/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.text.templates.persistence.TemplateReaderWriter;

import dwtx.jface.text.templates.persistence.TemplatePersistenceData; // packageimport
import dwtx.jface.text.templates.persistence.TemplatePersistenceMessages; // packageimport
import dwtx.jface.text.templates.persistence.TemplateStore; // packageimport


import dwt.dwthelper.utils;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import dwtx.dwtxhelper.Collection;


import java.util.MissingResourceException;
import java.util.ResourceBundle;


import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import dwtx.core.runtime.Assert;
import dwtx.jface.text.templates.Template;

/**
 * Serializes templates as character or byte stream and reads the same format
 * back.
 * <p>
 * Clients may instantiate this class, it is not intended to be
 * subclassed.</p>
 *
 * @since 3.0
 * @noextend This class is not intended to be subclassed by clients.
 */
public class TemplateReaderWriter {

    private static const String TEMPLATE_ROOT = "templates"; //$NON-NLS-1$
    private static const String TEMPLATE_ELEMENT = "template"; //$NON-NLS-1$
    private static const String NAME_ATTRIBUTE= "name"; //$NON-NLS-1$
    private static const String ID_ATTRIBUTE= "id"; //$NON-NLS-1$
    private static const String DESCRIPTION_ATTRIBUTE= "description"; //$NON-NLS-1$
    private static const String CONTEXT_ATTRIBUTE= "context"; //$NON-NLS-1$
    private static const String ENABLED_ATTRIBUTE= "enabled"; //$NON-NLS-1$
    private static const String DELETED_ATTRIBUTE= "deleted"; //$NON-NLS-1$
    /**
     * @since 3.1
     */
    private static const String AUTO_INSERTABLE_ATTRIBUTE= "autoinsert"; //$NON-NLS-1$

    /**
     * Create a new instance.
     */
    public this() {
    }

    /**
     * Reads templates from a reader and returns them. The reader must present
     * a serialized form as produced by the <code>save</code> method.
     *
     * @param reader the reader to read templates from
     * @return the read templates, encapsulated in instances of <code>TemplatePersistenceData</code>
     * @throws IOException if reading from the stream fails
     */
    public TemplatePersistenceData[] read(Reader reader)  {
        return read(reader, null);
    }

    /**
     * Reads the template with identifier <code>id</code> from a reader and
     * returns it. The reader must present a serialized form as produced by the
     * <code>save</code> method.
     *
     * @param reader the reader to read templates from
     * @param id the id of the template to return
     * @return the read template, encapsulated in an instances of
     *         <code>TemplatePersistenceData</code>
     * @throws IOException if reading from the stream fails
     * @since 3.1
     */
    public TemplatePersistenceData readSingle(Reader reader, String id)  {
        TemplatePersistenceData[] datas= read(new InputSource(reader), null, id);
        if (datas.length > 0)
            return datas[0];
        return null;
    }

    /**
     * Reads templates from a stream and adds them to the templates.
     *
     * @param reader the reader to read templates from
     * @param bundle a resource bundle to use for translating the read templates, or <code>null</code> if no translation should occur
     * @return the read templates, encapsulated in instances of <code>TemplatePersistenceData</code>
     * @throws IOException if reading from the stream fails
     */
    public TemplatePersistenceData[] read(Reader reader, ResourceBundle bundle)  {
        return read(new InputSource(reader), bundle, null);
    }

    /**
     * Reads templates from a stream and adds them to the templates.
     *
     * @param stream the byte stream to read templates from
     * @param bundle a resource bundle to use for translating the read templates, or <code>null</code> if no translation should occur
     * @return the read templates, encapsulated in instances of <code>TemplatePersistenceData</code>
     * @throws IOException if reading from the stream fails
     */
    public TemplatePersistenceData[] read(InputStream stream, ResourceBundle bundle)  {
        return read(new InputSource(stream), bundle, null);
    }

    /**
     * Reads templates from an <code>InputSource</code> and adds them to the templates.
     *
     * @param source the input source
     * @param bundle a resource bundle to use for translating the read templates, or <code>null</code> if no translation should occur
     * @param singleId the template id to extract, or <code>null</code> to read in all templates
     * @return the read templates, encapsulated in instances of <code>TemplatePersistenceData</code>
     * @throws IOException if reading from the stream fails
     */
    private TemplatePersistenceData[] read(InputSource source, ResourceBundle bundle, String singleId)  {
        try {
            Collection templates= new ArrayList();
            Set ids= new HashSet();

