import crypto from 'crypto';
/**
* Type that excludes empty strings
*/
type NonEmpty<T extends string> = T extends '' ? never : T;
/**
* Error thrown when a required string parameter is empty, null, or undefined
*/
export class EmptyStringError extends Error {
constructor() {
super('Parameter is missing or empty');
this.name = 'EmptyStringError';
}
}
/**
* Asserts that a string parameter is present and not empty
* @param value The string to validate
* @throws EmptyStringError if value is missing, null, undefined, empty, or whitespace-only
*/
export function assertNonEmpty<T extends string>(value: T): asserts value is NonEmpty<T> {
if (!value || !value.trim()) {
throw new EmptyStringError();
}
}
/**
* Normalizes a string by trimming whitespace and converting to lowercase
* Validates that the input is a non-empty string first
* @param input The string to normalize
* @returns The normalized string
*/
export function normalize(input: string): string {
assertNonEmpty(input);
const stringInput = String(input);
return stringInput.trim().toLowerCase();
}
/**
* Generates a Gravatar identifier from any string
* This normalizes the string and creates a SHA256 hash
* @param input The string to convert to an identifier
* @returns The Gravatar identifier (SHA256 hash)
*/
export function generateIdentifier(input: string): string {
// Normalize the input and generate hash
const normalizedInput = normalize(input);
return crypto.createHash('sha256').update(normalizedInput).digest('hex');
}
/**
* Handles errors for email-based tools with consistent error formatting
* @param error The error that occurred
* @param email The email parameter value (for error context)
* @param operation The operation being performed (e.g., "fetch profile", "fetch avatar")
* @returns Formatted error response object
*/
export function handleEmailToolError(error: unknown, email: string, operation: string) {
if (error instanceof EmptyStringError) {
return {
content: [
{
type: 'text',
text: `Failed to ${operation}: Email parameter is missing or empty. Please provide a valid email address.`,
},
],
isError: true,
};
}
return {
content: [
{
type: 'text',
text: `Failed to ${operation} for email "${email}": ${error instanceof Error ? error.message : String(error)}`,
},
],
isError: true,
};
}
/**
* Handles errors for ID-based tools with consistent error formatting
* @param error The error that occurred
* @param identifier The identifier parameter value (for error context)
* @param operation The operation being performed (e.g., "fetch profile", "fetch avatar")
* @returns Formatted error response object
*/
export function handleIdToolError(error: unknown, identifier: string, operation: string) {
if (error instanceof EmptyStringError) {
return {
content: [
{
type: 'text',
text: `Failed to ${operation}: Identifier parameter is missing or empty. Please provide a valid identifier.`,
},
],
isError: true,
};
}
return {
content: [
{
type: 'text',
text: `Failed to ${operation} for identifier "${identifier}": ${error instanceof Error ? error.message : String(error)}`,
},
],
isError: true,
};
}
