[templates] Add JS-calculated hovertext for date ages

On torrent listing and torrent view, mouse over the times to see "X hours Y minutes Z seconds ago" etc

nyaa/static/js/main.js

@@ -31,6 +31,51 @@ $(document).ready(function() {
 	});
 });
 
+function _format_time_difference(seconds) {
+	var units = [
+		["year", 365*24*60*60],
+		["month", 30*24*60*60],
+		["week", 7*24*60*60],
+		["day", 24*60*60],
+		["hour", 60*60],
+		["minute", 60],
+		["second", 1]
+	];
+	var suffix = " ago";
+	var prefix = "";
+	if (seconds < 0) {
+		suffix = "";
+		prefix = "After ";
+	}
+
+	var parts = [];
+	for (var i = 0; i < units.length; i++) {
+		var scale = units[i];
+
+		var m = (seconds / scale[1]) | 0;
+
+		if (m > 0) {
+			// N unit(s)
+			parts.push( m.toString() + " " + scale[0] + (m == 1 ? "" : "s") );
+			seconds -= m*scale[1];
+		}
+	}
+	return prefix + parts.join(" ") + suffix;
+}
+
+document.addEventListener("DOMContentLoaded", function(event) {
+	var now_timestamp = (Date.now() / 1000) | 0; // UTC timestamp in seconds
+
+	var timestamp_targets = document.querySelectorAll('[data-timestamp]');
+	for (var i = 0; i < timestamp_targets.length; i++) {
+		var target = timestamp_targets[i];
+		var torrent_timestamp = parseInt(target.getAttribute('data-timestamp'));
+		if (torrent_timestamp) {
+			var timedelta = now_timestamp - torrent_timestamp;
+			target.setAttribute('title', _format_time_difference(timedelta));
+		}
+	};
+});
 
 // 
 // This is the unminified version of the theme changer script in the layout.html @ line: 21