const cron = require('cron');
const { model } = require('mongoose');
const schema = require('./event.schema.js');
const LogModel = require('../logs/log.model.js');

const CronJob = cron.CronJob;

schema.methods.log = function(message) {
  const dateOpts = { timeStyle: 'medium', dateStyle: 'short' };
  const timestamp = new Date().toLocaleString('en', dateOpts);
  console.log(`[${timestamp}] ${this.name}: ${message}`);

  return LogModel.create({
    eventId: this._id,
    message
  });
};

schema.methods.start = function() {
  this.log('Event started')
  this.lastRunAt = new Date();
  this.status = 'running';
  return this.save();
};

schema.methods.complete = function() {
  this.log('Event complete')
  this.status = 'complete';
  return this.save();
};

schema.methods.fail = function(error) {
  this.log(error);
  this.error = error;
  this.status = 'failed';
  return this.save();
};

schema.methods.computeNextRunAt = function() {
  const job = new CronJob(this.schedule);
  const nextRunAt = job.nextDates();
  return new Date(nextRunAt);
};

schema.pre('save', function(next) {
  this.nextRunAt = this.computeNextRunAt();
  next();
});

schema.statics.findMissedEvents = async function () {
  return this.find({
    nextRunAt: {
      // TODO: skip single-fire events
      $lt: new Date()
    },
  });
};

schema.statics.findNextEvents = function(limit = 10) {
  return this.find(
    {
      nextRunAt: {
        $gt: new Date()
      },
    },
    null,
    {
      sort: {
        nextRunAt: 1
      },
      limit
    }
  )
};

const Model = model('Event', schema);


module.exports = Model;