/*******************************************************************************
 * Copyright (c) 2011, 2013 Formal Mind GmbH and University of Dusseldorf.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Michael Jastram - initial API and implementation
 ******************************************************************************/
package org.eclipse.rmf.reqif10.pror.util;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.eclipse.emf.common.command.CompoundCommand;
import org.eclipse.emf.common.notify.AdapterFactory;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.emf.edit.command.AddCommand;
import org.eclipse.emf.edit.command.SetCommand;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.emf.edit.provider.ItemProviderAdapter;
import org.eclipse.rmf.reqif10.AttributeDefinition;
import org.eclipse.rmf.reqif10.AttributeValue;
import org.eclipse.rmf.reqif10.AttributeValueEnumeration;
import org.eclipse.rmf.reqif10.AttributeValueXHTML;
import org.eclipse.rmf.reqif10.DatatypeDefinition;
import org.eclipse.rmf.reqif10.EnumValue;
import org.eclipse.rmf.reqif10.ReqIF;
import org.eclipse.rmf.reqif10.SpecElementWithAttributes;
import org.eclipse.rmf.reqif10.SpecHierarchy;
import org.eclipse.rmf.reqif10.SpecObjectType;
import org.eclipse.rmf.reqif10.SpecType;
import org.eclipse.rmf.reqif10.Specification;
import org.eclipse.rmf.reqif10.XhtmlContent;
import org.eclipse.rmf.reqif10.common.util.ProrXhtmlSimplifiedHelper;
import org.eclipse.rmf.reqif10.common.util.ReqIF10Util;
import org.eclipse.rmf.reqif10.common.util.ReqIFToolExtensionUtil;
import org.eclipse.rmf.reqif10.pror.configuration.Column;
import org.eclipse.rmf.reqif10.pror.configuration.ConfigurationFactory;
import org.eclipse.rmf.reqif10.pror.configuration.ConfigurationPackage;
import org.eclipse.rmf.reqif10.pror.configuration.LabelConfiguration;
import org.eclipse.rmf.reqif10.pror.configuration.ProrGeneralConfiguration;
import org.eclipse.rmf.reqif10.pror.configuration.ProrPresentationConfiguration;
import org.eclipse.rmf.reqif10.pror.configuration.ProrPresentationConfigurations;
import org.eclipse.rmf.reqif10.pror.configuration.ProrSpecViewConfiguration;
import org.eclipse.rmf.reqif10.pror.configuration.ProrToolExtension;
import org.eclipse.rmf.reqif10.util.ReqIF10Switch;

public class ConfigurationUtil {

	public static final String DEFAULT_LEFT_HEADER_COLUMN_NAME = "Lead Header Column";
	public static final int DEFAULT_LEFT_HEADER_COLUMN_WIDTH = 30;

	/**
	 * @return The Configuration element for the given
	 *         {@link DatatypeDefinition} or null if none is configured.
	 */
	public static ProrPresentationConfiguration getPresentationConfiguration(
			DatatypeDefinition dd) {
		ReqIF reqif = ReqIF10Util.getReqIF(dd);
		if (reqif == null)
			return null;
		ProrToolExtension prorToolExtension = getProrToolExtension(reqif);
		if (prorToolExtension == null)
			return null;
		ProrPresentationConfigurations extensions = prorToolExtension
				.getPresentationConfigurations();
		if (extensions == null)
			return null;
		for (ProrPresentationConfiguration config : extensions
				.getPresentationConfigurations()) {
			if (dd.equals(config.getDatatype()))
				return config;
		}
		return null;
	}

	/**
	 * Returns the {@link ProrPresentationConfiguration} that is associated with
	 * the {@link DatatypeDefinition} of the given {@link AttributeValue}. If
	 * either intermediate element is null, null is returned.
	 */
	public static ProrPresentationConfiguration getPresentationConfiguration(
			AttributeValue av) {
		DatatypeDefinition dd = ReqIF10Util.getDatatypeDefinition(av);
		if (av != null) {
			return getPresentationConfiguration(dd);
		}
		return null;
	}

