Initial commit: fristy.net personal site

lib/i18n/locales.ts

@@ -0,0 +1,48 @@
+export const LOCALES = ["tr", "en", "de"] as const;
+
+export type Locale = (typeof LOCALES)[number];
+
+export const DEFAULT_LOCALE: Locale = "tr";
+
+export const LOCALE_COOKIE = "locale";
+
+export const LOCALE_LABELS: Record<Locale, string> = {
+    tr: "TR",
+    en: "EN",
+    de: "DE",
+};
+
+export function isLocale(value: string): value is Locale {
+    return (LOCALES as readonly string[]).includes(value);
+}
+
+export function matchLocale(acceptLanguage: string | null): Locale {
+    if (!acceptLanguage) {
+        return DEFAULT_LOCALE;
+    }
+    const preferences = acceptLanguage
+        .split(",")
+        .map((part) => {
+            const [range, ...params] = part.trim().split(";");
+            let q = 1;
+            for (const param of params) {
+                const match = param.trim().match(/^q=([0-9.]+)$/);
+                if (match) {
+                    q = Number(match[1]);
+                }
+            }
+            return { range: range.toLowerCase(), q };
+        })
+        .sort((a, b) => b.q - a.q);
+
+    for (const { range } of preferences) {
+        if (range === "*") {
+            return DEFAULT_LOCALE;
+        }
+        const base = range.split("-")[0];
+        if (isLocale(base)) {
+            return base;
+        }
+    }
+    return DEFAULT_LOCALE;
+}