From 39fe6b5dbf3e7948846a338776a9874af125f374 Mon Sep 17 00:00:00 2001
From: Daniel Holmgren <dtholmgren@gmail.com>
Date: Wed, 24 Jan 2024 19:38:12 -0600
Subject: [PATCH] Add getRelationships route to appview (#2085)

* codegen

* add getRelationships route
---
 .../api/app/bsky/graph/getRelationships.ts    | 71 +++++++++++++++++++
 packages/bsky/src/api/index.ts                |  2 +
 .../views/__snapshots__/follows.test.ts.snap  | 28 ++++++++
 packages/bsky/tests/views/follows.test.ts     | 10 +++
 4 files changed, 111 insertions(+)
 create mode 100644 packages/bsky/src/api/app/bsky/graph/getRelationships.ts

diff --git a/packages/bsky/src/api/app/bsky/graph/getRelationships.ts b/packages/bsky/src/api/app/bsky/graph/getRelationships.ts
new file mode 100644
index 00000000000..5ac4f3107c4
--- /dev/null
+++ b/packages/bsky/src/api/app/bsky/graph/getRelationships.ts
@@ -0,0 +1,71 @@
+import { Server } from '../../../../lexicon'
+import AppContext from '../../../../context'
+import { Relationship } from '../../../../lexicon/types/app/bsky/graph/defs'
+
+export default function (server: Server, ctx: AppContext) {
+  server.app.bsky.graph.getRelationships({
+    handler: async ({ params }) => {
+      const { actor, others = [] } = params
+      if (others.length < 1) {
+        return {
+          encoding: 'application/json',
+          body: {
+            actor,
+            relationships: [],
+          },
+        }
+      }
+      const db = ctx.db.getPrimary()
+      const { ref } = db.db.dynamic
+      const res = await db.db
+        .selectFrom('actor')
+        .select([
+          'actor.did',
+          db.db
+            .selectFrom('follow')
+            .where('creator', '=', actor)
+            .whereRef('subjectDid', '=', ref('actor.did'))
+            .select('uri')
+            .as('following'),
+          db.db
+            .selectFrom('follow')
+            .whereRef('creator', '=', ref('actor.did'))
+            .where('subjectDid', '=', actor)
+            .select('uri')
+            .as('followedBy'),
+        ])
+        .where('actor.did', 'in', others)
+        .execute()
+
+      const relationshipsMap = res.reduce((acc, cur) => {
+        return acc.set(cur.did, {
+          did: cur.did,
+          following: cur.following ?? undefined,
+          followedBy: cur.followedBy ?? undefined,
+        })
+      }, new Map<string, Relationship>())
+
+      const relationships = others.map((did) => {
+        const relationship = relationshipsMap.get(did)
+        return relationship
+          ? {
+              $type: 'app.bsky.graph.defs#relationship',
+              ...relationship,
+            }
+          : {
+              $type: 'app.bsky.graph.defs#notFoundActor',
+              actor: did,
+              notFound: true,
+            }
+      })
+
+      return {
+        encoding: 'application/json',
+        body: {
+          actor,
+          relationships,
+        },
+      }
+    },
+  })
+}
diff --git a/packages/bsky/src/api/index.ts b/packages/bsky/src/api/index.ts
index 7628770507f..550f2d8596c 100644
--- a/packages/bsky/src/api/index.ts
+++ b/packages/bsky/src/api/index.ts
@@ -26,6 +26,7 @@ import getList from './app/bsky/graph/getList'
 import getLists from './app/bsky/graph/getLists'
 import getListMutes from './app/bsky/graph/getListMutes'
 import getMutes from './app/bsky/graph/getMutes'
+import getRelationships from './app/bsky/graph/getRelationships'
 import muteActor from './app/bsky/graph/muteActor'
 import unmuteActor from './app/bsky/graph/unmuteActor'
 import muteActorList from './app/bsky/graph/muteActorList'
@@ -82,6 +83,7 @@ export default function (server: Server, ctx: AppContext) {
   getLists(server, ctx)
   getListMutes(server, ctx)
   getMutes(server, ctx)
+  getRelationships(server, ctx)
   muteActor(server, ctx)
   unmuteActor(server, ctx)
   muteActorList(server, ctx)
diff --git a/packages/bsky/tests/views/__snapshots__/follows.test.ts.snap b/packages/bsky/tests/views/__snapshots__/follows.test.ts.snap
index c85b0549de7..dfb5ff2ecb3 100644
--- a/packages/bsky/tests/views/__snapshots__/follows.test.ts.snap
+++ b/packages/bsky/tests/views/__snapshots__/follows.test.ts.snap
@@ -569,3 +569,31 @@ Object {
   },
 }
 `;
+
+exports[`pds follow views fetches relationships between users 1`] = `
+Object {
+  "actor": "user(0)",
+  "relationships": Array [
+    Object {
+      "$type": "app.bsky.graph.defs#relationship",
+      "did": "user(1)",
+      "followedBy": "record(1)",
+      "following": "record(0)",
+    },
+    Object {
+      "$type": "app.bsky.graph.defs#relationship",
+      "did": "user(0)",
+    },
+    Object {
+      "$type": "app.bsky.graph.defs#relationship",
+      "did": "user(2)",
+      "following": "record(2)",
+    },
+    Object {
+      "$type": "app.bsky.graph.defs#notFoundActor",
+      "actor": "did:example:fake",
+      "notFound": true,
+    },
+  ],
+}
+`;
diff --git a/packages/bsky/tests/views/follows.test.ts b/packages/bsky/tests/views/follows.test.ts
index 8367f2d1f61..d0f640c6813 100644
--- a/packages/bsky/tests/views/follows.test.ts
+++ b/packages/bsky/tests/views/follows.test.ts
@@ -294,4 +294,14 @@ describe('pds follow views', () => {
       },
     )
   })
+
+  it('fetches relationships between users', async () => {
+    const res = await agent.api.app.bsky.graph.getRelationships({
+      actor: sc.dids.bob,
+      others: [sc.dids.alice, sc.dids.bob, sc.dids.carol, 'did:example:fake'],
+    })
+    expect(res.data.actor).toEqual(sc.dids.bob)
+    expect(res.data.relationships.length).toBe(4)
+    expect(forSnapshot(res.data)).toMatchSnapshot()
+  })
 })