/*
 * [Configure.java]
 *
 * Summary: Configure HtmlReflow from htmlreflowconfig.xml config file and put configuration in persisted store.
 *
 * Copyright: (c) 2006-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2010-01-17 initial release.
 */
package com.mindprod.htmlreflow;

import com.mindprod.common18.Misc;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;
import java.io.File;

import static java.lang.System.*;

/**
 * Configure HtmlReflow from htmlreflowconfig.xml config file and put configuration in persisted store.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2010-01-17 initial release.
 * @since 2010-01-17
 */
class Configure
    {
    /**
     * desired maxLineLength
     */
    private static final int DESIRED_LINE_LENGTH_DEFAULT = 140;

    /**
     * default maxLineLength
     */
    private static final int MAX_LINE_LENGTH_DEFAULT = 200;

    /**
     * extract an boolean value from the XML attributes, default yes
     *
     * @param attributes    attributes for the tag
     * @param attributeName name of the attribute
     *
     * @return true or false
     */
    private static boolean extractBooleanAttributeDefaultYes( final NamedNodeMap attributes, String attributeName )
        {
        final Node node = attributes.getNamedItem( attributeName );
        if ( node == null )
            {
            // XSD default does not supply value for missing attribute.
            return true;
            }
        return Misc.parseBoolean( node.getNodeValue(), false );
        }

    /**
     * extract an int value from the XML attributes, default 0
     *
     * @param attributes    attributes for the tag
     * @param attributeName name of the attribute
     * @param defaultValue  default if attribute not specified
     *
     * @return numeric value
     */
    private static int extractIntAttribute( final NamedNodeMap attributes, String attributeName, int defaultValue )
        {
        final Node node = attributes.getNamedItem( attributeName );
        if ( node == null )
            {
            // XSD default does not supply value for missing attribute.
            return defaultValue;
            }
        final String value = node.getNodeValue();
        if ( value == null )
            {
            // XSD default does not supply 0 automatically.
            return defaultValue;
            }
        try
            {
            return Integer.parseInt( value );
            }
        catch ( NumberFormatException e )
            {
            return defaultValue;
            }
        }

    /**
     * extract an enum value from the XML attributes for lineSeparator
     *
     * @param attributes    attributes for the tag
     * @param attributeName name of the attribute
     *
     * @return numeric value
     */
    private static String extractLineSeparatorAttribute( final NamedNodeMap attributes, String attributeName )
        {
        final Node node = attributes.getNamedItem( attributeName );
        if ( node == null )
            {
            // XSD default does not supply value for missing attribute.
            return System.getProperty( "line.separator" );
            }
        final String value = node.getNodeValue();
        if ( value == null || value.equals( "system" ) )
            {
            // XSD default does not supply 0 automatically.
            return System.getProperty( "line.separator" );
            }
        if ( value.equalsIgnoreCase( "Windows" ) )
            {
            return "\r\n";
            }
        if ( value.equalsIgnoreCase( "Unix" ) )
            {
            return "\n";
            }
        if ( value.equalsIgnoreCase( "Mac" ) )
            {
            return "\r";
            }
        return System.getProperty( "line.separator" );
        }

    /**
     * extract an enum NLs value from the XML attributes, default 0
     *
     * @param attributes    attributes for the tag
     * @param attributeName name of the attribute
     *
     * @return numeric value
     */
    private static int extractNlCountAttribute( final NamedNodeMap attributes, String attributeName )
        {
        final Node node = attributes.getNamedItem( attributeName );
        if ( node == null )
            {
            // XSD default does not supply value for missing attribute.
            return 0;
            }
        final String value = node.getNodeValue();
        if ( value == null || value.equalsIgnoreCase( "inline" ) )
            {
            return 0;
            }
        if ( value.equalsIgnoreCase( "newline" ) )
            {
            return 1;
            }
        if ( value.equalsIgnoreCase( "blankline" ) )
            {
            return 2;
            }
        return 0;
        }

    /**
     * extract an String value from the XML attributes, default ""
     *
     * @param attributes    attributes for the tag
     * @param attributeName name of the attribute
     *
     * @return numeric value
     */
    private static String extractStringAttribute( final NamedNodeMap attributes, String attributeName )
        {
        final Node node = attributes.getNamedItem( attributeName );
        if ( node == null )
            {
            // XSD default does not supply value for missing attribute.
            return "";
            }
        final String value = node.getNodeValue();
        if ( value == null )
            {
            // XSD default does not supply default automatically.
            return "";
            }
        return value;
        }

