import { authorize, unauthorized } from '../core/actions';
import { clearCookie, getCookieValue, getMainJs, resolveEnvAndMerchant } from '../core/utils';

const SHOPIFY_OG_AUTH_ENDPOINT = '/apps/subscriptions/auth/';
const SHOPIFY_OG_AUTH_BEGIN = 'og_auth_begin';
const SHOPIFY_OG_AUTH_END = 'og_auth_end';

type ShopifyOGAuth = {
  customerId: string;
  timestamp: number;
  signature: string;
};

/**
 * We tag shopify liquid this way.
 *   window.ogShopifyConfig = {
 *   {%- if customer -%}
 *     customer: {
 *       id: "{{customer.id}}",
 *       email: "{{customer.email}}",
 *       signature: "{{signature}}",
 *       timestamp: "{{timestamp}}",
 *     },
 *   {%- else -%}
 *     customer: null,
 *   {%- endif -%}
 */
type OgShopifyConfigCustomer = {
  id: string;
  signature: string;
  timestamp: string;
  email?: string;
};

type OgShopifyConfig = {
  customer?: OgShopifyConfigCustomer;
};

/**
 * We rely on window.ogShopifyConfig side of integration
 */
declare global {
  interface Window {
    og: {
      previewMode: boolean;
    };
    ogShopifyConfig: OgShopifyConfig;
    Shopify?: {
      routes?: {
        root: string;
      };
      currency?: {
        active: string;
        rate: string;
      };
    };
  }
}

const parseIntegrationTempAuth = (raw: string) => {
  const [id, timestamp, signature, email] = atob(raw).split('|');
  return {
    id,
    signature,
    timestamp,
    email
  } as OgShopifyConfigCustomer;
};
/**
 *
 * Markup needed for integration:
 * ```html
 * <script src="https://static.ordergroove.com/<merchant_id>/main.js" {% if customer -%}
 * {%- assign secret_key = shop.metafields.accentuate.theme_hash_key -%}
 * {%- assign timestamp = "now" | date: "%s" -%}
 * {%- assign signature = customer.id | append: "|" | append: timestamp | hmac_sha256: secret_key -%}
 * data-customer="{{customer.id | append: "|" | append: timestamp | append: "|" | append: signature | append: "|" | append: customer.email | base64_encode }}"
 * {%- endif %}></script>
 * ```
 */
export async function authorizeShopifyCustomer({ store }) {
  const [merchantId] = resolveEnvAndMerchant();
  const script = getMainJs();

  let customer = script?.dataset.customer
    ? parseIntegrationTempAuth(script.dataset.customer)
    : window.ogShopifyConfig?.customer;
  if (customer) {
    const val = await getOrCreateAuthCookie(customer);
    if (val) {
      const [sig_field, ts, sig] = val.split('|');
      store.dispatch(authorize(merchantId, sig_field, Number(ts), sig));
    }
  } else {
    clearCookie('og_auth');
    // after clearing the cookie, we need to make sure the store clears its own auth state
    store.dispatch(unauthorized('No customer found'));
  }
}
/**
 * Borrow from here https://github.com/ordergroove/shopify-app/blob/88becb621b29776a946ab0cd3ae215043e174626/server/lib/theme-partials/js/helpers/cookies.js#L18
 * @param customer
 * @returns
 */
export async function fetchOGSignature(customer: OgShopifyConfigCustomer) {
  try {
    const response = await fetch(
      `${SHOPIFY_OG_AUTH_ENDPOINT}?customer=${customer.id}&customer_signature=${customer.signature}&customer_timestamp=${customer.timestamp}`
    );
    const data = await response.text();
    const beginningIndex = data.lastIndexOf(SHOPIFY_OG_AUTH_BEGIN);

    if (beginningIndex < 0) throw 'Invalid response from OG auth endpoint';

    return JSON.parse(
      data.substring(beginningIndex + SHOPIFY_OG_AUTH_BEGIN.length, data.lastIndexOf(SHOPIFY_OG_AUTH_END))
    ) as ShopifyOGAuth;
  } catch (err) {
    console.error(err);
  }
}
/**
 * Original source https://github.com/ordergroove/shopify-app/blob/88becb621b29776a946ab0cd3ae215043e174626/server/lib/theme-partials/js/helpers/cookies.js#L56
 *
 * @param customer
 * @returns
 */
export async function getOrCreateAuthCookie(customer: OgShopifyConfigCustomer) {
  const ogAuthCookie = getCookieValue('og_auth');

  // The cookie hasn't expired yet so we don't need to refresh the auth
  if (ogAuthCookie) {
    return ogAuthCookie;
  }
  const { customerId, timestamp, signature } = await fetchOGSignature(customer);

  if (!customerId) return '';

  // set expiration to now + 2hrs
  const ogToday = new Date();
  const binarySignature = btoa(signature);
  ogToday.setTime(ogToday.getTime() + 2 * 60 * 60 * 1000);
  const value = `${customerId}|${timestamp}|${binarySignature}`;
  document.cookie = `og_auth=${value};expires=${ogToday.toUTCString()};secure;path=/`;
  return value;
}