/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.util.outputformatter;

import java.io.PrintStream;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;

import joptsimple.OptionParser;
import joptsimple.OptionSet;


/**
 * This is the default formatter for Jisql.  It outputs data in a &quot;normal&quot;
 * format that is similar to most other database command line formatters.
 *
 */
public class DefaultFormatter implements JisqlFormatter {
    private boolean trimColumns = false;
    private int columnWidth = 2048;		// can be overridden with the -w switch
    private char spacer = ' ';
    private boolean printNull = true;
    private boolean leftJustify = false;
    private boolean printHeader = true;
    private boolean debug = false;
	private String delimiter = " | ";


    /**
     * Sets a the option list for this formatter.  This formatter accepts the
     * following options:
     *
     * <li><b>-noheader</b> do not print the header column info.</li>
     * <li><b>-spacer</b> The character to use for &quot;empty&quot; space.  This
     * defaults to the space character.  From mrider - &quot;I added the ability to
     * specify the spacer for columns - which used to be the single char ' '. I did
     * this because of brain-dead Windows' command line copy/paste. It seems that when
     * a line of text ends in space, copy does not copy that space. Which makes it
     * difficult to copy/paste into another program. This can probably be ignored
     * most of the time.&quot;</li>
     * <li><b>-delimiter</b> Specify a single character delimiter for columns.</li>
     * <li><b>-trim</b> trim the spaces from columns.</li>
     * <li><b>-nonull</b> print an empty string instead of the word &quot;NULL&quot;
     * when there is a null value.<li>
     * <li><b>-left</b> left justify the output</li>
     * <li><b>-w</b> specify the max width of a column.  The default is 2048</li>
     * <li><b>-debug</b> add debug headers to the output</li>
     * </ul>
     *
     * @param parser the OptionParser to use.
     *
     */
    public void setSupportedOptions( OptionParser parser ) {
        parser.accepts( "trim" );
        parser.accepts( "w" ).withRequiredArg().ofType( Integer.class );
        parser.accepts( "spacer" ).withRequiredArg().ofType( String.class );
        parser.accepts( "left" );
        parser.accepts( "nonull" );
        parser.accepts( "noheader" );
        parser.accepts( "debug" );
        parser.accepts( "delimiter" ).withRequiredArg().ofType( String.class );
    }

    /**
     * Consumes any options that were specified on the command line.
     *
     * @param options the OptionSet that the main driver is using.
     *
     * @throws Exception if there is a problem parsing the command line arguments.
     *
     */
    public void consumeOptions( OptionSet options ) throws Exception {

        if( options.has( "trim" ) )
            trimColumns = true;

        if( options.has( "w" ) )
            columnWidth = (Integer)options.valueOf( "w" );

        if( options.has( "spacer" ) )
            spacer = ((String)(options.valueOf( "spacer" ))).charAt( 0 );

        if( options.has( "left" ) )
            leftJustify = true;

        if( options.has( "nonull" ) )
            printNull = false;

        if( options.has( "noheader" ) )
            printHeader = false;

        if( options.has( "debug" ) )
            debug = true;

        if( options.hasArgument( "delimiter" ) )
            delimiter = (String)options.valueOf( "delimiter" );
    }


    /**
     * Called to output a usage message to the command line window.  This
     * message should contain information on how to call the formatter.
     *
     * @param out the stream to print the output on
     *
     */
    public void usage( PrintStream out ) {
        out.println("\t-w specifies the maximum field width for a column.  The default is to output the full width of the column");
        out.println("\t-spacer changes the spacer between columns from a single space to the first character of the argument");
        out.println("\t-noheader do not print any header columns");
        out.println("\t-left left justify the output");
        out.println("\t-trim trim the data output.  This is useful when specifying a delimiter.");
        out.println("\t-nonull print the empty string instead of the word \"NULL\" for null values.");
        out.println("\t-debug shows extra information about the output." );
        out.println("\t-delimiter specifies the delimiter.  The default is \"" + delimiter + "\"." );

    }

    /**
     * Outputs a header for a query.  For the DefaultFormatter the data is output
     * by default unless the &quot;noheader&quot; option is specified.
     *
     * @param out - a PrintStream to send any output to.
     * @param metaData - the ResultSetMetaData for the output.
     *
     */
    public void formatHeader( PrintStream out, ResultSetMetaData metaData ) throws Exception {
        if( printHeader ) {
            int numColumns = metaData.getColumnCount();

            if( debug ) {
            	for (int i = 1; i <= numColumns; i++) {
                    out.print( formatLabel( metaData.getColumnTypeName(i),
                                            metaData.getColumnDisplaySize(i)));
                    out.print(delimiter);
            	}
            }
            //
            // output the column names
            //
            for (int i = 1; i <= numColumns; i++) {
                out.print( formatLabel( metaData.getColumnName(i),
                                        metaData.getColumnDisplaySize(i)));
                out.print(delimiter);
            }

            out.println();

