/*

  * Copyright 2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 1.0 (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.opensource.org/licenses/ecl1.php

  *

  * 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.kuali.rice.devtools.generators;

 import com.sun.codemodel.ClassType;

 import com.sun.codemodel.JAnnotationArrayMember;

 import com.sun.codemodel.JAnnotationUse;

 import com.sun.codemodel.JArray;

 import com.sun.codemodel.JBlock;

 import com.sun.codemodel.JClass;

 import com.sun.codemodel.JCodeModel;

 import com.sun.codemodel.JConditional;

 import com.sun.codemodel.JDefinedClass;

 import com.sun.codemodel.JDocComment;

 import com.sun.codemodel.JExpr;

 import com.sun.codemodel.JFieldRef;

 import com.sun.codemodel.JFieldVar;

 import com.sun.codemodel.JInvocation;

 import com.sun.codemodel.JMethod;

 import com.sun.codemodel.JMod;

 import com.sun.codemodel.JType;

 import com.sun.codemodel.JVar;

 import com.sun.codemodel.writer.SingleStreamCodeWriter;

 import org.apache.commons.lang.builder.EqualsBuilder;

 import org.apache.commons.lang.builder.HashCodeBuilder;

 import org.apache.commons.lang.builder.ToStringBuilder;

 import org.kuali.rice.core.api.CoreConstants;

 import org.kuali.rice.core.api.mo.ModelBuilder;

 import org.kuali.rice.core.api.mo.ModelObjectComplete;

 import javax.xml.bind.annotation.XmlAccessType;

 import javax.xml.bind.annotation.XmlAccessorType;

 import javax.xml.bind.annotation.XmlAnyElement;

 import javax.xml.bind.annotation.XmlElement;

 import javax.xml.bind.annotation.XmlRootElement;

 import javax.xml.bind.annotation.XmlType;

 import java.io.ByteArrayOutputStream;

 import java.io.Serializable;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * This is a description of what this class does - ewestfal don't forget to fill this in. 

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class ImmutableJaxbGenerator {

         public static void main(String[] args) throws Exception {

                 if (args.length > 2 || args.length < 1) {

                         System.err.println("There should be two arguments defined as follows:\n" + 

                                         "     1. Fully qualified class name of a 'contract' interface\n" + 

                                         "     2. [Optional] Fully qualified class name of the class to generate.  If not specified, will use the name of the contract interface class and remove \"Contract\" from the end of it.\n");

                         System.exit(1);

                 }

                 // argument one should be a fully qualified class name of a "contract" interface

                 String contractInterfaceName = args[0];

                 String className = null;

                 // argument two should be the fully qualified class name of the class to generate

                 if (args.length == 2) {

                         className = args[1];

                 } else {

                         if (!contractInterfaceName.endsWith("Contract")) {

                                 throw new IllegalArgumentException("If not explicitly specifying target classname, then contract class name must end with 'Contract'");

                         }

                         className = contractInterfaceName.substring(0, contractInterfaceName.lastIndexOf("Contract"));

                 }

                 Generator generator = new Generator(contractInterfaceName, className);

                 generator.generate();

         }

         public static class Generator {

                 private final String contractInterfaceName;

                 private final String className;

                 private final JCodeModel codeModel;

                 public Generator(String contractInterfaceName, String className) {

                         this.contractInterfaceName = contractInterfaceName;

                         this.className = className;

                         this.codeModel = new JCodeModel();

                 }

                 public void generate() throws Exception {

                         byte[] javaCode = generateJava();

                         System.out.println(new String(javaCode));

                 }

                 private byte[] generateJava() throws Exception {

                         JDefinedClass classModel = codeModel._class(JMod.PUBLIC | JMod.FINAL, className, ClassType.CLASS);

                         Class<?> contractInterface = Class.forName(contractInterfaceName);

                         classModel._implements(contractInterface);

                         classModel._implements(ModelObjectComplete.class);

                         List<FieldModel> fields = determineFields(contractInterface);

                         renderConstantsClass(classModel);

