/*
 * 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.tuscany.tools.java2wsdl.generate;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;

import javax.xml.namespace.QName;

import org.apache.axis2.description.java2wsdl.bytecode.MethodTable;
import org.apache.tuscany.sdo.util.DataObjectUtil;
import org.apache.ws.commons.schema.XmlSchema;
import org.apache.ws.commons.schema.XmlSchemaCollection;
import org.apache.ws.commons.schema.XmlSchemaComplexType;
import org.apache.ws.commons.schema.XmlSchemaElement;
import org.apache.ws.commons.schema.XmlSchemaForm;
import org.apache.ws.commons.schema.XmlSchemaImport;
import org.apache.ws.commons.schema.XmlSchemaInclude;
import org.apache.ws.commons.schema.XmlSchemaSequence;
import org.apache.ws.commons.schema.utils.NamespaceMap;
import org.codehaus.jam.JClass;
import org.codehaus.jam.JMethod;
import org.codehaus.jam.JParameter;
import org.codehaus.jam.JamClassIterator;
import org.codehaus.jam.JamService;
import org.codehaus.jam.JamServiceFactory;
import org.codehaus.jam.JamServiceParams;

public class TuscanySchemaGenerator implements TuscanyJava2WSDLConstants {
    public static final String NAME_SPACE_PREFIX = "stn_";
    public static final String PERIOD_SEPARATOR = ".";
    private static int prefixCount = 1;

    protected String attrFormDefault = null;
    protected String elementFormDefault = null;
    protected Hashtable targetNamespacePrefixMap = new Hashtable();
    protected Hashtable schemaMap = new Hashtable();
    protected Hashtable sdoAnnoMap = new Hashtable();
    protected XmlSchemaCollection xmlSchemaCollection = new XmlSchemaCollection();
    private TuscanyTypeTable typeTable = new TuscanyTypeTable();
    protected SchemaBuilder schemaBuilder = null;
    protected Map schemaLocationMap = null;

    private ClassLoader classLoader;
    private String className;

    // to keep loaded method using JAM
    private JMethod methods[];

    // to store byte code method using Axis 1.x codes
    private MethodTable methodTable;
    private String schemaTargetNameSpace;
    private String schema_namespace_prefix;
    private Class clazz;
    private ArrayList excludeMethods = new ArrayList();

    public TuscanySchemaGenerator(ClassLoader loader,
                                  String className,
                                  String schematargetNamespace,
                                  String schematargetNamespacePrefix,
                                  Map schemaLocMap) throws Exception {
        DataObjectUtil.initRuntime();
        this.classLoader = loader;
        this.className = className;
        clazz = Class.forName(className, true, loader);
        methodTable = new MethodTable(clazz);
        this.schemaTargetNameSpace = schematargetNamespace;
        this.schema_namespace_prefix = schematargetNamespacePrefix;
        this.schemaLocationMap = schemaLocMap;

        initializeSchemaMap(this.schemaTargetNameSpace, this.schema_namespace_prefix);
        schemaBuilder =
            new SchemaBuilder(xmlSchemaCollection, schemaMap, targetNamespacePrefixMap, typeTable,
                              getAttrFormDefault(), getElementFormDefault(), schemaLocMap, this.classLoader, null);
    }

    /**
     * Generates schema for all the parameters in method. First generates schema
     * for all different parameter type and later refers to them.
     * 
     * @return Returns XmlSchema.
     * @throws Exception
     */
    public Collection buildWSDLTypes() throws Exception {
        JamServiceFactory factory = JamServiceFactory.getInstance();
        JamServiceParams jam_service_parms = factory.createServiceParams();
        // setting the classLoder
        // jam_service_parms.setParentClassLoader(factory.createJamClassLoader(classLoader));
        // it can possible to add the classLoader as well
        jam_service_parms.addClassLoader(classLoader);
        jam_service_parms.includeClass(className);
        JamService service = factory.createService(jam_service_parms);

        JamClassIterator jClassIter = service.getClasses();
        // all most all the time the ittr will have only one class in it
        while (jClassIter.hasNext()) {
            JClass jclass = (JClass)jClassIter.next();
            // serviceName = jclass.getSimpleName();
            // todo in the future , when we support annotation we can use this
            // JAnnotation[] annotations = jclass.getAnnotations();

