const { Engine } = require('json-rules-engine')


/**
 * Setup a new engine
 */
let engine = new Engine()

// define a rule for detecting the player has exceeded foul limits.  Foul out any player who:
// (has committed 5 fouls AND game is 40 minutes) OR (has committed 6 fouls AND game is 48 minutes)
engine.addRule({
  conditions: {
    any: [{
      all: [{
        fact: 'gameDuration',
        operator: 'equal',
        value: 40
      }, {
        fact: 'personalFoulCount',
        operator: 'greaterThanInclusive',
        value: 5
      }]
    }, {
      all: [{
        fact: 'gameDuration',
        operator: 'equal',
        value: 48
      }, {
        fact: 'personalFoulCount',
        operator: 'greaterThanInclusive',
        value: 6
      }]
    }]
  },
  event: {  // define the event to fire when the conditions evaluate truthy
    type: 'fouledOut',
    params: {
      message: 'Player has fouled out!'
    }
  }
})

/**
 * Define facts the engine will use to evaluate the conditions above.
 * Facts may also be loaded asynchronously at runtime; see the advanced example below
 */
let facts = {
  personalFoulCount: 6,
  gameDuration: 40
}

// Run the engine to evaluate
engine
  .run(facts)
  .then(({ events }) => {
    events.map(event => console.log(event.params.message))
  })

/*
 * Output:
 *
 * Player has fouled out!
 */

const { Engine } = require('json-rules-engine')

// example client for making asynchronous requests to an api, database, etc
import apiClient from './account-api-client'

/**
 * Setup a new engine
 */
let engine = new Engine()

/**
 * Rule for identifying microsoft employees taking pto on christmas
 *
 * the account-information fact returns:
 *  { company: 'XYZ', status: 'ABC', ptoDaysTaken: ['YYYY-MM-DD', 'YYYY-MM-DD'] }
 */
let microsoftRule = {
  conditions: {
    all: [{
      fact: 'account-information',
      operator: 'equal',
      value: 'microsoft',
      path: '$.company' // access the 'company' property of "account-information"
    }, {
      fact: 'account-information',
      operator: 'in',
      value: ['active', 'paid-leave'], // 'status' can be active or paid-leave
      path: '$.status' // access the 'status' property of "account-information"
    }, {
      fact: 'account-information',
      operator: 'contains', // the 'ptoDaysTaken' property (an array) must contain '2016-12-25'
      value: '2016-12-25',
      path: '$.ptoDaysTaken' // access the 'ptoDaysTaken' property of "account-information"
    }]
  },
  event: {
    type: 'microsoft-christmas-pto',
    params: {
      message: 'current microsoft employee taking christmas day off'
    }
  }
}
engine.addRule(microsoftRule)

/**
 * 'account-information' fact executes an api call and retrieves account data, feeding the results
 * into the engine.  The major advantage of this technique is that although there are THREE conditions
 * requiring this data, only ONE api call is made.  This results in much more efficient runtime performance
 * and fewer network requests.
 */
engine.addFact('account-information', function (params, almanac) {
  console.log('loading account information...')
  return almanac.factValue('accountId')
    .then((accountId) => {
      return apiClient.getAccountInformation(accountId)
    })
})

// define fact(s) known at runtime
let facts = { accountId: 'lincoln' }
engine
  .run(facts)
  .then(({ events }) => {
    console.log(facts.accountId + ' is a ' + events.map(event => event.params.message))
  })

/*
 * OUTPUT:
 *
 * loading account information... // <-- API call is made ONCE and results recycled for all 3 conditions
 * lincoln is a current microsoft employee taking christmas day off
 */

// set debug flag in local storage & refresh page to see console output
localStorage.debug = 'json-rules-engine'