import * as dom from '../dom';
import * as types from '../types';

var global = window;

/**
 * Loading message/spinner
 * @param {Object} tf TableFilter instance
 */
export class Loader{

    constructor(tf){

        // TableFilter configuration
        var f = tf.fObj;
        //id of container element
        tf.loaderTgtId = f.loader_target_id || null;
        //div containing loader
        tf.loaderDiv = null;
        //defines loader text
        tf.loaderText = f.loader_text || 'Loading...';
        //defines loader innerHtml
        tf.loaderHtml = f.loader_html || null;
        //defines css class for loader div
        tf.loaderCssClass = f.loader_css_class || 'loader';
        //delay for hiding loader
        tf.loaderCloseDelay = 200;
        //callback function before loader is displayed
        tf.onShowLoader = types.isFn(f.on_show_loader) ?
            f.on_show_loader : null;
        //callback function after loader is closed
        tf.onHideLoader = types.isFn(f.on_hide_loader) ?
            f.on_hide_loader : null;

        this.tf = tf;

        var containerDiv = dom.create('div', ['id', tf.prfxLoader+tf.id]);
        containerDiv.className = tf.loaderCssClass;

        var targetEl = !tf.loaderTgtId ?
            (tf.gridLayout ? tf.tblCont : tf.tbl.parentNode) :
            dom.id(tf.loaderTgtId);
        if(!tf.loaderTgtId){
            targetEl.insertBefore(containerDiv, tf.tbl);
        } else {
            targetEl.appendChild(containerDiv);
        }
        tf.loaderDiv = dom.id(tf.prfxLoader+tf.id);
        if(!tf.loaderHtml){
            tf.loaderDiv.appendChild(dom.text(tf.loaderText));
        } else {
            tf.loaderDiv.innerHTML = tf.loaderHtml;
        }
    }

    show(p) {
        if(!this.tf.loader || !this.tf.loaderDiv ||
            this.tf.loaderDiv.style.display===p){
            return;
        }
        var o = this.tf;

        function displayLoader(){
            if(!o.loaderDiv){
                return;
            }
            if(o.onShowLoader && p!=='none'){
                o.onShowLoader.call(null, o);
            }
            o.loaderDiv.style.display = p;
            if(o.onHideLoader && p==='none'){
                o.onHideLoader.call(null, o);
            }
        }

        var t = p==='none' ? this.tf.loaderCloseDelay : 1;
        global.setTimeout(displayLoader, t);
    }

    remove(){
        if(!this.tf.loaderDiv){
            return;
        }
        var targetEl = !this.tf.loaderTgtId ?
            (this.tf.gridLayout ? this.tf.tblCont : this.tf.tbl.parentNode):
            dom.id(this.tf.loaderTgtId);
        targetEl.removeChild(this.tf.loaderDiv);
        this.tf.loaderDiv = null;
    }
}