'use strict';

const packageData = require('../../package.json');
const shared = require('../shared');

/**
 * Generates a Transport object for Sendmail
 *
 * Possible options can be the following:
 *
 *  * **path** optional path to sendmail binary
 *  * **newline** either 'windows' or 'unix'
 *  * **args** an array of arguments for the sendmail binary
 *
 * @constructor
 * @param {Object} optional config parameter for the AWS Sendmail service
 */
class JSONTransport {
    constructor(options) {
        options = options || {};

        this.options = options || {};

        this.name = 'JSONTransport';
        this.version = packageData.version;

        this.logger = shared.getLogger(this.options, {
            component: this.options.component || 'json-transport'
        });
    }

    /**
     * <p>Compiles a mailcomposer message and forwards it to handler that sends it.</p>
     *
     * @param {Object} emailMessage MailComposer object
     * @param {Function} callback Callback function to run when the sending is completed
     */
    send(mail, done) {
        // Sendmail strips this header line by itself
        mail.message.keepBcc = true;

        let envelope = mail.data.envelope || mail.message.getEnvelope();
        let messageId = mail.message.messageId();

        let recipients = [].concat(envelope.to || []);
        if (recipients.length > 3) {
            recipients.push('...and ' + recipients.splice(2).length + ' more');
        }
        this.logger.info(
            {
                tnx: 'send',
                messageId
            },
            'Composing JSON structure of %s to <%s>',
            messageId,
            recipients.join(', ')
        );

        setImmediate(() => {
            mail.normalize((err, data) => {
                if (err) {
                    this.logger.error(
                        {
                            err,
                            tnx: 'send',
                            messageId
                        },
                        'Failed building JSON structure for %s. %s',
                        messageId,
                        err.message
                    );
                    return done(err);
                }

                delete data.envelope;
                delete data.normalizedHeaders;

                return done(null, {
                    envelope,
                    messageId,
                    message: JSON.stringify(data)
                });
            });
        });
    }
}

module.exports = JSONTransport;