feat(easel): add localization

static/src/language.ts

@@ -0,0 +1,62 @@
+(() => {
+  const getStoredLanguage = () => {
+    const m = document.cookie.match(/language=(\w+)/);
+    return m ? m[1] : null;
+  };
+  const setStoredLanguage = (language: string) => (document.cookie = `language=${language}; max-age=34560000; path=/`);
+
+  const getPreferredLanguage = () => {
+    const storedLanguage = getStoredLanguage();
+    if (storedLanguage) {
+      return storedLanguage;
+    }
+    const result = window.navigator.language.split("-")[0];
+    return ["en", "ru"].includes(result) ? result : "en";
+  };
+
+  const setLanguage = (language: string) => {};
+
+  setLanguage(getPreferredLanguage());
+
+  const showActiveLanguage = (language: string, focus = false) => {
+    const languageSwitcher = document.querySelector("#bd-language");
+
+    if (!languageSwitcher) {
+      return;
+    }
+
+    const languageSwitcherText = document.querySelector("#bd-language-text");
+    const activeLanguageIcon = document.querySelector(".language-icon-active");
+    const btnToActive = document.querySelector(`[data-bs-language-value="${language}"]`);
+    const activeLanguageIconContent = btnToActive?.querySelector("span")?.textContent;
+
+    document.querySelectorAll("[data-bs-language-value]").forEach((element) => {
+      element.classList.remove("active");
+      element.setAttribute("aria-pressed", "false");
+    });
+
+    btnToActive.classList.add("active");
+    btnToActive.setAttribute("aria-pressed", "true");
+    activeLanguageIcon.textContent = activeLanguageIconContent;
+    const languageSwitcherLabel = `${languageSwitcherText.textContent} (${btnToActive.dataset.bsLanguageValue})`;
+    languageSwitcher.setAttribute("aria-label", languageSwitcherLabel);
+
+    if (focus) {
+      languageSwitcher.focus();
+    }
+  };
+
+  window.addEventListener("DOMContentLoaded", () => {
+    showActiveLanguage(getPreferredLanguage());
+
+    document.querySelectorAll("[data-bs-language-value]").forEach((toggle) => {
+      toggle.addEventListener("click", () => {
+        const language = toggle.getAttribute("data-bs-language-value") || "";
+        setStoredLanguage(language);
+        setLanguage(language);
+        showActiveLanguage(language, true);
+        window.location.reload();
+      });
+    });
+  });
+})();