rxjs/operators#materialize TypeScript Examples

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        this.users = JSON.parse(this.localStorage.getItem('users')) || [];
        return of(null).pipe(mergeMap(() => {
            // login user
            if (request.url.endsWith('/login') && request.method === 'POST') {
                return this.loginHandle(request);
            }

            // register user
            if (request.url.endsWith('/register') && request.method === 'POST') {
                const user = this.getStorageUser(request);
                return this.registerHandle(user);
            }

            // login user with external provider
            if (request.url.endsWith('/extlogin') && request.method === 'POST') {
                const user = this.getStorageExtUser(request);
                return this.registerHandle(user, true);
            }

            // Microsoft-specific OIDC discovery URI
            if (request.url.endsWith('ms-discovery/keys') && request.method === 'GET') {
                return of(new HttpResponse({ status: 200, body: msKeys }));
            }

            return next.handle(request);
        }))
        .pipe(materialize())
        .pipe(dematerialize());
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName
            })
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users);
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
        }

        function error(message) {
            return throwError({ error: { message } });
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorised' } });
        }

        function isLoggedIn() {
            return headers.get('Authorization') === `Basic ${window.btoa('test:test')}`;
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                token: 'fake-jwt-token'
            })
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users);
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
        }

        function error(message) {
            return throwError({ error: { message } });
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorised' } });
        }

        function isLoggedIn() {
            return headers.get('Authorization') === 'Bearer fake-jwt-token';
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                token: 'fake-jwt-token'
            })
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users);
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
        }

        function error(message) {
            return throwError({ error: { message } });
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorised' } });
        }

        function isLoggedIn() {
            return headers.get('Authorization') === 'Bearer fake-jwt-token';
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return handleRoute();

        function handleRoute() {
            switch (true) {
                case url.endsWith('/accounts/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/accounts') && method === 'GET':
                    return getAccounts();
                case url.match(/\/accounts\/\d+$/) && method === 'GET':
                    return getAccountById();
                case url.match(/\/accounts\/\d+$/) && method === 'PUT':
                    return updateAccount();
                case url.match(/\/accounts\/\d+$/) && method === 'DELETE':
                    return deleteAccount();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }
        }

        // route functions

        function authenticate() {
            const { accessToken } = body;

            return from(new Promise(resolve => {
                fetch(`https://graph.facebook.com/v8.0/me?access_token=${accessToken}`)
                    .then(response => resolve(response.json()));
            })).pipe(concatMap((data: any) => {
                if (data.error) return unauthorized(data.error.message);

                let account = accounts.find(x => x.facebookId === data.id);
                if (!account) {
                    // create new account if first time logging in
                    account = {
                        id: newAccountId(),
                        facebookId: data.id,
                        name: data.name,
                        extraInfo: `This is some extra info about ${data.name} that is saved in the API`
                    }
                    accounts.push(account);
                    localStorage.setItem(accountsKey, JSON.stringify(accounts));
                }

                return ok({
                    ...account,
                    token: generateJwtToken(account)
                });
            }));
        }

        function getAccounts() {
            if (!isLoggedIn()) return unauthorized();
            return ok(accounts);
        }

        function getAccountById() {
            if (!isLoggedIn()) return unauthorized();

            let account = accounts.find(x => x.id === idFromUrl());
            return ok(account);
        }

        function updateAccount() {
            if (!isLoggedIn()) return unauthorized();

            let params = body;
            let account = accounts.find(x => x.id === idFromUrl());

            // update and save account
            Object.assign(account, params);
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok(account);
        }

        function deleteAccount() {
            if (!isLoggedIn()) return unauthorized();

            // delete account then save
            accounts = accounts.filter(x => x.id !== idFromUrl());
            localStorage.setItem(accountsKey, JSON.stringify(accounts));
            return ok();
        }
        
