/* global APP, $, interfaceConfig */

import { toggleDialog } from '../../react/features/base/dialog';
import { sendAnalyticsEvent } from '../../react/features/analytics';
import { SpeakerStats } from '../../react/features/speaker-stats';

const logger = require('jitsi-meet-logger').getLogger(__filename);

/**
 * The reference to the shortcut dialogs when opened.
 */
let keyboardShortcutDialog = null;

/**
 * Shows or hides the keyboard shortcuts dialog.
 * @param {boolean} show whether to show or hide the dialog
 */
function showKeyboardShortcutsPanel(show) {
    if (show
            && !APP.UI.messageHandler.isDialogOpened()
            && keyboardShortcutDialog === null) {
        const msg = $('#keyboard-shortcuts').html();
        const buttons = { Close: true };

        keyboardShortcutDialog = APP.UI.messageHandler.openDialog(
            'keyboardShortcuts.keyboardShortcuts', msg, true, buttons);
    } else if (keyboardShortcutDialog !== null) {
        keyboardShortcutDialog.close();
        keyboardShortcutDialog = null;
    }
}

/**
 * Map of shortcuts. When a shortcut is registered it enters the mapping.
 * @type {{}}
 */
const _shortcuts = {};

/**
 * True if the keyboard shortcuts are enabled and false if not.
 * @type {boolean}
 */
let enabled = true;

/**
 * Maps keycode to character, id of popover for given function and function.
 */
const KeyboardShortcut = {
    init() {
        this._initGlobalShortcuts();

        window.onkeyup = e => {
            if (!enabled) {
                return;
            }
            const key = this._getKeyboardKey(e).toUpperCase();
            const num = parseInt(key, 10);

            if (!($(':focus').is('input[type=text]')
                || $(':focus').is('input[type=password]')
                || $(':focus').is('textarea'))) {
                if (_shortcuts.hasOwnProperty(key)) {
                    _shortcuts[key].function(e);
                } else if (!isNaN(num) && num >= 0 && num <= 9) {
                    APP.UI.clickOnVideo(num);
                }

            // esc while the smileys are visible hides them
            } else if (key === 'ESCAPE'
                && $('#smileysContainer').is(':visible')) {
                APP.UI.toggleSmileys();
            }
        };

        window.onkeydown = e => {
            if (!enabled) {
                return;
            }
            if (!($(':focus').is('input[type=text]')
                || $(':focus').is('input[type=password]')
                || $(':focus').is('textarea'))) {
                if (this._getKeyboardKey(e).toUpperCase() === ' ') {
                    if (APP.conference.isLocalAudioMuted()) {
                        sendAnalyticsEvent('shortcut.talk.released');
                        logger.log('Talk shortcut released');
                        APP.conference.muteAudio(false);
                    }
                }
            }
        };
    },

    /**
     * Enables/Disables the keyboard shortcuts.
     * @param {boolean} value - the new value.
     */
    enable(value) {
        enabled = value;
    },

    /**
     * Registers a new shortcut.
     *
     * @param shortcutChar the shortcut character triggering the action
     * @param shortcutAttr the "shortcut" html element attribute mappring an
     * element to this shortcut and used to show the shortcut character on the
     * element tooltip
     * @param exec the function to be executed when the shortcut is pressed
     * @param helpDescription the description of the shortcut that would appear
     * in the help menu
     */
    registerShortcut(// eslint-disable-line max-params
            shortcutChar,
            shortcutAttr,
            exec,
            helpDescription) {
        _shortcuts[shortcutChar] = {
            character: shortcutChar,
            shortcutAttr,
            function: exec
        };

        if (helpDescription) {
            this._addShortcutToHelp(shortcutChar, helpDescription);
        }
    },

    /**
     * Unregisters a shortcut.
     *
     * @param shortcutChar unregisters the given shortcut, which means it will
     * no longer be usable
     */
    unregisterShortcut(shortcutChar) {
        _shortcuts.remove(shortcutChar);

        this._removeShortcutFromHelp(shortcutChar);
    },

    /**
     * Returns the tooltip string for the given shortcut attribute.
     *
     * @param shortcutAttr indicates the popover associated with the shortcut
     * @returns {string} the tooltip string to add to the given shortcut popover
     * or an empty string if the shortcutAttr is null, an empty string or not
     * found in the shortcut mapping
     */
    getShortcutTooltip(shortcutAttr) {
        if (typeof shortcutAttr === 'string' && shortcutAttr.length > 0) {
            for (const key in _shortcuts) {
                if (_shortcuts.hasOwnProperty(key)
                    && _shortcuts[key].shortcutAttr
                    && _shortcuts[key].shortcutAttr === shortcutAttr) {
                    return ` (${_shortcuts[key].character})`;
                }
            }
        }