	/**
	 * Returns the {@link ProrToolExtension} associated with this {@link ReqIF}.
	 * If it doesn't exist yet, null is returned.
	 * <p>
	 */
	public static ProrToolExtension getProrToolExtension(ReqIF reqif) {
		if (reqif != null) {
			List<ProrToolExtension> extensions = ReqIFToolExtensionUtil
					.getToolExtensionsByType(reqif,
							ConfigurationPackage.eINSTANCE
									.getProrToolExtension());
			if (0 < extensions.size()) {
				return extensions.get(0);
			}
		}
		return null;
	}

	/**
	 * Returns the {@link ProrToolExtension} associated with this {@link ReqIF}.
	 * If it doesn't exist yet, it is created.
	 * <p>
	 */
	public static ProrToolExtension createProrToolExtension(ReqIF reqif,
			EditingDomain domain) {
		ProrToolExtension extension = getProrToolExtension(reqif);
		if (null == extension) {
			extension = ConfigurationFactory.eINSTANCE
					.createProrToolExtension();
			domain.getCommandStack().execute(
					ReqIFToolExtensionUtil.getAddToolExtensionCommand(reqif,
							extension));
		}
		return extension;
	}

	/**
	 * Returns the left header {@link Column} (which shows the hierarchy level)
	 * associated with this {@link Specification}. If it doesn't exist yet, it
	 * is created.
	 */
	public static Column getLeftHeaderColumn(Specification specification,
			EditingDomain domain) {

		ProrSpecViewConfiguration specViewConfiguration = createSpecViewConfiguration(
				specification, domain);

		Column leftHeaderColumn = specViewConfiguration.getLeftHeaderColumn();

		if (leftHeaderColumn == null) {
			leftHeaderColumn = ConfigurationFactory.eINSTANCE.createColumn();
			leftHeaderColumn.setLabel(DEFAULT_LEFT_HEADER_COLUMN_NAME);
			leftHeaderColumn.setWidth(DEFAULT_LEFT_HEADER_COLUMN_WIDTH);
			specViewConfiguration.setLeftHeaderColumn(leftHeaderColumn);
		}

		return leftHeaderColumn;

	}

	/**
	 * Retrieves all active {@link PresentationEditInterface} instances for the
	 * given object (which assumes to be part of a ReqIF model). If none is
	 * found, an empty set is returned.
	 */
	public static Set<PresentationEditInterface> getPresentationEditInterfaces(
			Object obj, AdapterFactory adapterFactory) {
		ReqIF reqif = ReqIF10Util.getReqIF(obj);
		ProrPresentationConfigurations configs = getPresentationConfigurations(reqif);
		if (configs != null) {
			Set<PresentationEditInterface> result = new HashSet<PresentationEditInterface>();
			for (ProrPresentationConfiguration config : configs
					.getPresentationConfigurations()) {
				ItemProviderAdapter ip = ProrUtil.getItemProvider(
						adapterFactory, config);
				if (ip instanceof PresentationEditInterface) {
					result.add((PresentationEditInterface) ip);
				}
			}
			return result;
		}
		return Collections.emptySet();
	}

	/**
	 * Finds the best labels, according to what is set in the preferences.
	 * 
	 * @param specElement
	 * @param adapterFactory
	 * @param adapterFactory
	 * @return
	 */
	public static String getSpecElementLabel(
			SpecElementWithAttributes specElement, AdapterFactory adapterFactory) {

		List<String> labels = getDefaultLabels(ReqIF10Util
				.getReqIF(specElement));

