api.js

'use strict'

var bodyParser = require('body-parser')
var indicative = require('indicative')
var Promise = require('bluebird')
var _ = require('lodash')
var nodemailer = require('nodemailer')
var API_VERSION = 1

/**
 * @param app
 * @param config
 * @param logging
 * @param {Repository} SmtpCredentialRepository
 * @param {Repository} TemplateRepository
 */
module.exports = function (app, config, logging, SmtpCredentialRepository, TemplateRepository) {
  app.enable('trust proxy')
  app.use(function (req, res, next) {
    res.header('Cache-Control', 'max-age=0, private')
    next()
  })

  var CONTENT_TYPE = 'application/vnd.' + config.get('app') + '.v' + API_VERSION + '+json'
  app.use(bodyParser.json({type: CONTENT_TYPE}))

  function errorResponse (res, err, status) {
    logging.info(err.message, {error: err})
    status = status || 500
    res.status(status)
      .set('Content-Type', CONTENT_TYPE)
      .send({
        $context: 'https://www.ietf.org/id/draft-ietf-appsawg-http-problem-01.txt',
        type: '/error/' + status,
        title: err.name,
        status: status,
        detail: err.message
      })
    /**
     * See https://datatracker.ietf.org/doc/draft-ietf-appsawg-http-problem/
     * @param {String} type     A URI reference [RFC3986] that identifies the problem type.
     *                          When dereferenced, it is encouraged to provide  human-readable documentation for the
     *                          problem type (e.g., using  HTML [W3C.REC-html401-19991224]). When this member is not
     *                          present, its value is assumed to be "about:blank".
     * @param {String} title    A short, human-readable summary of the problem type. It SHOULD NOT change from occurrence
     *                          to occurrence of the problem, except for purposes of localisation.
     * @param {Number} status   The HTTP status code ([RFC7231], Section 6) generated by the origin server for this
     *                          occurrence of the problem.
     * @param {String} detail   An human readable explanation specific to this occurrence of the problem.
     * @constructor
     */
  }

  function createValidationErrorResponse (res, errors) {
    return errorResponse(res, new Error(_.reduce(errors, function (msg, err) {
      msg.push(err.message)
      return msg
    }, []).join(', ')), 400)
  }

  function createResource (repo, bodySchema, req, res) {
    return Promise.join(
      indicative.validate(req.params, {id: 'alpha_numeric'}),
      indicative.validate(req.body, bodySchema)
      )
      .then(function () {
        return repo.store(req.params.id, req.body)
          .then(function () {
            return res.status(201)
              .set('Content-Type', CONTENT_TYPE)
              .set('Location', req.url)
              .send()
          })
          .catch(function (err) {
            return errorResponse(res, err)
          })
      })
      .catch(createValidationErrorResponse.bind(null, res))
  }

  app.put('/smtp_credentials/:id', createResource.bind(createResource, SmtpCredentialRepository,
    {
      dsn: ['required', 'regex:^[a-z]+://[^:]+:[^@]+@[^:]+:\\d+$'],
      email: 'required|email',
      bcc: 'email',
      name: 'required'
    }))
  app.put('/templates/:id', createResource.bind(createResource, TemplateRepository,
    {
      subject: 'required',
      html: 'required'
    }))

  function listResources (repo, transformer, req, res) {
    return repo.list()
      .then(function (items) {
        return res.status(200)
          .set('Content-Type', CONTENT_TYPE)
          .send(_.map(items, transformer.bind(transformer, req)))
      })
      .catch(function (err) {
        return errorResponse(res, err)
      })
  }

  app.get('/smtp_credentials', listResources.bind(listResources, SmtpCredentialRepository, function (req, item) {
    return {
      $context: 'https://jsonld.nametacker.com/SmtpCredentials',
      $id: req.url + '/' + item[0],
      dsn: item[1].dsn,
      email: item[1].email,
      name: item[1].name
    }
  }))
  app.get('/templates', listResources.bind(listResources, TemplateRepository, function (req, item) {
    return {
      $context: 'https://jsonld.nametacker.com/Template',
      $id: req.url + '/' + item[0],
      subject: item[1].subject,
      html: item[1].html
    }
  }))

  // Mail sending
  app.post('/send/:transport/:template', function (req, res) {
    return Promise.join(
      indicative.validate(req.params, {transport: 'alpha_numeric', template: 'alpha_numeric'}),
      indicative.validate(req.body, {
        to: 'required|email',
        name: 'required'
      })
      )
      .then(function () {
        return Promise.join(
          SmtpCredentialRepository.fetch(req.params.transport),
          TemplateRepository.fetch(req.params.template)
          )
          .spread(function (transport, template) {
            if (!transport || !template) {
              return res.status(404)
                .set('Content-Type', CONTENT_TYPE)
                .send()
            }
            // Try to apply template
            var subject
            var html
            return Promise.try(function () {
              subject = _.template(template.subject)(req.body)
              html = _.template(template.html)(req.body)
            }).then(function () {
              return Promise.try(function () {
                logging.info('Sending mail to "' + req.body.to + '" template: "' + req.params.template + '" via "' + req.params.transport + '"', req.body)
                var headers = {}
                headers['X-' + config.get('app')] = 'v' + config.get('version')
                var dsn = transport.dsn.match(/^([a-z]+):\/\/([^:]+):([^@]+)@([^:]+):(\d+)$/)
                var nodemailerConfig = {
                  host: dsn[4],
                  auth: {
                    user: dsn[2],
                    pass: dsn[3]
                  },
                  port: dsn[5],
                  secure: dsn[1] === 'ssl'
                }
                var transporter = nodemailer.createTransport(
                  nodemailerConfig,
                  {
                    from: '"' + transport.name + '" <' + transport.email + '>',
                    headers: headers
                  }
                )
                // Send response
                res.status(202)
                  .set('Content-Type', CONTENT_TYPE)
                  .send()
                // Send mail
                Promise.promisifyAll(transporter)
                var mailConfig = {
                  to: '"' + req.body.name + '" <' + req.body.to + '>',
                  subject: subject,
                  html: html
                }
                if (transport.bcc) {
                  mailConfig.bcc = transport.bcc
                }
                return transporter.sendMailAsync(mailConfig)
              })
              .then(function () {
                logging.info(
                  'Successfully send mail to "' + req.body.to +
                  '" template: "' + req.params.template + '" via "' + req.params.transport + '"',
                  {body: req.body}
                )
              })
              .catch(function (err) {
                logging.error('Failed to send mail to "' + req.body.to + '" template: "' + req.params.template +
                  '" via "' + req.params.transport + '"',
                  {
                    body: req.body,
                    error: err
                  }
                )
              })
            })
          })
          .catch(function (err) {
            return errorResponse(res, err, 400)
          })
      })
      .catch(createValidationErrorResponse.bind(null, res))
  })
}