                         renderElementsClass(classModel, fields);

                         renderClassLevelAnnotations(classModel, fields);

                         renderFields(classModel, fields);

                         renderFutureElementsField(classModel);                        

                         renderPrivateJaxbConstructor(classModel, fields);

                         renderBuilderConstructor(classModel, fields);

                         renderGetters(classModel, fields);

                         renderBuilderClass(classModel, fields, contractInterface);

                         renderStandardObjectMethods(classModel);

                         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

                         codeModel.build(new SingleStreamCodeWriter(outputStream));

                         return outputStream.toByteArray();

                 }

                 private List<FieldModel> determineFields(Class<?> contractInterface) throws Exception {

                         List<FieldModel> fieldModels = new ArrayList<FieldModel>();

                         Method[] methods = contractInterface.getMethods();

                         for (Method method : methods) {

                                 String methodName = method.getName();

                                 String fieldName = null;

                                 if (method.getReturnType() != Void.class && method.getParameterTypes().length == 0) {

                                         if (methodName.startsWith("get")) {

                                                 fieldName = Util.toLowerCaseFirstLetter(methodName.substring(3));

                                         } else if (methodName.startsWith("is")) {

                                                 fieldName = Util.toLowerCaseFirstLetter(methodName.substring(2));

                                         } else {

                                                 continue;

                                         }

                                         fieldModels.add(new FieldModel(fieldName, method.getReturnType()));

                                 }

                         }

                         return fieldModels;

                 }

                 private void renderConstantsClass(JDefinedClass classModel) throws Exception {

                         // define constants class

                         JDefinedClass constantsClass = classModel._class(JMod.STATIC, Util.CONSTANTS_CLASS_NAME);

                         // generate the javadoc on the top of the Constants class

                         JDocComment javadoc = constantsClass.javadoc();

                         javadoc.append(Util.CONSTANTS_CLASS_JAVADOC);

                         // render root element name

                         JFieldVar rootElementField = constantsClass.field(JMod.FINAL | JMod.STATIC, String.class, Util.ROOT_ELEMENT_NAME_FIELD);

                         rootElementField.init(JExpr.lit(Util.toLowerCaseFirstLetter(classModel.name())));

                         // render type name

                         JFieldVar typeNameField = constantsClass.field(JMod.FINAL | JMod.STATIC, String.class, Util.TYPE_NAME_FIELD);

                         typeNameField.init(JExpr.lit(classModel.name() + Util.TYPE_NAME_SUFFIX));

                         // hash code excludes array

                         JFieldVar hashCodeExcludesField = constantsClass.field(JMod.FINAL | JMod.STATIC, String[].class, Util.HASH_CODE_EQUALS_EXCLUDE_FIELD);

                         JArray excludeArray = JExpr.newArray(codeModel.ref(String.class));

                         JClass coreConstants = codeModel.ref(CoreConstants.class);

                         JFieldRef futureElementsRef = coreConstants.staticRef(Util.COMMON_ELEMENTS_CLASS).ref(Util.FUTURE_ELEMENTS_FIELD);

                         excludeArray.add(futureElementsRef);

                         hashCodeExcludesField.init(excludeArray);

                 }

                 private void renderElementsClass(JDefinedClass classModel, List<FieldModel> fields) throws Exception {

                         // define constants class

                         JDefinedClass elementsClass = classModel._class(JMod.STATIC, Util.ELEMENTS_CLASS_NAME);

                         // generate the javadoc on the top of the Elements class

                         JDocComment javadoc = elementsClass.javadoc();

                         javadoc.append(Util.ELEMENTS_CLASS_JAVADOC);

                         // go through each field and create a corresponding constant

                         for (FieldModel fieldModel : fields) {

                                 if (Util.isCommonElement(fieldModel.fieldName)) {

                                         continue;

                                 }

                                 JFieldVar elementFieldVar = elementsClass.field(JMod.FINAL | JMod.STATIC, String.class, Util.toConstantsVariable(fieldModel.fieldName));

                                 elementFieldVar.init(JExpr.lit(fieldModel.fieldName));