        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500));
        }

        function unauthorized(message = 'Unauthorized') {
            return throwError({ status: 401, error: { message } })
                .pipe(materialize(), delay(500), dematerialize());
        }

        function isLoggedIn() {
            return headers.get('Authorization')?.startsWith('Bearer fake-jwt-token');
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }

        function newAccountId() {
            return accounts.length ? Math.max(...accounts.map(x => x.id)) + 1 : 1;
        }

        function generateJwtToken(account) {
            // create token that expires in 15 minutes
            const tokenPayload = { 
                exp: Math.round(new Date(Date.now() + 15*60*1000).getTime() / 1000),
                id: account.id
            }
            return `fake-jwt-token.${btoa(JSON.stringify(tokenPayload))}`;
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users/refresh-token') && method === 'POST':
                    return refreshToken();
                case url.endsWith('/users/revoke-token') && method === 'POST':
                    return revokeToken();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            
            if (!user) return error('Username or password is incorrect');

            // add refresh token to user
            user.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                jwtToken: generateJwtToken()
            })
        }

        function refreshToken() {
            const refreshToken = getRefreshToken();
            
            if (!refreshToken) return unauthorized();

            const user = users.find(x => x.refreshTokens.includes(refreshToken));
            
            if (!user) return unauthorized();

            // replace old refresh token with a new one and save
            user.refreshTokens = user.refreshTokens.filter(x => x !== refreshToken);
            user.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                jwtToken: generateJwtToken()
            })
        }

        function revokeToken() {
            if (!isLoggedIn()) return unauthorized();
            
            const refreshToken = getRefreshToken();
            const user = users.find(x => x.refreshTokens.includes(refreshToken));
            
            // revoke token and save
            user.refreshTokens = user.refreshTokens.filter(x => x !== refreshToken);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users);
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
        }

        function error(message) {
            return throwError({ error: { message } });
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorized' } });
        }

        function isLoggedIn() {
            // check if jwt token is in auth header
            const authHeader = headers.get('Authorization');
            if (!authHeader.startsWith('Bearer fake-jwt-token')) return false;

            // check if token is expired
            const jwtToken = JSON.parse(atob(authHeader.split('.')[1]));
            const tokenExpired = Date.now() > (jwtToken.exp * 1000);
            if (tokenExpired) return false;

            return true;
        }

        function generateJwtToken() {
            // create token that expires in 15 minutes
            const tokenPayload = { exp: Math.round(new Date(Date.now() + 15*60*1000).getTime() / 1000) }
            return `fake-jwt-token.${btoa(JSON.stringify(tokenPayload))}`;
        }

        function generateRefreshToken() {
            const token = new Date().getTime().toString();

            // add token cookie that expires in 7 days
            const expires = new Date(Date.now() + 7*24*60*60*1000).toUTCString();
            document.cookie = `fakeRefreshToken=${token}; expires=${expires}; path=/`;

            return token;
        }

        function getRefreshToken() {
            // get refresh token from cookie
            return (document.cookie.split(';').find(x => x.includes('fakeRefreshToken')) || '=').split('=')[1];
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        return handleRoute();

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users/register') && method === 'POST':
                    return register();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                case url.match(/\/users\/\d+$/) && method === 'GET':
                    return getUserById();
                case url.match(/\/users\/\d+$/) && method === 'PUT':
                    return updateUser();
                case url.match(/\/users\/\d+$/) && method === 'DELETE':
                    return deleteUser();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                ...basicDetails(user),
                token: 'fake-jwt-token'
            })
        }

        function register() {
            const user = body

            if (users.find(x => x.username === user.username)) {
                return error('Username "' + user.username + '" is already taken')
            }

            user.id = users.length ? Math.max(...users.map(x => x.id)) + 1 : 1;
            users.push(user);
            localStorage.setItem(usersKey, JSON.stringify(users));
            return ok();
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users.map(x => basicDetails(x)));
        }

        function getUserById() {
            if (!isLoggedIn()) return unauthorized();

            const user = users.find(x => x.id === idFromUrl());
            return ok(basicDetails(user));
        }

        function updateUser() {
            if (!isLoggedIn()) return unauthorized();

            let params = body;
            let user = users.find(x => x.id === idFromUrl());

            // only update password if entered
            if (!params.password) {
                delete params.password;
            }