        return '';
    },

    /**
     * @param e a KeyboardEvent
     * @returns {string} e.key or something close if not supported
     */
    _getKeyboardKey(e) {
        if (typeof e.key === 'string') {
            return e.key;
        }
        if (e.type === 'keypress'
                && ((e.which >= 32 && e.which <= 126)
                    || (e.which >= 160 && e.which <= 255))) {
            return String.fromCharCode(e.which);
        }

        // try to fallback (0-9A-Za-z and QWERTY keyboard)
        switch (e.which) {
        case 27:
            return 'Escape';
        case 191:
            return e.shiftKey ? '?' : '/';
        }
        if (e.shiftKey || e.type === 'keypress') {
            return String.fromCharCode(e.which);
        }

        return String.fromCharCode(e.which).toLowerCase();

    },

    /**
     * Adds the given shortcut to the help dialog.
     *
     * @param shortcutChar the shortcut character
     * @param shortcutDescriptionKey the description of the shortcut
     * @private
     */
    _addShortcutToHelp(shortcutChar, shortcutDescriptionKey) {

        const listElement = document.createElement('li');
        const itemClass = 'shortcuts-list__item';

        listElement.className = itemClass;
        listElement.id = shortcutChar;

        const spanElement = document.createElement('span');

        spanElement.className = 'item-action';

        const kbdElement = document.createElement('kbd');
        const classes = 'aui-label regular-key';

        kbdElement.className = classes;
        kbdElement.innerHTML = shortcutChar;
        spanElement.appendChild(kbdElement);

        const descriptionElement = document.createElement('span');
        const descriptionClass = 'shortcuts-list__description';

        descriptionElement.className = descriptionClass;
        descriptionElement.setAttribute('data-i18n', shortcutDescriptionKey);
        APP.translation.translateElement($(descriptionElement));

        listElement.appendChild(spanElement);
        listElement.appendChild(descriptionElement);

        const parentListElement
            = document.getElementById('keyboard-shortcuts-list');

        if (parentListElement) {
            parentListElement.appendChild(listElement);
        }
    },

    /**
     * Removes the list element corresponding to the given shortcut from the
     * help dialog
     * @private
     */
    _removeShortcutFromHelp(shortcutChar) {
        const parentListElement
            = document.getElementById('keyboard-shortcuts-list');

        const shortcutElement = document.getElementById(shortcutChar);

        if (shortcutElement) {
            parentListElement.removeChild(shortcutElement);
        }
    },

    /**
     * Initialise global shortcuts.
     * Global shortcuts are shortcuts for features that don't have a button or
     * link associated with the action. In other words they represent actions
     * triggered _only_ with a shortcut.
     */
    _initGlobalShortcuts() {
        this.registerShortcut('ESCAPE', null, () => {
            showKeyboardShortcutsPanel(false);
        });

        this.registerShortcut('?', null, () => {
            sendAnalyticsEvent('shortcut.shortcut.help');
            showKeyboardShortcutsPanel(true);
        }, 'keyboardShortcuts.toggleShortcuts');

        // register SPACE shortcut in two steps to insure visibility of help
        // message
        this.registerShortcut(' ', null, () => {
            sendAnalyticsEvent('shortcut.talk.clicked');
            logger.log('Talk shortcut pressed');
            APP.conference.muteAudio(true);
        });
        this._addShortcutToHelp('SPACE', 'keyboardShortcuts.pushToTalk');

        if (!interfaceConfig.filmStripOnly) {
            this.registerShortcut('T', null, () => {
                sendAnalyticsEvent('shortcut.speakerStats.clicked');
                APP.store.dispatch(toggleDialog(SpeakerStats, {
                    conference: APP.conference
                }));
            }, 'keyboardShortcuts.showSpeakerStats');
        }

        /**
         * FIXME: Currently focus keys are directly implemented below in
         * onkeyup. They should be moved to the SmallVideo instead.
         */
        this._addShortcutToHelp('0', 'keyboardShortcuts.focusLocal');
        this._addShortcutToHelp('1-9', 'keyboardShortcuts.focusRemote');
    }
};

export default KeyboardShortcut;