import { ApiError } from '../types/bvg.js';
/**
* Base URL for the BVG API
*/
export const BVG_API_BASE_URL = 'https://v6.bvg.transport.rest';
/**
* HTTP client for BVG API calls with error handling
*/
export class BvgApiClient {
private baseUrl: string;
constructor(baseUrl: string = BVG_API_BASE_URL) {
this.baseUrl = baseUrl;
}
/**
* Make a GET request to the BVG API
*/
async get<T>(endpoint: string, params?: Record<string, string | number | boolean>): Promise<T> {
const url = new URL(endpoint, this.baseUrl);
// Add query parameters
if (params) {
Object.entries(params).forEach(([key, value]) => {
if (value !== undefined && value !== null) {
url.searchParams.append(key, String(value));
}
});
}
try {
const response = await fetch(url.toString(), {
headers: {
'Accept': 'application/json',
'User-Agent': 'mcp-bvg-server/1.0.0'
}
});
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
const data = await response.json();
// Check if the API returned an error
if (this.isApiError(data)) {
throw new Error(`BVG API error: ${data.msg}`);
}
return data;
} catch (error) {
if (error instanceof Error) {
throw new Error(`Failed to fetch from BVG API: ${error.message}`);
}
throw new Error('Unknown error occurred while fetching from BVG API');
}
}
/**
* Type guard to check if response is an API error
*/
private isApiError(data: any): data is ApiError {
return data && typeof data === 'object' && data.error === true && typeof data.msg === 'string';
}
}
/**
* Default BVG API client instance
*/
export const bvgApi = new BvgApiClient();
/**
* Format a date for API consumption
*/
export function formatDate(date: Date): string {
return date.toISOString();
}
/**
* Parse coordinates string into latitude and longitude
*/
export function parseCoordinates(coords: string): { latitude: number; longitude: number } {
const [lat, lon] = coords.split(',').map(s => parseFloat(s.trim()));
if (isNaN(lat) || isNaN(lon)) {
throw new Error('Invalid coordinates format. Expected "latitude,longitude"');
}
if (lat < -90 || lat > 90) {
throw new Error('Latitude must be between -90 and 90');
}
if (lon < -180 || lon > 180) {
throw new Error('Longitude must be between -180 and 180');
}
return { latitude: lat, longitude: lon };
}
/**
* Validate stop ID format
*/
export function validateStopId(stopId: string): boolean {
return typeof stopId === 'string' && stopId.length > 0;
}
/**
* Format duration in minutes to human readable string
*/
export function formatDuration(minutes: number): string {
if (minutes < 60) {
return `${minutes} min`;
}
const hours = Math.floor(minutes / 60);
const remainingMinutes = minutes % 60;
if (remainingMinutes === 0) {
return `${hours}h`;
}
return `${hours}h ${remainingMinutes}min`;
}