                         }

                 }

                 private void renderClassLevelAnnotations(JDefinedClass classModel, List<FieldModel> fields) throws Exception {

                         JFieldRef constantsClass = classModel.staticRef(Util.CONSTANTS_CLASS_NAME);

                         JFieldRef elementsClass = classModel.staticRef(Util.ELEMENTS_CLASS_NAME);

                         JClass coreConstants = codeModel.ref(CoreConstants.class);

                         JFieldRef commonElementsRef = coreConstants.staticRef("CommonElements");

                         // XmlRootElement

                         JAnnotationUse rootElementAnnotation = classModel.annotate(XmlRootElement.class);

                         rootElementAnnotation.param("name", constantsClass.ref(Util.ROOT_ELEMENT_NAME_FIELD));

                         // XmlAccessorType

                         JAnnotationUse xmlAccessorTypeAnnotation = classModel.annotate(XmlAccessorType.class);

                         xmlAccessorTypeAnnotation.param("value", XmlAccessType.NONE);

                         // XmlType

                         JAnnotationUse xmlTypeAnnotation = classModel.annotate(XmlType.class);

                         xmlTypeAnnotation.param("name", constantsClass.ref(Util.TYPE_NAME_FIELD));

                         JAnnotationArrayMember propOrderMember = xmlTypeAnnotation.paramArray("propOrder");

                         for (FieldModel field : fields) {

                                 if (Util.isCommonElement(field.fieldName)) {

                                         propOrderMember.param(commonElementsRef.ref(Util.toConstantsVariable(field.fieldName)));

                                 } else {

                                         propOrderMember.param(elementsClass.ref(Util.toConstantsVariable(field.fieldName)));

                                 }

                         }

                         propOrderMember.param(commonElementsRef.ref("FUTURE_ELEMENTS"));

                 }

                 private void renderFields(JDefinedClass classModel, List<FieldModel> fields) {

                         for (FieldModel fieldModel : fields) {

                                 renderField(classModel, fieldModel);

                         }

                 }

                 private void renderField(JDefinedClass classModel, FieldModel fieldModel) {

                         JFieldVar field = classModel.field(JMod.PRIVATE | JMod.FINAL, fieldModel.fieldType, fieldModel.fieldName);

                         JAnnotationUse annotation = field.annotate(XmlElement.class);

                         if (Util.isCommonElement(fieldModel.fieldName)) {

                                 JClass coreConstants = codeModel.ref(CoreConstants.class);

                                 JFieldRef commonElementsRef = coreConstants.staticRef("CommonElements");

                                 annotation.param("name", commonElementsRef.ref(Util.toConstantsVariable(fieldModel.fieldName)));

                         } else {

                                 JClass elementsClass = codeModel.ref(Util.ELEMENTS_CLASS_NAME);

                                 JFieldRef fieldXmlNameRef = elementsClass.staticRef(Util.toConstantsVariable(fieldModel.fieldName));

                                 annotation.param("name", fieldXmlNameRef);

                         }

                         annotation.param("required", false);

                 }

                 private void renderFutureElementsField(JDefinedClass classModel) throws Exception {

                         JType collectionType = codeModel.parseType("java.util.Collection<org.w3c.dom.Element>");

                         JFieldVar field = classModel.field(JMod.PRIVATE | JMod.FINAL, collectionType, "_futureElements");

                         field.init(JExpr._null());

                         JAnnotationUse annotation = field.annotate(SuppressWarnings.class);

                         annotation.param("value", "unused");

                         field.annotate(XmlAnyElement.class);

                 }

                 private void renderPrivateJaxbConstructor(JDefinedClass classModel, List<FieldModel> fields) {

                         JMethod method = classModel.constructor(JMod.PRIVATE);

                         JBlock body = method.body();

                         for (FieldModel fieldModel : fields) {

                                 body.directStatement("this." + fieldModel.fieldName + " = " + getInitString(fieldModel.fieldType) + ";");

                         }

                         method.javadoc().add("Private constructor used only by JAXB.");

