♻️ Refactor ThemeProvider

Author: alejsdev

frontend/src/components/theme-provider.tsx

@@ -1,11 +1,115 @@
-"use client"
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useState,
+} from "react"
 
-import * as React from "react"
-import { ThemeProvider as NextThemesProvider } from "next-themes"
+export type Theme = "dark" | "light" | "system"
+
+type ThemeProviderProps = {
+  children: React.ReactNode
+  defaultTheme?: Theme
+  storageKey?: string
+}
+
+type ThemeProviderState = {
+  theme: Theme
+  resolvedTheme: "dark" | "light"
+  setTheme: (theme: Theme) => void
+}
+
+const initialState: ThemeProviderState = {
+  theme: "system",
+  resolvedTheme: "light",
+  setTheme: () => null,
+}
+
+const ThemeProviderContext = createContext<ThemeProviderState>(initialState)
 
 export function ThemeProvider({
-    children,
-    ...props
-}: React.ComponentProps<typeof NextThemesProvider>) {
-    return <NextThemesProvider {...props}>{children}</NextThemesProvider>
-}
+  children,
+  defaultTheme = "system",
+  storageKey = "vite-ui-theme",
+  ...props
+}: ThemeProviderProps) {
+  const [theme, setTheme] = useState<Theme>(
+    () => (localStorage.getItem(storageKey) as Theme) || defaultTheme,
+  )
+
+  const getResolvedTheme = useCallback((theme: Theme): "dark" | "light" => {
+    if (theme === "system") {
+      return window.matchMedia("(prefers-color-scheme: dark)").matches
+        ? "dark"
+        : "light"
+    }
+    return theme
+  }, [])
+
+  const [resolvedTheme, setResolvedTheme] = useState<"dark" | "light">(() =>
+    getResolvedTheme(theme),
+  )
+
+  const updateTheme = useCallback((newTheme: Theme) => {
+    const root = window.document.documentElement
+
+    root.classList.remove("light", "dark")
+
+    if (newTheme === "system") {
+      const systemTheme = window.matchMedia("(prefers-color-scheme: dark)")
+        .matches
+        ? "dark"
+        : "light"
+
+      root.classList.add(systemTheme)
+      return
+    }
+
+    root.classList.add(newTheme)
+  }, [])
+
+  useEffect(() => {
+    updateTheme(theme)
+    setResolvedTheme(getResolvedTheme(theme))
+
+    const mediaQuery = window.matchMedia("(prefers-color-scheme: dark)")
+
+    const handleChange = () => {
+      if (theme === "system") {
+        updateTheme("system")
+        setResolvedTheme(getResolvedTheme("system"))
+      }
+    }
+
+    mediaQuery.addEventListener("change", handleChange)
+
+    return () => {
+      mediaQuery.removeEventListener("change", handleChange)
+    }
+  }, [theme, updateTheme, getResolvedTheme])
+
+  const value = {
+    theme,
+    resolvedTheme,
+    setTheme: (theme: Theme) => {
+      localStorage.setItem(storageKey, theme)
+      setTheme(theme)
+    },
+  }
+
+  return (
+    <ThemeProviderContext.Provider {...props} value={value}>
+      {children}
+    </ThemeProviderContext.Provider>
+  )
+}
+
+export const useTheme = () => {
+  const context = useContext(ThemeProviderContext)
+
+  if (context === undefined)
+    throw new Error("useTheme must be used within a ThemeProvider")
+
+  return context
+}