    /**
     * validate htmlreflow.xml configuration file with htmlreflow.xsd schema.
     * Current directory must contain htmlreflow.xsd and htmlreflow.xml
     *
     * @param args not used
     */
    public static void main( String[] args )
        {
        try
            {
            // build an XSD-aware SchemaFactory
            final SchemaFactory schemaFactory = SchemaFactory.newInstance( XMLConstants.W3C_XML_SCHEMA_NS_URI );
            // hook up mindless org.xml.sax.ErrorHandler implementation.
            schemaFactory.setErrorHandler( new XSDErrorHandler() );
            // get the custom xsd schema describing the required format for a htmlreflow.xml files.
            final Schema schemaXSD = schemaFactory.newSchema( new File( "htmlreflow.xsd" ) );
            // Create a Validator capable of validating config files according to our custom schema.
            final Validator validator = schemaXSD.newValidator();
            // Create a generic XML parser.
            final DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            // parse the htmlreflow.xml file as ordinary XML and get a DOM tree representation.
            final Document document = parser.parse( "htmlreflowconfig.xml" );
            final DOMSource domSource = new DOMSource( document );
            // Validate the htmlreflow.xml DOM tree against the stricter XSD schema
            validator.validate( domSource );
            // Extract information from the htmlreflow.xml configuration document tree
            final Node lineTag = document.getElementsByTagName( "line" ).item( 0 );
            final NamedNodeMap lineAttributes = lineTag.getAttributes();
            final int desiredLineLength = extractIntAttribute( lineAttributes,
                    "desiredlinelength",
                    DESIRED_LINE_LENGTH_DEFAULT );
            final int maxLineLength = extractIntAttribute( lineAttributes, "maxlinelength", MAX_LINE_LENGTH_DEFAULT );
            final String lineSeparator = extractLineSeparatorAttribute( lineAttributes, "lineseparator" );
            final NodeList tagNodes = document.getElementsByTagName( "tag" );
            final int count = tagNodes.getLength();
            TagConfig[] tags = new TagConfig[ count ];
            for ( int i = 0; i < count; i++ )
                {
                final NamedNodeMap tagAttributes = tagNodes.item( i ).getAttributes();
                final String tagName = extractStringAttribute( tagAttributes, "tagname" );
                final int beforeTag = extractNlCountAttribute( tagAttributes, "beforetag" );
                final int tagIndent = extractIntAttribute( tagAttributes, "tagindent", 0 );
                final int afterTag = extractNlCountAttribute( tagAttributes, "aftertag" );
                final int nestedIndent = extractIntAttribute( tagAttributes, "nestedindent", 0 );
                final int beforeSlashTag = extractNlCountAttribute( tagAttributes, "beforeslashtag" );
                final int afterSlashTag = extractNlCountAttribute( tagAttributes, "afterslashtag" );
                final boolean wrap = extractBooleanAttributeDefaultYes( tagAttributes, "wrap" );
                tags[ i ] = new TagConfig( tagName,
                        beforeTag,
                        tagIndent,
                        afterTag,
                        nestedIndent,
                        beforeSlashTag,
                        afterSlashTag,
                        wrap );
                }
            // Persist configuration to the Preferences API
            Persist.setDesiredLineLength( desiredLineLength );
            Persist.setMaxLineLength( maxLineLength );
            Persist.setLineSeparator( lineSeparator );
            Persist.setTags( tags );
            Persist.saveConfig();
            }
        catch ( Exception e )
            {
            err.println();
            e.printStackTrace( err );
            err.println();
            }
        } // end main
    }

/**
 * error handler for Parsing XML config file
 */
class XSDErrorHandler implements ErrorHandler
    {
    /**
     * default constructor
     */
    public XSDErrorHandler()
        {
        }

    /**
     * Receive notification of a recoverable error.
     * <p/>
     * <p>This corresponds to the definition of "error" in section 1.2
     * of the W3C XML 1.0 Recommendation.  For example, a validating
     * parser would use this callback to report the violation of a
     * validity constraint.  The default behaviour is to take no
     * action.</p>
     * <p/>
     * <p>The SAX parser must continue to provide normal parsing
     * events after invoking this method: it should still be possible
     * for the application to process the document through to the end.
     * If the application cannot do so, then the parser should report
     * a fatal error even if the XML recommendation does not require
     * it to do so.</p>
     * <p/>
     * <p>Filters may use this method to report other, non-XML errors
     * as well.</p>
     *
     * @param exception The error information encapsulated in a
     *                  SAX parse exception.
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *                                  wrapping another exception.
     * @see org.xml.sax.SAXParseException
     */
    public void error( SAXParseException exception )
            throws SAXException
        {
        err.println( exception );
        }

    /**
     * Receive notification of a non-recoverable error.
     * <p/>
     * <p><strong>There is an apparent contradiction between the
     * documentation for this method and the documentation for {@link
     * org.xml.sax.ContentHandler#endDocument}.  Until this ambiguity
     * is resolved in a future major release, clients should make no
     * assumptions about whether endDocument() will or will not be
     * invoked when the parser has reported a fatalError() or thrown
     * an exception.</strong></p>
     * <p/>
     * <p>This corresponds to the definition of "fatal error" in
     * section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
     * parser would use this callback to report the violation of a
     * well-formedness constraint.</p>
     * <p/>
     * <p>The application must assume that the document is unusable
     * after the parser has invoked this method, and should continue
     * (if at all) only for the sake of collecting additional error
     * messages: in fact, SAX parsers are free to stop reporting any
     * other events once this method has been invoked.</p>
     *
     * @param exception The error information encapsulated in a
     *                  SAX parse exception.
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *                                  wrapping another exception.
     * @see org.xml.sax.SAXParseException
     */
    public void fatalError( SAXParseException exception ) throws SAXException
        {
        err.println( exception );
        }

    /**
     * Receive notification of a warning.
     * <p/>
     * <p>SAX parsers will use this method to report conditions that
     * are not errors or fatal errors as defined by the XML
     * recommendation.  The default behaviour is to take no
     * action.</p>
     * <p/>
     * <p>The SAX parser must continue to provide normal parsing events
     * after invoking this method: it should still be possible for the
     * application to process the document through to the end.</p>
     * <p/>
     * <p>Filters may use this method to report other, non-XML warnings
     * as well.</p>
     *
     * @param exception The warning information encapsulated in a
     *                  SAX parse exception.
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *                                  wrapping another exception.
     * @see org.xml.sax.SAXParseException
     */
    public void warning( SAXParseException exception ) throws SAXException
        {
        err.println( exception );
        }
    }