/* global process */
const log    = require('../utils/logs.utils');          // Log Helper

const dbUser = process.env.OWL_DB_USER || 'owl';
const dbPass = process.env.OWL_DB_PASS || 'twittwoo';
const dbName = process.env.OWL_DB_NAME || 'owlboard';
const dbPort = process.env.OWL_DB_PORT || 27017;
const dbHost = process.env.OWL_DB_HOST || 'localhost';
const uri = `mongodb://${dbUser}:${dbPass}@${dbHost}:${dbPort}`;

const { MongoClient } = require('mongodb');

const client = new MongoClient(uri);
const db = client.db(dbName);

async function query(collection, query, returnId = false){
  await client.connect();
  log.out(`dbAccess.query: Connecting to collection: '${collection}'`, 'info');
  var qcoll = db.collection(collection);
  var qcursor = qcoll.find(query);
  if (!returnId) {
    qcursor.project({_id: 0});
  }
  log.out(`dbAccess.query: Running Query: ${JSON.stringify(query)}`, 'info');
  increment(collection);
  return (await qcursor.toArray());
}

async function queryProject(collection, query, projection) {
  await client.connect();
  log.out(`dbAccess.queryProject: Connecting to col: '${collection}'`, 'info');
  const qcoll = db.collection(collection);
  const qcursor = qcoll.find(query).project(projection);
  log.out(`dbAccess.query: Running Query: ${JSON.stringify(query)}, Projection: ${JSON.stringify(projection)}`, 'dbug');
  increment(collection);
  return await qcursor.toArray();
}

async function queryAggregate(collection, pipeline) {
  await client.connect();
  log.out(`dbAccess.queryProject: Connecting to col: '${collection}'`, 'info');
  log.out(`dbAccess.query: Running Aggregation: ${JSON.stringify(pipeline)}`, 'dbug');
  increment(collection);
  return await db.collection(collection).aggregate(pipeline).toArray();
}

async function increment(target) {
  log.out(`dbAccess.increment: Incrementing counter for: ${target}`, 'info');
  await client.connect();
  let col = db.collection('meta');
  let update = {};
  update[target] = 1;
  col.updateOne({target: 'counters'}, {$inc:update});
}

async function addUser(uuid, domain) { // Needs testing
  log.out('dbAccess.addUser: Adding user to database');
  let doc = {uuid: uuid, domain: domain, atime: new Date};
  await client.connect();
  let col = db.collection('users');
  let res = await col.insertOne(doc);
  if (res.insertedId) {
    return true;
  }
  return false;
}

async function addRegReq(uuid, domain) { // Needs testing
  log.out('dbAccess.addRegReq: Adding registration request');
  let doc = {uuid: uuid, time: new Date, domain: domain};
  await client.connect();
  let col = db.collection('registrations');
  let res = col.insertOne(doc);
  return res;
}

async function userAtime(uuid) { // Needs testing
  log.out('dbAccess.userAtime: Updating access time for user');
  let q = {uuid: uuid};
  let n = {$set: {uuid: uuid, atime: new Date}};
  await client.connect();
  let col = db.collection('users');
  let res = col.updateOne(q, n, {upsert: true});
  return res;
}

// Deletes one single registration request entry from the DB
async function delRegReq(uuid) {
  log.out('dbAccess.delRegReq: Deleting a Registration Request');
  let collection = 'registrations';
  await client.connect();
  let col = db.collection(collection);
  col.deleteOne({uuid: uuid});
}

async function colCount(collection) {
  log.out(`dbAccess.colCount: Counting entries in collection: ${collection}`);
  await client.connect();
  let col = db.collection(collection);
  let count = col.countDocuments();
  log.out(`dbAccess.colCount: Collection: ${collection} contains ${count}` +
          ' documents');
  return await count;
}

module.exports = {
  query,
  queryProject,
  queryAggregate,
  increment,
  addUser,
  userAtime,
  addRegReq,
  delRegReq,
  colCount
};