scottohara/loot

import angular from "angular";

export default class AuthenticationModel {
    private readonly SESSION_STORAGE_KEY = "lootAuthenticationKey";

    public constructor(
        private readonly $window: angular.IWindowService,
        private readonly $http: angular.IHttpService,
        private readonly $cacheFactory: angular.ICacheFactoryService,
    ) {}

    // Checks if the API authorisation header is set
    public get isAuthenticated(): boolean {
        // Get the encoded credentials from sessionStorage
        const authenticationKey: string | null =
            this.$window.sessionStorage.getItem(this.SESSION_STORAGE_KEY);

        if (null !== authenticationKey) {
            // Set the Authorization header for all http requests
            this.setAuthorisationHeader(authenticationKey);

            return true;
        }

        // Not authenticated
        return false;
    }

    // Validate the user credentials and set the API authorisation header
    public login(
        username: string | null,
        password: string | null,
    ): angular.IPromise<void> {
        // Base64 encode the credentials
        const authenticationKey: string = this.$window.btoa(
            `${username}:${password}`,
        );

        // Validate the credentials
        return this.$http
            .post("/logins", "", {
                headers: {
                    Authorization: this.authorisation(authenticationKey),
                },
            })
            .then((): void => {
                // Login successful, store the encoded credentials in sessionStorage
                this.$window.sessionStorage.setItem(
                    this.SESSION_STORAGE_KEY,
                    authenticationKey,
                );

                // Set the Authorization header for all http requests
                this.setAuthorisationHeader(authenticationKey);
            });
    }

    // Clear the API authorisation header and stored credentials
    public logout(): void {
        // Remove the encoded credentials from sessionStorage
        this.$window.sessionStorage.removeItem(this.SESSION_STORAGE_KEY);

        // Clear the Authorization header for all http requests
        this.setAuthorisationHeader("");

        // Clear all http caches (except the template cache)
        angular.forEach(
            this.$cacheFactory.info(),
            ({ id }: { id: string }): void => {
                if ("templates" !== id) {
                    this.$cacheFactory.get(id).removeAll();
                }
            },
        );
    }

    // Helper function to construct basic authorization header value
    private authorisation(authenticationKey: string): string {
        return `Basic ${authenticationKey}`;
    }

    // Set the Authorization header for all http requests
    private setAuthorisationHeader(authenticationKey: string): void {
        const headers: angular.IHttpRequestConfigHeaders = {
            ...this.$http.defaults.headers,
        };

        headers.common = { ...(headers.common as Record<string, unknown>) };
        headers.common.Authorization = this.authorisation(authenticationKey);
        this.$http.defaults.headers = headers;
    }
}

AuthenticationModel.$inject = ["$window", "$http", "$cacheFactory"];