import {i18n} from './i18n.js';
import {html, css} from 'lit-element';
import {unsafeHTML} from 'lit-html/directives/unsafe-html.js';
import JSONLD from 'vpu-common/jsonld';
import * as commonUtils from 'vpu-common/utils';
import * as commonStyles from 'vpu-common/styles';
import * as events from 'vpu-common/events.js';
import 'vpu-common/vpu-icon.js';
import VPULitElement from 'vpu-common/vpu-lit-element';
import  {KeycloakWrapper} from './keycloak.js';


const LoginStatus = Object.freeze({
    UNKNOWN: 'unknown',
    LOGGING_IN: 'logging-in',
    LOGGED_IN: 'logged-in',
    LOGGING_OUT: 'logging-out',
    LOGGED_OUT: 'logged-out',
});

/**
 * Keycloak auth web component
 * https://www.keycloak.org/docs/latest/securing_apps/index.html#_javascript_adapter
 *
 * Dispatches an event `vpu-auth-init` and sets some global variables:
 *   window.VPUAuthSubject: Keycloak username
 *   window.VPUAuthToken: Keycloak token to send with your requests
 *   window.VPUAuthTokenParsed: Keycloak token content
 *   window.VPUUserFullName: Full name of the user
 *   window.VPUPersonId: Person identifier of the user
 *   window.VPUPerson: Person json object of the user (optional, enable by setting the `load-person` attribute,
 *                     which will dispatch a `vpu-auth-person-init` event when loaded)
 */
export class Auth extends VPULitElement {
    constructor() {
        super();
        this.lang = 'de';
        this.forceLogin = false;
        this.loadPerson = false;
        this.showProfile = false;
        this.token = "";
        this.tokenParsed = null;
        this.subject = "";
        this.name = "";
        this.personId = "";
        this.tryLogin = false;
        this.person = null;
        this.entryPointUrl = commonUtils.getAPiUrl();
        this.keycloakConfig = null;

        const _getLoginData = () => {
            const message = {
                status: this._loginStatus,
                token: this.token,
            };
            return message;
        };

        this._loginStatus = LoginStatus.UNKNOWN;
        this._emitter = new events.EventEmitter('vpu-auth-update', 'vpu-auth-update-request');
        this._emitter.registerCallback(_getLoginData);

        // Create the events
        this.initEvent = new CustomEvent("vpu-auth-init", { "detail": "KeyCloak init event", bubbles: true, composed: true });
        this.personInitEvent = new CustomEvent("vpu-auth-person-init", { "detail": "KeyCloak person init event", bubbles: true, composed: true });
        this.profileEvent = new CustomEvent("vpu-auth-profile", { "detail": "Profile event", bubbles: true, composed: true });
        this.keycloakDataUpdateEvent = new CustomEvent("vpu-auth-keycloak-data-update", { "detail": "KeyCloak data was updated", bubbles: true, composed: true });

        this.closeDropdown = this.closeDropdown.bind(this);
        this._onKCChanged = this._onKCChanged.bind(this);
   }

    _onKCChanged(event) {
        const kc = event.detail;
        let newPerson = false;

        if (kc.authenticated) {
            let tokenChanged = (this.token !== kc.token);
            this.tokenParsed = kc.tokenParsed;
            this.name = kc.idTokenParsed.name;
            this.token = kc.token;

            this.subject = kc.subject;
            const personId = kc.idTokenParsed.preferred_username;
            if (personId !== this.personId) {
                this.person = null;
                newPerson = true;
            }
            this.personId = personId;

            window.VPUAuthSubject = this.subject;
            window.VPUAuthToken = this.token;
            window.VPUAuthTokenParsed = this.tokenParsed;
            window.VPUUserFullName = this.name;
            window.VPUPersonId = this.personId;
            window.VPUPerson = this.person;

            this._setLoginStatus(LoginStatus.LOGGED_IN, tokenChanged);
        } else {
            if (this._loginStatus === LoginStatus.LOGGED_IN) {
                this._setLoginStatus(LoginStatus.LOGGING_OUT);
            }
            this.name = "";
            this.token = "";
            this.tokenParsed = null;
            this.subject = "";
            this.personId = "";
            this.person = null;

