// {"request_idle_timeout_sec":10}
//
// vim:set sw=8 et:
//
// Scrolls to the bottom of the page. That's it at the moment.
//
var umbraAboveBelowOrOnScreen = function(e) {
        var eTop = e.getBoundingClientRect().top;
        if (eTop < window.scrollY) {
                return -1; // above
        } else if (eTop > window.scrollY + window.innerHeight) {
                return 1;  // below
        } else {
                return 0;  // on screen
        }
}

var UMBRA_IFRAME_SOUNDCLOUD_EMBEDDED_SELECTOR = "iframe";
var UMBRA_THINGS_TO_CLICK_SOUNDCLOUD_EMBEDDED_SELECTOR = "button.sc-button-play, button.playButton";
var MAX_IFRAME_RECURSE_DEPTH = 1; //0-based
var umbraState = {'idleSince':null};
var umbraAlreadyClicked = {};
var umbraFinished = false;
var umbraIntervalFunc = function() {

    var umbraSoundCloudEmbeddedElements = [];

    getUmbraSoundCloudEmbeddedElements(umbraSoundCloudEmbeddedElements);
	
    var clickedSomething = false;
    var somethingLeftBelow = false;
    var somethingLeftAbove = false;
    var missedAbove = 0;
    
    for (var i = 0; i < umbraSoundCloudEmbeddedElements.length; i++) {
    
            var targetId = umbraSoundCloudEmbeddedElements[i].id;
            var target = umbraSoundCloudEmbeddedElements[i].target;
            
            if (!(targetId in umbraAlreadyClicked)) {
            		
                    var where = umbraAboveBelowOrOnScreen(target);
                    
                    if (where == 0) { // on screen
                            // var pos = target.getBoundingClientRect().top;
                            // window.scrollTo(0, target.getBoundingClientRect().top - 100);
                            console.log("clicking at " + target.getBoundingClientRect().top + " on " + target.outerHTML);
                            if (target.click != undefined) {
                                    target.click();
                            }
                            umbraAlreadyClicked[targetId] = true;
                            clickedSomething = true;
                            umbraState.idleSince = null;
                            break;
                    } else if (where > 0) { 
                            somethingLeftBelow = true;
                    } else if (where < 0) {
                            somethingLeftAbove = true;
                    }
            }
    }
    
    if (!clickedSomething) {
        if (somethingLeftAbove) {
                console.log("scrolling UP because everything on this screen has been clicked but we missed something above");
                window.scrollBy(0, -500);
                umbraState.idleSince = null;
        } else if (somethingLeftBelow) {
                console.log("scrolling because everything on this screen has been clicked but there's more below document.body.clientHeight=" + document.body.clientHeight);
                window.scrollBy(0, 200);
                umbraState.idleSince = null;
        } else if (window.scrollY + window.innerHeight < document.documentElement.scrollHeight) {
                console.log("scrolling because we're not to the bottom yet document.body.clientHeight=" + document.body.clientHeight);
                window.scrollBy(0, 200);
                umbraState.idleSince = null;
        } else if (umbraState.idleSince == null) {
                umbraState.idleSince = Date.now();
        }
    }
	
	if (umbraState.idleSince == null) {
                umbraState.idleSince = Date.now();
    }
}

//try to detect sound cloud "Play" buttons and return them as targets for clicking
var getUmbraSoundCloudEmbeddedElements = function(soundCloudEmbeddedElements, currentIframeDepth, currentDocument,
		iframeElement) {
	
	//set default values for parameters
	currentIframeDepth = currentIframeDepth || 0;
	currentDocument = currentDocument || document;
	
	if (currentIframeDepth > MAX_IFRAME_RECURSE_DEPTH) {
		return;
	}
	
	//collect all buttons on current document first
	var button = [];
	
	button = currentDocument.querySelectorAll(UMBRA_THINGS_TO_CLICK_SOUNDCLOUD_EMBEDDED_SELECTOR);

	var cssPathIframe = iframeElement ? getElementCssPath(iframeElement) : "";
	
	for (var i = 0; i < button.length; i++) {
		soundCloudEmbeddedElements.push({"id" : cssPathIframe + getElementCssPath(button.item(i)), "target" : button.item(i)});
	}
	
	//now get all buttons in embedded iframes
	var iframe = [];
	
	iframe = currentDocument.querySelectorAll(UMBRA_IFRAME_SOUNDCLOUD_EMBEDDED_SELECTOR);
	
	for (var i = 0; i < iframe.length; i++) {
		getUmbraSoundCloudEmbeddedElements(soundCloudEmbeddedElements, currentIframeDepth + 1, iframe[i].contentWindow.document.body, iframe[i]);
	}
}

// If we haven't had anything to do (scrolled, clicked, etc) in this amount of
// time, then we consider ourselves finished with the page.
var UMBRA_USER_ACTION_IDLE_TIMEOUT_SEC = 10;

// Called from outside of this script.
var umbraBehaviorFinished = function() {
        if (umbraState.idleSince != null) {
                var idleTimeMs = Date.now() - umbraState.idleSince;
                if (idleTimeMs / 1000 > UMBRA_USER_ACTION_IDLE_TIMEOUT_SEC) {
                        return true;
                }
        }
        return false;
}

//copied from http://stackoverflow.com/questions/4588119/get-elements-css-selector-without-element-id
var getElementCssPath = function(element) {

	var names = [];
	  
	while (element.parentNode){
		if (element.id){
			names.unshift('#' + element.id);
			break;
		} else {
			if (element == element.ownerDocument.documentElement) {
				names.unshift(element.tagName);
			}
			else {
				for (var c = 1, e = element; e.previousElementSibling; e = e.previousElementSibling, c++);
				
				names.unshift(element.tagName + ":nth-child(" + c + ")");
			}
			
			element = element.parentNode;
		}
	}
	  
	return names.join(" > ");
}

var umbraIntervalId = setInterval(umbraIntervalFunc, 100);