/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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 org.apache.shiro.web.env;

 import org.apache.shiro.config.ConfigurationException;

 import org.apache.shiro.config.Ini;

 import org.apache.shiro.config.IniFactorySupport;

 import org.apache.shiro.io.ResourceUtils;

 import org.apache.shiro.util.CollectionUtils;

 import org.apache.shiro.util.Destroyable;

 import org.apache.shiro.util.Initializable;

 import org.apache.shiro.util.StringUtils;

 import org.apache.shiro.web.config.IniFilterChainResolverFactory;

 import org.apache.shiro.web.config.WebIniSecurityManagerFactory;

 import org.apache.shiro.web.filter.mgt.FilterChainResolver;

 import org.apache.shiro.web.mgt.WebSecurityManager;

 import org.apache.shiro.web.util.WebUtils;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import javax.servlet.ServletContext;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.Map;

 /**

  * {@link WebEnvironment} implementation configured by an {@link Ini} instance or {@code Ini} resource locations.

  *

  * @since 1.2

  */

 public class IniWebEnvironment extends ResourceBasedWebEnvironment implements Initializable, Destroyable {

     public static final String DEFAULT_WEB_INI_RESOURCE_PATH = "/WEB-INF/shiro.ini";

     private static final Logger log = LoggerFactory.getLogger(IniWebEnvironment.class);

     /**

      * The Ini that configures this WebEnvironment instance.

      */

     private Ini ini;

     /**

      * Initializes this instance by resolving any potential (explicit or resource-configured) {@link Ini}

      * configuration and calling {@link #configure() configure} for actual instance configuration.

      */

     public void init() {

         Ini ini = getIni();

         String[] configLocations = getConfigLocations();

         if (log.isWarnEnabled() && !CollectionUtils.isEmpty(ini) &&

                 configLocations != null && configLocations.length > 0) {

             log.warn("Explicit INI instance has been provided, but configuration locations have also been " +

                     "specified.  The {} implementation does not currently support multiple Ini config, but this may " +

                     "be supported in the future. Only the INI instance will be used for configuration.",

                     IniWebEnvironment.class.getName());

         }

         if (CollectionUtils.isEmpty(ini)) {

             log.debug("Checking any specified config locations.");

             ini = getSpecifiedIni(configLocations);

         }

         if (CollectionUtils.isEmpty(ini)) {

             log.debug("No INI instance or config locations specified.  Trying default config locations.");

             ini = getDefaultIni();

         }

         if (CollectionUtils.isEmpty(ini)) {

             String msg = "Shiro INI configuration was either not found or discovered to be empty/unconfigured.";

             throw new ConfigurationException(msg);

         }

         setIni(ini);

         configure();

     }

     protected void configure() {

         this.objects.clear();

         WebSecurityManager securityManager = createWebSecurityManager();

         setWebSecurityManager(securityManager);

         FilterChainResolver resolver = createFilterChainResolver();

         if (resolver != null) {

             setFilterChainResolver(resolver);

         }

     }

     protected Ini getSpecifiedIni(String[] configLocations) throws ConfigurationException {

         Ini ini = null;

         if (configLocations != null && configLocations.length > 0) {

             if (configLocations.length > 1) {

                 log.warn("More than one Shiro .ini config location has been specified.  Only the first will be " +

                         "used for configuration as the {} implementation does not currently support multiple " +

                         "files.  This may be supported in the future however.", IniWebEnvironment.class.getName());

             }

             //required, as it is user specified:

             ini = createIni(configLocations[0], true);

         }

         return ini;

     }

     protected Ini getDefaultIni() {

         Ini ini = null;

         String[] configLocations = getDefaultConfigLocations();

         if (configLocations != null) {

             for (String location : configLocations) {

                 ini = createIni(location, false);

                 if (!CollectionUtils.isEmpty(ini)) {

                     log.debug("Discovered non-empty INI configuration at location '{}'.  Using for configuration.",

                             location);

                     break;

                 }

             }

         }

         return ini;

     }

     /**

      * Creates an {@link Ini} instance reflecting the specified path, or {@code null} if the path does not exist and

      * is not required.

      * <p/>

      * If the path is required and does not exist or is empty, a {@link ConfigurationException} will be thrown.

      *

      * @param configLocation the resource path to load into an {@code Ini} instance.

      * @param required       if the path must exist and be converted to a non-empty {@link Ini} instance.

      * @return an {@link Ini} instance reflecting the specified path, or {@code null} if the path does not exist and

      *         is not required.

      * @throws ConfigurationException if the path is required but results in a null or empty Ini instance.

