'use strict';

/* global CloudCmd, DOM, $ */

require('../../css/view.css');

const itype = require('itype/legacy');
const rendy = require('rendy/legacy');
const exec = require('execon');
const currify = require('currify/legacy');
const {promisify} = require('es6-promisify');

const {time} = require('../../common/util');
const {FS} = require('../../common/cloudfunc');

const Files = require('../dom/files');
const Events = require('../dom/events');
const load = require('../dom/load');
const Images = require('../dom/images');

const testRegExp = currify((name, reg) => reg.test(name));
const lifo = currify((fn, el, cb, name) => fn(name, el, cb));

const addEvent = lifo(Events.add);
const getRegExp = (ext) => RegExp(`\\.${ext}$`, 'i');

module.exports.show = show;
module.exports.hide = hide;

let Loading = false;

const Name = 'View';
CloudCmd[Name] = module.exports;

const Info = DOM.CurrentInfo;
const Key = CloudCmd.Key;
const basename = (a) => a.split('/').pop();

let El, TemplateAudio, Overlay;

const Config = {
    beforeShow: (callback) => {
        Images.hide();
        Key.unsetBind();
        showOverlay();
        exec(callback);
    },
    beforeClose: (callback) => {
        Events.rmKey(listener);
        Key.setBind();
        exec(callback);
        hideOverlay();
    },
    afterShow: (callback) => {
        El.focus();
        exec(callback);
    },
    afterClose      : exec,
    fitToView       : true,
    loop            : false,
    openEffect      : 'none',
    closeEffect     : 'none',
    autoSize        : false,
    height          : '100%',
    width           : '100%',
    minWidth        : 0,
    minHeight       : 0,
    padding         : 0,
    preload         : 0,
    keys            : null,
    mouseWheel      : false,
    arrows          : false,
    helpers         : {
        overlay : null,
        title   : null
    }
};

module.exports.init = promisify((fn) => {
    Loading = true;
    
    exec.series([
        DOM.loadJquery,
        loadAll,
        (callback) => {
            Loading = false;
            callback();
        }
    ], fn);
    
    Config.parent = Overlay = load({
        id          : 'js-view',
        name        : 'div',
        className   : 'fancybox-overlay fancybox-overlay-fixed'
    });
    
    const events = [
        'click',
        'contextmenu',
    ];
    
    events.forEach(addEvent(Overlay, onOverLayClick));
});

function show(data, options) {
    const prefixUrl = CloudCmd.PREFIX_URL + FS;
    
    if (Loading)
        return;
    
    if (!options || options.bindKeys !== false)
        Events.addKey(listener);
    
    El = $('<div class="view" tabindex=0>');
    
    if (data) {
        const element = $(El).append(data);
        $.fancybox.open(element, initConfig(Config, options));
        return;
    }
    
    Images.show.load();
    
    const path = prefixUrl + Info.path;
    const type = getType(path);
    
    switch(type) {
    default:
        return Info.getData((error, data) => {
            if (error)
                return Images.hide();
            
            const element = document.createTextNode(data);
            /* add margin only for view text documents */
            El.css('margin', '2%');
            
            $.fancybox.open(El.append(element), Config);
        });
    
    case 'image':
        return showImage(path, prefixUrl);
    
    case 'media':
        return getMediaElement(path, (element) => {
            const media = DOM.getByDataName('js-media', element);
            const onKey = exec.with(onMediaKey, media);
            
            $.fancybox.open(element, {
                parent      : Overlay,
                beforeShow  : () => {
                    Config.beforeShow();
                    Events.addKey(onKey);
                },
                beforeClose : () => {
                    Config.beforeClose();
                    Events.rmKey(onKey);
                },
                afterShow: () => {
                    element
                        .querySelector('audio, video')
                        .focus();
                },
                helpers: {
                    overlay : null,
                    title   : null
                }
            });
        });
    }
}

function initConfig(Config, options) {
    const config = Object.assign({}, Config);
    
    if (!options)
        return config;
    