                 }

         private String getInitString(Class<?> clazz) {

             if (clazz == Boolean.TYPE) {

                 return "false";

             } else if (clazz == Character.TYPE) {

                 return "'\\\\u0000'";

             } else if (clazz == Long.TYPE) {

                 return "0L";

             } else if (clazz == Float.TYPE) {

                 return "0.0F";

             } else if (clazz == Double.TYPE) {

                 return "0.0D";

             } else if (clazz == Byte.TYPE || clazz == Short.TYPE || clazz == Integer.TYPE) {

                 return "0";

             } else {

                 return "null";

             }

         }

                 private void renderBuilderConstructor(JDefinedClass classModel, List<FieldModel> fields) {

                         JMethod method = classModel.constructor(JMod.PRIVATE);

                         method.param(codeModel.ref("Builder"), "builder");

                         JBlock body = method.body();

                         for (FieldModel fieldModel : fields) {

                                 body.directStatement("this." + fieldModel.fieldName + " = builder." + Util.generateGetter(fieldModel.fieldName, isBoolean(fieldModel.fieldType)) + ";");

                         }

                 }

                 private void renderGetters(JDefinedClass classModel, List<FieldModel> fields) {

             for (FieldModel fieldModel : fields) {

                 JMethod getterMethod = classModel.method(JMod.PUBLIC, fieldModel.fieldType, Util.generateGetterName(fieldModel.fieldName, isBoolean(fieldModel.fieldType)));

                                 JBlock methodBody = getterMethod.body();

                                 methodBody.directStatement("return this." + fieldModel.fieldName + ";");

                                 getterMethod.annotate(Override.class);

                         }

                 }

         private boolean isBoolean(Class<?> clazz) {

             return clazz == Boolean.TYPE || clazz == Boolean.class;

         }

                 private void renderBuilderClass(JDefinedClass classModel, List<FieldModel> fields, Class<?> contractInterface) throws Exception {

                         // define constants class

                         JDefinedClass builderClass = classModel._class(JMod.PUBLIC | JMod.STATIC | JMod.FINAL, Util.BUILDER_CLASS_NAME);

                         // create a literal version of the Builder class so that the code generator won't pre-pend Builder class references with outermost class

                         JClass literalBuilderClass = codeModel.ref("Builder");

                         // generate the javadoc on the top of the Elements class

                         JDocComment javadoc = builderClass.javadoc();

                         javadoc.append(Util.generateBuilderJavadoc(classModel.name(), contractInterface.getSimpleName()));

                         builderClass._implements(contractInterface);

                         builderClass._implements(ModelBuilder.class);

                         builderClass._implements(Serializable.class);

                         // render the builder fields

                         for (FieldModel fieldModel : fields) {

                                 builderClass.field(JMod.PRIVATE, fieldModel.fieldType, fieldModel.fieldName);

                         }

                         // render default empty constructor for builder

                         JMethod constructor = builderClass.constructor(JMod.PRIVATE);

                         constructor.body().directStatement("// TODO modify this constructor as needed to pass any required values and invoke the appropriate 'setter' methods");

                         renderBuilderDefaultCreate(builderClass, literalBuilderClass);

                         renderBuilderCreateContract(builderClass, literalBuilderClass, fields, contractInterface);

                         renderBuild(builderClass);

                         renderGetters(builderClass, fields);

                         renderSetters(builderClass, fields);

                 }

                 private void renderBuilderDefaultCreate(JDefinedClass builderClass, JClass literalBuilderClass) {

                         JMethod createMethod = builderClass.method(JMod.PUBLIC | JMod.STATIC, literalBuilderClass, "create");

                         JBlock createMethodBody = createMethod.body();

                         createMethodBody.directStatement("// TODO modify as needed to pass any required values and add them to the signature of the 'create' method");

                         createMethodBody.directStatement("return new Builder();");

                 }

                 private void renderBuilderCreateContract(JDefinedClass builderClass, JClass literalBuilderClass, List<FieldModel> fields, Class<?> contractInterface) {

