From d41b99b9135625c0d94053b612f5292f77caf87c Mon Sep 17 00:00:00 2001
From: Moriz Wahl <moriz.wahl@gmx.de>
Date: Mon, 6 Mar 2023 15:00:52 +0100
Subject: [PATCH] feat(backend): filter posts of my groups

---
 .../helpers/filterPostsOfMyGroups.js          | 40 +++++++++++++++++++
 backend/src/schema/resolvers/posts.js         |  3 ++
 backend/src/schema/types/type/Post.gql        |  1 +
 3 files changed, 44 insertions(+)
 create mode 100644 backend/src/schema/resolvers/helpers/filterPostsOfMyGroups.js

diff --git a/backend/src/schema/resolvers/helpers/filterPostsOfMyGroups.js b/backend/src/schema/resolvers/helpers/filterPostsOfMyGroups.js
new file mode 100644
index 000000000..a808a5582
--- /dev/null
+++ b/backend/src/schema/resolvers/helpers/filterPostsOfMyGroups.js
@@ -0,0 +1,40 @@
+import { mergeWith, isArray } from 'lodash'
+
+const getMyGroupIds = async (context) => {
+  const { user } = context
+  if (!(user && user.id)) return []
+  const session = context.driver.session()
+
+  const readTxResultPromise = await session.readTransaction(async (transaction) => {
+    const cypher = `
+      MATCH (group:Group)<-[membership:MEMBER_OF]-(:User { id: $userId })
+      WHERE membership.role IN ['usual', 'admin', 'owner']
+      RETURN collect(group.id) AS myGroupIds`
+    const getMyGroupIdsResponse = await transaction.run(cypher, { userId: user.id })
+    return getMyGroupIdsResponse.records.map((record) => record.get('myGroupIds'))
+  })
+  try {
+    const [myGroupIds] = readTxResultPromise
+    return myGroupIds
+  } finally {
+    session.close()
+  }
+}
+
+export const filterPostsOfMyGroups = async (params, context) => {
+  if (!(params.filter && params.filter.postsInMyGroups)) return params
+  delete params.filter.postsInMyGroups
+  const myGroupIds = await getMyGroupIds(context)
+  params.filter = mergeWith(
+    params.filter,
+    {
+      group: { id_in: myGroupIds },
+    },
+    (objValue, srcValue) => {
+      if (isArray(objValue)) {
+        return objValue.concat(srcValue)
+      }
+    },
+  )
+  return params
+}
diff --git a/backend/src/schema/resolvers/posts.js b/backend/src/schema/resolvers/posts.js
index 78515e641..d806f3803 100644
--- a/backend/src/schema/resolvers/posts.js
+++ b/backend/src/schema/resolvers/posts.js
@@ -6,6 +6,7 @@ import { mergeImage, deleteImage } from './images/images'
 import Resolver from './helpers/Resolver'
 import { filterForMutedUsers } from './helpers/filterForMutedUsers'
 import { filterInvisiblePosts } from './helpers/filterInvisiblePosts'
+import { filterPostsOfMyGroups } from './helpers/filterPostsOfMyGroups'
 import CONFIG from '../../config'
 
 const maintainPinnedPosts = (params) => {
@@ -21,12 +22,14 @@ const maintainPinnedPosts = (params) => {
 export default {
   Query: {
     Post: async (object, params, context, resolveInfo) => {
+      params = await filterPostsOfMyGroups(params, context)
       params = await filterInvisiblePosts(params, context)
       params = await filterForMutedUsers(params, context)
       params = await maintainPinnedPosts(params)
       return neo4jgraphql(object, params, context, resolveInfo)
     },
     profilePagePosts: async (object, params, context, resolveInfo) => {
+      params = await filterPostsOfMyGroups(params, context)
       params = await filterInvisiblePosts(params, context)
       params = await filterForMutedUsers(params, context)
       return neo4jgraphql(object, params, context, resolveInfo)
diff --git a/backend/src/schema/types/type/Post.gql b/backend/src/schema/types/type/Post.gql
index 9eac00b0b..6fc7a3215 100644
--- a/backend/src/schema/types/type/Post.gql
+++ b/backend/src/schema/types/type/Post.gql
@@ -82,6 +82,7 @@ input _PostFilter {
   emotions_single: _PostEMOTEDFilter
   emotions_every: _PostEMOTEDFilter
   group: _GroupFilter
+  postsInMyGroups: Boolean
 }
 
 enum _PostOrdering {