/**
 * @requires fs
 */
const fs = require('fs')
/**
 * @requires ./config.js
 * @description Loads the application configuration, containing the fileStore value
 */ 
const config = require('./config.js')
/**
 * @constant
 * @type {object}
 * @description Points to the location of the assessment JSON files from config().fileStore
 */
const fileStore = './src' + config().fileStore
/**
 * @constant
 * @type {array}
 * @description A list of assessment JSON files in the fileStore
 */
const files = fs.readdirSync(fileStore)
/**
 * @requires lunr
 */
const lunr = require('lunr')
/**
 * @constant
 * @type {integer}
 * @default 2007
 * @description This is the first year we want to create items for in the assessmentsByYear object. It represents when EASA time began
 */
const startYear = 2007

var assessments = new Array

/**
 * This block iterates through the assessment JSON files read from the fileStore location from config()
 * For each file, it parses the JSON and reads the fields needed for the index and search outputs
 * It places these into an object corresponding to the assessment type
 */
for (const key in files) {
  if (files[key] != 'index.json' && files[key] != 'search.json') {
    var data = JSON.parse(fs.readFileSync((fileStore + files[key])))
    var assessmentType = Object.keys(data)[0]
    /**
     * @type {object}
     * @description Because lunr interprets '-' as a special character, for the 'easa' assessment type we need a search field with it stripped out. This is in assessment.numberNoDash
     */
    var assessment = new Object
    switch (assessmentType) {
      case 'easa':
        var easa = eval('data.' + assessmentType)
        assessment.id = easa.id + '_v' + easa.revision
        assessment.number = easa.id
        assessment.numberNoDash = easa.id.replace(/-/g, '')
        assessment.agency = easa.agency
        assessment.title = easa.solution_name
        assessment.solution_name = easa.easa_name + ' ' + easa.solution_name
        assessment.date = easa.completion_date
        assessment.description =
          easa.brief_description + ' ' +
          easa.additional_description + ' ' +
          easa.changes
        break;
      case 'tsa':
        var tsa = eval('data.' + assessmentType)
        assessment.id = tsa.id
        assessment.number = tsa.id
        assessment.numberNoDash = tsa.id.replace(/-/g, '')
        assessment.agency = tsa.agency
        assessment.title = tsa.clarity_data.idea_name
        assessment.solution_name = tsa.clarity_data.idea_name
        assessment.date = tsa.completion_date
        assessment.description =
          tsa.description + ' ' +
          tsa.clarity_data.idea_objective
        break;
      default:
        break;
    }
    assessments[key] = assessment
  }
}

/**
 * @type {object}
 * @description This is the lunr search index, created by adding the appropriate fields from the assessments array and writing it to search.json
 */
var idx = lunr(function () {
  this.ref('id')
  this.field('numberNoDash')
  this.field('agency')
  this.field('solution_name')
  this.field('description')

  for (const assessment of assessments) {
    this.add(assessment)
  }
})

fs.writeFileSync(fileStore + 'search.json', JSON.stringify(idx))

/**
 * @type {object}
 * @description For the index that index.vue parses, we need to split the assessments array into years, starting with startYear. We then write this to index.json
 */
var assessmentsByYear = new Object
for (let index = startYear; index <= new Date().getFullYear(); index++) {
  assessmentsByYear[index.toString()] = assessments.filter((assessment) => assessment.id.slice(0,4) == index)
}

fs.writeFileSync(fileStore + 'index.json', JSON.stringify(assessmentsByYear))