Class MetadataManager

src/application/managers/MetadataManager.ts:12–99

 * Includes adding, deleting, and retrieving metadata associated with nodes.
 */
export class MetadataManager extends IManager implements IMetadataManager {
    /**
     * Adds metadata to existing nodes.
     */
    async addMetadata(metadata: MetadataAddition[]): Promise<MetadataResult[]> {
        try {
            this.emit('beforeAddMetadata', {metadata});

            const graph = await this.storage.loadGraph();
            const results: MetadataResult[] = [];

            for (const item of metadata) {
                GraphValidator.validateNodeExists(graph, item.nodeName);
                const node = graph.nodes.find(e => e.name === item.nodeName);

                if (!Array.isArray(node!.metadata)) {
                    node!.metadata = [];
                }

                const newMetadata = item.contents.filter(content =>
                    !node!.metadata.includes(content)
                );

                node!.metadata.push(...newMetadata);
                results.push({
                    nodeName: item.nodeName,
                    addedMetadata: newMetadata
                });
            }

            await this.storage.saveGraph(graph);

            this.emit('afterAddMetadata', {results});
            return results;
        } catch (error) {
            const errorMessage = error instanceof Error ? error.message : 'Unknown error occurred';
            throw new Error(errorMessage);
        }
    }

    /**
     * Deletes metadata from nodes.
     */
    async deleteMetadata(deletions: MetadataDeletion[]): Promise<void> {
        try {
            this.emit('beforeDeleteMetadata', {deletions});

            const graph = await this.storage.loadGraph();
            let deletedCount = 0;

            for (const deletion of deletions) {
                GraphValidator.validateNodeExists(graph, deletion.nodeName);
                const node = graph.nodes.find(e => e.name === deletion.nodeName);

                if (node) {
                    const initialMetadataCount = node.metadata.length;
                    node.metadata = node.metadata.filter(o =>
                        !deletion.metadata.includes(o)