            DocumentBuilderFactory factory= DocumentBuilderFactory.newInstance();
            DocumentBuilder parser= factory.newDocumentBuilder();
            Document document= parser.parse(source);

            NodeList elements= document.getElementsByTagName(TEMPLATE_ELEMENT);

            int count= elements.getLength();
            for (int i= 0; i !is count; i++) {
                Node node= elements.item(i);
                NamedNodeMap attributes= node.getAttributes();

                if (attributes is null)
                    continue;

                String id= getStringValue(attributes, ID_ATTRIBUTE, null);
                if (id !is null && ids.contains(id))
                    throw new IOException(TemplatePersistenceMessages.getString("TemplateReaderWriter.duplicate.id")); //$NON-NLS-1$

                if (singleId !is null && !singleId.equals(id))
                    continue;

                bool deleted = getBooleanValue(attributes, DELETED_ATTRIBUTE, false);

                String name= getStringValue(attributes, NAME_ATTRIBUTE);
                name= translateString(name, bundle);

                String description= getStringValue(attributes, DESCRIPTION_ATTRIBUTE, ""); //$NON-NLS-1$
                description= translateString(description, bundle);

                String context= getStringValue(attributes, CONTEXT_ATTRIBUTE);

                if (name is null || context is null)
                    throw new IOException(TemplatePersistenceMessages.getString("TemplateReaderWriter.error.missing_attribute")); //$NON-NLS-1$

                bool enabled = getBooleanValue(attributes, ENABLED_ATTRIBUTE, true);
                bool autoInsertable= getBooleanValue(attributes, AUTO_INSERTABLE_ATTRIBUTE, true);

                StringBuffer buffer= new StringBuffer();
                NodeList children= node.getChildNodes();
                for (int j= 0; j !is children.getLength(); j++) {
                    String value= children.item(j).getNodeValue();
                    if (value !is null)
                        buffer.append(value);
                }
                String pattern= buffer.toString();
                pattern= translateString(pattern, bundle);

                Template template_= new Template(name, description, context, pattern, autoInsertable);
                TemplatePersistenceData data= new TemplatePersistenceData(template_, enabled, id);
                data.setDeleted(deleted);

                templates.add(data);

                if (singleId !is null && singleId.equals(id))
                    break;
            }

            return (TemplatePersistenceData[]) templates.toArray(new TemplatePersistenceData[templates.size()]);

        } catch (ParserConfigurationException e) {
            Assert.isTrue(false);
        } catch (SAXException e) {
            Throwable t= e.getCause();
            if ( cast(IOException)t )
                throw cast(IOException) t;
            else if (t !is null)
                throw new IOException(t.getMessage());
            else
                throw new IOException(e.getMessage());
        }

        return null; // dummy
    }

    /**
     * Saves the templates as XML, encoded as UTF-8 onto the given byte stream.
     *
     * @param templates the templates to save
     * @param stream the byte output to write the templates to in XML
     * @throws IOException if writing the templates fails
     */
    public void save(TemplatePersistenceData[] templates, OutputStream stream)  {
        save(templates, new StreamResult(stream));
    }

    /**
     * Saves the templates as XML.
     *
     * @param templates the templates to save
     * @param writer the writer to write the templates to in XML
     * @throws IOException if writing the templates fails
     */
    public void save(TemplatePersistenceData[] templates, Writer writer)  {
        save(templates, new StreamResult(writer));
    }

    /**
     * Saves the templates as XML.
     *
     * @param templates the templates to save
     * @param result the stream result to write to
     * @throws IOException if writing the templates fails
     */
    private void save(TemplatePersistenceData[] templates, StreamResult result)  {
        try {
            DocumentBuilderFactory factory= DocumentBuilderFactory.newInstance();
            DocumentBuilder builder= factory.newDocumentBuilder();
            Document document= builder.newDocument();

            Node root= document.createElement(TEMPLATE_ROOT);
            document.appendChild(root);

            for (int i= 0; i < templates.length; i++) {
                TemplatePersistenceData data= templates[i];
                Template template_= data.getTemplate();

                Node node= document.createElement(TEMPLATE_ELEMENT);
                root.appendChild(node);

