// ============================================================
// ThemeProvider — 主题 Provider 组件
// ============================================================

import { useState, useEffect, useCallback, type ReactNode } from 'react';
import { ConfigProvider } from 'antd';

import { getThemeConfig } from '../theme/antd-theme';
import {
   ThemeContext,
   readStoredTheme,
   writeStoredTheme,
   applyHtmlTheme,
   STORAGE_KEY,
} from '../hooks/use-theme';
import type { ThemeContextValue } from '../hooks/use-theme';

interface ThemeProviderProps {
   children: ReactNode;
}

export function ThemeProvider({ children }: ThemeProviderProps) {
   const [isDark, setIsDark] = useState<boolean>(readStoredTheme);

   // 挂载时同步
   useEffect(() => {
      applyHtmlTheme(isDark);
   }, []); // eslint-disable-line react-hooks/exhaustive-deps

   const toggleTheme = useCallback(() => {
      setIsDark((prev) => {
         const next = !prev;
         writeStoredTheme(next);
         applyHtmlTheme(next);
         return next;
      });
   }, []);

   const setLight = useCallback(() => {
      setIsDark(false);
      writeStoredTheme(false);
      applyHtmlTheme(false);
   }, []);

   const setDark = useCallback(() => {
      setIsDark(true);
      writeStoredTheme(true);
      applyHtmlTheme(true);
   }, []);

   // 监听系统主题变化（仅用户从未手动切换时跟随）
   useEffect(() => {
      const mq = window.matchMedia('(prefers-color-scheme: dark)');
      const handleChange = (e: MediaQueryListEvent) => {
         const stored = localStorage.getItem(STORAGE_KEY);
         if (stored === null) {
            setIsDark(e.matches);
            applyHtmlTheme(e.matches);
         }
      };
      mq.addEventListener('change', handleChange);
      return () => mq.removeEventListener('change', handleChange);
   }, []);

   const ctx: ThemeContextValue = { isDark, toggleTheme, setLight, setDark };

   return (
      <ThemeContext.Provider value={ctx}>
         <ConfigProvider theme={getThemeConfig(isDark)}>{children}</ConfigProvider>
      </ThemeContext.Provider>
   );
}