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 * #%L
 * Alfresco Repository
 * %%
 * Copyright (C) 2005 - 2016 Alfresco Software Limited
 * %%
 * This file is part of the Alfresco software.
 * If the software was purchased under a paid Alfresco license, the terms of
 * the paid license agreement will prevail.  Otherwise, the software is
 * provided under the following open source license terms:
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */
package org.alfresco.ibatis;

import java.io.InputStream;
import java.util.Properties;
import javax.sql.DataSource;
import org.alfresco.util.resource.HierarchicalResourceLoader;
import org.apache.ibatis.builder.BaseBuilder;
import org.apache.ibatis.builder.BuilderException;
import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.datasource.DataSourceFactory;
import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.executor.loader.ProxyFactory;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.mapping.DatabaseIdProvider;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.reflection.DefaultReflectorFactory;
import org.apache.ibatis.reflection.MetaClass;
import org.apache.ibatis.reflection.ReflectorFactory;
import org.apache.ibatis.reflection.factory.ObjectFactory;
import org.apache.ibatis.reflection.wrapper.ObjectWrapperFactory;
import org.apache.ibatis.session.AutoMappingBehavior;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.LocalCacheScope;
import org.apache.ibatis.transaction.TransactionFactory;
import org.apache.ibatis.type.JdbcType;
import org.springframework.core.io.Resource;


/**
 * Extends the MyBatis XMLConfigBuilder to allow the selection of a {@link org.springframework.core.io.ResourceLoader}
 * that will be used to load the resources specified in the <b>mapper</b>'s <b>resource</b>.
 * <p>
 * By using the <b>resource.dialect</b> placeholder with hierarchical resource loading,
 * different resource files can be picked up for different dialects. This reduces duplication
 * when supporting multiple database configurations.
 * <pre>
 * &lt;configuration&gt;
 *    &lt;mappers&gt;
 *        &lt;mapper resource=&quot;org/x/y/#resource.dialect#/View1.xml&quot;/&gt;
 *        &lt;mapper resource=&quot;org/x/y/#resource.dialect#/View2.xml&quot;/&gt;
 *    &lt;/mappers&gt;
 * &lt;/configuration&gt;
 * <p/>
 * 
 * Much of the implementation is a direct copy of the MyBatis {@link org.apache.ibatis.builder.xml.XMLConfigBuilder}; some
 * of the <tt>protected</tt> methods do not have access to the object's state and can therefore
 * not be overridden successfully: <a href=https://issues.apache.org/jira/browse/IBATIS-589>IBATIS-589</a>

 * Pending a better way to extend/override, much of the implementation is a direct copy of the MyBatis 
 * {@link org.mybatis.spring.SqlSessionFactoryBean}; some of the <tt>protected</tt> methods do not have access to the object's state
 * and can therefore not be overridden successfully. 
 * 
 * This is equivalent to HierarchicalSqlMapConfigParser which extended iBatis (2.x).
 * See also: <a href=https://issues.apache.org/jira/browse/IBATIS-589>IBATIS-589</a>
 * and: <a href=http://code.google.com/p/mybatis/issues/detail?id=21</a>
 * 
 * @author Derek Hulley, janv
 * @since 4.0
 */
// note: effectively extends XMLConfigBuilder to use hierarchical resource loader
public class HierarchicalXMLConfigBuilder extends BaseBuilder
{
    private boolean parsed;
    private XPathParser parser;
    private String environment;
    private ReflectorFactory localReflectorFactory = new DefaultReflectorFactory();
    
    // EXTENDED
    final private HierarchicalResourceLoader resourceLoader;
    
    public HierarchicalXMLConfigBuilder(HierarchicalResourceLoader resourceLoader, InputStream inputStream, String environment, Properties props)
    {
        super(new Configuration());
        
        // EXTENDED
        this.resourceLoader = resourceLoader;
        