		// Iterate over the list of labels requested
		for (String label : labels) {

			for (AttributeValue value : specElement.getValues()) {
				AttributeDefinition ad = ReqIF10Util
						.getAttributeDefinition(value);
				if (ad == null)
					continue;

				if (label.equals(ad.getLongName())) {
					ProrPresentationConfiguration config = getPresentationConfig(value);

					ItemProviderAdapter ip = ProrUtil.getItemProvider(
							adapterFactory, config);
					if (ip instanceof PresentationEditInterface) {
						String customLabel = ((PresentationEditInterface) ip)
								.getLabel(value);
						if (customLabel != null)
							return customLabel;
					}

					Object result = ReqIF10Util.getTheValue(value);
					if (result != null) {

						// If we have an enumeration attribute
						if (value instanceof AttributeValueEnumeration
								&& result instanceof EList) {
							EList<?> list = (EList<?>) result;
							if (!list.isEmpty())
								return ((EnumValue) list.get(0)).getLongName();
							else
								return "";
						} else if (value instanceof AttributeValueXHTML
								&& result instanceof XhtmlContent) {
							XhtmlContent content = (XhtmlContent) result;
							String text = ProrXhtmlSimplifiedHelper
									.xhtmlToSimplifiedString(content);

							// Ignore empty XHTML
							if (text.trim().length() == 0) {
								continue;
							}

							// Shorten long XHTML
							if (text.length() > 20)
								text = text.substring(0, 17) + "...";
							return text;
						}
						return result.toString();

					}
				}
			}
		}
		return specElement.getIdentifier();
	}

	/**
	 * Returns the list of default Label names.
	 * 
	 * @return always a list, sometimes empty.
	 */
	public static List<String> getDefaultLabels(ReqIF reqif) {
		ProrToolExtension extension = getProrToolExtension(reqif);
		if (extension == null) {
			return Collections.emptyList();
		}
		ProrGeneralConfiguration generalConfig = extension
				.getGeneralConfiguration();
		if (generalConfig == null) {
			return Collections.emptyList();
		}

		LabelConfiguration labelConfig = generalConfig.getLabelConfiguration();
		if (labelConfig == null) {
			return Collections.emptyList();
		}

		return labelConfig.getDefaultLabel();
	}

	/**
	 * Retrieves the {@link ProrSpecViewConfiguration} for the given
	 * {@link Specification}. If none exists, it is built. The builder collects
	 * all attribute names of all SpecObjects and creates corresponding columns.
	 */
	public static ProrSpecViewConfiguration createSpecViewConfiguration(
			Specification specification, EditingDomain domain) {
		ProrToolExtension extension = createProrToolExtension(ReqIF10Util.getReqIF(specification), domain);
	
		EList<ProrSpecViewConfiguration> configs = extension
				.getSpecViewConfigurations();
		for (ProrSpecViewConfiguration config : configs) {
			if (config.getSpecification() != null
					&& config.getSpecification().equals(specification)) {
				return config;
			}
		}

		// None found, let's build a new one that includes all attribute names.
		ProrSpecViewConfiguration specViewConfig = ConfigurationFactory.eINSTANCE
				.createProrSpecViewConfiguration();
		specViewConfig.setSpecification(specification);

		// Collect all Types
		
		final List<SpecType> types = new ArrayList<SpecType>();
		ReqIF10Switch<SpecHierarchy> visitor = new ReqIF10Switch<SpecHierarchy>() {
			@Override
			public SpecHierarchy caseSpecHierarchy(SpecHierarchy specHierarchy) {
				if (specHierarchy.getObject() != null) {
					SpecObjectType type = specHierarchy.getObject().getType();
					if (type != null && !types.contains(type)) {
						types.add(type);
					}
				}
				return specHierarchy;
			}
		};
		int counter = 0;
		for (Iterator<EObject> i = EcoreUtil
				.getAllContents(specification, true); i.hasNext();) {
			visitor.doSwitch(i.next());
			// we only explore the first 50 elements for performance.
			if (counter++ == 50)
				break;
		}

