import axios, { AxiosError } from "axios";
import type { AxiosInstance, AxiosRequestConfig, AxiosResponse } from "axios";
import Cookies from "js-cookie";
import { AUTH_USER_ID, CLAIM_NAME } from "./env";

interface ClientConfig {
  baseURL: string;
  siteId: string;
}

class Client {
  private static instance: Client;
  private axiosInstance: AxiosInstance;

  private constructor(config: ClientConfig) {
    this.axiosInstance = axios.create({
      baseURL: config.baseURL,
      headers: {
        "Content-Type": "application/json",
        "X-Site-Id": config.siteId,
      },
      withCredentials: true,
    });


    this.axiosInstance.interceptors.request.use((config) => {
      const token = Cookies.get(CLAIM_NAME);
      const userId = Cookies.get(AUTH_USER_ID);

      if (!token || !userId) {
        throw new AxiosError(
          "The authentication token is invalid.",
          "UNAUTHORIZED",
          config,
          null,
          {
            data: { message: "The authentication token is invalid." },
            status: 401,
            statusText: "Unauthorized",
            headers: this.axiosInstance.defaults.headers,
            config: config,
          } as AxiosResponse
        );
      }

      config.headers[CLAIM_NAME] = token;
      config.headers[AUTH_USER_ID] = userId;

      return config;
    });
  }

  public static getInstance(config: ClientConfig): Client {
    if (!Client.instance) {
      Client.instance = new Client(config);
    }
    return Client.instance;
  }

  public async get<T = unknown, R = AxiosResponse<T>>(
    url: string,
    config?: AxiosRequestConfig
  ): Promise<R> {
    const response = await this.axiosInstance.get<T, R>(url, config);
    return response;
  }

  public async post<T = unknown, R = AxiosResponse<T>, D = unknown>(
    url: string,
    data?: D,
    config?: AxiosRequestConfig<D>
  ): Promise<R> {
    const response = await this.axiosInstance.post<T, R>(url, data, config);
    return response;
  }

  public async put<T = unknown, R = AxiosResponse<T>, D = unknown>(
    url: string,
    data?: D,
    config?: AxiosRequestConfig<D>
  ): Promise<R> {
    const response = await this.axiosInstance.put<T, R>(url, data, config);
    return response;
  }

  public async delete<T = unknown, R = AxiosResponse<T>>(
    url: string,
    config?: AxiosRequestConfig
  ): Promise<R> {
    const response = await this.axiosInstance.delete<T, R>(url, config);
    return response;
  }
}

export type { ClientConfig };
export { Client };