feat: backlinks (#974)

* feat: backlinks

* feat: backlinks

apps/web/partials/entity-page/entity-page-referenced-by-server-container.tsx

@@ -1,7 +1,13 @@
+import { Schema } from '@effect/schema';
+import { Effect, Either } from 'effect';
+import { dedupeWith } from 'effect/Array';
+
 import { PLACEHOLDER_SPACE_IMAGE } from '~/core/constants';
-import { Subgraph } from '~/core/io';
+import { Environment } from '~/core/environment';
+import { SubstreamVersionTypes } from '~/core/io/schema';
 import { fetchSpacesById } from '~/core/io/subgraph/fetch-spaces-by-id';
-import { Entities } from '~/core/utils/entity';
+import { versionTypesFragment } from '~/core/io/subgraph/fragments';
+import { graphql } from '~/core/io/subgraph/graphql';
 
 import { EntityPageReferencedBy } from './entity-page-referenced-by';
 import { ReferencedByEntity } from './types';
@@ -13,38 +19,164 @@ interface Props {
 }
 
 export async function EntityReferencedByServerContainer({ entityId, name }: Props) {
-  const related = await Subgraph.fetchEntities({
-    query: '',
-    filter: [{ field: 'linked-to', value: entityId }],
-  });
+  const backlinks = await fetchBacklinks(entityId);
 
-  const spacesForEntities = new Set(
-    related
-      .map(r => {
-        return Entities.nameTriple(r.triples)?.space ?? null;
-      })
-      .flatMap(s => (s ? [s] : []))
+  const referencedSpaces = dedupeWith(
+    backlinks.flatMap(e => e.currentVersion.version.versionSpaces.nodes),
+    (a, z) => a === z
   );
+  const spaces = await fetchSpacesById(referencedSpaces.map(s => s.spaceId));
 
-  const spaces = await fetchSpacesById([...spacesForEntities.values()]);
-
-  const referencedByEntities: ReferencedByEntity[] = related.map(e => {
-    const spaceId = Entities.nameTriple(e.triples)?.space ?? '';
-    const space = spaces.find(s => s.id === spaceId);
-    const spaceName = space?.spaceConfig?.name ?? null;
-    const spaceImage = space?.spaceConfig?.image ?? PLACEHOLDER_SPACE_IMAGE;
-
-    return {
-      id: e.id,
-      name: e.name,
-      types: e.types,
-      space: {
-        id: spaceId,
-        name: spaceName,
-        image: spaceImage,
-      },
-    };
-  });
+  const referencedByEntities: ReferencedByEntity[] = backlinks
+    .map(e => {
+      const firstSpaceId = e.currentVersion.version.versionSpaces.nodes[0]?.spaceId;
+
+      if (!firstSpaceId) {
+        return null;
+      }
+
+      const space = spaces.find(s => s.id === firstSpaceId);
+      const spaceName = space?.spaceConfig?.name ?? null;
+      const spaceImage = space?.spaceConfig?.image ?? PLACEHOLDER_SPACE_IMAGE;
+
+      return {
+        id: e.id,
+        name: e.currentVersion.version.name,
+        types: e.currentVersion.version.versionTypes.nodes.map(t => {
+          return {
+            id: t.type.entityId,
+            name: t.type.name,
+          };
+        }),
+        space: {
+          id: firstSpaceId,
+          name: spaceName,
+          image: spaceImage,
+        },
+      } satisfies ReferencedByEntity;
+    })
+    .filter(e => e !== null);
 
   return <EntityPageReferencedBy referencedByEntities={referencedByEntities} name={name} />;
 }
+
+const query = (entityId: string) => {
+  return `{
+    entities(filter: {
+      currentVersion: {
+        version: {
+          relationsByFromVersionId: {
+            some: {
+              toVersion: { entityId: { equalTo: "${entityId}" } }
+            }
+          }
+        }
+      }
+    }
+    orderBy: UPDATED_AT_BLOCK_DESC
+  )  {
+      nodes {
+        id
+        currentVersion {
+          version {
+            id
+            entityId
+            name
+            description
+            ${versionTypesFragment}
+            versionSpaces {
+              nodes {
+                spaceId
+              }
+            }
+          }
+        }
+      }
+    }
+  }`;
+};
+
+interface NetworkResult {
+  entities: { nodes: SubstreamBacklink[] };
+}
+
+const SubstreamBacklink = Schema.Struct({
+  id: Schema.String,
+  currentVersion: Schema.Struct({
+    version: Schema.Struct({
+      id: Schema.String,
+      name: Schema.NullOr(Schema.String),
+      versionTypes: SubstreamVersionTypes,
+      versionSpaces: Schema.Struct({
+        nodes: Schema.Array(
+          Schema.Struct({
+            spaceId: Schema.String,
+          })
+        ),
+      }),
+    }),
+  }),
+});
+
+type SubstreamBacklink = Schema.Schema.Type<typeof SubstreamBacklink>;
+
+async function fetchBacklinks(entityId: string) {
+  const endpoint = Environment.getConfig().api;
+
+  const graphqlFetchEffect = graphql<NetworkResult>({
+    endpoint,
+    query: query(entityId),
+  });
+
+  const graphqlFetchWithErrorFallbacks = Effect.gen(function* () {
+    const resultOrError = yield* Effect.either(graphqlFetchEffect);
+
+    if (Either.isLeft(resultOrError)) {
+      const error = resultOrError.left;
+
+      switch (error._tag) {
+        case 'AbortError':
+          // Right now we re-throw AbortErrors and let the callers handle it. Eventually we want
+          // the caller to consume the error channel as an effect. We throw here the typical JS
+          // way so we don't infect more of the codebase with the effect runtime.
+          throw error;
+        case 'GraphqlRuntimeError':
+          console.error(
+            `Encountered runtime graphql error in fetchEntities. queryString: ${query(entityId)}
+          `,
+            error.message
+          );
+
+          return {
+            entities: { nodes: [] },
+          };
+
+        default:
+          console.error(`${error._tag}: Unable to fetch entities backlinks`);
+          return {
+            entities: { nodes: [] },
+          };
+      }
+    }
+
+    return resultOrError.right;
+  });
+
+  const unknownEntities = await Effect.runPromise(graphqlFetchWithErrorFallbacks);
+
+  return unknownEntities.entities.nodes
+    .map(e => {
+      const decodedSpace = Schema.decodeEither(SubstreamBacklink)(e);
+
+      return Either.match(decodedSpace, {
+        onLeft: error => {
+          console.error(`Unable to decode entity ${e.id} with error ${error}`);
+          return null;
+        },
+        onRight: backlink => {
+          return backlink;
+        },
+      });
+    })
+    .filter(e => e !== null);
+}

apps/web/partials/entity-page/entity-page-referenced-by.tsx

@@ -26,7 +26,7 @@ export function EntityPageReferencedBy({ referencedByEntities }: ReferencedByEnt
   if (referencedByEntities.length === 0) return null;
 
   return (
-    <div>
+    <div className="px-4">
       <Text as="h2" variant="mediumTitle">
         Referenced by
       </Text>