            // update and save user
            Object.assign(user, params);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function deleteUser() {
            if (!isLoggedIn()) return unauthorized();

            users = users.filter(x => x.id !== idFromUrl());
            localStorage.setItem(usersKey, JSON.stringify(users));
            return ok();
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500)); // delay observable to simulate server api call
        }

        function error(message) {
            return throwError({ error: { message } })
                .pipe(materialize(), delay(500), dematerialize()); // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648);
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorized' } })
                .pipe(materialize(), delay(500), dematerialize());
        }

        function basicDetails(user) {
            const { id, username, firstName, lastName } = user;
            return { id, username, firstName, lastName };
        }

        function isLoggedIn() {
            return headers.get('Authorization') === 'Bearer fake-jwt-token';
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        return handleRoute();        

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                case url.match(/\/users\/\d+$/) && method === 'GET':
                    return getUserById();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }

        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                role: user.role,
                token: `fake-jwt-token.${user.id}`
            });
        }

        function getUsers() {
            if (!isAdmin()) return unauthorized();
            return ok(users);
        }

        function getUserById() {
            if (!isLoggedIn()) return unauthorized();

            // only admins can access other user records
            if (!isAdmin() && currentUser().id !== idFromUrl()) return unauthorized();

            const user = users.find(x => x.id === idFromUrl());
            return ok(user);
        }

        // helper functions

        function ok(body) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500)); // delay observable to simulate server api call
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'unauthorized' } })
                .pipe(materialize(), delay(500), dematerialize()); // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648);
        }

        function error(message) {
            return throwError({ status: 400, error: { message } })
                .pipe(materialize(), delay(500), dematerialize());
        }

        function isLoggedIn() {
            const authHeader = headers.get('Authorization') || '';
            return authHeader.startsWith('Bearer fake-jwt-token');
        }

        function isAdmin() {
            return isLoggedIn() && currentUser().role === Role.Admin;
        }

        function currentUser() {
            if (!isLoggedIn()) return;
            const id = parseInt(headers.get('Authorization').split('.')[1]);
            return users.find(x => x.id === id);
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;
        const alertService = this.alertService;

        return handleRoute();

        function handleRoute() {
            switch (true) {
                case url.endsWith('/accounts/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/accounts/refresh-token') && method === 'POST':
                    return refreshToken();
                case url.endsWith('/accounts/revoke-token') && method === 'POST':
                    return revokeToken();
                case url.endsWith('/accounts/register') && method === 'POST':
                    return register();
                case url.endsWith('/accounts/verify-email') && method === 'POST':
                    return verifyEmail();
                case url.endsWith('/accounts/forgot-password') && method === 'POST':
                    return forgotPassword();
                case url.endsWith('/accounts/validate-reset-token') && method === 'POST':
                    return validateResetToken();
                case url.endsWith('/accounts/reset-password') && method === 'POST':
                    return resetPassword();
                case url.endsWith('/accounts') && method === 'GET':
                    return getAccounts();
                case url.match(/\/accounts\/\d+$/) && method === 'GET':
                    return getAccountById();
                case url.endsWith('/accounts') && method === 'POST':
                    return createAccount();
                case url.match(/\/accounts\/\d+$/) && method === 'PUT':
                    return updateAccount();
                case url.match(/\/accounts\/\d+$/) && method === 'DELETE':
                    return deleteAccount();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { email, password } = body;
            const account = accounts.find(x => x.email === email && x.password === password && x.isVerified);
            
            if (!account) return error('Email or password is incorrect');

            // add refresh token to account
            account.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok({
                ...basicDetails(account),
                jwtToken: generateJwtToken(account)
            });
        }

        function refreshToken() {
            const refreshToken = getRefreshToken();
            
            if (!refreshToken) return unauthorized();

            const account = accounts.find(x => x.refreshTokens.includes(refreshToken));
            
            if (!account) return unauthorized();

            // replace old refresh token with a new one and save
            account.refreshTokens = account.refreshTokens.filter(x => x !== refreshToken);
            account.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok({
                ...basicDetails(account),
                jwtToken: generateJwtToken(account)
            });

        }

        function revokeToken() {
            if (!isAuthenticated()) return unauthorized();
            
            const refreshToken = getRefreshToken();
            const account = accounts.find(x => x.refreshTokens.includes(refreshToken));
            
