/*
 * Copyright 2019 A-SIT Plus GmbH
 * AT-specific eIDAS Connector has been developed in a cooperation between EGIZ,
 * A-SIT Plus GmbH, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "License");
 * You may not use this work except in compliance with the License.
 * You may obtain a copy of the License at:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * 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.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */

package at.asitplus.eidas.specific.connector.config;

import java.net.MalformedURLException;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ReloadableResourceBundleMessageSource;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.i18n.CookieLocaleResolver;
import org.thymeleaf.templateresolver.FileTemplateResolver;

import at.asitplus.eidas.specific.connector.MsEidasNodeConstants;
import at.gv.egiz.eaaf.core.api.idp.IConfiguration;
import at.gv.egiz.eaaf.core.impl.utils.FileUtils;

/**
 * Spring configurator for Web resources.
 * 
 * @author tlenz
 *
 */
@Configuration
@EnableWebMvc
public class StaticResourceConfiguration implements WebMvcConfigurer {
  private static final Logger log = LoggerFactory.getLogger(StaticResourceConfiguration.class);
  private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
      "/"
  };

  private static final String DEFAULT_MESSAGE_SOURCE = "classpath:properties/status_messages";

  @Autowired
  private IConfiguration basicConfig;

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    final String staticResources = basicConfig.getBasicConfiguration(
        MsEidasNodeConstants.PROP_CONFIG_WEBCONTENT_STATIC_PATH);
    try {
      if (StringUtils.isNotEmpty(staticResources)) {
        String absPath = FileUtils.makeAbsoluteUrl(staticResources, basicConfig
            .getConfigurationRootDirectory());
        if (!absPath.endsWith("/")) {
          absPath += "/";
        }

        registry.addResourceHandler("/static/**").addResourceLocations(absPath);
        log.info("Add Ressourcefolder: " + absPath + " for static Web content");

      } else {
        log.debug("No Ressourcefolder for static Web content");
      }

    } catch (final MalformedURLException e) {
      log.warn("Can NOT initialize ressourcefolder for static Web content", e);

    }

    registry.addResourceHandler("/**").addResourceLocations(CLASSPATH_RESOURCE_LOCATIONS);

  }

  /**
   * Internal i18n message source.
   * 
   * @return
   */
  @Bean
  public ReloadableResourceBundleMessageSource internalMessageSource() {
    final ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();

    // add default message source
    messageSource.setBasename(DEFAULT_MESSAGE_SOURCE);
    messageSource.setDefaultEncoding("UTF-8");
    return messageSource;

  }

  /**
   * External i18n message source.
   * 
   * @return
   */
  @Bean
  public ReloadableResourceBundleMessageSource messageSource() {
    final ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
    messageSource.setDefaultEncoding("UTF-8");
    messageSource.setParentMessageSource(internalMessageSource());

    final String staticResources = basicConfig.getBasicConfiguration(
        MsEidasNodeConstants.PROP_CONFIG_WEBCONTENT_PROPERTIES_PATH);
    try {
      if (StringUtils.isNotEmpty(staticResources)) {
        final String absPath = FileUtils.makeAbsoluteUrl(staticResources, basicConfig
            .getConfigurationRootDirectory());
        messageSource.setBasename(absPath);
        messageSource.setFallbackToSystemLocale(false);

      } else {
        log.debug("No Ressourcefolder for dynamic Web content templates");
      }

    } catch (final MalformedURLException e) {
      log.warn("Can NOT initialize ressourcefolder for dynamic Web content templates", e);

    }

    return messageSource;

  }

  /**
   * Cookie based i18n language selector.
   * 
   * @return
   */
  @Bean
  public CookieLocaleResolver localeResolver() {
    final CookieLocaleResolver localeResolver = new CookieLocaleResolver();
    localeResolver.setCookieName("currentLanguage");
    localeResolver.setCookieMaxAge(3600);
    return localeResolver;
  }
  
  
  /**
   * Thymeleaf based template resolver.
   * 
   * @return
   */
  @Bean(name = "templateResolver")
  public FileTemplateResolver templateResolver() {
    final String staticResources = basicConfig.getBasicConfiguration(
        MsEidasNodeConstants.PROP_CONFIG_WEBCONTENT_TEMPLATES_PATH);
    try {
      if (StringUtils.isNotEmpty(staticResources)) {
        String absPath = FileUtils.makeAbsoluteUrl(staticResources, basicConfig
            .getConfigurationRootDirectory());
        if (!absPath.endsWith("/")) {
          absPath += "/";
        }

        if (absPath.startsWith("file:")) {
          absPath = absPath.substring("file:".length());
        }

        final FileTemplateResolver viewResolver = new FileTemplateResolver();
        viewResolver.setPrefix(absPath);
        viewResolver.setSuffix(".html");
        viewResolver.setTemplateMode("HTML");
        viewResolver.setCacheable(false);

        log.info("Add Ressourcefolder: " + absPath + " for dynamic Web content templates");
        return viewResolver;

      } else {
        log.debug("No Ressourcefolder for dynamic Web content templates");
      }

    } catch (final MalformedURLException e) {
      log.warn("Can NOT initialize ressourcefolder for dynamic Web content templates", e);

    }

    // TODO: implement some backup solution
    return null;

  }
}