feat: Implement SPARQL-based ResourceStore

src/util/ResourceStoreController.ts

@@ -0,0 +1,124 @@
+import type { Representation } from '../ldp/representation/Representation';
+import type { ResourceIdentifier } from '../ldp/representation/ResourceIdentifier';
+import { ConflictHttpError } from './errors/ConflictHttpError';
+import { MethodNotAllowedHttpError } from './errors/MethodNotAllowedHttpError';
+import { NotFoundHttpError } from './errors/NotFoundHttpError';
+import { UnsupportedMediaTypeHttpError } from './errors/UnsupportedMediaTypeHttpError';
+import type { InteractionController } from './InteractionController';
+import { ensureTrailingSlash, trimTrailingSlashes } from './Util';
+
+export interface SetBehaviour {
+  /**
+   * Whether a new container or a resource should be created based on the given parameters.
+   */
+  isContainer: boolean;
+
+  /**
+   * The parent identifier path of the new resource.
+   */
+  path: string;
+
+  /**
+   * The identifier path the new resource should have.
+   */
+  newIdentifier: string;
+}
+
+export class ResourceStoreController {
+  private readonly baseRequestURI: string;
+  private readonly interactionController: InteractionController;
+  private readonly supportedDataTypes: Set<string>;
+
+  /**
+   * @param baseRequestURI - The base from the store. Will be stripped of all incoming URIs and added to all outgoing
+   * ones to find the relative path.
+   * @param interactionController - Instance of InteractionController to use.
+   * @param supportedDataTypes - All supported data types by the store.
+   */
+  public constructor(baseRequestURI: string, interactionController: InteractionController,
+    supportedDataTypes: Set<string>) {
+    this.baseRequestURI = trimTrailingSlashes(baseRequestURI);
+    this.interactionController = interactionController;
+    this.supportedDataTypes = supportedDataTypes;
+  }
+
+  /**
+   * Strips the baseRequestURI from the identifier and checks if the stripped base URI matches the store's one.
+   * @param identifier - Incoming identifier.
+   *
+   * @throws {@link NotFoundHttpError}
+   * If the identifier does not match the baseRequestURI path of the store.
+   *
+   * @returns A string representing the relative path.
+   */
+  public parseIdentifier(identifier: ResourceIdentifier): string {
+    if (!identifier.path.startsWith(this.baseRequestURI)) {
+      throw new NotFoundHttpError();
+    }
+    return identifier.path.slice(this.baseRequestURI.length);
+  }
+
+  /**
+   * Check if the given path is a valid path to perform a delete operation on.
+   * @param path - Path to check. Request URI without the base URI.
+   *
+   * @throws {@link MethodNotAllowedHttpError}
+   * If the path points to the root container.
+   */
+  public validateDeletePath(path: string): void {
+    if (path === '' || ensureTrailingSlash(path) === '/') {
+      throw new MethodNotAllowedHttpError('Cannot delete root container.');
+    }
+  }
+
+  /**
+   * Get the expected behaviour based on the incoming identifier and representation for a POST request.
+   * @param container - Incoming identifier.
+   * @param representation - Incoming representation.
+   */
+  public getBehaviourAddResource(container: ResourceIdentifier, representation: Representation): SetBehaviour {
+    // Throw an error if the data type is not supported by the store.
+    if (!this.supportedDataTypes.has(representation.dataType)) {
+      throw new UnsupportedMediaTypeHttpError(`This ResourceStore only supports
+       ${[ ...this.supportedDataTypes ].join(', ')} representations.`);
+    }
+
+    // Get the path from the request URI, and the Slug and Link header values.
+    const path = this.parseIdentifier(container);
+    const { slug } = representation.metadata;
+    const linkTypes = representation.metadata.linkRel?.type;
+
+    const isContainer = this.interactionController.isContainer(slug, linkTypes);
+    const newIdentifier = this.interactionController.generateIdentifier(isContainer, slug);
+
+    return { isContainer, path, newIdentifier };
+  }
+
+  /**
+   * Get the expected behaviour based on the incoming identifier and representation for a PUT request.
+   * @param identifier - Incoming identifier.
+   * @param representation - Incoming representation.
+   */
+  public getBehaviourSetRepresentation(identifier: ResourceIdentifier, representation: Representation): SetBehaviour {
+    // Throw an error if the data type is not supported by the store.
+    if (!this.supportedDataTypes.has(representation.dataType)) {
+      throw new UnsupportedMediaTypeHttpError(`This ResourceStore only supports
+       ${[ ...this.supportedDataTypes ].join(', ')} representations.`);
+    }
+
+    // Break up the request URI in the different parts `path` and `slug` as we know their semantics from addResource
+    // to call the InteractionController in the same way.
+    const [ , path, slug ] = /^(.*\/)([^/]+\/?)?$/u.exec(this.parseIdentifier(identifier)) ?? [];
+    if ((typeof path !== 'string' || ensureTrailingSlash(path) === '/') && typeof slug !== 'string') {
+      throw new ConflictHttpError('Container with that identifier already exists (root).');
+    }
+
+    // Get the Link header value.
+    const linkTypes = representation.metadata.linkRel?.type;
+
+    const isContainer = this.interactionController.isContainer(slug, linkTypes);
+    const newIdentifier = this.interactionController.generateIdentifier(isContainer, slug);
+
+    return { isContainer, path, newIdentifier };
+  }
+}