        ErrorContext.instance().resource("SQL Mapper Configuration");
        this.configuration.setVariables(props);
        this.parsed = false;
        this.environment = environment;
        this.parser = new XPathParser(inputStream, true, props, new XMLMapperEntityResolver());
    }

    public Configuration parse() {
      if (parsed) {
            throw new BuilderException("Each XMLConfigBuilder can only be used once.");
      }
      parsed = true;
      parseConfiguration(parser.evalNode("/configuration"));
        return configuration;
    }

    private void parseConfiguration(XNode root) {
        try {
            //issue #117 read properties first
            propertiesElement(root.evalNode("properties")); 
            typeAliasesElement(root.evalNode("typeAliases"));
            pluginElement(root.evalNode("plugins"));
            objectFactoryElement(root.evalNode("objectFactory"));
            objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
            reflectionFactoryElement(root.evalNode("reflectionFactory"));
            settingsElement(root.evalNode("settings"));
            // read it after objectFactory and objectWrapperFactory issue #631
            environmentsElement(root.evalNode("environments")); 
            databaseIdProviderElement(root.evalNode("databaseIdProvider"));
            typeHandlerElement(root.evalNode("typeHandlers"));
            mapperElement(root.evalNode("mappers"));
        } catch (Exception e) {
            throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
        }
    }

    private void typeAliasesElement(XNode parent) {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                if ("package".equals(child.getName())) {
                    String typeAliasPackage = child.getStringAttribute("name");
                    configuration.getTypeAliasRegistry().registerAliases(typeAliasPackage);
                } else {
                    String alias = child.getStringAttribute("alias");
                    String type = child.getStringAttribute("type");
                    try {
                        Class<?> clazz = Resources.classForName(type);
                        if (alias == null) {
                            typeAliasRegistry.registerAlias(clazz);
                        } else {
                            typeAliasRegistry.registerAlias(alias, clazz);
                        }
                    } catch (ClassNotFoundException e) {
                        throw new BuilderException("Error registering typeAlias for '" + alias + "'. Cause: " + e, e);
                    }
                }
            }
        }
    }

    private void pluginElement(XNode parent) throws Exception {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                String interceptor = child.getStringAttribute("interceptor");
                Properties properties = child.getChildrenAsProperties();
                Interceptor interceptorInstance = (Interceptor) resolveClass(interceptor).newInstance();
                interceptorInstance.setProperties(properties);
                configuration.addInterceptor(interceptorInstance);
            }
        }
    }

    private void objectFactoryElement(XNode context) throws Exception {
      if (context != null) {
        String type = context.getStringAttribute("type");
        Properties properties = context.getChildrenAsProperties();
        ObjectFactory factory = (ObjectFactory) resolveClass(type).newInstance();
        factory.setProperties(properties);
        configuration.setObjectFactory(factory);
      }
    }
    
    private void objectWrapperFactoryElement(XNode context) throws Exception {
      if (context != null) {
        String type = context.getStringAttribute("type");
        ObjectWrapperFactory factory = (ObjectWrapperFactory) resolveClass(type).newInstance();
        configuration.setObjectWrapperFactory(factory);
      }
    }

    private void reflectionFactoryElement(XNode context) throws Exception {
      if (context != null) {
        String type = context.getStringAttribute("type");
        ReflectorFactory factory = (ReflectorFactory) resolveClass(type).newInstance();
        configuration.setReflectorFactory(factory);
      }
    }

    private void propertiesElement(XNode context) throws Exception {
      if (context != null) {
        Properties defaults = context.getChildrenAsProperties();
        String resource = context.getStringAttribute("resource");
        String url = context.getStringAttribute("url");
        if (resource != null && url != null) {
          throw new BuilderException("The properties element cannot specify both a URL and a resource based property file reference.  Please specify one or the other.");
        }
        if (resource != null) {
          defaults.putAll(Resources.getResourceAsProperties(resource));
        } else if (url != null) {
          defaults.putAll(Resources.getUrlAsProperties(url));
        }
        Properties vars = configuration.getVariables();
        if (vars != null) {
          defaults.putAll(vars);
        }
        parser.setVariables(defaults);
        configuration.setVariables(defaults);
      }
    }

