mongo.js

// Establish connection with the server
var connectionString = process.env.CURATES_DB_URI || process.env.WERCKER_MONGODB_URL;

var mongoose = require('mongoose');
mongoose.connect(connectionString);
var db = mongoose.connection;

// Attach useful listeners to the database
db.on('error', function(error) {
  console.error('Mongoose encountered an error:', error);
});

db.once('open', function() {
  console.log('Mongoose successfully opened connection with the database');
});

// Set up Schema
var collectionSchema = new mongoose.Schema({
  title: {
    type: String,
    required: true
  },
  url: {
    type: String,
    required: true
  },
  user: {
    type: {
      provider: String,
      id: String,
      fullName: String,
      givenName: String
    },
    required: true
  },
  description: {
    type: String,
    required: true
  },
  links: [{
    url: String,
    title: String,
    description: String,
    stars: {
      type: Number,
      default: 0
    }
  }],
  userStars: {
    type: [],
    default: []
  },
  createdAt: {
    type: Date,
    default: Date.now
  },
  updatedAt: {
    type: Date,
    default: Date.now
  },
  stars: {
    type: Number,
    default: 0
  }
});
var Collection = mongoose.model('Collection', collectionSchema);

// Used to retrieve only these fields in some queries
var metaFields = '_id title url user description stars';

// mongo will be exported. This is the interface for using the database.
var mongo = {};

// An function for mapping a collection title to a url
mongo.mapTitleToUrl = function(title) {
  // These are the allowed charachters, all others are removed
  return title.replace(/[^A-Za-z0-9\-]/g, '').toLowerCase();
};

// Attempts to create a new collection
// If there is already a collection in the db with the same url,
// returns null, else
// Returns a promise
mongo.create = function(coll) {
  // Sets the url if it not already set
  // Should this even be an option? maybe it should require the
  // url to be set here?
  if (!coll.url) {
    coll.url = mongo.mapTitleToUrl(coll.title);
  }
  // Check that url is unique
  return mongo.findByUrl(coll.url).then(function(collection) {
    if (collection) return null;
    return Collection.create(coll);
  });
};

// Attempts to find the collection with the given id
// Returns a promise
mongo.findById = function(id) {
  return Collection.findById(id).exec();
};

// Attempts to find ONE collection by the given title
// Returns a promise
mongo.findByTitle = function(title) {
  return Collection.findOne({
    title: title
  }).exec();
};

// Attempts to find ONE collection with the given url
// There should never be multiple collections with the same url
// Returns a promise
mongo.findByUrl = function(url) {
  return Collection.findOne({
    url: url
  }).exec();
};

// Saves changes of the given collection to the database
// Note: url, title, and user should not be changed, TODO: validate for this?
// Returns a promise that resolves to the new collection
mongo.update = function(collection) {
  // default find by id (fastest)
  if (collection._id) {
    var id = collection._id;
    delete collection._id;
    collection.updatedAt = Date.now();
    return Collection.findByIdAndUpdate(id, collection).exec();
  } else {
    // find by title (mostly to make testing easier)
    collection.updatedAt = Date.now();
    return Collection.findOneAndUpdate({
        title: collection.title
      },
      collection
    ).exec();
  }
};

// Adds a link to the given document
// Expects data to have _id and links properties:
//  {
//    _id: the collection to add to
//    links: [
//      { url: String, title: String, description: String }
//    ]
//  }
// Can add an arbitrary number of links
mongo.addLink = function(data) {
  return Collection.findByIdAndUpdate(data._id, {
    $push: {
      links: {
        $each: data.links
      }
    }
  }).exec();
};

// If the provided user has not already starred this
// collection, adds a star to the collection
//
// Expects data to have _id and user properties:
//  {
//    _id: the collection to add to
//    user: [
//      {
//        provider: String,
//        id: String,
//        fullName: String,
//        givenName: String
//      }
//    ]
//  }
// Returns a promise that resolves to the updated collections
mongo.addStar = function(data) {
  // Stringify the user
  // This should be unique to every user
  var userString = data.user.provider + data.user.id;
  return Collection.findByIdAndUpdate(data._id, {
    $addToSet: { userStars: userString }
  }).exec()
  .then(function(collection) {
    var update = {};
    update._id = collection._id;
    update.stars = collection.userStars.length;
    return mongo.update(update);
  });
};

// Returns a promise that resolves to an array of objects, each
// containing the meta data of all the collections in the database
mongo.getAllCollections = function() {
  return Collection.find({}, metaFields).exec();
};

// Returns a promise that resolves to an array of objects, each
// containing the meta data of all the collections created by the
// given user
mongo.getUserCollections = function(user) {
  return Collection.find({
    'user.provider': user.provider,
    'user.id': user.id
  }, metaFields).exec();
};

module.exports = mongo;