/*
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed 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.jbpm.bpmn2.xml;

import java.util.HashSet;
import java.util.List;
import java.util.Map;

import org.drools.core.xml.BaseAbstractHandler;
import org.drools.core.xml.ExtensibleXmlParser;
import org.drools.core.xml.Handler;
import org.jbpm.bpmn2.core.Definitions;
import org.jbpm.bpmn2.core.Interface;
import org.jbpm.bpmn2.core.Interface.Operation;
import org.jbpm.bpmn2.core.ItemDefinition;
import org.jbpm.compiler.xml.ProcessBuildData;
import org.jbpm.process.core.ContextContainer;
import org.jbpm.process.core.context.variable.Variable;
import org.jbpm.process.core.context.variable.VariableScope;
import org.jbpm.process.core.datatype.DataType;
import org.jbpm.process.core.datatype.impl.type.BooleanDataType;
import org.jbpm.process.core.datatype.impl.type.FloatDataType;
import org.jbpm.process.core.datatype.impl.type.IntegerDataType;
import org.jbpm.process.core.datatype.impl.type.ObjectDataType;
import org.jbpm.process.core.datatype.impl.type.StringDataType;
import org.jbpm.process.core.datatype.impl.type.UndefinedDataType;
import org.jbpm.ruleflow.core.RuleFlowProcess;
import org.jbpm.workflow.core.NodeContainer;
import org.jbpm.workflow.core.node.ForEachNode;
import org.jbpm.workflow.core.node.WorkItemNode;
import org.kie.api.definition.process.Node;
import org.kie.api.definition.process.Process;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

public class DefinitionsHandler extends BaseAbstractHandler implements Handler {

    @SuppressWarnings("unchecked")
    public DefinitionsHandler() {
        if ((this.validParents == null) && (this.validPeers == null)) {
            this.validParents = new HashSet();
            this.validParents.add(null);

            this.validPeers = new HashSet();
            this.validPeers.add(null);

            this.allowNesting = false;
        }
    }

    public Object start(final String uri, final String localName,
            final Attributes attrs, final ExtensibleXmlParser parser)
            throws SAXException {
        parser.startElementBuilder(localName, attrs);
        return new Definitions();
    }

    public Object end(final String uri, final String localName,
            final ExtensibleXmlParser parser) throws SAXException {
        final Element element = parser.endElementBuilder();
        Definitions definitions = (Definitions) parser.getCurrent();
        String namespace = element.getAttribute("targetNamespace");
        List<Process> processes = ((ProcessBuildData) parser.getData()).getProcesses();
        Map<String, ItemDefinition> itemDefinitions = (Map<String, ItemDefinition>) ((ProcessBuildData) parser.getData()).getMetaData("ItemDefinitions");

        List<Interface> interfaces = (List<Interface>) ((ProcessBuildData) parser.getData()).getMetaData("Interfaces");

        for (Process process : processes) {
            RuleFlowProcess ruleFlowProcess = (RuleFlowProcess) process;
            ruleFlowProcess.setMetaData("TargetNamespace", namespace);
            postProcessItemDefinitions(ruleFlowProcess, itemDefinitions, parser.getClassLoader());
            postProcessInterfaces(ruleFlowProcess, interfaces);
        }
        definitions.setTargetNamespace(namespace);
        return definitions;
    }

    public Class<?> generateNodeFor() {
        return Definitions.class;
    }

    private void postProcessInterfaces(NodeContainer nodeContainer, List<Interface> interfaces) {

