chore: Refactoring event processors and service architecture (#2495)

2021-08-27 21:42:13 -07:00
parent 86f008293a
commit 28aef82af9
61 changed files with 1610 additions and 1498 deletions
--- a/server/queues/processors/backlinks.js
+++ b/server/queues/processors/backlinks.js
@ -0,0 +1,132 @@
+// @flow
+import { Document, Backlink } from "../../models";
+import { Op } from "../../sequelize";
+import type { DocumentEvent, RevisionEvent } from "../../types";
+import parseDocumentIds from "../../utils/parseDocumentIds";
+import slugify from "../../utils/slugify";
+
+export default class BacklinksProcessor {
+  async on(event: DocumentEvent | RevisionEvent) {
+    switch (event.name) {
+      case "documents.publish": {
+        const document = await Document.findByPk(event.documentId);
+        if (!document) return;
+
+        const linkIds = parseDocumentIds(document.text);
+
+        await Promise.all(
+          linkIds.map(async (linkId) => {
+            const linkedDocument = await Document.findByPk(linkId);
+            if (!linkedDocument || linkedDocument.id === event.documentId) {
+              return;
+            }
+
+            await Backlink.findOrCreate({
+              where: {
+                documentId: linkedDocument.id,
+                reverseDocumentId: event.documentId,
+              },
+              defaults: {
+                userId: document.lastModifiedById,
+              },
+            });
+          })
+        );
+
+        break;
+      }
+      case "documents.update": {
+        const document = await Document.findByPk(event.documentId);
+        if (!document) return;
+
+        // backlinks are only created for published documents
+        if (!document.publishedAt) return;
+
+        const linkIds = parseDocumentIds(document.text);
+        const linkedDocumentIds = [];
+
+        // create or find existing backlink records for referenced docs
+        await Promise.all(
+          linkIds.map(async (linkId) => {
+            const linkedDocument = await Document.findByPk(linkId);
+            if (!linkedDocument || linkedDocument.id === event.documentId) {
+              return;
+            }
+
+            await Backlink.findOrCreate({
+              where: {
+                documentId: linkedDocument.id,
+                reverseDocumentId: event.documentId,
+              },
+              defaults: {
+                userId: document.lastModifiedById,
+              },
+            });
+            linkedDocumentIds.push(linkedDocument.id);
+          })
+        );
+
+        // delete any backlinks that no longer exist
+        await Backlink.destroy({
+          where: {
+            documentId: {
+              [Op.notIn]: linkedDocumentIds,
+            },
+            reverseDocumentId: event.documentId,
+          },
+        });
+        break;
+      }
+      case "documents.title_change": {
+        const document = await Document.findByPk(event.documentId);
+        if (!document) return;
+
+        // might as well check
+        const { title, previousTitle } = event.data;
+        if (!previousTitle || title === previousTitle) break;
+
+        // update any link titles in documents that lead to this one
+        const backlinks = await Backlink.findAll({
+          where: {
+            documentId: event.documentId,
+          },
+          include: [{ model: Document, as: "reverseDocument" }],
+        });
+
+        await Promise.all(
+          backlinks.map(async (backlink) => {
+            const previousUrl = `/doc/${slugify(previousTitle)}-${
+              document.urlId
+            }`;
+
+            // find links in the other document that lead to this one and have
+            // the old title as anchor text. Go ahead and update those to the
+            // new title automatically
+            backlink.reverseDocument.text = backlink.reverseDocument.text.replace(
+              `[${previousTitle}](${previousUrl})`,
+              `[${title}](${document.url})`
+            );
+            await backlink.reverseDocument.save({
+              silent: true,
+              hooks: false,
+            });
+          })
+        );
+
+        break;
+      }
+      case "documents.delete": {
+        await Backlink.destroy({
+          where: {
+            [Op.or]: [
+              { reverseDocumentId: event.documentId },
+              { documentId: event.documentId },
+            ],
+          },
+        });
+        break;
+      }
+      default:
+    }
+  }
+}