                         JMethod createContractMethod = builderClass.method(JMod.PUBLIC | JMod.STATIC, literalBuilderClass, "create");

                         JVar contractParam = createContractMethod.param(contractInterface, "contract");

                         JBlock body = createContractMethod.body();

                         JConditional nullContractCheck = body._if(contractParam.eq(JExpr._null()));

                         nullContractCheck._then().directStatement("throw new IllegalArgumentException(\"contract was null\");");

                         body.directStatement("// TODO if create() is modified to accept required parameters, this will need to be modified");

                         body.directStatement("Builder builder = create();");

                         for (FieldModel fieldModel : fields) {

                                 String fieldName = fieldModel.fieldName;

                                 body.directStatement("builder." + Util.generateSetter(fieldName, "contract." + Util.generateGetter(fieldName, isBoolean(fieldModel.fieldType))) + ";");

                         }

                         body.directStatement("return builder;");

                 }

                 private void renderBuild(JDefinedClass builderClass) {

                         JMethod buildMethod = builderClass.method(JMod.PUBLIC, builderClass.outer(), "build");

                         buildMethod.body().directStatement("return new " + builderClass.outer().name() + "(this);");

                 }

                 private void renderSetters(JDefinedClass builderClass, List<FieldModel> fields) {

                         for (FieldModel fieldModel : fields) {

                                 String fieldName = fieldModel.fieldName;

                                 JMethod setterMethod = builderClass.method(JMod.PUBLIC, codeModel.VOID, Util.generateSetterName(fieldName));

                                 setterMethod.param(fieldModel.fieldType, fieldName);

                                 setterMethod.body().directStatement("// TODO add validation of input value if required and throw IllegalArgumentException if needed");

                                 setterMethod.body().directStatement("this." + fieldName + " = " + fieldName + ";");

                         }

                 }

                 /**

                  * Generates standard hashCode, equals, and toString methods

                  */

                 private void renderStandardObjectMethods(JDefinedClass classModel) {

                         JClass constantsClass = codeModel.ref(Util.CONSTANTS_CLASS_NAME);

                         JFieldRef hashCodeEqualsExcludes = constantsClass.staticRef(Util.HASH_CODE_EQUALS_EXCLUDE_FIELD);

                         // hashCode

                         JMethod hashCodeMethod = classModel.method(JMod.PUBLIC, codeModel.INT, "hashCode");

                         JInvocation hcInvoke = codeModel.ref(HashCodeBuilder.class).staticInvoke("reflectionHashCode");

                         hcInvoke.arg(JExpr._this());

                         hcInvoke.arg(hashCodeEqualsExcludes);

                         hashCodeMethod.body()._return(hcInvoke);

                         hashCodeMethod.annotate(Override.class);

                         // equals

                         JMethod equalsMethod = classModel.method(JMod.PUBLIC, codeModel.BOOLEAN, "equals");

                         JVar objectParam = equalsMethod.param(Object.class, "object");

                         JInvocation equalsInvoke = codeModel.ref(EqualsBuilder.class).staticInvoke("reflectionEquals");

                         equalsInvoke.arg(objectParam);

                         equalsInvoke.arg(JExpr._this());

                         equalsInvoke.arg(hashCodeEqualsExcludes);

                         equalsMethod.body()._return(equalsInvoke);

                         equalsMethod.annotate(Override.class);

                         // toString

                         JMethod toStringMethod = classModel.method(JMod.PUBLIC, String.class, "toString");

                         JInvocation toStringInvoke = codeModel.ref(ToStringBuilder.class).staticInvoke("reflectionToString");

                         toStringInvoke.arg(JExpr._this());

                         toStringMethod.body()._return(toStringInvoke);

                         toStringMethod.annotate(Override.class);

                 }

         }

         private static class FieldModel {

                 private final String fieldName;

                 private final Class<?> fieldType;

                 private FieldModel(String fieldName, Class<?> fieldType) {

                         this.fieldName = fieldName;

                         this.fieldType = fieldType;

                 }

         }

 }