            /**
             * Schema generation done in two stage 1. Load all the methods and
             * create type for methods parameters (if the parameters are Bean
             * then it will create Complex types for those , and if the
             * parameters are simple type which describe in SimpleTypeTable
             * nothing will happen) 2. In the next stage for all the methods
             * messages and port types will be created
             */
            methods = jclass.getDeclaredMethods();

            // since we do not support overload
            HashMap uniqueMethods = new HashMap();
            XmlSchemaComplexType methodSchemaType = null;
            XmlSchemaSequence sequence = null;
            for (int i = 0; i < methods.length; i++) {
                String methodName = methods[i].getSimpleName();
                JMethod jMethod = methods[i];
                // no need to think about this method , since that is system
                // config method
                if (excludeMethods.contains(jMethod.getSimpleName())) {
                    continue;
                }
                // if (jMethod.getSimpleName().equals("init")
                // || "setOperationContext".equals(jMethod.getSimpleName())
                // || "destroy".equals(jMethod.getSimpleName()))
                // continue;
                if (uniqueMethods.get(jMethod.getSimpleName()) != null) {
                    throw new Exception(" Sorry we don't support methods overloading !!!! ");
                }

                if (!jMethod.isPublic()) {
                    // no need to generate Schema for non public methods
                    continue;
                }

                uniqueMethods.put(jMethod.getSimpleName(), jMethod);
                JParameter[] paras = jMethod.getParameters();
                String parameterNames[] = null;
                if (paras.length > 0) {
                    parameterNames = methodTable.getParameterNames(methodName);
                    sequence = new XmlSchemaSequence();

                    // create the schema type for the method wrapper
                    methodSchemaType = createSchemaTypeForMethodPart(jMethod.getSimpleName());
                    methodSchemaType.setParticle(sequence);
                }

                for (int j = 0; j < paras.length; j++) {
                    JParameter methodParameter = paras[j];
                    JClass paraType = methodParameter.getType();
                    generateSchemaForType(sequence, paraType, (parameterNames != null && parameterNames[j] != null)
                        ? parameterNames[j] : methodParameter.getSimpleName());
                }
                // for its return type
                JClass returnType = jMethod.getReturnType();
                if (!returnType.isVoidType()) {
                    methodSchemaType = createSchemaTypeForMethodPart(jMethod.getSimpleName() + RESPONSE);
                    sequence = new XmlSchemaSequence();
                    methodSchemaType.setParticle(sequence);
                    generateSchemaForType(sequence, returnType, "return");
                }
            }
            // generateWrapperElements(methods);
        }
        return schemaMap.values();
    }

    private QName generateSchemaForType(XmlSchemaSequence sequence, JClass type, String partName) throws Exception {
        boolean isArrayType = type.isArrayType();
        if (isArrayType) {
            type = type.getArrayComponentType();
        }

        String classTypeName = type.getQualifiedName();

        QName schemaTypeName = typeTable.getSimpleSchemaTypeName(classTypeName);
        if (schemaTypeName == null) {
            schemaTypeName = schemaBuilder.generateSchema(type);
            addContentToMethodSchemaType(sequence, schemaTypeName, partName, type.isArrayType());
            addImportORInclude((XmlSchema)schemaMap.get(schemaTargetNameSpace), schemaTypeName);

        } else {
            addContentToMethodSchemaType(sequence, schemaTypeName, partName, type.isArrayType());
        }

        return schemaTypeName;
    }

    private void addContentToMethodSchemaType(XmlSchemaSequence sequence,
                                              QName schemaTypeName,
                                              String paraName,
                                              boolean isArray) {
        XmlSchemaElement elt1 = new XmlSchemaElement();
        elt1.setName(paraName);
        elt1.setSchemaTypeName(schemaTypeName);
        sequence.getItems().add(elt1);

        if (isArray) {
            elt1.setMaxOccurs(Long.MAX_VALUE);
            elt1.setMinOccurs(0);
        }
    }

    private XmlSchemaComplexType createSchemaTypeForMethodPart(String localPartName) {
        XmlSchema xmlSchema = (XmlSchema)schemaMap.get(schemaTargetNameSpace);
        QName elementName = new QName(this.schemaTargetNameSpace, localPartName, this.schema_namespace_prefix);
        XmlSchemaComplexType complexType = new XmlSchemaComplexType(xmlSchema);

