(function($){

	$.fn.filter_visible = function(depth) {

		depth = depth || 3;

		var is_visible = function() {

			var p = $(this), i;

			for(i=0; i<depth-1; ++i) {

				if (!p.is(':visible')) return false;

				p = p.parent();

			}

			return true;

		}

		return this.filter(is_visible);

	};

	$.table_hotkeys = function(table, keys, opts) {

		opts = $.extend($.table_hotkeys.defaults, opts);

		var selected_class, destructive_class, set_current_row, adjacent_row_callback, get_adjacent_row, adjacent_row, prev_row, next_row, check, get_first_row, get_last_row, make_key_callback, first_row;

		selected_class = opts.class_prefix + opts.selected_suffix;

		destructive_class = opts.class_prefix + opts.destructive_suffix

		set_current_row = function (tr) {

			if ($.table_hotkeys.current_row) $.table_hotkeys.current_row.removeClass(selected_class);

			tr.addClass(selected_class);

			tr[0].scrollIntoView(false);

			$.table_hotkeys.current_row = tr;

		};

		adjacent_row_callback = function(which) {

			if (!adjacent_row(which) && $.isFunction(opts[which+'_page_link_cb'])) {

				opts[which+'_page_link_cb']();

			}

		};

		get_adjacent_row = function(which) {

			var first_row, method;

			if (!$.table_hotkeys.current_row) {

				first_row = get_first_row();

				$.table_hotkeys.current_row = first_row;

				return first_row[0];

			}

			method = 'prev' == which? $.fn.prevAll : $.fn.nextAll;

			return method.call($.table_hotkeys.current_row, opts.cycle_expr).filter_visible()[0];

		};

		adjacent_row = function(which) {

			var adj = get_adjacent_row(which);

			if (!adj) return false;

			set_current_row($(adj));

			return true;

		};

		prev_row = function() { return adjacent_row('prev'); };

		next_row = function() { return adjacent_row('next'); };

		check = function() {

			$(opts.checkbox_expr, $.table_hotkeys.current_row).each(function() {

				this.checked = !this.checked;

			});

		};

		get_first_row = function() {

			return $(opts.cycle_expr, table).filter_visible().eq(opts.start_row_index);

		};

		get_last_row = function() {

			var rows = $(opts.cycle_expr, table).filter_visible();

			return rows.eq(rows.length-1);

		};

		make_key_callback = function(expr) {

			return function() {

				if ( null == $.table_hotkeys.current_row ) return false;

				var clickable = $(expr, $.table_hotkeys.current_row);

				if (!clickable.length) return false;

				if (clickable.is('.'+destructive_class)) next_row() || prev_row();

				clickable.click();

			}

		};

		first_row = get_first_row();

		if (!first_row.length) return;

		if (opts.highlight_first)

			set_current_row(first_row);

		else if (opts.highlight_last)

			set_current_row(get_last_row());

		$.hotkeys.add(opts.prev_key, opts.hotkeys_opts, function() {return adjacent_row_callback('prev')});

		$.hotkeys.add(opts.next_key, opts.hotkeys_opts, function() {return adjacent_row_callback('next')});

		$.hotkeys.add(opts.mark_key, opts.hotkeys_opts, check);

		$.each(keys, function() {

			var callback, key;

			if ($.isFunction(this[1])) {

				callback = this[1];

				key = this[0];

				$.hotkeys.add(key, opts.hotkeys_opts, function(event) { return callback(event, $.table_hotkeys.current_row); });

			} else {

				key = this;

				$.hotkeys.add(key, opts.hotkeys_opts, make_key_callback('.'+opts.class_prefix+key));

			}

		});

	};

	$.table_hotkeys.current_row = null;

	$.table_hotkeys.defaults = {cycle_expr: 'tr', class_prefix: 'vim-', selected_suffix: 'current',

		destructive_suffix: 'destructive', hotkeys_opts: {disableInInput: true, type: 'keypress'},

		checkbox_expr: ':checkbox', next_key: 'j', prev_key: 'k', mark_key: 'x',

		start_row_index: 2, highlight_first: false, highlight_last: false, next_page_link_cb: false, prev_page_link_cb: false};

})(jQuery);