import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import {
ListResourcesRequestSchema,
ReadResourceRequestSchema,
ErrorCode,
McpError,
} from '@modelcontextprotocol/sdk/types.js';
import * as path from 'path';
import { FileSystemService } from '../services/fileSystem.js';
/**
* ResourceHandlers - Handles MCP resource requests for vault files
*/
export class ResourceHandlers {
private fileSystemService: FileSystemService;
/**
* Constructor for ResourceHandlers
* @param fileSystemService the filesystem service instance
*/
constructor(fileSystemService: FileSystemService) {
this.fileSystemService = fileSystemService;
}
/**
* Setup handlers
* @param server the server instance
*/
setupHandlers(server: Server): void {
server.setRequestHandler(ListResourcesRequestSchema, this.handleListResources.bind(this));
server.setRequestHandler(ReadResourceRequestSchema, this.handleReadResource.bind(this));
}
/**
* Handle list resources
* @returns the list of resources
*/
private async handleListResources() {
try {
const files = await this.fileSystemService.listVaultFiles();
return { resources: files.map(this.mapFileToResource) };
} catch (error) {
this.logError('listing resources', error);
throw this.createInternalError('list resources', error);
}
}
/**
* Map file to resource
* @param file the file
* @returns the resource
*/
private mapFileToResource(file: string) {
return {
uri: `obsidian://${encodeURIComponent(file)}`,
name: path.basename(file),
mimeType: 'text/markdown',
description: `Markdown note: ${file}`,
};
}
/**
* Handle read resource
* @param request the request
* @returns the content of the resource
*/
private async handleReadResource(request: any) {
try {
const filePath = this.extractFilePathFromUri(request.params.uri);
const content = await this.fileSystemService.readNote(filePath);
return {
contents: [
{
uri: request.params.uri,
mimeType: 'text/markdown',
text: content,
},
],
};
} catch (error) {
this.logError('reading resource', error);
throw this.createInternalError('read resource', error);
}
}
/**
* Extract file path from URI
* @param uri the URI
* @returns the file path
*/
private extractFilePathFromUri(uri: string): string {
const match = uri.match(/^obsidian:\/\/(.+)$/);
if (!match) {
throw new McpError(
ErrorCode.InvalidRequest,
`Invalid URI format: ${uri}`
);
}
return decodeURIComponent(match[1]);
}
/**
* Log error
* @param action the action
* @param error the error
*/
private logError(action: string, error: unknown): void {
console.error(`Error ${action}:`, error);
}
/**
* Create internal error
* @param action the action
* @param error the error
* @returns the internal error
*/
private createInternalError(action: string, error: unknown): McpError {
return new McpError(
ErrorCode.InternalError,
`Failed to ${action}: ${error instanceof Error ? error.message : String(error)}`
);
}
}