            // revoke token and save
            account.refreshTokens = account.refreshTokens.filter(x => x !== refreshToken);
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok();
        }

        function register() {
            const account = body;

            if (accounts.find(x => x.email === account.email)) {
                // display email already registered "email" in alert
                setTimeout(() => {
                    alertService.info(`
                        <h4>Email Already Registered</h4>
                        <p>Your email ${account.email} is already registered.</p>
                        <p>If you don't know your password please visit the <a href="${location.origin}/account/forgot-password">forgot password</a> page.</p>
                        <div><strong>NOTE:</strong> The fake backend displayed this "email" so you can test without an api. A real backend would send a real email.</div>
                    `, { autoClose: false });
                }, 1000);

                // always return ok() response to prevent email enumeration
                return ok();
            }

            // assign account id and a few other properties then save
            account.id = newAccountId();
            if (account.id === 1) {
                // first registered account is an admin
                account.role = Role.Admin;
            } else {
                account.role = Role.User;
            }
            account.dateCreated = new Date().toISOString();
            account.verificationToken = new Date().getTime().toString();
            account.isVerified = false;
            account.refreshTokens = [];
            delete account.confirmPassword;
            accounts.push(account);
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            // display verification email in alert
            setTimeout(() => {
                const verifyUrl = `${location.origin}/account/verify-email?token=${account.verificationToken}`;
                alertService.info(`
                    <h4>Verification Email</h4>
                    <p>Thanks for registering!</p>
                    <p>Please click the below link to verify your email address:</p>
                    <p><a href="${verifyUrl}">${verifyUrl}</a></p>
                    <div><strong>NOTE:</strong> The fake backend displayed this "email" so you can test without an api. A real backend would send a real email.</div>
                `, { autoClose: false });
            }, 1000);

            return ok();
        }
        
        function verifyEmail() {
            const { token } = body;
            const account = accounts.find(x => !!x.verificationToken && x.verificationToken === token);
            
            if (!account) return error('Verification failed');
            
            // set is verified flag to true if token is valid
            account.isVerified = true;
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok();
        }

        function forgotPassword() {
            const { email } = body;
            const account = accounts.find(x => x.email === email);
            
            // always return ok() response to prevent email enumeration
            if (!account) return ok();
            
            // create reset token that expires after 24 hours
            account.resetToken = new Date().getTime().toString();
            account.resetTokenExpires = new Date(Date.now() + 24*60*60*1000).toISOString();
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            // display password reset email in alert
            setTimeout(() => {
                const resetUrl = `${location.origin}/account/reset-password?token=${account.resetToken}`;
                alertService.info(`
                    <h4>Reset Password Email</h4>
                    <p>Please click the below link to reset your password, the link will be valid for 1 day:</p>
                    <p><a href="${resetUrl}">${resetUrl}</a></p>
                    <div><strong>NOTE:</strong> The fake backend displayed this "email" so you can test without an api. A real backend would send a real email.</div>
                `, { autoClose: false });
            }, 1000);

            return ok();
        }
        
        function validateResetToken() {
            const { token } = body;
            const account = accounts.find(x =>
                !!x.resetToken && x.resetToken === token &&
                new Date() < new Date(x.resetTokenExpires)
            );
            
            if (!account) return error('Invalid token');
            
            return ok();
        }

        function resetPassword() {
            const { token, password } = body;
            const account = accounts.find(x =>
                !!x.resetToken && x.resetToken === token &&
                new Date() < new Date(x.resetTokenExpires)
            );
            
            if (!account) return error('Invalid token');
            
            // update password and remove reset token
            account.password = password;
            account.isVerified = true;
            delete account.resetToken;
            delete account.resetTokenExpires;
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok();
        }

        function getAccounts() {
            if (!isAuthenticated()) return unauthorized();
            return ok(accounts.map(x => basicDetails(x)));
        }

        function getAccountById() {
            if (!isAuthenticated()) return unauthorized();

            let account = accounts.find(x => x.id === idFromUrl());

            // user accounts can get own profile and admin accounts can get all profiles
            if (account.id !== currentAccount().id && !isAuthorized(Role.Admin)) {
                return unauthorized();
            }

            return ok(basicDetails(account));
        }

        function createAccount() {
            if (!isAuthorized(Role.Admin)) return unauthorized();

            const account = body;
            if (accounts.find(x => x.email === account.email)) {
                return error(`Email ${account.email} is already registered`);
            }

