import { OpenAIChatModel, OpenAIMessage, OpenAIChatResult, OpenAISpeechModel, OpenAITTSResult, OpenAITTSVoice } from "../types";
export declare class OpenAI {
    /**
     * Initialize a new OpenAI chat instance
     * @param apiKey: string - The user's OpenAI authentication key
     * @param model (Optional): OpenAIChatModel - one of the available chat model provided by OpenAI. Defaults to "gpt-40-mini", the cheapest one
     * @returns An instance of OpenAI Chat model
     */
    static chat(apiKey: string, model?: OpenAIChatModel): Chat;
    /**
     * Initialize a new OpenAI TTS instance
     * @param apiKey: string - The user's OpenAI authentication key
     * @returns An instance of OpenAI TTS model
     */
    static textToSpeech(apiKey: string): TextToSpeech;
}
export declare class Chat {
    private apiKey;
    private headers;
    readonly model: OpenAIChatModel;
    readonly endpoint: string;
    /**
     * Constructs a new instance of OpenAI Chat class
     * @param openAIKey: string - The user's OpenAI authentication key
     * @param model: OpenAIChatModel - one of the available chat model provided by OpenAI
     */
    constructor(openAIKey: string, model: OpenAIChatModel);
    /**
     *
     * @param messages: OpenAIMessage[] - an array of OpenAIMessages representing the conversation history.
     * @param system (Optional): string - The system prompt or content that guides the model's behavior.
     * @returns A proimise that resolves to a OpenAIChatResult containing the generated chat output.
     * @throws An error if the API request fails
     */
    generate(messages: OpenAIMessage[], system?: string): Promise<OpenAIChatResult>;
}
export declare class TextToSpeech {
    private apiKey;
    private headers;
    readonly model: OpenAISpeechModel;
    readonly endpoint: string;
    /**
     * Constructs a new instance of OpenAI TTS class
     * @param openAIKey: string - The user's OpenAI authentication key
     */
    constructor(openAIKey: string);
    /**
     *
     * @param text: string | undefined - The text that you want to convert to speech.
     * @param returnType (Optional): "filename" | "buffer" | "base64" - Specifies the format in which the result should be returned.
     * @param filename (Optional): string - The name of the file to save the speech when `returnType` is "filename". Defaults to "speech.mp3".
     * @param voice (Optional): OpenAITTSVoice - The voice model to use for the speech synthesis. Defaults to "alloy"
     * @returns A promise that resolves to the result of the conversion, depending on the `returnType`
     *   - If `returnType` is "filename", the promise resolves to the file path of the saved audio.
     *   - If `returnType` is "buffer", the promise resolves to a `Buffer` containing the audio data.
     *   - If `returnType` is "base64", the promise resolves to a Base64-encoded string of the audio data.
     *   - If no valid `returnType` is specified, it returns `undefined`.
     * @throws Error - Throws an error if the input `text` is undefined or if there is a failure during the request to the API.
     */
    convert(text: string | undefined, returnType?: "filename" | "buffer" | "base64", filename?: string, voice?: OpenAITTSVoice): Promise<OpenAITTSResult>;
}
/**
 * Processes and validates the given filename, ensuring that it has the correct format and file extension.
 *
 * @param originalFilename: string - The original filename or file path provided by the user.
 * @returns string - The processed filename with a valid ".mp3" extension and proper path structure.
 */
export declare const processFilename: (originalFilename: string) => string;