import axios, {
  AxiosBasicCredentials,
  type AxiosRequestConfig,
  type Method,
  type RawAxiosRequestHeaders,
} from "axios";
import { APIError } from "./api_error";

interface Params {
  endpoint: string;
  method?: Method;
  data?: unknown;
  headers?: RawAxiosRequestHeaders;
  config?: AxiosRequestConfig;
}

export class API {
  private static get api_baseurl(): string {
    // in production mode, return "proto://hostname/api"
    if (process.env.NODE_ENV === "production") {
      return `${window.location.protocol}//${window.location.host}/api`;
    } else if (process.env.NODE_ENV !== "development") {
      // not in prouction or development mode
      console.warn("Unexpected NODE_ENV value");
    }

    // in development mode, return "proto://hostname:8000/api"
    return `${window.location.protocol}//${window.location.hostname}:8000/api`;
  }

  private static readonly axios = axios.create({
    timeout: 10e3,
    baseURL: this.api_baseurl,
  });

  private static readonly creds_key = "advent22/credentials";

  public static set creds(value: AxiosBasicCredentials | null) {
    if (value === null) {
      localStorage.removeItem(this.creds_key);
    } else {
      localStorage.setItem(this.creds_key, JSON.stringify(value));
    }
  }

  public static get creds(): AxiosBasicCredentials {
    const auth_json = localStorage.getItem(this.creds_key);
    if (auth_json !== null) {
      return JSON.parse(auth_json);
    } else {
      return { username: "", password: "" };
    }
  }

  private static get_axios_config({
    endpoint,
    method = "GET",
    data,
    headers = {},
    config = {},
  }: Params): AxiosRequestConfig {
    return {
      url: endpoint,
      method: method,
      data: data,
      auth: this.creds,
      headers: headers,
      ...config,
    };
  }

  public static async request<T = string>(p: Params): Promise<T>;
  public static async request<T = string>(p: string): Promise<T>;
  public static async request<T = string>(p: Params | string): Promise<T> {
    if (typeof p === "string") p = { endpoint: p };

    try {
      const response = await this.axios.request<T>(this.get_axios_config(p));
      return response.data;
    } catch (reason) {
      console.error(`Failed to query ${p.endpoint}: ${reason}`);
      throw new APIError(reason, p.endpoint);
    }
  }
}