export type ApiResponse<T> = {
  data: T;
  success: boolean;
  error?: string;
};

export type RequestOptions = {
  params?: Record<string, string | number | boolean>;
  headers?: Record<string, string>;
};

const API_BASE_URL = process.env.REACT_APP_API_URL || 'http://calendi.test';

export class ApiError extends Error {
  status: number;
  
  constructor(message: string, status: number) {
    super(message);
    this.status = status;
    this.name = 'ApiError';
  }
}

export async function get<T>(endpoint: string, options?: RequestOptions): Promise<T> {
  const url = buildUrl(endpoint, options?.params);
  const response = await fetch(url, {
    method: 'GET',
    headers: {
      'Content-Type': 'application/json',
      ...options?.headers
    }
  });
  
  return handleResponse<T>(response);
}

export async function post<T>(endpoint: string, data: unknown, options?: RequestOptions): Promise<T> {
  const url = buildUrl(endpoint, options?.params);
  const response = await fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      ...options?.headers
    },
    body: JSON.stringify(data)
  });
  
  return handleResponse<T>(response);
}

export async function put<T>(endpoint: string, data: unknown, options?: RequestOptions): Promise<T> {
  const url = buildUrl(endpoint, options?.params);
  const response = await fetch(url, {
    method: 'PUT',
    headers: {
      'Content-Type': 'application/json',
      ...options?.headers
    },
    body: JSON.stringify(data)
  });
  
  return handleResponse<T>(response);
}

export async function del<T>(endpoint: string, options?: RequestOptions): Promise<T> {
  const url = buildUrl(endpoint, options?.params);
  const response = await fetch(url, {
    method: 'DELETE',
    headers: {
      'Content-Type': 'application/json',
      ...options?.headers
    }
  });
  
  return handleResponse<T>(response);
}

function buildUrl(endpoint: string, params?: Record<string, string | number | boolean>): string {
  const url = new URL(`${API_BASE_URL}${endpoint}`);
  url.port = window.location.port;
  
  if (params) {
    Object.entries(params).forEach(([key, value]) => {
      url.searchParams.append(key, String(value));
    });
  }
  
  return url.toString();
}

async function handleResponse<T>(response: Response): Promise<T> {
  if (!response.ok) {
    const errorText = await response.text();
    throw new ApiError(errorText || `Request failed with status ${response.status}`, response.status);
  }
  
  try {
    return await response.json() as T;
  } catch (error) {
    throw new ApiError('Failed to parse response', 500);
  }
}