import { hasCapability } from '../tools.js';
/**
 * Enables IMAP extensions on the server.
 *
 * @param connection - IMAP connection instance
 * @param extensionList - List of extension names to enable
 * @returns Set of enabled extensions, false on failure, or undefined if not applicable
 */
export default async function enable(connection, extensionList) {
    // ENABLE is part of base IMAP4rev2, so rev2-only servers may omit the token
    if (!hasCapability(connection, 'ENABLE') || connection.state !== connection.states.AUTHENTICATED) {
        // nothing to do here
        return;
    }
    // Pre-filter: only request extensions the server actually advertised in its
    // CAPABILITY response. Requesting unsupported extensions would cause an error.
    // Compared case-insensitively - the capability map keeps canonical casing for
    // some keys (e.g. IMAP4rev2).
    let advertised = new Set([...connection.capabilities.keys()].map(capability => capability.toUpperCase()));
    extensionList = extensionList.filter(extension => advertised.has(extension.toUpperCase()));
    if (!extensionList.length) {
        return;
    }
    let response;
    try {
        let enabled = new Set();
        response = await connection.exec('ENABLE', extensionList.map((extension) => ({ type: 'ATOM', value: extension.toUpperCase() })), {
            untagged: {
                // The untagged ENABLED response is a flat list of extension names
                // (e.g., "* ENABLED CONDSTORE UTF8=ACCEPT"), NOT key-value pairs.
                // Each attribute is a single extension identifier.
                ENABLED: async (untagged) => {
                    if (!untagged.attributes || !untagged.attributes.length) {
                        return;
                    }
                    untagged.attributes.forEach(attr => {
                        let value = attr.value;
                        if (value && typeof value === 'string') {
                            enabled.add(value.toUpperCase().trim());
                        }
                    });
                }
            }
        });
        // Merge instead of replace - the untagged ENABLED response only lists
        // extensions enabled by this command (RFC 5161), so a replace would drop
        // grants from an earlier ENABLE call
        connection.enabled = new Set([...connection.enabled, ...enabled]);
        if (connection.enabled.has('QRESYNC')) {
            // ENABLE QRESYNC is a CONDSTORE enabling command (RFC 7162 3.2.3), whether or not the
            // server lists CONDSTORE in its ENABLED answer. Apache James advertises only QRESYNC
            // and leaves a lone ENABLE CONDSTORE unanswered, which the RFC allows.
            connection.enabled.add('CONDSTORE');
        }
        response.next();
        return connection.enabled;
    }
    catch (err) {
        connection.log.warn({ err, cid: connection.id });
        return false;
    }
}