        XmlSchemaElement globalElement = new XmlSchemaElement();
        globalElement.setSchemaType(complexType);
        globalElement.setName(formGlobalElementName(localPartName));
        globalElement.setQName(elementName);

        xmlSchema.getItems().add(globalElement);
        xmlSchema.getElements().add(elementName, globalElement);

        typeTable.addComplexSchemaType(this.schemaTargetNameSpace, globalElement.getName(), elementName);

        return complexType;
    }

    private String formGlobalElementName(String typeName) {
        String firstChar = typeName.substring(0, 1);
        return typeName.replaceFirst(firstChar, firstChar.toLowerCase());
    }

    public TuscanyTypeTable getTypeTable() {
        return typeTable;
    }

    public JMethod[] getMethods() {
        return methods;
    }

    private String generatePrefix() {
        return NAME_SPACE_PREFIX + prefixCount++;
    }

    public void setExcludeMethods(ArrayList excludeMethods) {
        this.excludeMethods = excludeMethods;
    }

    private void initializeSchemaMap(String targetNamespace, String targetNamespacePrefix) {
        XmlSchema xmlSchema = new XmlSchema(targetNamespace, xmlSchemaCollection);
        xmlSchema.setAttributeFormDefault(getAttrFormDefaultSetting());
        xmlSchema.setElementFormDefault(getElementFormDefaultSetting());

        targetNamespacePrefixMap.put(targetNamespace, targetNamespacePrefix);
        schemaMap.put(targetNamespace, xmlSchema);

        NamespaceMap prefixmap = new NamespaceMap();
        prefixmap.put(TuscanyTypeTable.XS_URI_PREFIX, TuscanyTypeTable.XML_SCHEMA_URI);
        prefixmap.put(targetNamespacePrefix, targetNamespace);
        xmlSchema.setNamespaceContext(prefixmap);
    }

    private void setFormDefaults() {

    }

    public Hashtable getSdoAnnoMap() {
        return sdoAnnoMap;
    }

    public void setSdoAnnoMap(Hashtable sdoAnnoMap) {
        this.sdoAnnoMap = sdoAnnoMap;
    }

    private void addImportORInclude(XmlSchema xmlSchema, QName schemaTypeName) {
        // decide whether there must be an import or an include
        if (xmlSchema.getTargetNamespace().equals(schemaTypeName.getNamespaceURI())) {
            XmlSchema containingSchema = (XmlSchema)schemaMap.get(schemaTypeName.getNamespaceURI());
            // if the type is not defined in the Schema then include
            if (containingSchema.getTypeByName(schemaTypeName) == null) {
                String schemaLocation = null;
                if ((schemaLocation = (String)schemaLocationMap.get(schemaTypeName.getNamespaceURI())) != null) {
                    schemaLocation = DEFAULT_SCHEMA_LOCATION;
                }

                XmlSchemaInclude includeElement = new XmlSchemaInclude();
                includeElement.setSchemaLocation(schemaLocation);

                if (!xmlSchema.getIncludes().contains(includeElement)) {
                    xmlSchema.getIncludes().add(includeElement);
                }
            }
        } else {
            if (!((NamespaceMap)xmlSchema.getNamespaceContext()).values().contains(schemaTypeName.getNamespaceURI())) {
                XmlSchemaImport importElement = new XmlSchemaImport();
                importElement.setNamespace(schemaTypeName.getNamespaceURI());
                xmlSchema.getItems().add(importElement);
                ((NamespaceMap)xmlSchema.getNamespaceContext()).put(generatePrefix(), schemaTypeName.getNamespaceURI());
            }
        }
    }

    private XmlSchemaForm getAttrFormDefaultSetting() {
        if (FORM_DEFAULT_UNQUALIFIED.equals(getAttrFormDefault())) {
            return new XmlSchemaForm(XmlSchemaForm.UNQUALIFIED);
        } else {
            return new XmlSchemaForm(XmlSchemaForm.QUALIFIED);
        }
    }

    private XmlSchemaForm getElementFormDefaultSetting() {
        if (FORM_DEFAULT_UNQUALIFIED.equals(getElementFormDefault())) {
            return new XmlSchemaForm(XmlSchemaForm.UNQUALIFIED);
        } else {
            return new XmlSchemaForm(XmlSchemaForm.QUALIFIED);
        }
    }

    public String getAttrFormDefault() {
        return attrFormDefault;
    }

    public void setAttrFormDefault(String attrFormDefault) {
        this.attrFormDefault = attrFormDefault;
    }

    public String getElementFormDefault() {
        return elementFormDefault;
    }

    public void setElementFormDefault(String elementFormDefault) {
        this.elementFormDefault = elementFormDefault;
    }
}