/**
 * Used to isolate the type of content to retrieve from the message.
 * @typedef {Object} MessageContent
 * @public
 * @property {string} [type] - Message content type. Valid types: from, date, subject, body, archive, file.
 * @property {string} [name] - A custom description for the content type.
 * @property {RegExp|string} [archive] - Identifier to isolate the desired attachment when type is 'archive'.
 *   Use a regular expression for pattern matching or a string for a literal match. Required if type is 'archive'.
 * @property {RegExp|string} [file] - Identifier to isolate the desired attachment when type is 'file' or 'archive'.
 *   Use a regular expression for pattern matching or a string for a literal match. Required if type is 'file' or 'archive'.
 * @property {number?} [maxLength] - Maximum number of characters to retrieve from the content.
 */
/**
 * Configurable options provided to the Gmail adaptor.
 * @typedef {Object} Options
 * @public
 * @property {string?} [query] - Gmail search query string.
 * @property {Array<string|MessageContent>} [contents=['from', 'date', 'subject']]
 *   An array of strings or MessageContent objects used to specify which parts of the message to retrieve.
 * @property {Array<string>} [processedIds] - Ignore message ids which have already been processed.
 * @property {string?} [email] - The user account to retrieve messages from. Defaults to the authenticated user.
 * @property {int?} [maxResults] - Maximum number of messages to process per request. Default is 1000.
 * @property {boolean} [fetchAttachments=true] - Whether to download file and archive attachments.
 *   When false, matched attachments are returned as filename-only objects without content.
 */
/**
 * Downloads contents from messages of a Gmail account.
 * @public
 * @function
 * @param {Options} options - Customized options including desired contents and query.
 * @state {Array} data - The returned message objects, of the form `{ messageId, ...contents } `
 * @state {Array<string>} processedIds - An array of string ids processed by this request
 * @returns {Operation}
 * @example <caption>Get a message with a specific subject</caption>
 * getContentsFromMessages(
 *   {
 *     query: 'subject:my+test+message'
 *   }
 * )
 * @example <caption>Get messages after a specific date, with subject and report.txt attachment</caption>
 * getContentsFromMessages(
 *   {
 *     query: 'after:15/01/2025',
 *     contents: [
 *       'subject',
 *       { type: 'file', name: 'metadata', file: 'report.txt'}
 *     ]
 *   }
 * )
 * @example <caption>Get metadata without downloading requested attachments</caption>
 * getContentsFromMessages(
 *   {
 *     query: 'after:2026/07/01',
 *     contents: [
 *       'body',
 *       { type: 'file', name: 'report', file: /\.xlsx$/ }
 *     ],
 *     fetchAttachments: false
 *   }
 * )
 */
export function getContentsFromMessages(options: Options): Operation;
/**
 * Configurable fields for composing an outbound Gmail message.
 * @typedef {Object} SendMessageOptions
 * @property {string} to - Recipient email address.
 * @property {string} subject - Subject line of the email.
 * @property {string} body - Email body content.
 * @property {Array<{ filename: string, content: string|Buffer }>} [attachments] - Optional list of files to attach.
 */
/**
 * Sends a Gmail message using the provided configuration.
 * Supports attachments and standard email fields like subject, body, and recipients.
 *
 * @public
 * @function
 * @param {SendMessageOptions|SendMessageOptions[]} message - The message configuration object or array of objects.
 * @state {Object} data - The Gmail API response from sending the message.
 * @returns {Operation}
 * @example
 * sendMessage({
 *   to: 'recipient@example.org',
 *   subject: 'Test Message',
 *   body: 'Hello from OpenFn!',
 *   attachments: [
 *     { filename: 'test.txt', content: 'Some text content' }
 *   ]
 * })
 */
export function sendMessage(message: SendMessageOptions | SendMessageOptions[]): Operation;
/**
 * Configurable options provided to getMessageById.
 * @typedef {Object} MessageIdOptions
 * @public
 * @property {Array<string|MessageContent>} [contents=['from', 'date', 'subject']]
 *   An array of strings or MessageContent objects used to specify which parts of the message to retrieve.
 * @property {string?} [email] - The user account to retrieve messages from. Defaults to the authenticated user.
 * @property {boolean} [fetchAttachments=true] - Whether to download file and archive attachments.
 *   When false, matched attachments are returned as filename-only objects without content.
 */
/**
 * Downloads contents from a single message of a Gmail account, identified by
 * its Gmail API message id.
 * @public
 * @function
 * @param {string} messageId - Gmail API message id to fetch.
 * @param {MessageIdOptions} [options] - Customized options including desired contents.
 * @state {Object} data - The returned message object, of the form `{ messageId, ...contents } `
 * @returns {Operation}
 * @example <caption>Download attachments for a specific message identified by an earlier step</caption>
 * getMessageById(
 *   $.data.messageId,
 *   {
 *     contents: [
 *       { type: 'file', name: 'report', file: /\.xlsx$/ }
 *     ]
 *   }
 * )
 */
export function getMessageById(messageId: string, options?: MessageIdOptions): Operation;
/**
 * Execute a sequence of operations.
 * Wraps `language-common/execute`, and prepends initial state for http.
 * @private
 * @param {...Function} operations - Operations to be performed.
 * @returns {Operation}
 */
export function execute(...operations: Function[]): Operation;
/**
 * Used to isolate the type of content to retrieve from the message.
 */
export type MessageContent = any;
/**
 * Configurable options provided to the Gmail adaptor.
 */
export type Options = any;
/**
 * Configurable fields for composing an outbound Gmail message.
 */
export type SendMessageOptions = {
    /**
     * - Recipient email address.
     */
    to: string;
    /**
     * - Subject line of the email.
     */
    subject: string;
    /**
     * - Email body content.
     */
    body: string;
    /**
     * - Optional list of files to attach.
     */
    attachments?: Array<{
        filename: string;
        content: string | Buffer;
    }>;
};
/**
 * Configurable options provided to getMessageById.
 */
export type MessageIdOptions = any;
export { alterState, combine, cursor, dataPath, dataValue, each, field, fields, fn, fnIf, lastReferenceValue, log, merge, sourceValue } from "@openfn/language-common";