feat: link and unlink document to resource model

packages/server/src/services/Attachments/UnlinkAttachment.ts

@@ -0,0 +1,39 @@
+import { Inject, Service } from 'typedi';
+import HasTenancyService from '../Tenancy/TenancyService';
+import {
+  validateLinkModelEntryExists,
+  validateLinkModelExists,
+} from './_utils';
+
+@Service()
+export class UnlinkAttachment {
+  @Inject()
+  private tenancy: HasTenancyService;
+
+  /**
+   *
+   * @param {number} tenantId
+   * @param {string} filekey
+   * @param {string} modelRef
+   * @param {number} modelId
+   */
+  async unlink(
+    tenantId: number,
+    filekey: string,
+    modelRef: string,
+    modelId: number
+  ) {
+    const { DocumentLink, ...models } = this.tenancy.models(tenantId);
+    const LinkModel = models[modelRef];
+    validateLinkModelExists(LinkModel);
+
+    const foundLinkModel = await LinkModel.query().findById(modelId);
+    validateLinkModelEntryExists(foundLinkModel);
+
+    // Delete the document link.
+    await DocumentLink.query()
+      .where('modelRef', modelRef)
+      .where('modelId', modelId)
+      .delete();
+  }
+}