/**
 * A accordion component - <strike>UX/COE Compliant</strike><BR>
 *  class:
 *	normal - no ux/coe decorations
 *	uxcoe  - skined based on our current UX/COE Design
 *
 * <BR><BR><img src=../images/accordion.png width=50% style="border:1px lime dashed";>
 * <BR><BR><a href="../html/accordion.html">DEMO</a>
 */
class Accordion extends HTMLElement {
    constructor() {
        console.group("Accordion.constructor")
	
        super();

        console.groupEnd();
    };
    
    /**
     * Set observable values here. When Changed, attributeChangedCallback is invoked
     * @observedAttributes
     */
    static get observedAttributes() {
        console.group("Accordion.observedAttributes");

	let observables = ["single", "active", "width", "height"];
	console.log(observables);

        console.groupEnd();
        return observables;
    };

    /**
     * This function is called when this is attached to DOM
     * @connectedCallback. 
     */
    connectedCallback() {
        console.group("Accordion.connectedCallback")
	
	let self = this;

	// FETCH ALL INTERESTING ELEMENTS
	this._fetchElements();

	// FETCH ALL ATTRIBUTES
	this._fetchAttributes();

	this.dom.panels = this.querySelectorAll("wc-panel");

	// CLOSE ALL EXCEPT ACTIVE PANEL
	for (let i=0; i < this.dom.panels.length; i++) {
	    let panel = this.dom.panels[i];

	    // IF NO CLASS DEFINED, USE DEFAULT UXCOE
	    if (this.classList.contains("uxcoe")) {
		panel.classList.add("uxcoe");
	    } else {
		panel.classList.add("normal");
	    }

	    if (this.properties.active != i) {
		panel.close(false);
	    }
	}

	// IF IT IS SINGLE, SUBSCRIBE TO PANEL EVENTS
	if (this.properties.single == "true") {
	    wc.subscribe("wc-panel", function(e) {
		self._onClick(e);
	    });
	}
	
	// WRAP UP AND ADD STATS
	this._finalize();

	this.style.visibility = "visible";

        console.groupEnd();
    };

    /**
     * Invoked When component is removed. Usually with a .remove() function call
     * @disconnectedCallback
     */
    disconnectedCallback() {
        console.group("Maker.disconnectedCallback")

	// CLEANUP NOW

        console.groupEnd();
    };

    /**
     * Invoked When component is removed. Usually with a .remove() function call
     * @disconnectedCallback
     */
    disconnectedCallback() {
        console.group("Accordion.disconnectedCallback")

	/* CLEAN UP NOW */

        console.groupEnd();
    };

    /**
     * Called with .setAttribute(...) function call
     * @attributeChangedCallback
     */
    attributeChangedCallback(attr, oldval, newval) {
        console.group("Accordion.attributeChangedCallback:", attr, oldval, newval);

	this.properties = this.properties || [];

	// EXAMPLE ONLY. replace with observables
	switch(attr)
	{
	    case "width":
	    this.properties.width = newval;
	    this.style.width = this.properties.width;
	    break;

	    case "height":
	    this.properties.height = newval;
	    this.setAttribute("style", "height:" + this.properties.height);
	    break;

	    case "single":
	    this.properties.single = newval;
	    break;

	    case "active":
	    this.properties.active = newval;
	    break;
	}
	
        console.groupEnd();
    };

    /**
     * Stores DOM elements of interest for future use
     * @_fetchElements
     */
    _fetchElements() {
	console.group("Accordion._fetchElements");
	
	this.dom = this.dom || [];

	this.dom.content = this.innerHTML;

	console.groupEnd();
    };

    /**
     * Component attributes are _fetched and defaults are set if undefined
     * @_fetchAttributes
     * @param {string} author component owner
     * @param {string} version Latest version of this component
     * @param {string} [width=100%] panel width
     * @param {boolean} [single=true] only one panel at a time
     * @param {integer} [active=0] index of active panel
     */
    _fetchAttributes() {
	console.group("Accordion._fetchAttributes");
	
	this.properties = {
	    "cname"   : "Accordion",
	    "author"  : "Mel Heravi",
	    "version" : "1.0",
	    "user"    : "Mel",
	    "bg"      : "yellow",
	    "width"   : "100%",
	    "height"  : "100%",
	    "single"  : "true",
	    "active"  : 0
	};

	if (this.hasAttribute("active")) {
	    this.properties.active = this.getAttribute("active");
	    console.log("active: ", this.properties.active);
	}

	if (this.hasAttribute("width")) {
	    this.properties.width = this.getAttribute("width");
	    this.width = this.properties.width;
	    console.log("width: ", this.properties.width);
	}

	if (this.hasAttribute("single")) {
	    this.properties.single = this.getAttribute("single");
	    console.log("single: ", this.properties.single);
	}

	console.groupEnd();
    };

    /**
     * A sample callback usage function - see connectedCallback()
     * @onClick
     */
    /**
     * Invoked when user clicks on the panel header. 
     * Only available if "collapsible" parameter is true
     * @onClick
     */
    _onClick(e) {
	console.group("Accordion._onClick:", e);
	
	let target = e.target;

	if (e.detail.parentid == this.id) {
	    for (let i = 0; i < this.dom.panels.length; i++){
		let panel = this.dom.panels[i];

		panel.close(false);
	    }

	    target.open(false);
	}

	console.groupEnd();
    };

    /**
     * Destroy the instance object and artifacts
     * @_destroy
     */
    destroy() {
	console.group("Message.destroy:", this.id);

	delete this;

	// REMOVE ITEM FROM DOM
	this.parentNode.removeChild(this);

	console.groupEnd();
    };

    /**
     * SAVE DATA FOR ANALYTICS
     * @__finalize
     */
    _finalize() {
	console.group("Accordion._finalize:", this.id);

	this.classList.add("wc");

	// ADD ANALYTICS HERE
	wc.getStats(this, this.properties.cname, this.properties.version);
	
	console.groupEnd();
    };

    /**
     * FOR TESTING PURPOSES
     * @test
     */
    static test() {
	console.group("Accordion.test");

	console.log("testing results will be printed here...");

	console.groupEnd();
	return true;
    }
}

window.customElements.define('wc-accordion', Accordion);