'use strict';

var packageData = require('../package.json');
var EventEmitter = require('events').EventEmitter;
var util = require('util');

module.exports = function (options) {
    return new StubTransport(options);
};

function StubTransport(options) {
    EventEmitter.call(this);
    this.options = options || {};
    this.name = 'Stub';
    this.version = packageData.version;
}
util.inherits(StubTransport, EventEmitter);

StubTransport.prototype.isIdle = function () {
    return true;
};

StubTransport.prototype.verify = function (callback) {
    setImmediate(function () {
        if (this.options.error) {
            return callback(new Error(this.options.error));
        }
        return callback(null, true);
    }.bind(this));
};

StubTransport.prototype.send = function (mail, callback) {

    if (this.options.error) {
        setImmediate(function () {
            callback(new Error(this.options.error));
        }.bind(this));
        return;
    }

    if (this.options.keepBcc) {
        mail.message.keepBcc = true;
    }

    var message = mail.message.createReadStream();
    var chunks = [];
    var chunklen = 0;
    var envelope = mail.data.envelope || mail.message.getEnvelope();

    this._log('info', 'envelope', JSON.stringify(envelope));
    this.emit('envelope', envelope);

    message.on('error', function (err) {
        setImmediate(function () {
            callback(err);
        });
    });

    message.on('data', function (chunk) {
        chunks.push(chunk);
        chunklen += chunk.length;

        this._log('verbose', 'message', chunk.toString());
        this.emit('data', chunk.toString());
    }.bind(this));

    message.on('end', function () {
        setImmediate(function () {
            var messageId = (mail.message.getHeader('message-id') || '').replace(/[<>\s]/g, '');
            var response = Buffer.concat(chunks, chunklen);
            var info = {
                envelope: mail.data.envelope || mail.message.getEnvelope(),
                messageId: messageId,
                response: response
            };
            this._log('info', 'end', 'Processed <%s> (%sB)', messageId, response.length);
            this.emit('end', info);
            callback(null, info);
        }.bind(this));
    }.bind(this));
};

/**
 * Log emitter
 * @param {String} level Log level
 * @param {String} type Optional type of the log message
 * @param {String} message Message to log
 */
StubTransport.prototype._log = function ( /* level, type, message */ ) {
    var args = Array.prototype.slice.call(arguments);
    var level = (args.shift() || 'INFO').toUpperCase();
    var type = (args.shift() || '');
    var message = util.format.apply(util, args);

    this.emit('log', {
        name: packageData.name,
        version: packageData.version,
        level: level,
        type: type,
        message: message
    });
};