OpenAI: Generate Image

function main() {
    ////// == 工程コンフィグ・ワークフローデータの参照 / Config & Data Retrieving ==
    const auth = configs.getObject('conf_Auth');   /// REQUIRED
    const model = retrieveModel();
    const prompt = configs.get('conf_Prompt');
    if (prompt === '') {
        throw new Error('Prompt is empty.');
    }

    const size = retrieveSize();
    const format = retrieveSelectItem('conf_Format');
    const quality = retrieveSelectItem('conf_Quality');
    const fileName = configs.get('conf_FileName');
    if (fileName === '') {
        throw new Error('File name is empty.');
    }

    ////// == 演算 / Calculating ==
    const newFile = generateImage(auth, model, prompt, size, format, quality, fileName);

    saveFileData('conf_File', newFile);
}

/**
 * config からモデル ID を読み出す
 * モデル ID として不正な場合はエラー
 * @return {String}
 */
const retrieveModel = () => {
    const model = configs.get('conf_Model');
    const reg = new RegExp('^[a-z0-9.-]+$');
    if (!reg.test(model)) {
        throw new Error('Model is invalid. It contains an invalid character.');
    }
    return model;
};

/**
 * config からサイズを読み出す
 * 形式: WIDTHxHEIGHT (例: 1024x1024)
 * 指定なしの場合は undefined
 * 形式が不正な場合はエラー
 * 細かなバリデーションは API に任せ、ここではチェックしない
 * @return {String}
 */
const retrieveSize = () => {
    const size = retrieveSelectItem('conf_Size');
    if (size === undefined) {
        return undefined;
    }

    // 基本的な形式チェック: 数字x数字（1〜4桁）
    const formatRegex = /^([1-9]\d{0,3})x([1-9]\d{0,3})$/;
    if (!formatRegex.test(size)) {
        throw new Error('Size is invalid. It must be WIDTHxHEIGHT.');
    }

    return size;
};

/**
 * form-type="SELECT_ITEM" の設定値を取得する
 * 空の場合、undefined を返す
 * @param configName
 * @returns {undefined|String}
 */
const retrieveSelectItem = (configName) => {
    const value = configs.get(configName);
    if (value === '') {
        return undefined;
    }
    return value;
};

/**
 * 画像生成
 * @param auth
 * @param model
 * @param prompt
 * @param size
 * @param format
 * @param quality
 * @returns {String} answer1
 */
const generateImage = (auth, model, prompt, size, format, quality, fileName) => {
    // https://platform.openai.com/docs/guides/safety-best-practices
    // Sending end-user IDs in your requests can be a useful tool to help OpenAI monitor and detect abuse.
    const user = `m${processInstance.getProcessModelInfoId().toString()}`;

    /// prepare json
    const requestJson = {
        model,
        prompt,
        size,
        output_format: format,
        quality,
        user,
        n: 1,
    };

    const response = httpClient.begin().authSetting(auth)
        .body(JSON.stringify(requestJson), 'application/json')
        .post('https://api.openai.com/v1/images/generations');

    const responseCode = response.getStatusCode();
    const responseBody = response.getResponseAsString();
    if (responseCode !== 200) {
        engine.log(responseBody);
        throw new Error(`Failed to request. status: ${responseCode}`);
    }
    const responseJson = JSON.parse(responseBody);
    const usage = responseJson.usage;
    engine.log(`Input Tokens: ${usage.input_tokens}`);
    engine.log(`Output Tokens: ${usage.output_tokens}`);
    engine.log(`Total Tokens: ${usage.total_tokens}`);

    const image = base64.decodeFromStringToByteArray(responseJson.data[0].b64_json);

    let contentType = "image/png";
    if (format !== undefined) {
        contentType = `image/${format}`;
    }

    return new com.questetra.bpms.core.event.scripttask.NewQfile(
        fileName,
        contentType,
        image
    );
};

/**
 * データ項目への保存
 * @param configName
 * @param newFile
 */
const saveFileData = (configName, newFile) => {
    const def = configs.getObject(configName);
    if (def === null) {
        return;
    }
    let files = engine.findData(def);
    if (files === null) {
        files = new java.util.ArrayList();
    }
    files.add(newFile);
    engine.setData(def, files);
};