      */

     protected Ini createIni(String configLocation, boolean required) throws ConfigurationException {

         Ini ini = null;

         if (configLocation != null) {

             ini = convertPathToIni(configLocation, required);

         }

         if (required && CollectionUtils.isEmpty(ini)) {

             String msg = "Required configuration location '" + configLocation + "' does not exist or did not " +

                     "contain any INI configuration.";

             throw new ConfigurationException(msg);

         }

         return ini;

     }

     protected FilterChainResolver createFilterChainResolver() {

         FilterChainResolver resolver = null;

         Ini ini = getIni();

         if (!CollectionUtils.isEmpty(ini)) {

             //only create a resolver if the 'filters' or 'urls' sections are defined:

             Ini.Section urls = ini.getSection(IniFilterChainResolverFactory.URLS);

             Ini.Section filters = ini.getSection(IniFilterChainResolverFactory.FILTERS);

             if (!CollectionUtils.isEmpty(urls) || !CollectionUtils.isEmpty(filters)) {

                 //either the urls section or the filters section was defined.  Go ahead and create the resolver:

                 IniFilterChainResolverFactory factory = new IniFilterChainResolverFactory(ini, this.objects);

                 resolver = factory.getInstance();

             }

         }

         return resolver;

     }

     protected WebSecurityManager createWebSecurityManager() {

         WebIniSecurityManagerFactory factory;

         Ini ini = getIni();

         if (CollectionUtils.isEmpty(ini)) {

             factory = new WebIniSecurityManagerFactory();

         } else {

             factory = new WebIniSecurityManagerFactory(ini);

         }

         WebSecurityManager wsm = (WebSecurityManager)factory.getInstance();

         //SHIRO-306 - get beans after they've been created (the call was before the factory.getInstance() call,

         //which always returned null.

         Map<String, ?> beans = factory.getBeans();

         if (!CollectionUtils.isEmpty(beans)) {

             this.objects.putAll(beans);

         }

         return wsm;

     }

     /**

      * Returns an array with two elements, {@code /WEB-INF/shiro.ini} and {@code classpath:shiro.ini}.

      *

      * @return an array with two elements, {@code /WEB-INF/shiro.ini} and {@code classpath:shiro.ini}.

      */

     protected String[] getDefaultConfigLocations() {

         return new String[]{

                 DEFAULT_WEB_INI_RESOURCE_PATH,

                 IniFactorySupport.DEFAULT_INI_RESOURCE_PATH

         };

     }

     /**

      * Converts the specified file path to an {@link Ini} instance.

      * <p/>

      * If the path does not have a resource prefix as defined by {@link org.apache.shiro.io.ResourceUtils#hasResourcePrefix(String)}, the

      * path is expected to be resolvable by the {@code ServletContext} via

      * {@link javax.servlet.ServletContext#getResourceAsStream(String)}.

      *

      * @param path     the path of the INI resource to load into an INI instance.

      * @param required if the specified path must exist

      * @return an INI instance populated based on the given INI resource path.

      */

     private Ini convertPathToIni(String path, boolean required) {

         //TODO - this logic is ugly - it'd be ideal if we had a Resource API to polymorphically encaspulate this behavior

         Ini ini = null;

         if (StringUtils.hasText(path)) {

             InputStream is = null;

             //SHIRO-178: Check for servlet context resource and not only resource paths:

             if (!ResourceUtils.hasResourcePrefix(path)) {

                 is = getServletContextResourceStream(path);

             } else {

                 try {

                     is = ResourceUtils.getInputStreamForPath(path);

                 } catch (IOException e) {

                     if (required) {

                         throw new ConfigurationException(e);

                     } else {

                         if (log.isDebugEnabled()) {

                             log.debug("Unable to load optional path '" + path + "'.", e);

                         }

                     }

                 }

             }

             if (is != null) {

                 ini = new Ini();

                 ini.load(is);

             } else {

                 if (required) {

                     throw new ConfigurationException("Unable to load resource path '" + path + "'");

                 }

             }

         }

         return ini;

     }

     //TODO - this logic is ugly - it'd be ideal if we had a Resource API to polymorphically encaspulate this behavior

     private InputStream getServletContextResourceStream(String path) {

         InputStream is = null;

         path = WebUtils.normalize(path);

         ServletContext sc = getServletContext();

         if (sc != null) {

             is = sc.getResourceAsStream(path);

         }

         return is;

     }

     /**

      * Returns the {@code Ini} instance reflecting this WebEnvironment's configuration.

      *

      * @return the {@code Ini} instance reflecting this WebEnvironment's configuration.

      */

     public Ini getIni() {

         return this.ini;

     }

     /**

      * Allows for configuration via a direct {@link Ini} instance instead of via

      * {@link #getConfigLocations() config locations}.

      * <p/>

      * If the specified instance is null or empty, the fallback/default resource-based configuration will be used.

      *

      * @param ini the ini instance to use for creation.

      */

     public void setIni(Ini ini) {

         this.ini = ini;

     }

 }