            window.VPUAuthSubject = this.subject;
            window.VPUAuthToken = this.token;
            window.VPUAuthTokenParsed = this.tokenParsed;
            window.VPUUserFullName = this.name;
            window.VPUPersonId = this.personId;
            window.VPUPerson = this.person;

            this._setLoginStatus(LoginStatus.LOGGED_OUT);
        }

        const that = this;

        if (newPerson) {
            this.dispatchEvent(this.initEvent);
        }

        if (newPerson && this.loadPerson) {
            JSONLD.initialize(this.entryPointUrl, (jsonld) => {
                // find the correct api url for the current person
                // we are fetching the logged-in person directly to respect the REST philosophy
                // see: https://github.com/api-platform/api-platform/issues/337
                const apiUrl = jsonld.getApiUrlForEntityName("Person") + '/' + that.personId;

                fetch(apiUrl, {
                    headers: {
                        'Content-Type': 'application/ld+json',
                        'Authorization': 'Bearer ' + that.token,
                    },
                })
                .then(response => response.json())
                .then((person) => {
                    that.person = person;
                    window.VPUPerson = person;
                    that.dispatchEvent(that.personInitEvent);
                    this._setLoginStatus(this._loginStatus, true);
                });
            }, {}, that.lang);
        }

        this.dispatchEvent(this.keycloakDataUpdateEvent);
    }

    _setLoginStatus(status, force) {
        if (this._loginStatus === status && !force)
            return;

        this._loginStatus = status;
        this._emitter.emit();
    }

    /**
     * See: https://lit-element.polymer-project.org/guide/properties#initialize
     */
    static get properties() {
        return {
            lang: { type: String },
            forceLogin: { type: Boolean, attribute: 'force-login' },
            tryLogin: { type: Boolean, attribute: 'try-login' },
            loadPerson: { type: Boolean, attribute: 'load-person' },
            showProfile: { type: Boolean, attribute: 'show-profile' },
            entryPointUrl: { type: String, attribute: 'entry-point-url' },
            keycloakConfig: { type: Object, attribute: 'keycloak-config' },
            name: { type: String, attribute: false },
            token: { type: String, attribute: false },
            subject: { type: String, attribute: false },
            personId: { type: String, attribute: false },
            person: { type: Object, attribute: false },
            _loginStatus: { type: String, attribute: false },
        };
    }

    _getScope() {
        if (this.keycloakConfig !== null) {
            return this.keycloakConfig.scope || "";
        }
        return "";
    }

    connectedCallback() {
        super.connectedCallback();

        // Keycloak config
        let baseURL = commonUtils.setting('keyCloakBaseURL');
        let realm = commonUtils.setting('keyCloakRealm');
        let clientId = commonUtils.setting('keyCloakClientId');
        let silentCheckSsoRedirectUri = '';
        if (this.keycloakConfig !== null) {
            baseURL = this.keycloakConfig.url || baseURL;
            realm = this.keycloakConfig.realm || realm;
            clientId = this.keycloakConfig.clientId || clientId;
            silentCheckSsoRedirectUri = this.keycloakConfig.silentCheckSsoRedirectUri || silentCheckSsoRedirectUri;
        }
        if (!baseURL || !realm || !clientId) {
            throw Error("Keycloak config not set");
        }

        this._kcwrapper = new KeycloakWrapper(baseURL, realm, clientId, silentCheckSsoRedirectUri);
        this._kcwrapper.addEventListener('changed', this._onKCChanged);

        const handleLogin = async () => {
            if (this.forceLogin || this._kcwrapper.isLoggingIn()) {
                this._setLoginStatus(LoginStatus.LOGGING_IN);
                await this._kcwrapper.login({lang: this.lang, scope: this._getScope()});
            } else if (this.tryLogin) {
                this._setLoginStatus(LoginStatus.LOGGING_IN);
                await this._kcwrapper.tryLogin();
                if (this._loginStatus === LoginStatus.LOGGING_IN)
                    this._setLoginStatus(LoginStatus.LOGGED_OUT);
            } else {
                this._setLoginStatus(LoginStatus.LOGGED_OUT);
            }
        };

