module.exports = function (RED) {
    'use strict'
    const mongo = require('mongodb')
    const ObjectID = require('mongodb').ObjectID
    const MongoClient = mongo.MongoClient

    function MongoConfigNode(n) {
        RED.nodes.createNode(this, n)
        this.hostname = n.hostname
        this.port = n.port
        this.db = n.db
        this.name = n.name


        var url = 'mongodb://'
        if (this.credentials && this.credentials.user && this.credentials.password) {
            url += this.credentials.user + ':' + this.credentials.password + '@'
        }
        url += this.hostname + ':' + this.port + '/' + this.db

        this.url = url
    }

    RED.nodes.registerType('mongodb-config', MongoConfigNode, {
        credentials: {
            user: { type: 'text' },
            password: { type: 'password' }
        }
    })

    function ensureValidSelectorObject(selector) {
        if (selector != null && (typeof selector != 'object' || Buffer.isBuffer(selector))) {
            return {}
        }
        return selector
    }

    function MongoNode(n) {
        RED.nodes.createNode(this, n)
        this.collection = n.collection
        this.mongodb = n.mongodb
        this.payonly = n.payonly || false;
        this.operation = n.operation || 'find'
        this.mongoConfig = RED.nodes.getNode(this.mongodb)
        this.status({ fill: 'grey', shape: 'ring', text: RED._('mongodb.status.connecting') })
        var node = this
        var noerror = true
        this.upsert = n.upsert || false;
        this.multi = n.multi || false;

        var connectToDB = function () {
            MongoClient.connect(
                node.mongoConfig.url,
                function (err, db) {
                    if (err) {
                        node.status({ fill: 'red', shape: 'ring', text: RED._('mongodb.status.error') })
                        if (noerror) {
                            node.error(err)
                        }
                        noerror = false
                        node.tout = setTimeout(connectToDB, 10000)
                    } else {
                        node.status({ fill: 'green', shape: 'dot', text: RED._('mongodb.status.connected') })
                        node.clientDb = db
                        noerror = true
                        var coll
                        if (node.collection) {
                            coll = db.collection(node.collection)
                        }
                        node.on('input', function (msg) {
                            if (!node.collection) {
                                if (msg.collection) {
                                    coll = db.collection(msg.collection)
                                } else {
                                    node.error(RED._('mongodb.errors.nocollection'))
                                    return
                                }
                            } else {
                                coll = db.collection(node.collection)
                            }
                            var selector
                            if (node.operation === 'find') {
                                msg.projection = msg.projection || {}
                                selector = ensureValidSelectorObject(msg.payload)
                                var limit = msg.limit
                                if (typeof limit === 'string' && !isNaN(limit)) {
                                    limit = Number(limit)
                                } else if (typeof limit === 'undefined') {
                                    limit = 0
                                }
                                var skip = msg.skip
                                if (typeof skip === 'string' && !isNaN(skip)) {
                                    skip = Number(skip)
                                } else if (typeof skip === 'undefined') {
                                    skip = 0
                                }

                                coll
                                    .find(selector, msg.projection)
                                    .sort(msg.sort)
                                    .limit(limit)
                                    .skip(skip)
                                    .toArray(function (err, items) {
                                        if (err) {
                                            node.error(err)
                                        } else {
                                            msg.payload = items
                                            delete msg.projection
                                            delete msg.sort
                                            delete msg.limit
                                            delete msg.skip
                                            node.send(msg)
                                        }
                                    })
                            } else if (node.operation === 'count') {
                                selector = ensureValidSelectorObject(msg.payload)
                                coll.count(selector, function (err, count) {
                                    if (err) {
                                        node.error(err)
                                    } else {
                                        msg.payload = count
                                        node.send(msg)
                                    }
                                })
                            } else if (node.operation === 'aggregate') {
                                msg.payload = Array.isArray(msg.payload) ? msg.payload : []
                                coll.aggregate(msg.payload, function (err, result) {
                                    if (err) {
                                        node.error(err)
                                    } else {
                                        msg.payload = result
                                        node.send(msg)
                                    }
                                })
                            } else if (node.operation === 'store') {
                                if (node.payonly) {
                                    if (typeof msg.payload !== 'object') {
                                        msg.payload = { payload: msg.payload }
                                    }
                                    if (msg.hasOwnProperty('_id') && !msg.payload.hasOwnProperty('_id')) {
                                        msg.payload._id = msg._id
                                    }
                                    coll.save(msg.payload, function (err, item) {
                                        if (err) {
                                            node.error(err, msg)
                                        } else {
                                            msg.payload = item
                                            node.send(msg)
                                        }
                                    })
                                }
                                else {
                                    coll.save(msg, function (err, item) {
                                        if (err) {
                                            node.error(err, msg);
                                        }
                                    });
                                }
                            } else if (node.operation === 'insert') {
                                if (node.payonly) {
                                    if (typeof msg.payload !== 'object') {
                                        msg.payload = { payload: msg.payload }
                                    }
                                    if (msg.hasOwnProperty('_id') && !msg.payload.hasOwnProperty('_id')) {
                                        msg.payload._id = msg._id
                                    }
                                    coll.insert(msg.payload, function (err, item) {
                                        if (err) {
                                            node.error(err, msg)
                                        } else {
                                            msg.payload = item
                                            node.send(msg)
                                        }
                                    })
                                }
                                else {
                                    coll.insert(msg, function (err, item) {
                                        if (err) {
                                            node.error(err, msg);
                                        }
                                    });
                                }
                            } else if (node.operation === 'update') {
                                if (typeof msg.payload !== 'object') {
                                    msg.payload = { payload: msg.payload }
                                }
                                var query = msg.query || {}
                                var payload = msg.payload || {}
                                var options = {
                                    upsert: node.upsert,
                                    multi: node.multi
                                }
                                if (ObjectID.isValid(msg.query._id)) {
                                    msg.query._id = new ObjectID(msg.query._id)
                                }
                                coll.update(query, payload, options, function (err, item) {
                                    if (err) {
                                        node.error(err, msg)
                                    } else {
                                        msg.payload = item
                                        node.send(msg)
                                    }
                                })
                            } else if (node.operation === 'delete') {
                                coll.remove(msg.payload, function (err, items) {
                                    if (err) {
                                        node.error(err, msg)
                                    } else {
                                        msg.payload = items
                                        node.send(msg)
                                    }
                                })
                            }
                        })
                    }
                }
            )
        }

        if (node.mongoConfig) {
            connectToDB()
        } else {
            node.error(RED._('mongodb.errors.missingconfig'))
        }

        node.on('close', function () {
            node.status({})
            if (node.tout) {
                clearTimeout(node.tout)
            }
            if (node.clientDb) {
                node.clientDb.close()
            }
        })
    }
    RED.nodes.registerType('mongodb', MongoNode)
}