$(document).ready(function() {
	
	/* 
	 * The display is not yet object oriented. It's procedural code
	 * broken off into functions. It makes use of libphotofloat's
	 * PhotoFloat class for the network and management logic.
	 * 
	 * All of this could potentially be object oriented, but presently
	 * it should be pretty readable and sufficient. The only thing to
	 * perhaps change in the future would be to consolidate calls to
	 * jQuery selectors. And perhaps it'd be nice to move variable
	 * declarations to the top, to stress that JavaScript scope is
	 * for an entire function and always hoisted.
	 * 
	 * None of the globals here polutes the global scope, as everything
	 * is enclosed in an anonymous function.
	 * 
	 */
	
	
	/* Globals */
	
	var currentAlbum = null;
	var currentPhoto = null;
	var currentPhotoIndex = -1;
	var previousAlbum = null;
	var previousPhoto = null;
	var originalTitle = document.title;
	var photoFloat = new PhotoFloat();
	
	
	/* Entry point for most events */
	
	function hashParsed(album, photo, photoIndex) {
		undie();
		$("#loading").hide();
		if (album == currentAlbum && photo == currentPhoto)
			return;
		previousAlbum = currentAlbum;
		previousPhoto = currentPhoto;
		currentAlbum = album;
		currentPhoto = photo;
		currentPhotoIndex = photoIndex;
		setTitle();
		showAlbum(previousAlbum != currentAlbum);
		if (photo != null)
			showPhoto();
	}
	
	
	/* Displays */
	
	function setTitle() {
		var title = "";
		var documentTitle = "";
		var components;
		if (currentAlbum.path.length == 0)
			components = [originalTitle];
		else {
			components = currentAlbum.path.split("/");
			components.unshift(originalTitle);
		}
		if (currentPhoto != null)
			documentTitle += photoFloat.trimExtension(currentPhoto.name);
		var last = "";
		for (var i = 0; i < components.length; ++i) {
			if (i || currentPhoto != null)
				documentTitle += " \u00ab ";
			if (i)
				last += "/" + components[i];
			if (i < components.length - 1 || currentPhoto != null)
				title += "<a href=\"#!/" + (i == 0 ? "" : photoFloat.cachePath(last.substring(1))) + "\">";
			title += components[i];
			documentTitle += components[components.length - 1 - i];
			if (i < components.length - 1 || currentPhoto != null) {
				title += "</a>";
				title += " &raquo; ";
			}
		}
		if (currentPhoto != null)
			title += photoFloat.trimExtension(currentPhoto.name);
		$("#title").html(title);
		document.title = documentTitle;
	}
	function showAlbum(populate) {
		if (currentPhoto == null && previousPhoto == null)
			$("html, body").stop().animate({ scrollTop: 0 }, "slow");
		
		if (populate) {
			var photos = [];
			for (var i = 0; i < currentAlbum.photos.length; ++i) {
				var link = $("<a href=\"#!/" + photoFloat.photoHash(currentAlbum, currentAlbum.photos[i]) + "\"></a>");
				var image = $("<img title=\"" + photoFloat.trimExtension(currentAlbum.photos[i].name) + "\" alt=\"" + photoFloat.trimExtension(currentAlbum.photos[i].name) + "\" src=\"" + photoFloat.photoPath(currentAlbum, currentAlbum.photos[i], 150, true) + "\" height=\"150\" width=\"150\" />");
				link.append(image);
				image.get(0).photo = currentAlbum.photos[i];
				photos.push(link);
			}
			var thumbsElement = $("#thumbs");
			thumbsElement.empty();
			thumbsElement.append.apply(thumbsElement, photos);
			
			var subalbums = [];
			for (var i = currentAlbum.albums.length - 1; i >= 0; --i) {
				var link = $("<a href=\"#!/" + photoFloat.albumHash(currentAlbum.albums[i]) + "\"></a>");
				var image = $("<div title=\"" + currentAlbum.albums[i].date + "\" class=\"album-button\">" + currentAlbum.albums[i].path + "</div>");
				link.append(image);
				subalbums.push(link);
				(function(theAlbum, theImage) {
					photoFloat.albumPhoto(theAlbum, function(album, photo) {
						theImage.css("background-image", "url(" + photoFloat.photoPath(album, photo, 150, true) + ")");
					});
				})(currentAlbum.albums[i], image);
			}
			var subalbumsElement = $("#subalbums");
			subalbumsElement.empty();
			subalbumsElement.append.apply(subalbumsElement, subalbums);
		}
		
