'use strict';

const events = require('../events.js');
const api = require('../api.js');

class TopNavigationItem {
    constructor(accessKey, title, url, available, imageUrl) {
        this.accessKey = accessKey;
        this.title = title;
        this.url = url;
        this.available = available === undefined ? true : available;
        this.imageUrl = imageUrl === undefined ? null : imageUrl;
        this.key = null;
    }
};

class TopNavigation extends events.EventTarget {
    constructor() {
        super();
        this.activeItem = null;
        this._keyToItem = new Map();
        this._items = [];
    }

    getAll() {
        return this._items;
    }

    get(key) {
        if (!this._keyToItem.has(key)) {
            throw `An item with key ${key} does not exist.`;
        }
        return this._keyToItem.get(key);
    }

    add(key, item) {
        item.key = key;
        if (this._keyToItem.has(key)) {
            throw `An item with key ${key} was already added.`;
        }
        this._keyToItem.set(key, item);
        this._items.push(item);
    }

    activate(key) {
        this.activeItem = null;
        this.dispatchEvent(new CustomEvent('activate', {
            detail: {
                key: key,
                item: key ? this.get(key) : null,
            },
        }));
    }

    setTitle(title) {
        api.fetchConfig().then(() => {
            document.oldTitle = null;
            document.title = api.getName() + (title ? (' – ' + title) : '');
        });
    }

    showAll() {
        for (let item of this._items) {
            item.available = true;
        }
    }

    show(key) {
        this.get(key).available = true;
    }

    hide(key) {
        this.get(key).available = false;
    }
};

function _makeTopNavigation() {
    const ret = new TopNavigation();
    ret.add('home', new TopNavigationItem('H', 'Home', ''));
    ret.add('posts', new TopNavigationItem('P', 'Posts', 'posts'));
    ret.add('upload', new TopNavigationItem('U', 'Upload', 'upload'));
    ret.add('comments', new TopNavigationItem('C', 'Comments', 'comments'));
    ret.add('tags', new TopNavigationItem('T', 'Tags', 'tags'));
    ret.add('users', new TopNavigationItem('S', 'Users', 'users'));
    ret.add('account', new TopNavigationItem('A', 'Account', 'user/{me}'));
    ret.add('register', new TopNavigationItem('R', 'Register', 'register'));
    ret.add('login', new TopNavigationItem('L', 'Log in', 'login'));
    ret.add('logout', new TopNavigationItem('O', 'Logout', 'logout'));
    ret.add('help', new TopNavigationItem('E', 'Help', 'help'));
    ret.add(
        'settings',
        new TopNavigationItem(
            null,
            '<i class=\'fa fa-cog\'></i>',
            'settings'));
    return ret;
}

module.exports = _makeTopNavigation();