        handleLogin();

        this.updateComplete.then(() => {
            window.onresize = () => {
                this.updateDropdownWidth();
            };
        });

        document.addEventListener('click', this.closeDropdown);
    }

    /**
     * Set the dropdown width to almost the width of the web component
     * We need to set the width manually because a percent width is in relation to the viewport
     */
    updateDropdownWidth() {
        const dropdown = this._("div.dropdown-menu");

        if (!dropdown) {
            return;
        }

        dropdown.setAttribute("style", `width: ${this.offsetWidth - 5}px`);
    }

    disconnectedCallback() {
        this._kcwrapper.removeEventListener('changed', this._onKCChanged);
        document.removeEventListener('click', this.closeDropdown);
        super.disconnectedCallback();
    }

    onLoginClicked(e) {
        this._kcwrapper.login({lang: this.lang, scope: this._getScope()});
        e.preventDefault();
    }

    onLogoutClicked(e) {
        // Keycloak will redirect right away without emitting events, so we have
        // to do this manually here
        if (this._loginStatus === LoginStatus.LOGGED_IN) {
            this._setLoginStatus(LoginStatus.LOGGING_OUT);
        }
        this._kcwrapper.logout();
    }

    update(changedProperties) {
        changedProperties.forEach((oldValue, propName) => {
            if (propName === "lang") {
                i18n.changeLanguage(this.lang);
            }
        });

        super.update(changedProperties);
    }

    static get styles() {
        // language=css
        return css`
            ${commonStyles.getThemeCSS()}

            :host {
                display: inline-block;
            }

            a {
                color: currentColor;
                cursor: pointer;
                text-decoration: none;
            }

            img {
                border-width: var(--vpu-border-width);
                border-color: var(--vpu-dark);
                border-style: solid;
            }

            .dropdown.is-active .dropdown-menu, .dropdown.is-hoverable:hover .dropdown-menu {
                display: block;
            }

            .dropdown-menu {
                display: none;
                min-width: 8em;
                padding-top: 4px;
                position: absolute;
                z-index: 20;
                border: solid 1px black;
                border-radius: var(--vpu-border-radius);
                overflow: hidden;
                background-color: white;
            }

            .dropdown-content {
                background-color: white;
                padding-bottom: 0.5rem;
                padding-top: 0.5rem;
            }

            .dropdown-content img {
                max-width: 120px;
            }

            .menu a {
                /*padding: 0.3em;*/
                font-weight: 400;
                color: #000;
                display: block;
                text-decoration: none;
            }

            .menu a:hover {
                color: #E4154B;
            }

            .menu a.selected { color: white; background-color: black; }

            .dropdown-item {
                color: #4a4a4a;
                display: block;
                font-size: 0.875rem;
                line-height: 1.5;
                padding: 0.375rem 1rem;
                position: relative;
            }

              .dropdown, img.login {
                cursor: pointer;
            }

            a.dropdown-item {
                width: initial !important;
            }

            .main-button {
                min-width: 150px;
            }

            .dropdown-trigger {
                white-space: nowrap;
            }

            vpu-icon {
                height: 1em;
                width: 1em;
                vertical-align: -0.1rem;
            }

            .loginbox svg {
                width: 1.2em;
                height: 1.2em;
                top: 0.15em;
                position: relative;
            }

            .loginbox {
                display: flex;

                align-items: center;
                padding: 0 0.1em;
                transition: background-color 0.15s, color 0.15s;
            }

            .loginbox:hover {
                background-color: var(--vpu-dark);
                color: var(--vpu-light);
                cursor: pointer;
                transition: none;
            }

