/*********************************************************************************
 * Copyright (c) 2022 Robert Bosch GmbH and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Robert Bosch GmbH - initial API and implementation
 ********************************************************************************
 */

package org.eclipse.app4mc.amalthea.converters300.impl;

import java.io.File;
import java.util.List;
import java.util.Map;

import org.eclipse.app4mc.amalthea.converters.common.ServiceConstants;
import org.eclipse.app4mc.amalthea.converters.common.base.ICache;
import org.eclipse.app4mc.amalthea.converters.common.base.IConverter;
import org.eclipse.app4mc.amalthea.converters.common.converter.AbstractConverter;
import org.eclipse.app4mc.amalthea.converters.common.utils.AmaltheaNamespaceRegistry;
import org.eclipse.app4mc.amalthea.converters.common.utils.HelperUtil;
import org.eclipse.app4mc.util.sessionlog.SessionLogger;
import org.jdom2.Attribute;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.Namespace;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;

@Component(
		property = {
			ServiceConstants.INPUT_MODEL_VERSION_PROPERTY + "=2.2.0",
			ServiceConstants.OUTPUT_MODEL_VERSION_PROPERTY + "=3.0.0"
		},
		service = IConverter.class)

public class DatatypeConverter extends AbstractConverter {

	private static final String ID = "id";
	private static final String NAME = "name";
	private static final String HREF = "href";
	private static final String TYPE = "type";
	private static final String TYPE_DEF = "typeDef";
	private static final String TYPE_DATA_TYPE_DEFINITION = "?type=DataTypeDefinition";
	private static final String DATA_TYPE = "dataType";

	@Reference
	SessionLogger logger;

	@Override
	@Activate
	protected void activate(Map<String, Object> properties) {
		super.activate(properties);
	}

	@Override
	public void convert(File targetFile, Map<File, Document> fileDocumentMapping, List<ICache> caches) {
		logger.info("Migration from {0} to {1} : Executing Datatype converter for model file : {2}",
				getInputModelVersion(), getOutputModelVersion(), targetFile.getName());

		basicConvert(targetFile, fileDocumentMapping);
	}

	private void basicConvert(File file, Map<File, Document> map) {
		// get document root
		final Document document = map.get(file);
		if (document == null) {
			return;
		}

		final Element rootElement = document.getRootElement();

		updateSoftwareDatatypes(rootElement);
		updateComponentDatatypes(rootElement);
	}

	private void updateSoftwareDatatypes(Element rootElement) {
		final Namespace am = AmaltheaNamespaceRegistry.getNamespace(getInputModelVersion(), "am");
		final Namespace xsi = AmaltheaNamespaceRegistry.getGenericNamespace("xsi");
		final Namespace xmi = AmaltheaNamespaceRegistry.getGenericNamespace("xmi");

		// get types of Labels and Channels

		final StringBuilder xpathBuilder = new StringBuilder();
		xpathBuilder.append("./swModel/labels/dataType");
		xpathBuilder.append("|");
		xpathBuilder.append("./swModel/channels/elementType");
		final List<Element> entries = HelperUtil.getXpathResult(rootElement, xpathBuilder.toString(), Element.class, am, xsi);

		if (entries == null) {
			return;
		}

		// Change types

		for (Element entry : entries) {
			Element parent = entry.getParentElement(); // Channel or Label

			Attribute typeAttr = entry.getAttribute(TYPE, xsi);
			if ("am:TypeRef".equals(typeAttr.getValue())) {

				// *** top level element is a type reference ***

				Attribute attribute = entry.getAttribute(TYPE_DEF);
				Element child = entry.getChild(TYPE_DEF);

				if (attribute != null ) {
					// handle local reference
					parent.setAttribute(entry.getName(), entry.getAttributeValue(TYPE_DEF));
					entry.detach();
				}

				if (child != null ) {
					// handle cross file reference
					typeAttr.setValue(child.getAttributeValue(TYPE, xsi));
					if (child.getAttribute(HREF) != null) {
						entry.setAttribute(child.getAttribute(HREF).clone());						
					}
					child.detach();
				}

				if (attribute == null && child == null) {
					// no valid reference
					entry.detach();
				}

			} else {

				// *** inline type definition ***

				String parentId = parent.getAttributeValue(ID, xmi);
				String parentIdWithoutType = parentId.substring(0, parentId.lastIndexOf("?type="));
				String parentName = parent.getAttributeValue(NAME);

				String parentType = parent.getName().replace("s", ""); // "label" or "channel"
				String postfix = " (migrated " + parentType + " type)";

				String genId = parentIdWithoutType + HelperUtil.encodeName(postfix) + TYPE_DATA_TYPE_DEFINITION;
				String genName = parentName + postfix;

				// refer to new datatype (local reference)
				parent.setAttribute(entry.getName(), genId);

				// create new datatype (in same file)
				Element newTypeDefinition = new Element("typeDefinitions");
				newTypeDefinition.setAttribute(TYPE, "am:DataTypeDefinition", xsi);
				newTypeDefinition.setAttribute(ID, genId, xmi);
				newTypeDefinition.setAttribute(NAME, genName);

				// set namespace according to parent element
				HelperUtil.copyElementAttributeOrElement(parent, newTypeDefinition, "namespace");

				// move local type definition to new datatype
				entry.detach();
				entry.setName(DATA_TYPE);                                                                                                                                                                                                                          
				newTypeDefinition.addContent(entry);

				// add new type to content tree
				rootElement.getChild("swModel").addContent(newTypeDefinition);
			}
		}
	}

	private void updateComponentDatatypes(Element rootElement) {
		final Namespace am = AmaltheaNamespaceRegistry.getNamespace(getInputModelVersion(), "am");
		final Namespace xsi = AmaltheaNamespaceRegistry.getGenericNamespace("xsi");

		// get types of Labels and Channels

		final StringBuilder xpathBuilder = new StringBuilder();
		xpathBuilder.append("./componentsModel/interfaces");
		xpathBuilder.append("|");
		xpathBuilder.append("./componentsModel/interfaces//subInterfaces");
		final List<Element> entries = HelperUtil.getXpathResult(rootElement, xpathBuilder.toString(), Element.class, am, xsi);

		if (entries == null) {
			return;
		}

		// Change element name from "datatype" to "dataType"

		for (Element entry : entries) {
			Attribute attribute = entry.getAttribute("datatype");
			if (attribute != null) {
				attribute.setName(DATA_TYPE);
			}

			Element child = entry.getChild("datatype");
			if (child != null) {
				child.setName(DATA_TYPE);
			}
		}
	}

}