    private void settingsElement(XNode context) throws Exception {
        if (context != null) {
            Properties props = context.getChildrenAsProperties();
            // Check that all settings are known to the configuration class
            MetaClass metaConfig = MetaClass.forClass(Configuration.class, localReflectorFactory);
            for (Object key : props.keySet()) {
                if (!metaConfig.hasSetter(String.valueOf(key))) {
                    throw new BuilderException("The setting " + key + " is not known.  Make sure you spelled it correctly (case sensitive).");
                }
            }
            configuration.setAutoMappingBehavior(AutoMappingBehavior.valueOf(props.getProperty("autoMappingBehavior", "PARTIAL")));
            configuration.setCacheEnabled(booleanValueOf(props.getProperty("cacheEnabled"), true));
            configuration.setProxyFactory((ProxyFactory) createInstance(props.getProperty("proxyFactory")));
            configuration.setLazyLoadingEnabled(booleanValueOf(props.getProperty("lazyLoadingEnabled"), false));
            configuration.setAggressiveLazyLoading(booleanValueOf(props.getProperty("aggressiveLazyLoading"), true));
            configuration.setMultipleResultSetsEnabled(booleanValueOf(props.getProperty("multipleResultSetsEnabled"), true));
            configuration.setUseColumnLabel(booleanValueOf(props.getProperty("useColumnLabel"), true));
            configuration.setUseGeneratedKeys(booleanValueOf(props.getProperty("useGeneratedKeys"), false));
            configuration.setDefaultExecutorType(ExecutorType.valueOf(props.getProperty("defaultExecutorType", "SIMPLE")));
            configuration.setDefaultStatementTimeout(integerValueOf(props.getProperty("defaultStatementTimeout"), null));
            configuration.setDefaultFetchSize(integerValueOf(props.getProperty("defaultFetchSize"), null));
            configuration.setMapUnderscoreToCamelCase(booleanValueOf(props.getProperty("mapUnderscoreToCamelCase"), false));
            configuration.setSafeRowBoundsEnabled(booleanValueOf(props.getProperty("safeRowBoundsEnabled"), false));
            configuration.setLocalCacheScope(LocalCacheScope.valueOf(props.getProperty("localCacheScope", "SESSION")));
            configuration.setJdbcTypeForNull(JdbcType.valueOf(props.getProperty("jdbcTypeForNull", "OTHER")));
            configuration.setLazyLoadTriggerMethods(stringSetValueOf(props.getProperty("lazyLoadTriggerMethods"), "equals,clone,hashCode,toString"));
            configuration.setSafeResultHandlerEnabled(booleanValueOf(props.getProperty("safeResultHandlerEnabled"), true));
            configuration.setDefaultScriptingLanguage(resolveClass(props.getProperty("defaultScriptingLanguage")));
            configuration.setCallSettersOnNulls(booleanValueOf(props.getProperty("callSettersOnNulls"), false));
            configuration.setLogPrefix(props.getProperty("logPrefix"));
            configuration.setLogImpl(resolveClass(props.getProperty("logImpl")));
        }
    }

    private void environmentsElement(XNode context) throws Exception {
        if (context != null) {
            if (environment == null) {
                environment = context.getStringAttribute("default");
            }
            for (XNode child : context.getChildren()) {
                String id = child.getStringAttribute("id");
                if (isSpecifiedEnvironment(id)) {
                    TransactionFactory txFactory = transactionManagerElement(child.evalNode("transactionManager"));
                    DataSourceFactory dsFactory = dataSourceElement(child.evalNode("dataSource"));
                    DataSource dataSource = dsFactory.getDataSource();
                    Environment.Builder environmentBuilder = new Environment.Builder(id)
                            .transactionFactory(txFactory)
                            .dataSource(dataSource);
                    configuration.setEnvironment(environmentBuilder.build());
                }
            }
        }
    }

    private void databaseIdProviderElement(XNode context) throws Exception {
        DatabaseIdProvider databaseIdProvider = null;
        if (context != null) {
            String type = context.getStringAttribute("type");
            Properties properties = context.getChildrenAsProperties();
            databaseIdProvider = (DatabaseIdProvider) resolveClass(type).newInstance();
            databaseIdProvider.setProperties(properties);
        }
        Environment environment = configuration.getEnvironment();
        if (environment != null && databaseIdProvider != null) {
            String databaseId = databaseIdProvider.getDatabaseId(environment.getDataSource());
            configuration.setDatabaseId(databaseId);
        }
    }