        for (Node node : nodeContainer.getNodes()) {
            if (node instanceof NodeContainer) {
                postProcessInterfaces((NodeContainer) node, interfaces);
            }
            if (node instanceof WorkItemNode && "Service Task".equals(((WorkItemNode) node).getMetaData("Type"))) {
                WorkItemNode workItemNode = (WorkItemNode) node;
                if (interfaces == null) {
                    throw new IllegalArgumentException("No interfaces found");
                }
                String operationRef = (String) workItemNode.getMetaData("OperationRef");
                String implementation = (String) workItemNode.getMetaData("Implementation");
                Operation operation = null;
                for (Interface i : interfaces) {
                    operation = i.getOperation(operationRef);
                    if (operation != null) {
                        break;
                    }
                }
                if (operation == null) {
                    throw new IllegalArgumentException("Could not find operation " + operationRef);
                }
                // avoid overriding parameters set by data input associations
                if (workItemNode.getWork().getParameter("Interface") == null) {
                    workItemNode.getWork().setParameter("Interface", operation.getInterface().getName());
                }
                if (workItemNode.getWork().getParameter("Operation") == null) {
                    workItemNode.getWork().setParameter("Operation", operation.getName());
                }
                if (workItemNode.getWork().getParameter("ParameterType") == null && operation.getMessage() != null) {
                    workItemNode.getWork().setParameter("ParameterType", operation.getMessage().getType());
                }
                // parameters to support web service invocation 
                if (implementation != null) {
                    workItemNode.getWork().setParameter("interfaceImplementationRef", operation.getInterface().getImplementationRef());
                    workItemNode.getWork().setParameter("operationImplementationRef", operation.getImplementationRef());
                    workItemNode.getWork().setParameter("implementation", implementation);
                }
            }
        }
    }

    private void postProcessItemDefinitions(NodeContainer nodeContainer, Map<String, ItemDefinition> itemDefinitions, ClassLoader cl) {
        if (nodeContainer instanceof ContextContainer) {
            setVariablesDataType((ContextContainer) nodeContainer, itemDefinitions, cl);
        }
        // process composite context node of for each to enhance its variables with types
        if (nodeContainer instanceof ForEachNode) {
            setVariablesDataType(((ForEachNode) nodeContainer).getCompositeNode(), itemDefinitions, cl);
        }
        for (Node node : nodeContainer.getNodes()) {
            if (node instanceof NodeContainer) {
                postProcessItemDefinitions((NodeContainer) node, itemDefinitions, cl);
            }
            if (node instanceof ContextContainer) {
                setVariablesDataType((ContextContainer) node, itemDefinitions, cl);
            }
        }
    }

    private void setVariablesDataType(ContextContainer container, Map<String, ItemDefinition> itemDefinitions, ClassLoader cl) {
        VariableScope variableScope = (VariableScope) container.getDefaultContext(VariableScope.VARIABLE_SCOPE);
        if (variableScope != null) {
            for (Variable variable : variableScope.getVariables()) {
                setVariableDataType(variable, itemDefinitions, cl);
            }
        }
    }

    private void setVariableDataType(Variable variable, Map<String, ItemDefinition> itemDefinitions, ClassLoader cl) {
        // retrieve type from item definition

        String itemSubjectRef = (String) variable.getMetaData("ItemSubjectRef");
        if (UndefinedDataType.getInstance().equals(variable.getType()) && itemDefinitions != null && itemSubjectRef != null) {
            DataType dataType = new ObjectDataType();
            ItemDefinition itemDefinition = itemDefinitions.get(itemSubjectRef);
            if (itemDefinition != null) {
                String structureRef = itemDefinition.getStructureRef();

                if ("java.lang.Boolean".equals(structureRef) || "Boolean".equals(structureRef)) {
                    dataType = new BooleanDataType();

                } else if ("java.lang.Integer".equals(structureRef) || "Integer".equals(structureRef)) {
                    dataType = new IntegerDataType();

                } else if ("java.lang.Float".equals(structureRef) || "Float".equals(structureRef)) {
                    dataType = new FloatDataType();

                } else if ("java.lang.String".equals(structureRef) || "String".equals(structureRef)) {
                    dataType = new StringDataType();

                } else if ("java.lang.Object".equals(structureRef) || "Object".equals(structureRef)) {
                    // use FQCN of Object
                    dataType = new ObjectDataType("java.lang.Object");

                } else {
                    dataType = new ObjectDataType(structureRef, cl);
                }

            }
            variable.setType(dataType);
        }
    }

}