            // assign account id and a few other properties then save
            account.id = newAccountId();
            account.dateCreated = new Date().toISOString();
            account.isVerified = true;
            account.refreshTokens = [];
            delete account.confirmPassword;
            accounts.push(account);
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok();
        }

        function updateAccount() {
            if (!isAuthenticated()) return unauthorized();

            let params = body;
            let account = accounts.find(x => x.id === idFromUrl());

            // user accounts can update own profile and admin accounts can update all profiles
            if (account.id !== currentAccount().id && !isAuthorized(Role.Admin)) {
                return unauthorized();
            }

            // only update password if included
            if (!params.password) {
                delete params.password;
            }
            // don't save confirm password
            delete params.confirmPassword;

            // update and save account
            Object.assign(account, params);
            localStorage.setItem(accountsKey, JSON.stringify(accounts));

            return ok(basicDetails(account));
        }

        function deleteAccount() {
            if (!isAuthenticated()) return unauthorized();

            let account = accounts.find(x => x.id === idFromUrl());

            // user accounts can delete own account and admin accounts can delete any account
            if (account.id !== currentAccount().id && !isAuthorized(Role.Admin)) {
                return unauthorized();
            }

            // delete account then save
            accounts = accounts.filter(x => x.id !== idFromUrl());
            localStorage.setItem(accountsKey, JSON.stringify(accounts));
            return ok();
        }
        
        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500)); // delay observable to simulate server api call
        }

        function error(message) {
            return throwError({ error: { message } })
                .pipe(materialize(), delay(500), dematerialize()); // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648);
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorized' } })
                .pipe(materialize(), delay(500), dematerialize());
        }

        function basicDetails(account) {
            const { id, title, firstName, lastName, email, role, dateCreated, isVerified } = account;
            return { id, title, firstName, lastName, email, role, dateCreated, isVerified };
        }

        function isAuthenticated() {
            return !!currentAccount();
        }

        function isAuthorized(role) {
            const account = currentAccount();
            if (!account) return false;
            return account.role === role;
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }

        function newAccountId() {
            return accounts.length ? Math.max(...accounts.map(x => x.id)) + 1 : 1;
        }

        function currentAccount() {
            // check if jwt token is in auth header
            const authHeader = headers.get('Authorization');
            if (!authHeader.startsWith('Bearer fake-jwt-token')) return;

            // check if token is expired
            const jwtToken = JSON.parse(atob(authHeader.split('.')[1]));
            const tokenExpired = Date.now() > (jwtToken.exp * 1000);
            if (tokenExpired) return;

            const account = accounts.find(x => x.id === jwtToken.id);
            return account;
        }

        function generateJwtToken(account) {
            // create token that expires in 15 minutes
            const tokenPayload = { 
                exp: Math.round(new Date(Date.now() + 15*60*1000).getTime() / 1000),
                id: account.id
            }
            return `fake-jwt-token.${btoa(JSON.stringify(tokenPayload))}`;
        }

        function generateRefreshToken() {
            const token = new Date().getTime().toString();

            // add token cookie that expires in 7 days
            const expires = new Date(Date.now() + 7*24*60*60*1000).toUTCString();
            document.cookie = `fakeRefreshToken=${token}; expires=${expires}; path=/`;

            return token;
        }

        function getRefreshToken() {
            // get refresh token from cookie
            return (document.cookie.split(';').find(x => x.includes('fakeRefreshToken')) || '=').split('=')[1];
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        return handleRoute();

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                case url.match(/\/users\/\d+$/) && method === 'GET':
                    return getUserById();
                case url.endsWith('/users') && method === 'POST':
                    return createUser();
                case url.match(/\/users\/\d+$/) && method === 'PUT':
                    return updateUser();
                case url.match(/\/users\/\d+$/) && method === 'DELETE':
                    return deleteUser();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function getUsers() {
            return ok(users.map(x => basicDetails(x)));
        }

        function getUserById() {
            const user = users.find(x => x.id === idFromUrl());
            return ok(basicDetails(user));
        }

        function createUser() {
            const user = body;

            if (users.find(x => x.email === user.email)) {
                return error(`User with the email ${user.email} already exists`);
            }

