Extracted metadata get/set methods into internal metadata module

no issue

- This is the refactor similar to what has been done with Memeber model being passed in directly in the constructor
- Relevent discussion here TryGhost/Members#105 (review)

ghost/members-api/index.js

@@ -5,6 +5,7 @@ const StripePaymentProcessor = require('./lib/stripe');
 
 const Tokens = require('./lib/tokens');
 const Users = require('./lib/users');
+const Metadata = require('./lib/metadata');
 const common = require('./lib/common');
 
 module.exports = function MembersApi({
@@ -25,8 +26,8 @@ module.exports = function MembersApi({
         getHTML,
         getSubject
     },
-    setMetadata,
-    getMetadata,
+    memberStripeCustomerModel,
+    stripeCustomerSubscriptionModel,
     memberModel,
     logger
 }) {
@@ -35,13 +36,14 @@ module.exports = function MembersApi({
     }
 
     const {encodeIdentityToken, decodeToken} = Tokens({privateKey, publicKey, issuer});
+    const metadata = Metadata({memberStripeCustomerModel, stripeCustomerSubscriptionModel});
 
     const stripeStorage = {
         async get(member) {
-            return getMetadata('stripe', member);
+            return metadata.getMetadata('stripe', member);
         },
-        async set(metadata) {
-            return setMetadata('stripe', metadata);
+        async set(data) {
+            return metadata.setMetadata('stripe', data);
         }
     };
     const stripe = paymentConfig.stripe ? new StripePaymentProcessor(paymentConfig.stripe, stripeStorage, common.logging) : null;

ghost/members-api/lib/metadata.js

@@ -0,0 +1,57 @@
+let MemberStripeCustomer;
+let StripeCustomerSubscription;
+
+async function setMetadata(module, metadata) {
+    if (module !== 'stripe') {
+        return;
+    }
+
+    if (metadata.customer) {
+        await MemberStripeCustomer.upsert(metadata.customer, {
+            customer_id: metadata.customer.customer_id
+        });
+    }
+
+    if (metadata.subscription) {
+        await StripeCustomerSubscription.upsert(metadata.subscription, {
+            subscription_id: metadata.subscription.subscription_id
+        });
+    }
+
+    return;
+}
+
+async function getMetadata(module, member) {
+    if (module !== 'stripe') {
+        return;
+    }
+
+    const customers = (await MemberStripeCustomer.findAll({
+        filter: `member_id:${member.id}`
+    })).toJSON();
+
+    const subscriptions = await customers.reduce(async (subscriptionsPromise, customer) => {
+        const customerSubscriptions = await StripeCustomerSubscription.findAll({
+            filter: `customer_id:${customer.customer_id}`
+        });
+        return (await subscriptionsPromise).concat(customerSubscriptions.toJSON());
+    }, []);
+
+    return {
+        customers: customers,
+        subscriptions: subscriptions
+    };
+}
+
+module.exports = function ({
+    memberStripeCustomerModel,
+    stripeCustomerSubscriptionModel
+}) {
+    MemberStripeCustomer = memberStripeCustomerModel;
+    StripeCustomerSubscription = stripeCustomerSubscriptionModel;
+
+    return {
+        setMetadata,
+        getMetadata
+    };
+};