fix(repository): Move backend code into subdirectory

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

backend/src/media/media-upload.entity.ts

@@ -0,0 +1,82 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import {
+  Column,
+  CreateDateColumn,
+  Entity,
+  ManyToOne,
+  PrimaryColumn,
+} from 'typeorm';
+
+import { Note } from '../notes/note.entity';
+import { User } from '../users/user.entity';
+import { BackendType } from './backends/backend-type.enum';
+
+export type BackendData = string | null;
+
+@Entity()
+export class MediaUpload {
+  @PrimaryColumn()
+  id: string;
+
+  @ManyToOne((_) => Note, (note) => note.mediaUploads, {
+    nullable: true,
+  })
+  note: Promise<Note | null>;
+
+  @ManyToOne((_) => User, (user) => user.mediaUploads, {
+    nullable: false,
+  })
+  user: Promise<User>;
+
+  @Column({
+    nullable: false,
+  })
+  backendType: string;
+
+  @Column()
+  fileUrl: string;
+
+  @Column({
+    nullable: true,
+    type: 'text',
+  })
+  backendData: BackendData | null;
+
+  @CreateDateColumn()
+  createdAt: Date;
+
+  // eslint-disable-next-line @typescript-eslint/no-empty-function
+  private constructor() {}
+
+  /**
+   * Create a new media upload enity
+   * @param id the id of the upload
+   * @param note the note the upload should be associated with. This is required despite the fact the note field is optional, because it's possible to delete a note without also deleting the associated media uploads, but a note is required for the initial creation.
+   * @param user the user that owns the upload
+   * @param extension which file extension the upload has
+   * @param backendType on which type of media backend the upload is saved
+   * @param backendData the backend data returned by the media backend
+   * @param fileUrl the url where the upload can be accessed
+   */
+  public static create(
+    id: string,
+    note: Note,
+    user: User,
+    extension: string,
+    backendType: BackendType,
+    fileUrl: string,
+  ): Omit<MediaUpload, 'createdAt'> {
+    const upload = new MediaUpload();
+    upload.id = id;
+    upload.note = Promise.resolve(note);
+    upload.user = Promise.resolve(user);
+    upload.backendType = backendType;
+    upload.backendData = null;
+    upload.fileUrl = fileUrl;
+    return upload;
+  }
+}