            //
            // output pretty dividers
            //
            for (int i = 1; i <= numColumns; i++) {
                out.print( formatSeparator( metaData.getColumnName(i),
                                            metaData.getColumnDisplaySize(i)));

                if (i == numColumns)
                    out.print("-|");
                else
                    out.print("-+-");
            }

            out.println();
        }
    }


    /**
     * Called to output the data.
     *
     * @param out the PrintStream to output data to.
     * @param resultSet the ResultSet for the row.
     * @param metaData the ResultSetMetaData for the row.
     *
     *
     */
    public void formatData( PrintStream out, ResultSet resultSet, ResultSetMetaData metaData ) throws Exception {

        while( resultSet.next() ) {
            int numColumns = metaData.getColumnCount();

            for (int i = 1; i <= numColumns; i++) {
                out.print( formatValue( metaData.getColumnName(i),
                                        resultSet.getString(i),
                                        metaData.getColumnDisplaySize(i)));
                out.print( delimiter );
            }

            out.println();
        }
    }


    /**
     * Outputs a footer for a query.  This is called after all data has been
     * exhausted.  This method isn't used in the DefaultFormatter.
     *
     * @param out the PrintStream to output data to.
     * @param metaData the ResultSetMetaData for the output.
     *
     */
    public void formatFooter( PrintStream out, ResultSetMetaData metaData ) throws Exception {
    }


    /**
     * Formats a label for output.
     *
     * @param s - the label to format
     * @param width - the width of the field
     *
     * @return the formated label
     *
     */
	private String formatLabel(String s, int width) {
		if (s == null)
			s = "NULL";

		if (columnWidth != 0) {
			if (width > columnWidth)
				width = columnWidth;
		}

		if (width < s.length())
			width = s.length();

		int len = s.length();

		if (len >= width)
			return s.substring(0, width);

		int fillWidth = width - len;
		StringBuilder fill = new StringBuilder(fillWidth);
		for (int i = 0; i < fillWidth; ++i)
			fill.append(spacer);
		if (leftJustify)
			return s + fill;
		else if (s.startsWith("-"))
			return "-" + fill + s.substring(1);
		else
			return fill + s;
	}

	/**
	 * Formats a separator for display.
	 *
	 * @param s - the field for which the separator is being generated
	 * @param width - the width of the field
	 *
	 * @return the formated separator
	 *
	 */
	private String formatSeparator(String s, int width) {
	    s = "NULL";

		if (columnWidth != 0) {
			if (width > columnWidth)
				width = columnWidth;
		}

		if (width < s.length())
			width = s.length();

		int len = s.length();

		if (len >= width)
			width = len;

		StringBuilder fill = new StringBuilder(width);
		for (int i = 0; i < width; ++i)
			fill.append('-');

        if( trimColumns )
		    return fill.toString().trim();
        else
		    return fill.toString();
	}

	/**
	 * Formats a value for display.
	 *
	 * @param label the label associated with the value (for width purposes)
	 * @param s - the value to format
	 * @param width - the width of the field from the db.
	 *
	 * @return the formatted field.
	 *
	 */
	private String formatValue(String label, String s, int width) {
		if (s == null) {
            if( printNull )
			    s = "NULL";
            else
                s = "";
        }

		if (columnWidth != 0) {
			if (width > columnWidth)
				width = columnWidth;
		}

		if (width < label.length())
			width = label.length();

		int len = s.length();

		if (len >= width) {
                if( trimColumns )
			        return s.substring(0, width).trim();
                else
			        return s.substring(0, width);
        }

		int fillWidth = width - len;
		StringBuilder fill = new StringBuilder(fillWidth);
		for (int i = 0; i < fillWidth; ++i)
			fill.append(spacer);

        StringBuilder returnValue = new StringBuilder();

		if (leftJustify)
			returnValue.append( s + fill );
		else if (s.startsWith("-"))
			returnValue.append( "-" + fill + s.substring(1) );
		else {
		    returnValue.append( fill + s );
        }

        if( trimColumns ) {
            return returnValue.toString().trim();
        }
        else {
            return returnValue.toString();
        }
	}
}