            // assign user id and a few other properties then save
            user.id = newUserId();
            delete user.confirmPassword;
            users.push(user);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function updateUser() {
            let params = body;
            let user = users.find(x => x.id === idFromUrl());

            if (params.email !== user.email && users.find(x => x.email === params.email)) {
                return error(`User with the email ${params.email} already exists`);
            }

            // only update password if entered
            if (!params.password) {
                delete params.password;
            }

            // update and save user
            Object.assign(user, params);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function deleteUser() {
            users = users.filter(x => x.id !== idFromUrl());
            localStorage.setItem(usersKey, JSON.stringify(users));
            return ok();
        }

        // helper functions

        function ok(body?: any) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500)); // delay observable to simulate server api call
        }

        function error(message: any) {
            return throwError({ error: { message } })
                .pipe(materialize(), delay(500), dematerialize()); // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648);
        }

        function basicDetails(user: any) {
            const { id, title, firstName, lastName, email, role } = user;
            return { id, title, firstName, lastName, email, role };
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }

        function newUserId() {
            return users.length ? Math.max(...users.map(x => x.id)) + 1 : 1;
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users/refresh-token') && method === 'POST':
                    return refreshToken();
                case url.endsWith('/users/revoke-token') && method === 'POST':
                    return revokeToken();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            
            if (!user) return error('Username or password is incorrect');

            // add refresh token to user
            user.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                jwtToken: generateJwtToken()
            })
        }

        function refreshToken() {
            const refreshToken = getRefreshToken();
            
            if (!refreshToken) return unauthorized();

            const user = users.find(x => x.refreshTokens.includes(refreshToken));
            
            if (!user) return unauthorized();

            // replace old refresh token with a new one and save
            user.refreshTokens = user.refreshTokens.filter(x => x !== refreshToken);
            user.refreshTokens.push(generateRefreshToken());
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                jwtToken: generateJwtToken()
            })
        }

        function revokeToken() {
            if (!isLoggedIn()) return unauthorized();
            
            const refreshToken = getRefreshToken();
            const user = users.find(x => x.refreshTokens.includes(refreshToken));
            
            // revoke token and save
            user.refreshTokens = user.refreshTokens.filter(x => x !== refreshToken);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function getUsers() {
            if (!isLoggedIn()) return unauthorized();
            return ok(users);
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
        }

        function error(message) {
            return throwError({ error: { message } });
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'Unauthorized' } });
        }

        function isLoggedIn() {
            // check if jwt token is in auth header
            const authHeader = headers.get('Authorization');
            if (!authHeader.startsWith('Bearer fake-jwt-token')) return false;

            // check if token is expired
            const jwtToken = JSON.parse(atob(authHeader.split('.')[1]));
            const tokenExpired = Date.now() > (jwtToken.exp * 1000);
            if (tokenExpired) return false;

            return true;
        }

        function generateJwtToken() {
            // create token that expires in 15 minutes
            const tokenPayload = { exp: Math.round(new Date(Date.now() + 15*60*1000).getTime() / 1000) }
            return `fake-jwt-token.${btoa(JSON.stringify(tokenPayload))}`;
        }

        function generateRefreshToken() {
            const token = new Date().getTime().toString();

            // add token cookie that expires in 7 days
            const expires = new Date(Date.now() + 7*24*60*60*1000).toUTCString();
            document.cookie = `fakeRefreshToken=${token}; expires=${expires}; path=/`;

            return token;
        }

        function getRefreshToken() {
            // get refresh token from cookie
            return (document.cookie.split(';').find(x => x.includes('fakeRefreshToken')) || '=').split('=')[1];
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        // wrap in delayed observable to simulate server api call
        return of(null)
            .pipe(mergeMap(handleRoute))
            .pipe(materialize()) // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648)
            .pipe(delay(500))
            .pipe(dematerialize());

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users/authenticate') && method === 'POST':
                    return authenticate();
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                case url.match(/\/users\/\d+$/) && method === 'GET':
                    return getUserById();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }

        }

        // route functions

        function authenticate() {
            const { username, password } = body;
            const user = users.find(x => x.username === username && x.password === password);
            if (!user) return error('Username or password is incorrect');
            return ok({
                id: user.id,
                username: user.username,
                firstName: user.firstName,
                lastName: user.lastName,
                role: user.role,
                token: `fake-jwt-token.${user.id}`
            });
        }

        function getUsers() {
            if (!isAdmin()) return unauthorized();
            return ok(users);
        }

        function getUserById() {
            if (!isLoggedIn()) return unauthorized();

