// Copyright 2005-2007 onetsoft.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.onetsoft.fastjsp;

import com.onetsoft.fastjsp.util.CookieUtils;
import com.onetsoft.fastjsp.util.LocaleUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.Locale;

/**
 * Locale管理
 *
 * @author <a href="mailto:hgw@onetsoft.com">hgw</a>
 */
public class LocaleStateManagerImpl implements LocaleStateManager {

    private static String ATTRIBUTE_NAME = "fastjsp_locale";
    private static int MAX_COOKIE_AGE = 60 * 60 * 24 * 3;  

    private Locale locale = null;
    private boolean changed = false;

    public LocaleStateManagerImpl() {
    }

    public Locale getLocale() {
        return locale;
    }

    public void setLocale(Locale locale) {
        if (locale == null) throw new NullPointerException("Null parameter \"locale\".");
        if (!this.locale.equals(locale)) {
            changed = true;
            this.locale = locale;
        }
    }

    public void init(PageCycle cycle) {
        HttpSession s = cycle.getRequest().getSession(false);
        if (s != null)
            locale = (Locale) s.getAttribute(ATTRIBUTE_NAME);
        if (locale == null) {
            locale = loadFromCookie(cycle.getRequest());
            if (locale == null) {
                locale = ((AbstractPageCycle) cycle).service.servicer.module.locale;
                saveCookie(cycle.getRequest(), cycle.getResponse());
            }
            if (s != null)
                saveSession(cycle.getRequest());                    
        }
    }

    public void commitChange(PageCycle cycle) {
        if (changed) {
            saveSession(cycle.getRequest());
            saveCookie(cycle.getRequest(), cycle.getResponse());
            changed = false;
        }
    }

    private Locale loadFromCookie(HttpServletRequest request) {
        Cookie cookie = CookieUtils.getCookie(request, ATTRIBUTE_NAME);
        if (cookie == null)
            return null;
        return LocaleUtils.parseLocale(cookie.getValue(), null);
    }

    private void saveSession(HttpServletRequest request) {
        HttpSession s = request.getSession(false);
        if (s != null)
            s.setAttribute(ATTRIBUTE_NAME, locale);
    }

    private void saveCookie(HttpServletRequest request, HttpServletResponse response) {
        CookieUtils.deleteCookie(request, response, CookieUtils.getCookie(request, ATTRIBUTE_NAME));
        CookieUtils.setCookie(request, response, ATTRIBUTE_NAME, locale.toString(), MAX_COOKIE_AGE);
    }
}