import { CommerceAPIConfig } from 'lib/commerce/api'
import { GetAllProductsQueryVariables } from '../schema'
import fetchAPI from './utils/fetch-api'

export interface Images {
  small?: ImageOptions
  medium?: ImageOptions
  large?: ImageOptions
  xl?: ImageOptions
}

export interface ImageOptions {
  width: number
  height?: number
}

export type ProductImageVariables = Pick<
  GetAllProductsQueryVariables,
  | 'imgSmallWidth'
  | 'imgSmallHeight'
  | 'imgMediumWidth'
  | 'imgMediumHeight'
  | 'imgLargeWidth'
  | 'imgLargeHeight'
  | 'imgXLWidth'
  | 'imgXLHeight'
>

export interface BigcommerceConfigOptions extends CommerceAPIConfig {
  images?: Images
}

export interface BigcommerceConfig extends BigcommerceConfigOptions {
  readonly imageVariables?: ProductImageVariables
}

const API_URL = process.env.BIGCOMMERCE_STOREFRONT_API_URL
const API_TOKEN = process.env.BIGCOMMERCE_STOREFRONT_API_TOKEN

if (!API_URL) {
  throw new Error(
    `The environment variable BIGCOMMERCE_STOREFRONT_API_URL is missing and it's required to access your store`
  )
}

if (!API_TOKEN) {
  throw new Error(
    `The environment variable BIGCOMMERCE_STOREFRONT_API_TOKEN is missing and it's required to access your store`
  )
}

export class Config {
  private config: BigcommerceConfig

  constructor(config: BigcommerceConfigOptions) {
    this.config = {
      ...config,
      get imageVariables() {
        const { images } = this
        return images
          ? {
              imgSmallWidth: images.small?.width,
              imgSmallHeight: images.small?.height,
              imgMediumWidth: images.medium?.height,
              imgMediumHeight: images.medium?.height,
              imgLargeWidth: images.large?.height,
              imgLargeHeight: images.large?.height,
              imgXLWidth: images.xl?.height,
              imgXLHeight: images.xl?.height,
            }
          : undefined
      },
    }
  }

  getConfig() {
    return this.config
  }

  setConfig(newConfig: Partial<BigcommerceConfig>) {
    Object.assign(this.config, newConfig)
  }
}

const config = new Config({
  commerceUrl: API_URL,
  apiToken: API_TOKEN,
  fetch: fetchAPI,
})

export function getConfig() {
  return config.getConfig()
}

export function setConfig(newConfig: Partial<BigcommerceConfig>) {
  return config.setConfig(newConfig)
}