */
export interface LanguageModelCreateOptions extends LanguageModelCreateCoreOptions {
    signal?: AbortSignal;
    initialPrompts?: LanguageModelMessage[];
}
/**
 * Options for an on-device language model prompt.
 * @beta
 */
export interface LanguageModelPromptOptions {
    responseConstraint?: object;
}
/**
 * Options for the expected inputs for an on-device language model.
 * @beta
 */ export interface LanguageModelExpected {
    type: LanguageModelMessageType;
    languages?: string[];
}
/**
 * An on-device language model prompt.
 * @beta
 */
export type LanguageModelPrompt = LanguageModelMessage[];
/**
 * An on-device language model message.
 * @beta
 */
export interface LanguageModelMessage {
    role: LanguageModelMessageRole;
    content: LanguageModelMessageContent[];
}
/**
 * An on-device language model content object.
 * @beta
 */
export interface LanguageModelMessageContent {
    type: LanguageModelMessageType;
    value: LanguageModelMessageContentValue;
}
/**
 * Allowable roles for on-device language model usage.
 * @beta
 */
export type LanguageModelMessageRole = 'system' | 'user' | 'assistant';
/**
 * Allowable types for on-device language model messages.
 * @beta
 */
export type LanguageModelMessageType = 'text' | 'image' | 'audio';
/**
 * Content formats that can be provided as on-device message content.
 * @beta
 */
export type LanguageModelMessageContentValue = ImageBitmapSource | AudioBuffer | BufferSource | string;