                NamedNodeMap attributes= node.getAttributes();

                String id= data.getId();
                if (id !is null) {
                    Attr idAttr= document.createAttribute(ID_ATTRIBUTE);
                    idAttr.setValue(id);
                    attributes.setNamedItem(idAttr);
                }

                if (template_ !is null) {
                    Attr name= document.createAttribute(NAME_ATTRIBUTE);
                    name.setValue(template_.getName());
                    attributes.setNamedItem(name);
                }

                if (template_ !is null) {
                    Attr description= document.createAttribute(DESCRIPTION_ATTRIBUTE);
                    description.setValue(template_.getDescription());
                    attributes.setNamedItem(description);
                }

                if (template_ !is null) {
                    Attr context= document.createAttribute(CONTEXT_ATTRIBUTE);
                    context.setValue(template_.getContextTypeId());
                    attributes.setNamedItem(context);
                }

                Attr enabled= document.createAttribute(ENABLED_ATTRIBUTE);
                enabled.setValue(data.isEnabled() ? Boolean.toString(true) : Boolean.toString(false));
                attributes.setNamedItem(enabled);

                Attr deleted= document.createAttribute(DELETED_ATTRIBUTE);
                deleted.setValue(data.isDeleted() ? Boolean.toString(true) : Boolean.toString(false));
                attributes.setNamedItem(deleted);

                if (template_ !is null) {
                    Attr autoInsertable= document.createAttribute(AUTO_INSERTABLE_ATTRIBUTE);
                    autoInsertable.setValue(template_.isAutoInsertable() ? Boolean.toString(true) : Boolean.toString(false));
                    attributes.setNamedItem(autoInsertable);
                }

                if (template_ !is null) {
                    Text pattern= document.createTextNode(template_.getPattern());
                    node.appendChild(pattern);
                }
            }


            Transformer transformer=TransformerFactory.newInstance().newTransformer();
            transformer.setOutputProperty(OutputKeys.METHOD, "xml"); //$NON-NLS-1$
            transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
            DOMSource source = new DOMSource(document);

            transformer.transform(source, result);

        } catch (ParserConfigurationException e) {
            Assert.isTrue(false);
        } catch (TransformerException e) {
            if (cast(IOException)e.getException() )
                throw cast(IOException) e.getException();
            Assert.isTrue(false);
        }
    }

    private bool getBooleanValue(NamedNodeMap attributes, String attribute, bool defaultValue)  {
        Node enabledNode= attributes.getNamedItem(attribute);
        if (enabledNode is null)
            return defaultValue;
        else if (enabledNode.getNodeValue().equals(Boolean.toString(true)))
            return true;
        else if (enabledNode.getNodeValue().equals(Boolean.toString(false)))
            return false;
        else
            throw new SAXException(TemplatePersistenceMessages.getString("TemplateReaderWriter.error.illegal_boolean_attribute")); //$NON-NLS-1$
    }

    private String getStringValue(NamedNodeMap attributes, String name)  {
        String val= getStringValue(attributes, name, null);
        if (val is null)
            throw new SAXException(TemplatePersistenceMessages.getString("TemplateReaderWriter.error.missing_attribute")); //$NON-NLS-1$
        return val;
    }

    private String getStringValue(NamedNodeMap attributes, String name, String defaultValue) {
        Node node= attributes.getNamedItem(name);
        return node is null ? defaultValue : node.getNodeValue();
    }

    private String translateString(String str, ResourceBundle bundle) {
        if (bundle is null)
            return str;

        int idx= str.indexOf('%');
        if (idx is -1) {
            return str;
        }
        StringBuffer buf= new StringBuffer();
        int k= 0;
        while (idx !is -1) {
            buf.append(str.substring(k, idx));
            for (k= idx + 1; k < str.length() && !Character.isWhitespace(str.charAt(k)); k++) {
                // loop
            }
            String key= str.substring(idx + 1, k);
            buf.append(getBundleString(key, bundle));
            idx= str.indexOf('%', k);
        }
        buf.append(str.substring(k));
        return buf.toString();
    }

    private String getBundleString(String key, ResourceBundle bundle) {
        if (bundle !is null) {
            try {
                return bundle.getString(key);
            } catch (MissingResourceException e) {
                return '!' + key + '!';
            }
        }
        return TemplatePersistenceMessages.getString(key); // default messages
    }
}