amcgee/remjs

var _ = require('lodash');
var BPromise = require('bluebird');
var Datastore = require('nedb');
var path = require('path');
var events = require('events');

BPromise.promisifyAll(Datastore.prototype);

var NeDBCursor = function(original) {
    this.original = BPromise.promisifyAll(original);
};
NeDBCursor.prototype.limit = function(count) {
    this.original.limit(count);
    return this;
};
NeDBCursor.prototype.skip = function(count) {
    this.original.skip(count);
    return this;
};
NeDBCursor.prototype.sort = function(order) {
    this.original.sort(order);
    return this;
};
NeDBCursor.prototype.toArray = function(callback) {
    return this.original.execAsync()
    .nodeify(callback);
};
NeDBCursor.prototype.stream = function() {
    var stream = new events.EventEmitter();
    this.original.execAsync()
    .catch(function(e) {
        stream.emit('error', e);
    })
    .each(function(item) {
        stream.emit('data', item);
    })
    .then(function() {
        stream.emit('end');
    });
    return stream;
};

var NeDBCollection = function(file) {
    this.db = new Datastore({ filename: file, autoload: true });
};

NeDBCollection.prototype.findOne = function(query, projection, callback) {
    return this.db.findOneAsync(query, projection)
    .nodeify(callback);
};
NeDBCollection.prototype.find = function(query, projection) {
    return new NeDBCursor( this.db.find(query, projection) );
};
NeDBCollection.prototype.insert = function(obj, opt, callback) {
    return this.db.insertAsync(obj)
    .then(function(obj) {
        return [obj];
    })
    .nodeify(callback);
};
NeDBCollection.prototype.update = function(query, obj, opt, callback) {
    return this.db.updateAsync(query, obj, opt)
    .nodeify(callback);
};
NeDBCollection.prototype.remove = function(query, opt, callback) {
    return this.db.removeAsync(query, opt)
    .nodeify(callback);
};

var NeDBEngine = function(options) {
    this.options = _.cloneDeep(options || {});
    this.dbs = {};
    if ( !this.options.dbFiles && !this.options.rootDirectory ) {
        throw new Error("No database files specified for NeDB engine.");
    }

    _.forEach( this.options.dbFiles, function(file, name) {
        this.dbs[name] = this._create( name, file );
    }.bind(this));
};
NeDBEngine.prototype.collection = function(name) {
    if ( !this.dbs[name] ) {
        this.dbs[name] = this._create( name );
    }
    return this.dbs[name];
};
NeDBEngine.prototype._create = function( name, file ) {
    if ( !file && this.options.createCollection ) {
        return this.options.createCollection( name );
    }
    else {
        if ( !file ) {
            if ( !this.options.rootDirectory ) {
                throw new Error(
                "Unknown collection specified and no NeDB root directory specified." );
            }
            file = path.join( this.options.rootDirectory, name + '.db' );
        }

        return new NeDBCollection(file);
    }
};

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