feat: Implement basic general folder support (#2051)

- Related: #1748

src/view/item.ts

@@ -0,0 +1,143 @@
+import { FolderConfig } from '../config/schema/folders';
+
+export enum ViewMediaType {
+  Clip = 'clip',
+  Snapshot = 'snapshot',
+  Recording = 'recording',
+}
+
+export enum VideoContentType {
+  MP4 = 'mp4',
+  HLS = 'hls',
+}
+
+export interface ViewMediaSourceOptions {
+  cameraID?: string;
+  folder?: FolderConfig;
+}
+
+export class ViewMedia {
+  protected _mediaType: ViewMediaType;
+  protected _cameraID: string | null;
+  protected _folder: FolderConfig | null;
+
+  constructor(mediaType: ViewMediaType, options?: ViewMediaSourceOptions) {
+    this._mediaType = mediaType;
+    this._cameraID = options?.cameraID ?? null;
+    this._folder = options?.folder ?? null;
+  }
+  public getCameraID(): string | null {
+    return this._cameraID;
+  }
+  public getFolder(): FolderConfig | null {
+    return this._folder;
+  }
+  public getMediaType(): ViewMediaType {
+    return this._mediaType;
+  }
+  public getVideoContentType(): VideoContentType | null {
+    return null;
+  }
+  public getID(): string | null {
+    return null;
+  }
+  public getStartTime(): Date | null {
+    return null;
+  }
+  public getEndTime(): Date | null {
+    return null;
+  }
+  public getUsableEndTime(): Date | null {
+    return this.getEndTime() ?? (this.inProgress() ? new Date() : this.getStartTime());
+  }
+  public inProgress(): boolean | null {
+    return null;
+  }
+  public getContentID(): string | null {
+    return null;
+  }
+  public getTitle(): string | null {
+    return null;
+  }
+  public getThumbnail(): string | null {
+    return null;
+  }
+  public getIcon(): string | null {
+    return null;
+  }
+  public isFavorite(): boolean | null {
+    return null;
+  }
+  public includesTime(seek: Date): boolean {
+    const startTime = this.getStartTime();
+    const endTime = this.getUsableEndTime();
+    return !!startTime && !!endTime && seek >= startTime && seek <= endTime;
+  }
+
+  // Sets the favorite attribute (if any). This purely sets the media item as a
+  // favorite in JS.
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  public setFavorite(_favorite: boolean): void {
+    return;
+  }
+  public getWhere(): string[] | null {
+    return null;
+  }
+}
+
+export interface EventViewMedia extends ViewMedia {
+  getScore(): number | null;
+  getWhat(): string[] | null;
+  getTags(): string[] | null;
+  isGroupableWith(that: EventViewMedia): boolean;
+}
+
+export interface RecordingViewMedia extends ViewMedia {
+  getEventCount(): number | null;
+}
+
+interface ViewFolderParameters {
+  icon?: string | null;
+  id?: string | null;
+  title?: string | null;
+  thumbnail?: string | null;
+}
+
+export class ViewFolder {
+  private _folder: FolderConfig;
+
+  private _icon: string | null;
+  private _id: string | null;
+  private _title: string | null;
+  private _thumbnail: string | null;
+
+  constructor(folder: FolderConfig, params?: ViewFolderParameters) {
+    this._folder = folder;
+
+    this._icon = params?.icon ?? null;
+    this._id = params?.id ?? null;
+    this._title = params?.title ?? null;
+    this._thumbnail = params?.thumbnail ?? null;
+  }
+
+  public getFolder(): FolderConfig {
+    return this._folder;
+  }
+  public getID(): string | null {
+    return this._id;
+  }
+  public getTitle(): string | null {
+    return this._title;
+  }
+  public getThumbnail(): string | null {
+    return this._thumbnail;
+  }
+  public getIcon(): string | null {
+    return this._icon;
+  }
+  public isFavorite(): boolean | null {
+    return null;
+  }
+}
+
+export type ViewItem = ViewMedia | ViewFolder;