feat: add workspace theme toggle

modules/shared/components/ThemeToggle.tsx

@@ -0,0 +1,91 @@
+"use client";
+
+import { Moon, Monitor, Sun } from "lucide-react";
+import { useEffect, useState } from "react";
+
+import { cn } from "@/lib/utils";
+
+type ThemeMode = "light" | "dark" | "system";
+
+const storageKey = "teatea-theme";
+
+const themeOptions: Array<{
+  mode: ThemeMode;
+  label: string;
+  icon: React.ComponentType<{ className?: string; "aria-hidden"?: boolean }>;
+}> = [
+  { mode: "light", label: "浅色主题", icon: Sun },
+  { mode: "dark", label: "深色主题", icon: Moon },
+  { mode: "system", label: "跟随系统", icon: Monitor },
+];
+
+function getStoredTheme(): ThemeMode {
+  if (typeof window === "undefined") {
+    return "system";
+  }
+
+  const storedTheme = window.localStorage.getItem(storageKey);
+  return storedTheme === "light" || storedTheme === "dark" || storedTheme === "system" ? storedTheme : "system";
+}
+
+function applyTheme(mode: ThemeMode): void {
+  const prefersDark = window.matchMedia("(prefers-color-scheme: dark)").matches;
+  document.documentElement.classList.toggle("dark", mode === "dark" || (mode === "system" && prefersDark));
+  document.documentElement.style.colorScheme = mode === "dark" || (mode === "system" && prefersDark) ? "dark" : "light";
+}
+
+export function ThemeToggle(): React.ReactElement {
+  const [theme, setTheme] = useState<ThemeMode>("system");
+
+  useEffect(() => {
+    const storedTheme = getStoredTheme();
+    setTheme(storedTheme);
+    applyTheme(storedTheme);
+
+    const media = window.matchMedia("(prefers-color-scheme: dark)");
+    const handleChange = (): void => {
+      if (getStoredTheme() === "system") {
+        applyTheme("system");
+      }
+    };
+
+    media.addEventListener("change", handleChange);
+    return () => media.removeEventListener("change", handleChange);
+  }, []);
+
+  function handleThemeChange(nextTheme: ThemeMode): void {
+    window.localStorage.setItem(storageKey, nextTheme);
+    setTheme(nextTheme);
+    applyTheme(nextTheme);
+  }
+
+  return (
+    <div
+      aria-label="主题切换"
+      className="inline-flex h-10 shrink-0 items-center rounded-md border bg-card p-1 shadow-sm"
+      role="group"
+    >
+      {themeOptions.map((option) => {
+        const Icon = option.icon;
+        const isSelected = theme === option.mode;
+
+        return (
+          <button
+            aria-label={option.label}
+            aria-pressed={isSelected}
+            className={cn(
+              "inline-flex size-8 items-center justify-center rounded-sm text-muted-foreground transition-colors hover:bg-secondary hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background",
+              isSelected && "bg-primary text-primary-foreground hover:bg-primary hover:text-primary-foreground",
+            )}
+            key={option.mode}
+            onClick={() => handleThemeChange(option.mode)}
+            title={option.label}
+            type="button"
+          >
+            <Icon className="size-4" aria-hidden={true} />
+          </button>
+        );
+      })}
+    </div>
+  );
+}