Factory.js

import BlankNode from './lib/BlankNode.js'
import DefaultGraph from './lib/DefaultGraph.js'
import fromTerm from './lib/fromTerm.js'
import Literal from './lib/Literal.js'
import NamedNode from './lib/NamedNode.js'
import Quad from './lib/Quad.js'
import Variable from './lib/Variable.js'

const dirLangStringDatatype = new NamedNode('http://www.w3.org/1999/02/22-rdf-syntax-ns#dirLangString')
const langStringDatatype = new NamedNode('http://www.w3.org/1999/02/22-rdf-syntax-ns#langString')
const stringDatatype = new NamedNode('http://www.w3.org/2001/XMLSchema#string')

class DataFactory {
  constructor () {
    this.init()
  }

  init () {
    this._data = {
      blankNodeCounter: 0,
      defaultGraph: new DefaultGraph()
    }
  }

  namedNode (value) {
    return new NamedNode(value)
  }

  blankNode (value) {
    value = value || ('b' + (++this._data.blankNodeCounter))

    return new BlankNode(value)
  }

  literal (value, languageOrDatatype) {
    if (typeof languageOrDatatype === 'string') {
      return new Literal(value, languageOrDatatype, langStringDatatype)
    } else if (typeof languageOrDatatype?.language === 'string') {
      return new Literal(
        value,
        languageOrDatatype.language,
        languageOrDatatype.direction ? dirLangStringDatatype : langStringDatatype,
        languageOrDatatype.direction)
    } else {
      return new Literal(value, '', languageOrDatatype || stringDatatype)
    }
  }

  variable (value) {
    return new Variable(value)
  }

  defaultGraph () {
    return this._data.defaultGraph
  }

  quad (subject, predicate, object, graph = this.defaultGraph()) {
    return new Quad(subject, predicate, object, graph)
  }

  fromTerm (original) {
    return fromTerm(this, original)
  }

  fromQuad (original) {
    return fromTerm(this, original)
  }
}

DataFactory.exports = [
  'blankNode',
  'defaultGraph',
  'fromQuad',
  'fromTerm',
  'literal',
  'namedNode',
  'quad',
  'variable'
]

export default DataFactory