    Object.keys(options).forEach((name) => {
        const isConfig = !!config[name];
        const item = options[name];
        const isFunc = itype.function(item);
        
        if (!isFunc || !isConfig) {
            config[name] = options[name];
            return;
        }
        
        const func = config[name];
        config[name] = () => {
            exec.series([func, item]);
        };
    });
    
    return config;
}

function hide() {
    $.fancybox.close();
}

function showImage(href, prefixUrl) {
    const makeTitle = (path) => {
        return {
            href: prefixUrl + path,
            title: basename(path),
        };
    };
    
    const names = Info.files
        .map(DOM.getCurrentPath)
        .filter(isImage);
    
    const titles = names
        .map(makeTitle);
    
    const index = names.indexOf(Info.path);
    const imageConfig = {
        index,
        autoSize    : true,
        type        : 'image',
        prevEffect  : 'none',
        nextEffect  : 'none',
        arrows      : true,
        keys        : true,
        helpers     : {
            overlay : null,
            title   : {}
        }
    };
    
    const config = {
        ...Config,
        ...imageConfig,
    };
    
    $.fancybox.open(titles, config);
}

function isImage(name) {
    const images = [
        'jp(e|g|eg)',
        'gif',
        'png',
        'bmp',
        'webp',
        'svg',
        'ico'
    ];
    
    return images
        .map(getRegExp)
        .some(testRegExp(name));
}

function isMedia(name) {
    return isAudio(name) || isVideo(name);
}

function isAudio(name) {
    return /\.(mp3|ogg|m4a)$/i.test(name);
}

function isVideo(name) {
    return /\.(mp4|avi)$/i.test(name);
}

function getType(name) {
    if (isImage(name))
        return 'image';
    
    if (isMedia(name))
        return 'media';
}

function getMediaElement(src, callback) {
    check(src, callback);
    
    Files.get('view/media-tmpl', (error, template) => {
        const {name} = Info;
        
        if (error)
            return alert(error);
        
        if (!TemplateAudio)
            TemplateAudio   = template;
        
        const is = isAudio(name);
        const type =  is ? 'audio' : 'video';
        
        const rendered = rendy(TemplateAudio, {
            src,
            type,
            name,
        });
        
        const [element] = $(rendered);
        callback(element);
    });
}

function check(src, callback) {
    if (typeof src !== 'string')
        throw Error('src should be a string!');
    
    if (typeof callback !== 'function')
        throw Error('callback should be a function');
}

function onMediaKey(media, event) {
    const {keyCode} = event;
    
    if (keyCode === Key.SPACE) {
        if (media.paused)
            media.play();
        else
            media.pause();
    }
}

/**
 * function loads css and js of FancyBox
 * @callback   -  executes, when everything loaded
 */
function loadAll(callback) {
    time(Name + ' load');
    
    DOM.loadRemote('fancybox', () => {
        const {PREFIX} = CloudCmd;
        
        load.css(PREFIX + '/dist/view.css', callback);
        
        load.style({
            id      : 'view-inlince-css',
            inner   : [
                '.fancybox-title-float-wrap .child {',
                '-webkit-border-radius: 0;',
                '-moz-border-radius: 0;',
                'border-radius: 0;',
                '}'
            ].join('')
        });
    });
}

function onOverLayClick(event) {
    const {target} = event;
    const isOverlay = target === Overlay;
    const position = {
        x: event.clientX,
        y: event.clientY
    };
      
    if (!isOverlay)
        return;
    
    hideOverlay();
    hide();
    
    setCurrentByPosition(position);
}

function setCurrentByPosition(position) {
    const element = DOM.getCurrentByPosition(position);
    
    if (!element)
        return;
    
    const {
        files,
        filesPassive,
    } = Info;
    
    const isFiles = ~files.indexOf(element);
    const isFilesPassive = ~filesPassive.indexOf(element);
    
    if (!isFiles && !isFilesPassive)
        return;
    
    const isCurrent = DOM.isCurrentFile(element);
    
    if (isCurrent)
        return;
    
    DOM.setCurrentFile(element);
}

function hideOverlay() {
    Overlay.classList.remove('view-overlay');
}

function showOverlay() {
    Overlay.classList.add('view-overlay');
}

function listener({keyCode}) {
    if (keyCode === Key.ESC)
        hide();
}