		
		// Collect all names from the types.  We use a list to maintain order.
		final List<String> colNames = new ArrayList<String>();
		for (SpecType type : types) {
			for (AttributeDefinition ad : type.getSpecAttributes()) {
				
				String colName = ad.getLongName();
				if (colName != null && !colNames.contains(colName)) {
					colNames.add(ad.getLongName());
				}
			}
		}
		

		// Build all Columns from the names
		boolean unifiedColumn = false;
		for (String colName : colNames) {
			Column column = ConfigurationFactory.eINSTANCE.createColumn();

			// See whether we need a unified column or not.
			if (colName.equals("ReqIF.Text") || colName.equals("ReqIF.ChapterName")) {
				if (unifiedColumn) continue;
				column = ConfigurationFactory.eINSTANCE.createUnifiedColumn();
				colName = "Main";
				unifiedColumn = true;
			}
			
			column.setWidth(100);
			column.setLabel(colName);
			specViewConfig.getColumns().add(column);
		}
		domain.getCommandStack()
				.execute(
						AddCommand
								.create(domain,
										extension,
										ConfigurationPackage.Literals.PROR_TOOL_EXTENSION__SPEC_VIEW_CONFIGURATIONS,
										specViewConfig));

		return specViewConfig;

	}

	public static ProrPresentationConfiguration getPresentationConfig(
			AttributeValue value) {
		DatatypeDefinition dd = ReqIF10Util.getDatatypeDefinition(value);
		ProrPresentationConfiguration config = getPresentationConfiguration(dd);
		return config;
	}

	/**
	 * @return the {@link ProrPresentationConfigurations} for the given
	 *         {@link ReqIf} and {@link EditingDomain}.
	 */
	public static ProrPresentationConfigurations getPresentationConfigurations(
			ReqIF reqif) {
		ProrToolExtension uiExtension = ConfigurationUtil
				.getProrToolExtension(reqif);
		return uiExtension == null ? null : uiExtension
				.getPresentationConfigurations();
	}

	/**
	 * If a ReqIF has no labels yet, this method configures some smart defaults.
	 */
	public static void setDefaultLabelsIfNecessary(
			AdapterFactory adapterFactory, EditingDomain editingDomain,
			ReqIF reqif) {
		CompoundCommand cmd = new CompoundCommand();

		ProrToolExtension extension = createProrToolExtension(reqif,
				editingDomain);
		ProrGeneralConfiguration generalConfig = extension
				.getGeneralConfiguration();
		if (generalConfig == null) {
			generalConfig = ConfigurationFactory.eINSTANCE
					.createProrGeneralConfiguration();
			cmd.append(SetCommand
					.create(editingDomain,
							extension,
							ConfigurationPackage.Literals.PROR_TOOL_EXTENSION__GENERAL_CONFIGURATION,
							generalConfig));
		}
		LabelConfiguration labelConfig = generalConfig.getLabelConfiguration();
		if (labelConfig == null) {
			labelConfig = ConfigurationFactory.eINSTANCE
					.createLabelConfiguration();
			cmd.append(SetCommand
					.create(editingDomain,
							generalConfig,
							ConfigurationPackage.Literals.PROR_GENERAL_CONFIGURATION__LABEL_CONFIGURATION,
							labelConfig));
		} else {
			// If there is already a label configuration, we leave it alone.
			return;
		}
		labelConfig.getDefaultLabel().add("ReqIF.ChapterNumber");
		labelConfig.getDefaultLabel().add("ReqIF.ChapterName");
		labelConfig.getDefaultLabel().add("ReqIF.Name");
		labelConfig.getDefaultLabel().add("ReqIF.Text");
		labelConfig.getDefaultLabel().add("ID");
		labelConfig.getDefaultLabel().add("Name");
		labelConfig.getDefaultLabel().add("Description");

		editingDomain.getCommandStack().execute(cmd);
	}

}