import { CartBaseController } from './cart_base_controller'

/*
 * Manages the cart and its contents.
 *
 * We need to create an order in Spree API to get a token that allows to
 * make changes to it.
 *
 * The order contains attributes for the order and other data can be
 * included, like line items, variants, payments, promotions, shipments,
 * billing and shipping addresses, and the user.
 *
 * Variants are products added to the cart.  To remove an item or change
 * its quantity, a line item for the variant must be found.  We store
 * this information into localStorage so we don't have to make annoying
 * queries to JSON:API everytime.
 */

export default class extends CartBaseController {
  static targets = [ 'quantity', 'subtotal', 'addedQuantity' ]

  connect () {
    if (!this.hasQuantityTarget) return

    /*
     * When the quantity selector changes, we update the order to have
     * that amount of items.
     *
     * TODO: Go back to previous amount if there's not enough.
     */
    this.quantityTarget.addEventListener('change', async (event) => {
      const quantity = event.target.value

      if (quantity < 1) return;

      const orderToken = await this.tokenGetOrCreate()

      event.target.disabled = true

      const response = await this.spree.cart.setQuantity({ orderToken }, {
        line_item_id: this.product.line_item.id,
        quantity,
        include: 'line_items'
      })

      event.target.disabled = false
      event.target.focus()

      // If we're failing here it could be due to a missing order, so we
      // ask the user to decide what they want to do about it
      if (response.isFail()) {
        this.handleFailure(response)
        return
      }

      this.cart = response
      this.subtotalUpdate()
      this.counterUpdate()
      await this.itemStore()

      if (!this.hasSubtotalTarget) return

      this.subtotalTarget.innerText = this.product.line_item.attributes.discounted_amount
    })
  }

  subtotalUpdate () {
    window.dispatchEvent(new Event('cart:subtotal:update'))
  }

  /*
   * Creates an order and stores the data into localStorage.
   *
   * @return [String]
   */
  async cartCreate () {
    const response = await this.spree.cart.create()

    // If we fail here it's probably a server error, so we inform the
    // user.
    if (response.isFail()) {
      this.handleFailure(response)
      return
    }

    this.cart = response
    this.storage.setItem('token', response.success().data.attributes.token)

    return this.token
  }

  /*
   * Gets the order token and creates a cart if it doesn't exist.
   *
   * @return [String]
   */
  async tokenGetOrCreate () {
    let token = this.storage.getItem('token')

    return token || await this.cartCreate()
  }

  /*
   * The variant ID is used to identify products
   *
   * @return [String]
   */
  get variantId () {
    return this.data.get('variantId')
  }

  get product () {
    return JSON.parse(this.storage.getItem(this.storageId))
  }

  /*
   * Obtains the line_item_id by a variant_id by inspecting the cart and
   * its included items
   *
   * @return [Object]
   */
  findLineItem () {
    const line_item = this.cart.included.find(x => (x.type === 'line_item' && x.relationships.variant.data.id == this.variantId))

    return (line_item || {})
  }

  get storageId () {
    return `cart:item:${this.variantId}`
  }

  /*
   * Stores an item for later usage.
   *
   * @see {./order_controller.js}
   */
  itemStore () {
    this.storage.setItem(this.storageId, JSON.stringify({
      variant_id: this.variantId,
      line_item: this.findLineItem(),
      image: this.data.get('image'),
      title: this.data.get('title'),
      url: this.data.get('url'),
      stock: this.data.get('stock'),
      in_stock: this.data.get('inStock'),
      extra: this.data.get('extra') ? this.data.get('extra').split('|') : []
    }))
  }

  /*
   * Adds item to cart.  This is meant to be used by an "Add to cart"
   * button.  If the item already exists in the cart it updates the
   * quantity by +1.
   *
   * The item needs a variant ID to be added.
   */
  async add(event, quantity = 1, floating_alert = true) {
    const addedQuantity = this.addedQuantity()
    if (addedQuantity > 1) quantity = addedQuantity

    const orderToken = await this.tokenGetOrCreate()
    const response = await this.spree.cart.addItem({ orderToken }, { variant_id: this.variantId, quantity, include: 'line_items' })

    if (response.isFail()) {
      this.handleFailure(response)
      return
    }

    this.cart = response
    this.itemStore()
    this.counterUpdate()
    this.fireCajon()

    if (floating_alert) {
      const site = await this.site()
      const content = site.cart.added
      window.dispatchEvent(new CustomEvent('floating:alert', { detail: { content }}))
    }
  }

  /*
   * Remove the element from the cart.  It contacts the API and if the
   * item is removed, it removes itself from the page and the storage.
   */
  async remove () {
    if (!this.product.line_item) return

    const orderToken = this.token
    const response = await this.spree.cart.removeItem({ orderToken }, this.product.line_item.id, { include: 'line_items' })

    if (response.isFail()) {
      this.handleFailure(response)
      return
    }

    this.cart = response
    this.storage.removeItem(this.storageId)
    this.element.remove()
    this.subtotalUpdate()
    this.counterUpdate()
  }

  /*
   * Shows variants
   */
  async variants () {
    const template = 'variants'
    const data = {
      product: {
        variant_id: this.data.get('variantId'),
        digital_variant_id: this.data.get('digitalVariantId'),
        image: this.data.get('image'),
        title: this.data.get('title'),
        price: this.data.get('price'),
        digital_price: this.data.get('digitalPrice'),
        in_stock: this.data.get('inStock'),
        extra: this.data.get('extra').split('|')
      }
    }

    window.dispatchEvent(new CustomEvent('notification', { detail: { template, data } }))
  }

  /*
   * Recovers the order if something failed
   */
  async recover () {
    // Removes the failing token
    this.storage.removeItem('token')

    // Stores the previous cart
    const cart = this.cart

    // Get a new token and cart
    await this.tokenGetOrCreate()

    // Add previous items and their quantities to the new cart by
    // mimicking user's actions
    //
    // XXX: We don't use forEach because it's not async
    for (const variant of cart.data.relationships.variants.data) {
      this.data.set('variantId', variant.id)

      const product = this.product

      this.data.set('image', product.image)
      this.data.set('title', product.title)
      this.data.set('extra', product.extra.join('|'))

      await this.add(null, product.line_item.attributes.quantity, false)
    }
  }

  /*
   * Si le compradore aumenta la cantidad antes de agregar
   */
  addedQuantity () {
    if (!this.hasAddedQuantityTarget) return 0

    const addedQuantity = parseInt(this.addedQuantityTarget.value)

    return (isNaN(addedQuantity) ? 0 : addedQuantity)
  }
}