X-Git-Url: https://git.auder.net/?p=vchess.git;a=blobdiff_plain;f=utils%2Flanguage.js;fp=utils%2Flanguage.js;h=52c3842d99deee066ada1872b3746eb07b2e314d;hp=0000000000000000000000000000000000000000;hb=298c42e63ae321526693e9ce418c4113af36e025;hpb=067c675b75072c496f9665c4bf801cdc3d40398d

diff --git a/utils/language.js b/utils/language.js
new file mode 100644
index 00000000..52c3842d
--- /dev/null
+++ b/utils/language.js
@@ -0,0 +1,27 @@
+// Select a language based on browser preferences, or cookie
+module.exports = function(req, res)
+{
+	// If preferred language already set:
+	if (!!req.cookies["lang"])
+		return req.cookies["lang"];
+
+	// Else: search and set it
+	const supportedLang = ["en","es","fr"];
+	const langString = req.headers["accept-language"];
+	let langArray = langString
+		.replace(/;q=[0-9.]+/g, "") //priority
+		.replace(/-[A-Z]+/g, "") //region (skipped for now...)
+		.split(",") //may have some duplicates, but removal is too costly
+	let bestLang = "en"; //default: English
+	for (let lang of langArray)
+	{
+		if (supportedLang.includes(lang))
+		{
+			bestLang = lang;
+			break;
+		}
+	}
+	// Cookie expires in 183 days (expressed in milliseconds)
+	res.cookie('lang', bestLang, { maxAge: 183*24*3600*1000 });
+	return bestLang;
+}