            // only admins can access other user records
            if (!isAdmin() && currentUser().id !== idFromUrl()) return unauthorized();

            const user = users.find(x => x.id === idFromUrl());
            return ok(user);
        }

        // helper functions

        function ok(body) {
            return of(new HttpResponse({ status: 200, body }));
        }

        function unauthorized() {
            return throwError({ status: 401, error: { message: 'unauthorized' } });
        }

        function error(message) {
            return throwError({ status: 400, error: { message } });
        }

        function isLoggedIn() {
            const authHeader = headers.get('Authorization') || '';
            return authHeader.startsWith('Bearer fake-jwt-token');
        }

        function isAdmin() {
            return isLoggedIn() && currentUser().role === Role.Admin;
        }

        function currentUser() {
            if (!isLoggedIn()) return;
            const id = parseInt(headers.get('Authorization').split('.')[1]);
            return users.find(x => x.id === id);
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }
    }

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const { url, method, headers, body } = request;

        return handleRoute();

        function handleRoute() {
            switch (true) {
                case url.endsWith('/users') && method === 'GET':
                    return getUsers();
                case url.match(/\/users\/\d+$/) && method === 'GET':
                    return getUserById();
                case url.endsWith('/users') && method === 'POST':
                    return createUser();
                case url.match(/\/users\/\d+$/) && method === 'PUT':
                    return updateUser();
                case url.match(/\/users\/\d+$/) && method === 'DELETE':
                    return deleteUser();
                default:
                    // pass through any requests not handled above
                    return next.handle(request);
            }    
        }

        // route functions

        function getUsers() {
            return ok(users.map(x => basicDetails(x)));
        }

        function getUserById() {
            const user = users.find(x => x.id === idFromUrl());
            return ok(basicDetails(user));
        }

        function createUser() {
            const user = body;

            if (users.find(x => x.email === user.email)) {
                return error(`User with the email ${user.email} already exists`);
            }

            // assign user id and a few other properties then save
            user.id = newUserId();
            delete user.confirmPassword;
            users.push(user);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function updateUser() {
            let params = body;
            let user = users.find(x => x.id === idFromUrl());

            // only update password if entered
            if (!params.password) {
                delete params.password;
            }

            // update and save user
            Object.assign(user, params);
            localStorage.setItem(usersKey, JSON.stringify(users));

            return ok();
        }

        function deleteUser() {
            users = users.filter(x => x.id !== idFromUrl());
            localStorage.setItem(usersKey, JSON.stringify(users));
            return ok();
        }

        // helper functions

        function ok(body?) {
            return of(new HttpResponse({ status: 200, body }))
                .pipe(delay(500)); // delay observable to simulate server api call
        }

        function error(message) {
            return throwError({ error: { message } })
                .pipe(materialize(), delay(500), dematerialize()); // call materialize and dematerialize to ensure delay even if an error is thrown (https://github.com/Reactive-Extensions/RxJS/issues/648);
        }

        function basicDetails(user) {
            const { id, title, firstName, lastName, email, role } = user;
            return { id, title, firstName, lastName, email, role };
        }

        function idFromUrl() {
            const urlParts = url.split('/');
            return parseInt(urlParts[urlParts.length - 1]);
        }

        function newUserId() {
            return users.length ? Math.max(...users.map(x => x.id)) + 1 : 1;
        }
    }

intercept(
    request: HttpRequest<any>,
    next: HttpHandler
  ): Observable<any> {
    const { url, method, body } = request;

    if (
      url.endsWith("/getAllUsers") ||
      url.endsWith("/getAllUsers") ||
      url.endsWith("/updateUsers")
    ) {
      // wrap in delayed observable to simulate server api call
      return of(null)
        .pipe(mergeMap(handleRoute))
        .pipe(materialize())
        .pipe(delay(1000))
        .pipe(dematerialize());
    }

    return next.handle(request);