		if (currentPhoto == null) {
			$("#thumbs img").removeClass("current-thumb");
			$("#album-view").removeClass("photo-view-container");
			$("#subalbums").show();
			$("#photo-view").hide();
		}
		setTimeout(scrollToThumb, 1);
	}
	function getDecimal(fraction) {
		if (fraction[0] < fraction[1])
			return fraction[0] + "/" + fraction[1];
		return (fraction[0] / fraction[1]).toString();
	}
	function scaleImage() {
		var image = $("#photo");
		if (image.get(0) == this)
			$(window).bind("resize", scaleImage);
		var container = $("#photo-view");
		if (image.css("width") != "100%" && container.height() * image.width() / image.height() > container.width())
			image.css("width", "100%").css("height", "auto");
		else if (image.css("height") != "100%")
			image.css("height", "100%").css("width", "auto");
	}
	function showPhoto() {
		var maxSize = 800;
		var width = currentPhoto.size[0];
		var height = currentPhoto.size[1];
		if (width > height) {
			height = height / width * maxSize;
			width = maxSize;
		} else {
			width = width / height * maxSize;
			height = maxSize;
		}
		$(window).unbind("resize", scaleImage);
		var photoSrc = photoFloat.photoPath(currentAlbum, currentPhoto, maxSize, false);
		$("#photo")
			.attr("width", width).attr("height", height)
			.attr("src", photoSrc)
			.attr("alt", currentPhoto.name)
			.attr("title", currentPhoto.date)
			.load(scaleImage);
		$("head").append("<link rel=\"image_src\" href=\"" + photoSrc + "\" />");
		
		var previousPhoto = currentAlbum.photos[
			(currentPhotoIndex - 1 < 0) ? (currentAlbum.photos.length - 1) : (currentPhotoIndex - 1)
		];
		var nextPhoto = currentAlbum.photos[
			(currentPhotoIndex + 1 >= currentAlbum.photos.length) ? 0 : (currentPhotoIndex + 1)
		];
		$.preloadImages(photoFloat.photoPath(currentAlbum, nextPhoto, maxSize, false), photoFloat.photoPath(currentAlbum, previousPhoto, maxSize, false));
		
		var nextLink = "#!/" + photoFloat.photoHash(currentAlbum, nextPhoto);
		$("#next-photo").attr("href", nextLink);
		$("#next").attr("href", nextLink);
		$("#back").attr("href", "#!/" + photoFloat.photoHash(currentAlbum, previousPhoto));
		$("#original-link").attr("target", "_blank").attr("href", photoFloat.originalPhotoPath(currentAlbum, currentPhoto));

		var text = "<table>";
		if (currentPhoto.make != undefined) text += "<tr><td>Camera Maker</td><td>" + currentPhoto.make + "</td></tr>";
		if (currentPhoto.model != undefined) text += "<tr><td>Camera Model</td><td>" + currentPhoto.model + "</td></tr>";
		if (currentPhoto.date != undefined) text += "<tr><td>Time Taken</td><td>" + currentPhoto.date + "</td></tr>";
		if (currentPhoto.size != undefined) text += "<tr><td>Resolution</td><td>" + currentPhoto.size[0] + " x " + currentPhoto.size[1] + "</td></tr>";
		if (currentPhoto.aperture != undefined) text += "<tr><td>Aperture</td><td> f/" + getDecimal(currentPhoto.aperture) + "</td></tr>";
		if (currentPhoto.focalLength != undefined) text += "<tr><td>Focal Length</td><td>" + getDecimal(currentPhoto.focalLength) + " mm</td></tr>";
		if (currentPhoto.iso != undefined) text += "<tr><td>ISO</td><td>" + currentPhoto.iso + "</td></tr>";
		if (currentPhoto.exposureTime != undefined) text += "<tr><td>Exposure Time</td><td>" + getDecimal(currentPhoto.exposureTime) + " sec</td></tr>";
		if (currentPhoto.exposureProgram != undefined) text += "<tr><td>Exposure Program</td><td>" + currentPhoto.exposureProgram + "</td></tr>";
		if (currentPhoto.exposureCompensation != undefined) text += "<tr><td>Exposure Compensation</td><td>" + getDecimal(currentPhoto.exposureCompensation) + "</td></tr>";
		if (currentPhoto.spectralSensitivity != undefined) text += "<tr><td>Spectral Sensitivity</td><td>" + currentPhoto.spectralSensitivity + "</td></tr>";
		if (currentPhoto.flash != undefined) text += "<tr><td>Flash</td><td>" + currentPhoto.flash + "</td></tr>";
		if (currentPhoto.orientation != undefined) text += "<tr><td>Orientation</td><td>" + currentPhoto.orientation + "</td></tr>";
		text += "</table>";
		$("#metadata").html(text);
		