    private TransactionFactory transactionManagerElement(XNode context) throws Exception {
      if (context != null) {
        String type = context.getStringAttribute("type");
        Properties props = context.getChildrenAsProperties();
        TransactionFactory factory = (TransactionFactory) resolveClass(type).newInstance();
        factory.setProperties(props);
        return factory;
      }
      throw new BuilderException("Environment declaration requires a TransactionFactory.");
    }

    private DataSourceFactory dataSourceElement(XNode context) throws Exception {
      if (context != null) {
        String type = context.getStringAttribute("type");
        Properties props = context.getChildrenAsProperties();
        DataSourceFactory factory = (DataSourceFactory) resolveClass(type).newInstance();
        factory.setProperties(props);
        return factory;
      }
      throw new BuilderException("Environment declaration requires a DataSourceFactory.");
    }

    private void typeHandlerElement(XNode parent) throws Exception {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                if ("package".equals(child.getName())) {
                    String typeHandlerPackage = child.getStringAttribute("name");
                    typeHandlerRegistry.register(typeHandlerPackage);
                } else {
                    String javaTypeName = child.getStringAttribute("javaType");
                    String jdbcTypeName = child.getStringAttribute("jdbcType");
                    String handlerTypeName = child.getStringAttribute("handler");
                    Class<?> javaTypeClass = resolveClass(javaTypeName);
                    JdbcType jdbcType = resolveJdbcType(jdbcTypeName);
                    Class<?> typeHandlerClass = resolveClass(handlerTypeName);
                    if (javaTypeClass != null) {
                        if (jdbcType == null) {
                            typeHandlerRegistry.register(javaTypeClass, typeHandlerClass);
                        } else {
                            typeHandlerRegistry.register(javaTypeClass, jdbcType, typeHandlerClass);
                        }
                    } else {
                        typeHandlerRegistry.register(typeHandlerClass);
                    }
                }
            }
        }
    }

    private void mapperElement(XNode parent) throws Exception {
        if (parent != null) {
            for (XNode child : parent.getChildren()) {
                if ("package".equals(child.getName())) {
                    String mapperPackage = child.getStringAttribute("name");
                    configuration.addMappers(mapperPackage);
                } else {
                    String resource = child.getStringAttribute("resource");
                    String url = child.getStringAttribute("url");
                    String mapperClass = child.getStringAttribute("class");
                    if (resource != null && url == null && mapperClass == null) {
                        ErrorContext.instance().resource(resource);

                        // // EXTENDED
                        // inputStream = Resources.getResourceAsStream(resource);
                        InputStream inputStream = null;
                        Resource res = resourceLoader.getResource(resource);
                        if (res != null && res.exists())
                        {
                            inputStream = res.getInputStream();
                        }
                        else {
                            throw new BuilderException("Failed to get resource: "+resource);
                        }

                        //InputStream inputStream = Resources.getResourceAsStream(resource);
                        XMLMapperBuilder mapperParser = new XMLMapperBuilder(inputStream, configuration, resource, configuration.getSqlFragments());
                        mapperParser.parse();
                    } else if (resource == null && url != null && mapperClass == null) {
                        ErrorContext.instance().resource(url);
                        InputStream inputStream = Resources.getUrlAsStream(url);
                        XMLMapperBuilder mapperParser = new XMLMapperBuilder(inputStream, configuration, url, configuration.getSqlFragments());
                        mapperParser.parse();
                    } else if (resource == null && url == null && mapperClass != null) {
                        Class<?> mapperInterface = Resources.classForName(mapperClass);
                        configuration.addMapper(mapperInterface);
                    } else {
                        throw new BuilderException("A mapper element may only specify a url, resource or class, but not more than one.");
                    }
                }
            }
        }
    }

    private boolean isSpecifiedEnvironment(String id) {
        if (environment == null) {
            throw new BuilderException("No environment specified.");
        } else if (id == null) {
            throw new BuilderException("Environment requires an id attribute.");
        } else if (environment.equals(id)) {
            return true;
        }
        return false;
    }
}
