import type { ResourceContent, ResourceMetadata } from "../types.js";
/**
* Abstract base class for all MCP resources
* Provides common functionality and enforces interface contract
*/
export abstract class BaseResource {
/**
* Get resource metadata (name, description, URI pattern)
*/
abstract getMetadata(): ResourceMetadata;
/**
* Read resource content based on URI
* @param uri Full resource URI (e.g., waha://chats/overview?limit=10)
*/
abstract read(uri: string): Promise<ResourceContent>;
/**
* Check if this resource can handle the given URI
* @param uri Resource URI to check
*/
abstract canHandle(uri: string): boolean;
/**
* Parse URI parameters from query string
* @param uri Full URI with optional query parameters
* @returns Parsed parameters object
*/
protected parseUriParams(uri: string): Record<string, string> {
const params: Record<string, string> = {};
try {
const url = new URL(uri);
url.searchParams.forEach((value, key) => {
params[key] = value;
});
} catch (error) {
// If URI parsing fails, return empty params
console.error(`Failed to parse URI params from: ${uri}`, error);
}
return params;
}
/**
* Extract path from URI (without protocol and query)
* @param uri Full URI
* @returns Path component
*/
protected extractPath(uri: string): string {
try {
const url = new URL(uri);
return url.pathname;
} catch (error) {
// Fallback: extract path manually
const withoutProtocol = uri.split('://')[1] || uri;
const withoutQuery = withoutProtocol.split('?')[0];
return withoutQuery;
}
}
/**
* Validate required parameters
* @throws Error if required params are missing
*/
protected validateParams(
params: Record<string, string>,
required: string[]
): void {
const missing = required.filter(key => !params[key]);
if (missing.length > 0) {
throw new Error(
`Missing required parameters: ${missing.join(', ')}`
);
}
}
/**
* Get numeric parameter with default value
*/
protected getNumberParam(
params: Record<string, string>,
key: string,
defaultValue: number,
max?: number
): number {
const value = params[key];
if (!value) return defaultValue;
const num = parseInt(value, 10);
if (isNaN(num)) return defaultValue;
return max !== undefined ? Math.min(num, max) : num;
}
/**
* Get boolean parameter with default value
*/
protected getBooleanParam(
params: Record<string, string>,
key: string,
defaultValue: boolean
): boolean {
const value = params[key];
if (!value) return defaultValue;
return value === 'true' || value === '1';
}
}