		$("#album-view").addClass("photo-view-container");
		$("#subalbums").hide();
		$("#photo-view").show();
	}
	function scrollToThumb() {
		var photo = currentPhoto
		if (photo == null) {
			photo = previousPhoto;
			if (photo == null)
				return;
		}
		var thumb;
		$("#thumbs img").each(function() {
			if (this.photo == photo) {
				thumb = $(this);
				return false;
			}
		});
		if (typeof thumb === "undefined")
			return;
		if (currentPhoto != null) {
			var scroller = $("#album-view");
			scroller.stop().animate({ scrollLeft: thumb.position().left + scroller.scrollLeft() - scroller.width() / 2 + thumb.width() / 2 }, "slow");
		} else
			$("html, body").stop().animate({ scrollTop: thumb.offset().top - $(window).height() / 2 + thumb.height() }, "slow");
		
		if (currentPhoto != null) {
			$("#thumbs img").removeClass("current-thumb");
			thumb.addClass("current-thumb");
		}
	}
	
	
	/* Error displays */
	
	function die() {
		$("#error-overlay").fadeTo(500, 0.8);
		$("#error-text").fadeIn(2500);
		$("body, html").css("overflow", "hidden");
	}
	function undie() {
		$("#error-text, #error-overlay").fadeOut(500);
		$("body, html").css("overflow", "auto");
	}
	
	
	/* Event listeners */
	
	$(window).hashchange(function() {
		$("#loading").show();
		$("link[rel=image_src]").remove();
		photoFloat.parseHash(location.hash, hashParsed, die);
	});
	$(window).hashchange();
	$(document).keydown(function(e){
		if (currentPhoto == null)
			return true;
		if (e.keyCode == 39) {
			window.location.href = $("#next").attr("href");
			return false;
		} else if (e.keyCode == 37) {
			window.location.href = $("#back").attr("href");
			return false;
		}
		return true;
	});
	$(document).mousewheel(function(event, delta) {
		if (currentPhoto == null)
			return true;
		if (delta < 0) {
			window.location.href = $("#next").attr("href");
			return false;
		} else if (delta > 0) {
			window.location.href = $("#back").attr("href");
			return false;
		}
		return true;
	});
	$("#photo-box").mouseenter(function() {
		$("#photo-links").stop().fadeTo("slow", 0.50).css("display", "inline");
	});
	$("#photo-box").mouseleave(function() {
		$("#photo-links").stop().fadeOut("slow");
	});
	$("#next, #back").mouseenter(function() {
		$(this).fadeTo("slow", 1);
	});
	$("#next, #back").mouseleave(function() {
		$(this).fadeTo("slow", 0.35);
	});
	$("#metadata-link").click(function() {
		if (!$("#metadata").is(":visible"))
			$("#metadata").stop()
				.css("height", 0)
				.css("padding-top", 0)
				.css("padding-bottom", 0)
				.show()
				.animate({ height: $("#metadata > table").height(), paddingTop: 3, paddingBottom: 3 }, "slow", function() {
					$(this).css("height", "auto");
					$("#metadata-link").text($("#metadata-link").text().replace("show", "hide"));
				});
		else
			$("#metadata").stop().animate({ height: 0, paddingTop: 0, paddingBottom: 0 }, "slow", function() {
				$(this).hide();
				$("#metadata-link").text($("#metadata-link").text().replace("hide", "show"));
			});
	});
});