import { UnauthorizedError } from '../errors/unauthorized.error.js';
import { APIError } from '../errors/api.error.js';

export const UnauthorizedStatusCode = 401;

export class APIClient {
  	constructor(baseURL = 'http://localhost:8001/api/v1') {
		this.baseURL = baseURL;
		this.login = this.login.bind(this);
		this.logout = this.logout.bind(this);
		this.retrieveSessionUser = this.retrieveSessionUser.bind(this);
		this.listUsers = this.listUsers.bind(this);
		this.listRequests = this.listRequests.bind(this);
		this.createUser = this.createUser.bind(this);
  	}

	login(username, password) {
		  return this._callAPI('/login', { username, password }, 'POST')
		  	.then(result => result.data);
	}

	logout() {
	  	return this._callAPI('/logout')
	}

	retrieveSessionUser() {
		return this._callAPI('/me')
		.then(result => result.data);
	}

	listUsers() {
	  	return this._callAPI('/users')
	}

	listRequests() {

	}

	createRequest(request) {

	}

	createUser(username, password) {
		return this._callAPI('/users', { username, password }, 'POST')
			.then(this._withAPIErrorMiddleware('create_user'))
			.then(result => result.data);
	}

	updateRequestStatus(reqID, newStatus) {

	}

	_callAPI(path, body, method='GET') {
	  return fetch(this.baseURL + path, {
		method,
		headers: {
			'Content-Type': 'application/json',
		},
		mode: 'cors',
		credentials: 'include',
		body: JSON.stringify(body),
	  })
	  .then(this._withUnauthorizedErrorMiddleware())
	  .then(res => res.json())
	}

	_withUnauthorizedErrorMiddleware() {
		return res => {
			if (res.status === UnauthorizedStatusCode) {
				throw new UnauthorizedError();
			}
			return res;
		}
	}

	_withAPIErrorMiddleware(endpoint) {
		return result => {
			if (result.error) {
				const { code, message, data } = result.error;
				throw new APIError(endpoint, code, message, data);
			}
			return result;
		}
	}

}