/* global Node */

const uuid = require('uuid')
const REF_ID = 'applitools-ref-id'

type RefType = 'cypress-driver' | 'element' | 'context' | 'driver' | 'function'

type Ref = {
  [REF_ID]: string
  type?: RefType
}

class Refer {
  store: Map<string, any>
  relation: Map<string, Set<Ref>>

  constructor() {
    this.store = new Map()
    this.relation = new Map()
  }

  isRef(ref: any): ref is Ref {
    // isRef(ref) {
    return Boolean(ref && ref[REF_ID])
  }

  check(value: any): RefType | undefined {
    // check(value) {
    if (!value) return
    if (value === '__CYPRESS_DRIVER__') {
      return 'cypress-driver'
    } else if (value.nodeType === Node.ELEMENT_NODE) {
      return 'element'
    } else if (value.nodeType === Node.DOCUMENT_NODE || value.ownerDocument) {
      return 'context'
    } else if (value.constructor && value.constructor.name === 'Window') {
      return 'driver'
    } else if (typeof value === 'function') {
      return 'function'
    }
  }

  ref(value: any, parentRef?: Ref) {
    // ref(value, parentRef) {
    const refType = this.check(value)
    if (refType) {
      const ref = uuid.v4()
      this.store.set(ref, value)
      if (parentRef) {
        let childRefs = this.relation.get(parentRef[REF_ID])
        if (!childRefs) {
          childRefs = new Set()
          this.relation.set(parentRef[REF_ID], childRefs)
        }
        childRefs.add({[REF_ID]: ref})
      }
      return {[REF_ID]: ref, type: refType}
    } else if (Array.isArray(value)) {
      return value.map(value => this.ref(value, parentRef))
    } else if (typeof value === 'object' && value !== null) {
      return Object.entries(value).reduce((obj, [key, value]) => {
        return Object.assign(obj, {[key]: this.ref(value, parentRef)})
      }, {})
    } else {
      return value
    }
  }

  deref(ref) {
    if (this.isRef(ref)) {
      const value = this.store.get(ref[REF_ID])
      return value === '__CYPRESS_DRIVER__' ? (cy as any).state('document') : value
    } else {
      return ref
    }
  }

  destroy(ref) {
    if (!this.isRef(ref)) return
    const childRefs = this.relation.get(ref[REF_ID])
    if (childRefs) {
      childRefs.forEach(childRef => this.destroy(childRef))
    }
    this.store.delete(ref[REF_ID])
  }
}

module.exports = Refer