import { App, TFile } from 'obsidian';
import { McpError, ErrorCode } from '@modelcontextprotocol/sdk/types.js';
import { IResourceReadService } from '../interfaces/IRequestHandlerServices';
import { logger } from '../../utils/logger';
/**
* Resource content interface for MCP resource reading
*/
interface ResourceContent {
uri: string;
text: string;
mimeType: string;
}
/**
* Service for reading vault resource content
* Applies Single Responsibility Principle by focusing solely on resource content retrieval
*/
export class ResourceReadService implements IResourceReadService {
constructor(private app: App) {}
/**
* Read resource content by URI
* @param uri Resource URI to read
* @returns Promise resolving to resource content
*/
async readResource(uri: string): Promise<{ contents: ResourceContent[] }> {
try {
logger.systemLog(`ResourceReadService: Reading resource ${uri}`);
const content = await this.getResourceContent(uri);
return {
contents: [{
uri,
text: content,
mimeType: "text/markdown"
}]
};
} catch (error) {
if (error instanceof McpError) {
throw error;
}
logger.systemError(error as Error, 'ResourceReadService');
throw new McpError(ErrorCode.InternalError, 'Failed to read resource', error);
}
}
/**
* Read multiple resources by URIs (future enhancement)
* @param uris Array of resource URIs to read
* @returns Promise resolving to array of resource contents
*/
async readMultipleResources(uris: string[]): Promise<{ contents: ResourceContent[] }> {
try {
logger.systemLog(`ResourceReadService: Reading ${uris.length} resources`);
const contents: ResourceContent[] = [];
for (const uri of uris) {
try {
const content = await this.getResourceContent(uri);
contents.push({
uri,
text: content,
mimeType: "text/markdown"
});
} catch (error) {
logger.systemWarn(`ResourceReadService: Failed to read resource ${uri}`);
// Continue with other resources, but log the failure
}
}
return { contents };
} catch (error) {
logger.systemError(error as Error, 'ResourceReadService');
throw new McpError(ErrorCode.InternalError, 'Failed to read multiple resources', error);
}
}
/**
* Get resource content from vault file
* @param uri Resource URI
* @returns Promise resolving to file content
* @private
*/
private async getResourceContent(uri: string): Promise<string> {
// Parse obsidian:// URI to get file path
const path = this.parseResourceUri(uri);
// Get file from vault
const file = this.app.vault.getAbstractFileByPath(path);
if (!(file instanceof TFile)) {
throw new McpError(ErrorCode.InvalidParams, `Resource not found: ${uri}`);
}
// Read file content
return await this.app.vault.read(file);
}
/**
* Parse resource URI to extract file path
* @param uri Resource URI (e.g., "obsidian://path/to/file.md")
* @returns File path
* @private
*/
private parseResourceUri(uri: string): string {
if (!uri.startsWith('obsidian://')) {
throw new McpError(ErrorCode.InvalidParams, `Invalid resource URI format: ${uri}`);
}
return uri.replace('obsidian://', '');
}
/**
* Check if resource exists in vault
* @param uri Resource URI
* @returns Promise resolving to boolean
*/
async resourceExists(uri: string): Promise<boolean> {
try {
const path = this.parseResourceUri(uri);
const file = this.app.vault.getAbstractFileByPath(path);
return file instanceof TFile;
} catch (error) {
logger.systemWarn(`ResourceReadService: Resource existence check failed for ${uri}`);
return false;
}
}
}
