import { getUserAgent } from '../config/server-config.js';
export interface AvatarParams {
avatarIdentifier: string;
size?: number;
defaultOption?: string;
forceDefault?: boolean;
rating?: string;
}
export interface AvatarResult {
buffer: Buffer;
mimeType: string;
}
/**
* Detect MIME type from HTTP response headers
*/
function detectMimeType(response: Response): string {
const contentType = response.headers.get('content-type');
// Validate it's an image MIME type
if (contentType && contentType.startsWith('image/')) {
return contentType;
}
// Fallback to PNG for safety, since Gravatar defaults to returning PNG images
return 'image/png';
}
/**
* Fetch avatar image by identifier
*/
export async function fetchAvatar(params: AvatarParams): Promise<AvatarResult> {
// Build avatar URL
let url = `https://gravatar.com/avatar/${params.avatarIdentifier}`;
const queryParams = new URLSearchParams();
if (params.size) {
queryParams.append('s', params.size.toString());
}
if (params.defaultOption) {
queryParams.append('d', params.defaultOption);
}
if (params.forceDefault) {
queryParams.append('f', 'y');
}
if (params.rating) {
queryParams.append('r', params.rating);
}
// Add query string to URL if there are any parameters
const queryString = queryParams.toString();
if (queryString) {
url += `?${queryString}`;
}
// Fetch the image
const response = await fetch(url, {
headers: {
'User-Agent': getUserAgent(),
},
});
if (!response.ok) {
// Provide specific error messages for common cases
let message: string;
switch (response.status) {
case 404:
message = `No avatar found for identifier: ${params.avatarIdentifier}.`;
break;
case 400:
message = `Invalid avatar request parameters for identifier: ${params.avatarIdentifier}. Check the identifier format and parameters.`;
break;
case 403:
message = `Avatar access denied for identifier: ${params.avatarIdentifier}`;
break;
case 429:
message = `Rate limit exceeded. Please try again later.`;
break;
default:
message = `Failed to fetch avatar (${response.status}): ${response.statusText}`;
}
throw new Error(message);
}
// Detect MIME type from response headers
const mimeType = detectMimeType(response);
// Convert the response to a buffer
const arrayBuffer = await response.arrayBuffer();
const buffer = Buffer.from(arrayBuffer);
return {
buffer,
mimeType,
};
}
