TechCorp/lib/i18n/useTranslation.ts

'use client';

import { useState, useEffect, useRef, useCallback } from 'react';
import { useRouter, usePathname, useSearchParams } from 'next/navigation';
import { Language, defaultLanguage } from './config';
import { getTranslation } from './translations';
import {
    getLanguageFromPath,
    removeLanguageFromPath,
    addLanguageToPath,
    getStoredLanguage,
    setStoredLanguage,
    getBrowserLanguage,
} from './utils';

export const useTranslation = (initialLanguage?: Language) => {
    const router = useRouter();
    const pathname = usePathname();
    const searchParams = useSearchParams();
    const isChangingLanguage = useRef(false);

    const [language, setLanguage] = useState<Language>(() => {
        if (initialLanguage) return initialLanguage;
        return defaultLanguage;
    });

    const [isInitialized, setIsInitialized] = useState(false);

    const t = getTranslation(language);

    const changeLanguage = useCallback(
        (newLanguage: Language) => {
            if (isChangingLanguage.current) return;

            isChangingLanguage.current = true;
            setLanguage(newLanguage);
            setStoredLanguage(newLanguage);

            // 使用 setTimeout 来避免状态更新冲突
            setTimeout(() => {
                // 首页特殊处理，切换语言时加上 ?lang=xx
                if (pathname === '/' || pathname === '') {
                    const url = newLanguage === defaultLanguage ? '/' : `/?lang=${newLanguage}`;
                    router.push(url);
                }
                // 产品页面特殊处理
                else if (pathname === '/products') {
                    const url =
                        newLanguage === defaultLanguage
                            ? '/products'
                            : `/products?lang=${newLanguage}`;
                    router.push(url);
                }
                // 新闻页面特殊处理
                else if (pathname === '/news') {
                    const url =
                        newLanguage === defaultLanguage ? '/news' : `/news?lang=${newLanguage}`;
                    router.push(url);
                }
                // 其他页面保持原有逻辑
                else {
                    const currentPath = removeLanguageFromPath(pathname);
                    const newPath = addLanguageToPath(currentPath, newLanguage);
                    if (newPath !== pathname) {
                        router.push(newPath);
                    }
                }

                // 重置标志
                setTimeout(() => {
                    isChangingLanguage.current = false;
                }, 100);
            }, 0);
        },
        [pathname, router],
    );

    const getLocalizedPath = useCallback(
        (path: string) => {
            return addLanguageToPath(path, language);
        },
        [language],
    );

    // 初始化语言设置
    useEffect(() => {
        if (isInitialized || isChangingLanguage.current) return;

        let detectedLanguage = defaultLanguage;

        if (initialLanguage) {
            detectedLanguage = initialLanguage;
        } else {
            // 首页和产品页面支持 ?lang=xx
            const search = searchParams ? `?${searchParams.toString()}` : '';
            const urlLanguage = getLanguageFromPath(pathname, search);

            if (urlLanguage !== defaultLanguage) {
                detectedLanguage = urlLanguage;
            } else {
                // 尝试从存储中获取语言
                const storedLanguage = getStoredLanguage();
                if (storedLanguage !== defaultLanguage) {
                    detectedLanguage = storedLanguage;
                } else {
                    // 最后尝试浏览器语言
                    detectedLanguage = getBrowserLanguage();
                }
            }
        }

        if (detectedLanguage !== language) {
            setLanguage(detectedLanguage);
        }

        setIsInitialized(true);
    }, [initialLanguage, pathname, searchParams, language, isInitialized]);

    // 监听URL变化，但避免在语言切换过程中触发
    useEffect(() => {
        if (!isInitialized || isChangingLanguage.current) return;

        const search = searchParams ? `?${searchParams.toString()}` : '';
        const urlLanguage = getLanguageFromPath(pathname, search);

        if (urlLanguage !== language) {
            setLanguage(urlLanguage);
        }
    }, [pathname, searchParams, language, isInitialized]);

    return {
        language,
        t,
        changeLanguage,
        getLocalizedPath,
        isInitialized,
    };
};