Add i18n support

server/i18n.ts

@@ -0,0 +1,16 @@
+import { signal } from "@preact/signals";
+
+export type I18NMap = { [x: string]: string | I18NMap };
+
+export const i18n_map = signal<I18NMap>({});
+const NOT_FOUND = "__NOT_FOUND__";
+
+export default function t(key: string) {
+    const keys = key.split(".");
+    let map: string | I18NMap = i18n_map.value;
+    for (const k of keys) {
+        if (typeof map === "string") return NOT_FOUND;
+        else map = map[k];
+    }
+    return typeof map === "string" ? map : NOT_FOUND;
+}

server/i18ns.ts

@@ -0,0 +1,72 @@
+import { exists } from "std/fs/exists.ts";
+import { parse } from "std/jsonc/mod.ts";
+import { join } from "std/path/mod.ts";
+import { I18NMap } from "./i18n.ts";
+import { pick } from "accept-language-parser/";
+
+const whole_maps = new Map<string, I18NMap>();
+const LANGUAGES = ["zh-cn"];
+type MODULE = "common";
+const MODULES: MODULE[] = ["common"];
+
+export async function load_translation(signal?: AbortSignal) {
+    const base = import.meta.resolve("../translation").slice(8);
+    const enmap: I18NMap = {};
+    for (const m of MODULES) {
+        const t = await Deno.readTextFile(join(base, "en", m + ".jsonc"), {
+            signal,
+        });
+        const v = <I18NMap> <unknown> parse(t);
+        enmap[m] = v;
+    }
+    whole_maps.set("en", enmap);
+    for (const l of LANGUAGES) {
+        const map: I18NMap = {};
+        for (const m of MODULES) {
+            const p = join(base, l, m + ".jsonc");
+            if (await exists(p)) {
+                const t = await Deno.readTextFile(join(base, l, m + ".jsonc"), {
+                    signal,
+                });
+                const v = <I18NMap> <unknown> Object.assign(
+                    structuredClone(enmap[m]),
+                    parse(t),
+                );
+                map[m] = v;
+            } else map[m] = enmap[m];
+        }
+        whole_maps.set(l, map);
+    }
+}
+
+export function get_i18nmap(lang: string, ...modules: MODULE[]) {
+    const m = whole_maps.get(lang);
+    if (!m) throw Error(`Language ${lang} is not supported.`);
+    if (!modules.length) return m;
+    const r: I18NMap = {};
+    for (const n of modules) {
+        r[n] = m[n];
+    }
+    return r;
+}
+
+export function i18n_handle_request(req: Request) {
+    const u = new URL(req.url);
+    const lang = u.searchParams.get("lang");
+    if (lang && (lang === "en" || LANGUAGES.includes(lang))) {
+        return lang;
+    } else {
+        const a = req.headers.get("Accept-Language");
+        const l = (a
+            ? pick(LANGUAGES, a) || pick(LANGUAGES, a, { loose: true })
+            : null) || "en";
+        const params = new URLSearchParams();
+        params.append("lang", l);
+        for (const p of u.searchParams.entries()) {
+            if (p[0] !== "lang") {
+                params.append(p[0], p[1]);
+            }
+        }
+        return Response.redirect(`${u.origin}${u.pathname}?${params}`);
+    }
+}