# src/modules/noResults.js

    import {Feature} from './feature';
    import Dom from '../dom';
    import Types from '../types';

    export class NoResults extends Feature{

        /**
         * No results message UI component
         * @param {Object} tf TableFilter instance
         */
        constructor(tf){
            super(tf, 'noResults');

            //configuration object
            let f = this.config.no_results_message;

            this.content = f.content || 'No results';
            this.customContainer = f.custom_container || null;
            this.customContainerId = f.custom_container_id || null;
            this.isExternal = !Types.isEmpty(this.customContainer) ||
                !Types.isEmpty(this.customContainerId);
            this.cssClass = f.css_class || 'no-results';

            this.cont = null;

            //callback before message is displayed
            this.onBeforeShowMsg = Types.isFn(f.on_before_show_msg) ?
                f.on_before_show_msg : null;
            //callback after message is displayed
            this.onAfterShowMsg = Types.isFn(f.on_after_show_msg) ?
                f.on_after_show_msg : null;
            //callback before message is hidden
            this.onBeforeHideMsg = Types.isFn(f.on_before_hide_msg) ?
                f.on_before_hide_msg : null;
            //callback after message is hidden
            this.onAfterHideMsg = Types.isFn(f.on_after_hide_msg) ?
                f.on_after_hide_msg : null;

            this.prfxNoResults = 'nores_';
        }

        init(){
            if(this.initialized){
                return;
            }
            let tf = this.tf;
            let target = this.customContainer || Dom.id(this.customContainerId) ||
                tf.tbl;

            //container
            let cont = Dom.create('div', ['id', this.prfxNoResults+tf.id]);
            cont.className = this.cssClass;
            cont.innerHTML = this.content;

            if(this.isExternal){
                target.appendChild(cont);
            } else {
                target.parentNode.insertBefore(cont, target.nextSibling);
            }

            this.cont = cont;

            // subscribe to after-filtering event
            this.emitter.on(['after-filtering'], ()=> this.toggle());

            this.initialized = true;
            this.hide();
        }

        toggle(){
            if(this.tf.nbVisibleRows > 0){
                this.hide();
            } else {
                this.show();
            }
        }

        show(){
            if(!this.initialized || !this.isEnabled()){
                return;
            }

            if(this.onBeforeShowMsg){
                this.onBeforeShowMsg.call(null, this.tf, this);
            }

            this.setWidth();
            this.cont.style.display = 'block';

            if(this.onAfterShowMsg){
                this.onAfterShowMsg.call(null, this.tf, this);
            }
        }

        hide(){
            if(!this.initialized || !this.isEnabled()){
                return;
            }

            if(this.onBeforeHideMsg){
                this.onBeforeHideMsg.call(null, this.tf, this);
            }

            this.cont.style.display = 'none';

            if(this.onBeforeHideMsg){
                this.onBeforeHideMsg.call(null, this.tf, this);
            }
        }

        setWidth(){
            if(!this.initialized || this.isExternal || !this.isEnabled()){
                return;
            }
            if(this.tf.gridLayout){
                let gridLayout = this.tf.feature('gridLayout');
                this.cont.style.width = gridLayout.tblCont.clientWidth + 'px';
            } else {
                this.cont.style.width = this.tf.tbl.clientWidth + 'px';
            }

        }

        destroy(){
            if(!this.initialized){
                return;
            }
            Dom.remove(this.cont);
            this.cont = null;
            // unsubscribe to after-filtering event
            this.emitter.off(['after-filtering'], ()=> this.toggle());

            this.initialized = false;
        }
    }