    function handleRoute(): any {
      switch (true) {
        case url.endsWith("/getAllUsers") && method === "GET":
          return getAllUsers();
        case url.endsWith("/getAllUsers") && method === "POST":
          return getAllUsersWithOptions(body);
        case url.endsWith("/updateUsers") && method === "POST":
          return updateUsers(body);
      }
    }

    function getAllUsers() {
      return ok(data);
    }

    function getAllUsersWithOptions(loadOptions: any) {
      let data2 = data;

      if (loadOptions.filterColumns && loadOptions.filterColumns.length > 0) {
        data2 = filterData(data2, loadOptions.filterColumns);
      }

      if (loadOptions.sortColumns && loadOptions.sortColumns.length > 0) {
        for (const element of loadOptions.sortColumns) {
          data2 = _.orderBy(data2, element.dataField, element.sortDirection);
        }
      }

      const startIndex = (loadOptions.pageNumber - 1) * loadOptions.pageSize;
      const endIndex = Math.min(
        startIndex + loadOptions.pageSize - 1,
        data2.length - 1
      );

      const result = {
        data: data2.slice(startIndex, endIndex + 1),
        total: data2.length,
      };
      return ok(result);
    }

    function filterData(dataSource: any, filterColumns: any[]) {
      for (const element of filterColumns) {
        if (element.filterOperator === "startswith") {
          dataSource = _.filter(dataSource, (a) => {
            if (!a[element.dataField]) {
              return false;
            }
            return _.startsWith(
              a[element.dataField].toLowerCase(),
              element.filterValue.toLowerCase()
            );
          });
        } else if (element.filterOperator === "endswith") {
          dataSource = _.filter(dataSource, (a) => {
            if (!a[element.dataField]) {
              return false;
            }
            return _.endsWith(
              a[element.dataField].toLowerCase(),
              element.filterValue.toLowerCase()
            );
          });
        } else if (element.filterOperator === "contains") {
          dataSource = _.filter(dataSource, (a) => {
            if (!a[element.dataField]) {
              return false;
            }
            return (
              a[element.dataField]
                .toLowerCase()
                .indexOf(element.filterValue.toLowerCase()) !== -1
            );
          });
        } else if (element.filterOperator === "gt") {
          if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] > Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) >
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          }
        } else if (element.filterOperator === "ge") {
          if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] >= Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) >=
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          }
        } else if (element.filterOperator === "lt") {
          if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] < Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) <
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          }
        } else if (element.filterOperator === "le") {
          if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] <= Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) <=
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          }
        } else if (element.filterOperator === "eq") {
          if (element.dataType === "boolean") {
            if (element.filterValue === "true") {
              dataSource = _.filter(dataSource, (a) => {
                return a[element.dataField] === true;
              });
            } else {
              dataSource = _.filter(dataSource, (a) => {
                return a[element.dataField] === false;
              });
            }
          } else if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] === Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) ===
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          } else if (element.dataType === "string") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].toLowerCase() ===
                element.filterValue.toLowerCase()
              );
            });
          }
        } else if (element.filterOperator === "ne") {
          if (element.dataType === "boolean") {
            if (element.filterValue === "true") {
              dataSource = _.filter(dataSource, (a) => {
                return a[element.dataField] !== true;
              });
            } else {
              dataSource = _.filter(dataSource, (a) => {
                return a[element.dataField] !== false;
              });
            }
          } else if (element.dataType === "number") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return a[element.dataField] !== Number(element.filterValue);
            });
          } else if (element.dataType === "date") {
            dataSource = _.filter(dataSource, (a) => {
              if (!a[element.dataField]) {
                return false;
              }
              return (
                a[element.dataField].setHours(0, 0, 0, 0) !==
                new Date(element.filterValue).setHours(0, 0, 0, 0)
              );
            });
          }
        }
      }
      return dataSource;
    }

    function ok(response: any) {
      return of(
        new HttpResponse({
          status: 200,
          body: JSON.parse(JSON.stringify(response)),
        })
      );
    }

    function updateUsers(keys: any[]) {
      const records = data.filter((element) => {
        if (keys.indexOf(element.Id) > -1) {
          return element;
        }
      });
      if (records) {
        records.forEach((element: any) => {
          element.FirstName = element.FirstName + " updated";
        });
      }
      return ok(true);
    }
  }