const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL || "http://localhost:8080";

export class ApiError extends Error {
  constructor(
    message: string,
    public statusCode: number,
    public code?: string
  ) {
    super(message);
    this.name = "ApiError";
  }
}

export async function apiRequest<T>(
  endpoint: string,
  options: RequestInit = {}
): Promise<T> {
  const url = `${API_BASE_URL}${endpoint}`;

  const defaultHeaders = {
    "Content-Type": "application/json",
  };

  const config: RequestInit = {
    ...options,
    headers: {
      ...defaultHeaders,
      ...options.headers,
    },
  };

  try {
    const response = await fetch(url, config);

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({}));
      throw new ApiError(
        errorData.message || `HTTP error! status: ${response.status}`,
        response.status,
        errorData.code
      );
    }

    return await response.json();
  } catch (error) {
    if (error instanceof ApiError) {
      throw error;
    }
    throw new ApiError("Network error", 0);
  }
}

export const api = {
  get: <T>(endpoint: string, headers?: HeadersInit) =>
    apiRequest<T>(endpoint, { method: "GET", headers }),

  post: <T>(endpoint: string, data?: unknown, headers?: HeadersInit) =>
    apiRequest<T>(endpoint, {
      method: "POST",
      body: JSON.stringify(data),
      headers,
    }),

  put: <T>(endpoint: string, data?: unknown, headers?: HeadersInit) =>
    apiRequest<T>(endpoint, {
      method: "PUT",
      body: JSON.stringify(data),
      headers,
    }),

  delete: <T>(endpoint: string, headers?: HeadersInit) =>
    apiRequest<T>(endpoint, { method: "DELETE", headers }),
};