import type { Cart, LineItem, ProductVariant, SelectedOption } from '@commerce/types/cart';
import MissingLineItemVariantError from '../../errors/MissingLineItemVariantError';
import { requireConfigValue } from '../../isomorphic-config';
import type { OrderAttr } from '@spree/storefront-api-v2-sdk/types/interfaces/Order';
import type { ProductAttr } from '@spree/storefront-api-v2-sdk/types/interfaces/Product';
import type { Image } from '@commerce/types/common';
import { jsonApi } from '@spree/storefront-api-v2-sdk';
import createGetAbsoluteImageUrl from '../create-get-absolute-image-url';
import getMediaGallery from '../get-media-gallery';
import type {
  LineItemAttr,
  OptionTypeAttr,
  SpreeProductImage,
  SpreeSdkResponse,
  VariantAttr
} from '../../types';

const placeholderImage = requireConfigValue('lineItemPlaceholderImageUrl') as string | false;

const isColorProductOption = (productOptionType: OptionTypeAttr) => {
  return productOptionType.attributes.presentation === 'Color';
};

const normalizeVariant = (
  spreeSuccessResponse: SpreeSdkResponse,
  spreeVariant: VariantAttr
): ProductVariant => {
  const spreeProduct = jsonApi.findSingleRelationshipDocument<ProductAttr>(
    spreeSuccessResponse,
    spreeVariant,
    'product'
  );

  if (spreeProduct === null) {
    throw new MissingLineItemVariantError(
      `Couldn't find product for variant with id ${spreeVariant.id}.`
    );
  }

  const spreeVariantImageRecords = jsonApi.findRelationshipDocuments<SpreeProductImage>(
    spreeSuccessResponse,
    spreeVariant,
    'images'
  );

  let lineItemImage;

  const variantImage = getMediaGallery(
    spreeVariantImageRecords,
    createGetAbsoluteImageUrl(requireConfigValue('imageHost') as string)
  )[0];

  if (variantImage) {
    lineItemImage = variantImage;
  } else {
    const spreeProductImageRecords = jsonApi.findRelationshipDocuments<SpreeProductImage>(
      spreeSuccessResponse,
      spreeProduct,
      'images'
    );

    const productImage = getMediaGallery(
      spreeProductImageRecords,
      createGetAbsoluteImageUrl(requireConfigValue('imageHost') as string)
    )[0];

    lineItemImage = productImage;
  }

  const image: Image =
    lineItemImage ?? (placeholderImage === false ? undefined : { url: placeholderImage });

  return {
    id: spreeVariant.id,
    sku: spreeVariant.attributes.sku,
    name: spreeProduct.attributes.name,
    requiresShipping: true,
    price: parseFloat(spreeVariant.attributes.price),
    listPrice: parseFloat(spreeVariant.attributes.price),
    image,
    isInStock: spreeVariant.attributes.in_stock,
    availableForSale: spreeVariant.attributes.purchasable,
    ...(spreeVariant.attributes.weight === '0.0'
      ? {}
      : {
          weight: {
            value: parseFloat(spreeVariant.attributes.weight),
            unit: 'KILOGRAMS'
          }
        })
    // TODO: Add height, width and depth when Measurement type allows distance measurements.
  };
};

const normalizeLineItem = (
  spreeSuccessResponse: SpreeSdkResponse,
  spreeLineItem: LineItemAttr
): LineItem => {
  const variant = jsonApi.findSingleRelationshipDocument<VariantAttr>(
    spreeSuccessResponse,
    spreeLineItem,
    'variant'
  );

  if (variant === null) {
    throw new MissingLineItemVariantError(
      `Couldn't find variant for line item with id ${spreeLineItem.id}.`
    );
  }

  const product = jsonApi.findSingleRelationshipDocument<ProductAttr>(
    spreeSuccessResponse,
    variant,
    'product'
  );

  if (product === null) {
    throw new MissingLineItemVariantError(
      `Couldn't find product for variant with id ${variant.id}.`
    );
  }

  // CartItem.tsx expects path without a '/' prefix unlike pages/product/[slug].tsx and others.
  const path = `${product.attributes.slug}`;

  const spreeOptionValues = jsonApi.findRelationshipDocuments(
    spreeSuccessResponse,
    variant,
    'option_values'
  );

  const options: SelectedOption[] = spreeOptionValues.map((spreeOptionValue) => {
    const spreeOptionType = jsonApi.findSingleRelationshipDocument<OptionTypeAttr>(
      spreeSuccessResponse,
      spreeOptionValue,
      'option_type'
    );

    if (spreeOptionType === null) {
      throw new MissingLineItemVariantError(
        `Couldn't find option type of option value with id ${spreeOptionValue.id}.`
      );
    }

    const label = isColorProductOption(spreeOptionType)
      ? spreeOptionValue.attributes.name
      : spreeOptionValue.attributes.presentation;

    return {
      id: spreeOptionValue.id,
      name: spreeOptionType.attributes.presentation,
      value: label
    };
  });

  return {
    id: spreeLineItem.id,
    variantId: variant.id,
    productId: product.id,
    name: spreeLineItem.attributes.name,
    quantity: spreeLineItem.attributes.quantity,
    discounts: [], // TODO: Implement when the template starts displaying them.
    path,
    variant: normalizeVariant(spreeSuccessResponse, variant),
    options
  };
};

const normalizeCart = (spreeSuccessResponse: SpreeSdkResponse, spreeCart: OrderAttr): Cart => {
  const lineItems = jsonApi
    .findRelationshipDocuments<LineItemAttr>(spreeSuccessResponse, spreeCart, 'line_items')
    .map((lineItem) => normalizeLineItem(spreeSuccessResponse, lineItem));

  return {
    id: spreeCart.id,
    createdAt: spreeCart.attributes.created_at.toString(),
    currency: { code: spreeCart.attributes.currency },
    taxesIncluded: true,
    lineItems,
    lineItemsSubtotalPrice: parseFloat(spreeCart.attributes.item_total),
    subtotalPrice: parseFloat(spreeCart.attributes.item_total),
    totalPrice: parseFloat(spreeCart.attributes.total),
    customerId: spreeCart.attributes.token,
    email: spreeCart.attributes.email,
    discounts: [] // TODO: Implement when the template starts displaying them.
  };
};

export { normalizeLineItem };

export default normalizeCart;