const schema = require('schm')
const moment = require('moment')

const dateDefault = {
  date: moment().toISOString(),
  month: moment().format('MMMM'),
  year: moment().format('YYYY')
}

const extraStuff = prevSchema => prevSchema.merge({
  parsers: {
    transformDate: (formedDefaultOrPassedRequest, propValue, schemaProp, schema, request, someOtherStuff) => {
      console.log('----- parsers transformDate -----')
      // This is the default formed or what is in the request
      // The formed default is only passed if the request does not contain the schemaProp
      console.log('formedDefaultOrPassedRequest', formedDefaultOrPassedRequest)
      // transformDate value, in this case it is true
      console.log('propValue', propValue)
      // In this case it is occ, as the transformDate property is inside the occ object
      console.log('schemaProp', schemaProp)
      // the schema for this property (occ), this may contain the default if set
      console.log('schema', schema)
      // What has been requested to be parsed
      console.log('request', request)

      // Here we're going to just return some junk because we can
      // We could do some manipulation
      return {
        date: "aaaa",
        month: 'eee',
        year: 'ddd'
      }
    }
  },
  validators: {
    checkDate: (valueToCheck, options, schemaProp, schema, request, someOtherStuff) => {
      console.log('----- validators checkDate -----')
      // This is the value to check
      console.log('valueToCheck', valueToCheck)
      // What is the value of checkDate defined on the schema
      console.log('options', options)
      // In this case it is occ, as the checkDate property is inside the occ object
      console.log('schemaProp', schemaProp)
      // the schema for this property (occ), this may contain the default if set
      console.log('schema', schema)
      // What has been requested to be parsed/validated
      console.log('request', request)
      // Be careful, the validator will still run if the options said checkDate is false
      // Lets check if the date is a value ISO8601 date
      return {
        valid: moment(valueToCheck.date, 'YYYY-MM-DDTHH:mm:ssZ').isValid(),
        message: 'Not a valid date',
      }
    }
  }
})

const someSchema = schema({
  name: { type: String, default: null },
  occ: { 
    type: {
      date: { type: String, default: moment().toISOString() },
      month: { type: String, default: moment().format('MMMM') },
      year: { type: String, default: moment().format('YYYY')  },
    },
    default: dateDefault,
    transformDate: true,
    checkDate: true
  }
}, extraStuff)

var req = {
  name: "MrAwesome",
  occ: {
    date: "2016-12-01T13:30:30.705Z",
    month: "December",
    year: "2016"
  }
}

const valid = schema.validate(req, someSchema)
.then((res) => {
  console.log('----- result -----')
  console.log(res)
})
.catch((err) => { 
  console.log('----- error -----')
  console.log(err)
})

----- parsers transformDate -----
formedDefaultOrPassedRequest { date: '2016-12-01T13:30:30.705Z',
  month: 'December',
  year: '2016' }
propValue true
schemaProp occ
schema { type:
   { date:
      { type: [Function: String],
        default: '2018-06-28T10:23:59.877Z' },
     month: { type: [Function: String], default: 'June' },
     year: { type: [Function: String], default: '2018' } },
  default: { date: '2018-06-28T10:23:59.873Z', month: 'June', year: '2018' },
  transformDate: true,
  checkDate: true }
request { name: 'MrAwesome',
  occ:
   { date: '2016-12-01T13:30:30.705Z',
     month: 'December',
     year: '2016' } }
----- validators checkDate -----
valueToCheck { date: 'aaaa', month: 'eee', year: 'ddd' }
options { optionValue: true }
schemaProp occ
schema { type:
   { date:
      { type: [Function: String],
        default: '2018-06-28T10:23:59.877Z' },
     month: { type: [Function: String], default: 'June' },
     year: { type: [Function: String], default: '2018' } },
  default: { date: '2018-06-28T10:23:59.873Z', month: 'June', year: '2018' },
  transformDate: true,
  checkDate: true }
request { name: 'MrAwesome',
  occ: { date: 'aaaa', month: 'eee', year: 'ddd' } }
----- error -----
[ { param: 'occ',
    validator: 'checkDate',
    checkDate: true,
    message: 'Not a valid date' } ]