            .loginbox:hover svg path {
                fill: var(--vpu-light);
            }

            .loginbox .icon, .authbox {
                display: inline-block;
            }

            .loginbox .label {
                padding-left: 0.2em;
            }
        `;
    }

    setChevron(name) {
        const chevron = this.shadowRoot.querySelector("#menu-chevron-icon");
        if (chevron !== null) {
            chevron.name = name;
        }
    }

    onDropdownClick(event) {
        event.stopPropagation();
        event.currentTarget.classList.toggle('is-active');
        this.setChevron(event.currentTarget.classList.contains('is-active') ? 'chevron-up' : 'chevron-down');
        this.updateDropdownWidth();
    }

    closeDropdown() {
        var dropdowns = this.shadowRoot.querySelectorAll('.dropdown');
        dropdowns.forEach(function (el) {
            el.classList.remove('is-active');
        });
        this.setChevron('chevron-down');
    }

    onProfileClicked(event) {
        event.preventDefault();
        this.dispatchEvent(this.profileEvent);
    }

    renderLoggedIn() {
        const imageURL = (this.person && this.person.image) ? this.person.image : null;

        return html`
            <div class="dropdown" @click="${this.onDropdownClick}">
                <div class="dropdown-trigger">
                    <a href="#">
                        <span>${this.name}</span>
                        <vpu-icon name="chevron-down" id="menu-chevron-icon"></vpu-icon>
                    </a>
                </div>
                <div class="dropdown-menu" id="dropdown-menu2" role="menu">
                    <div class="dropdown-content" @blur="${this.closeDropdown}">
                        ${imageURL ? html`<div class="dropdown-item"><img alt="" src="${imageURL}"></div>` : ''}
                        <div class="menu">
                            ${this.showProfile ? html`<a href="#" @click="${this.onProfileClicked}" class="dropdown-item">${i18n.t('profile')}</a>` :''}
                            <a href="#" @click="${this.onLogoutClicked}" class="dropdown-item">${i18n.t('logout')}</a>
                        </div>
                    </div>
                </div>
            </div>
        `;
    }

    renderLoggedOut() {
        let loginSVG = `
        <svg
           viewBox="0 0 100 100"
           y="0px"
           x="0px"
           id="icon"
           role="img"
           version="1.1">
        <g
           id="g6">
            <path
           style="stroke-width:1.33417916"
           id="path2"
           d="m 42.943908,38.894934 5.885859,6.967885 H 5.4215537 c -1.8393311,0 -3.4334181,1.741972 -3.4334181,4.064599 0,2.322628 1.4714649,4.064599 3.4334181,4.064599 H 48.829767 L 42.943908,60.9599 c -1.348843,1.596808 -1.348843,4.064599 0,5.661406 1.348843,1.596808 3.433418,1.596808 4.782261,0 L 61.705085,49.927418 47.726169,33.378693 c -1.348843,-1.596806 -3.433418,-1.596806 -4.782261,0 -1.348843,1.596807 -1.348843,4.064599 0,5.516241 z" />
            <path
           id="path4"
           d="m 50,2.3007812 c -18.777325,0 -35.049449,10.9124408 -42.8261719,26.7246098 H 13.390625 C 20.672112,16.348362 34.336876,7.8007812 50,7.8007812 73.3,7.8007812 92.300781,26.7 92.300781,50 92.300781,73.3 73.3,92.300781 50,92.300781 c -15.673389,0 -29.345175,-8.60579 -36.623047,-21.326172 H 7.1640625 C 14.942553,86.8272 31.242598,97.800781 50.099609,97.800781 76.399609,97.800781 97.900391,76.4 97.900391,50 97.800391,23.7 76.3,2.3007812 50,2.3007812 Z" />
        </g>
        </svg>
        `;

        return html`
            <a href="#" @click="${this.onLoginClicked}">
                <div class="loginbox">
                    <div class="icon">${unsafeHTML(loginSVG)}</div>
                    <div class="label">${i18n.t('login')}</div>
                </div>
            </a>
        `;
    }

    render() {
        commonUtils.initAssetBaseURL('vpu-auth-src');
        const loggedIn = (this._loginStatus === LoginStatus.LOGGED_IN);
        return html`
            <div class="authbox">
                ${loggedIn ? this.renderLoggedIn() : this.renderLoggedOut()}
            </div>
        `;
    }
}