/*
 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * The MIT License
 *
 * Copyright (c) 2004-2014 Paul R. Holser, Jr.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package jdk.internal.joptsimple;

import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import jdk.internal.joptsimple.internal.Rows;
import jdk.internal.joptsimple.internal.Strings;

import static jdk.internal.joptsimple.ParserRules.*;
import static jdk.internal.joptsimple.internal.Classes.*;
import static jdk.internal.joptsimple.internal.Strings.*;

/**
 * <p>A help formatter that allows configuration of overall row width and column separator width.</p>
 *
 * <p>The formatter produces a two-column output. The left column is for the options, and the right column for their
 * descriptions. The formatter will allow as much space as possible for the descriptions, by minimizing the option
 * column's width, no greater than slightly less than half the overall desired width.</p>
 *
 * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>
 */
public class BuiltinHelpFormatter implements HelpFormatter {
    private final Rows nonOptionRows;
    private final Rows optionRows;

    /**
     * Makes a formatter with a pre-configured overall row width and column separator width.
     */
    BuiltinHelpFormatter() {
        this( 80, 2 );
    }

    /**
     * Makes a formatter with a given overall row width and column separator width.
     *
     * @param desiredOverallWidth how many characters wide to make the overall help display
     * @param desiredColumnSeparatorWidth how many characters wide to make the separation between option column and
     * description column
     */
    public BuiltinHelpFormatter( int desiredOverallWidth, int desiredColumnSeparatorWidth ) {
        nonOptionRows = new Rows( desiredOverallWidth * 2, 0 );
        optionRows = new Rows( desiredOverallWidth, desiredColumnSeparatorWidth );
    }

    public String format( Map<String, ? extends OptionDescriptor> options ) {
        Comparator<OptionDescriptor> comparator =
            new Comparator<OptionDescriptor>() {
                public int compare( OptionDescriptor first, OptionDescriptor second ) {
                    return first.options().iterator().next().compareTo( second.options().iterator().next() );
                }
            };

        Set<OptionDescriptor> sorted = new TreeSet<OptionDescriptor>( comparator );
        sorted.addAll( options.values() );

        addRows( sorted );

        return formattedHelpOutput();
    }

    private String formattedHelpOutput() {
        StringBuilder formatted = new StringBuilder();
        String nonOptionDisplay = nonOptionRows.render();
        if ( !Strings.isNullOrEmpty( nonOptionDisplay ) )
            formatted.append( nonOptionDisplay ).append( LINE_SEPARATOR );
        formatted.append( optionRows.render() );

        return formatted.toString();
    }

    private void addRows( Collection<? extends OptionDescriptor> options ) {
        addNonOptionsDescription( options );

        if ( options.isEmpty() )
            optionRows.add( "No options specified", "" );
        else {
            addHeaders( options );
            addOptions( options );
        }

        fitRowsToWidth();
    }

    private void addNonOptionsDescription( Collection<? extends OptionDescriptor> options ) {
        OptionDescriptor nonOptions = findAndRemoveNonOptionsSpec( options );
        if ( shouldShowNonOptionArgumentDisplay( nonOptions ) ) {
            nonOptionRows.add( "Non-option arguments:", "" );
            nonOptionRows.add(createNonOptionArgumentsDisplay(nonOptions), "");
        }
    }

    private boolean shouldShowNonOptionArgumentDisplay( OptionDescriptor nonOptions ) {
        return !Strings.isNullOrEmpty( nonOptions.description() )
            || !Strings.isNullOrEmpty( nonOptions.argumentTypeIndicator() )
            || !Strings.isNullOrEmpty( nonOptions.argumentDescription() );
    }

    private String createNonOptionArgumentsDisplay(OptionDescriptor nonOptions) {
        StringBuilder buffer = new StringBuilder();
        maybeAppendOptionInfo( buffer, nonOptions );
        maybeAppendNonOptionsDescription( buffer, nonOptions );

        return buffer.toString();
    }

    private void maybeAppendNonOptionsDescription( StringBuilder buffer, OptionDescriptor nonOptions ) {
        buffer.append( buffer.length() > 0 && !Strings.isNullOrEmpty( nonOptions.description() ) ? " -- " : "" )
            .append( nonOptions.description() );
    }

    private OptionDescriptor findAndRemoveNonOptionsSpec( Collection<? extends OptionDescriptor> options ) {
        for ( Iterator<? extends OptionDescriptor> it = options.iterator(); it.hasNext(); ) {
            OptionDescriptor next = it.next();
            if ( next.representsNonOptions() ) {
                it.remove();
                return next;
            }
        }

        throw new AssertionError( "no non-options argument spec" );
    }

    private void addHeaders( Collection<? extends OptionDescriptor> options ) {
        if ( hasRequiredOption( options ) ) {
            optionRows.add("Option (* = required)", "Description");
            optionRows.add("---------------------", "-----------");
        } else {
            optionRows.add("Option", "Description");
            optionRows.add("------", "-----------");
        }
    }

    private boolean hasRequiredOption( Collection<? extends OptionDescriptor> options ) {
        for ( OptionDescriptor each : options ) {
            if ( each.isRequired() )
                return true;
        }

        return false;
    }

    private void addOptions( Collection<? extends OptionDescriptor> options ) {
        for ( OptionDescriptor each : options ) {
            if ( !each.representsNonOptions() )
                optionRows.add( createOptionDisplay( each ), createDescriptionDisplay( each ) );
        }
    }

    private String createOptionDisplay( OptionDescriptor descriptor ) {
        StringBuilder buffer = new StringBuilder( descriptor.isRequired() ? "* " : "" );

        for ( Iterator<String> i = descriptor.options().iterator(); i.hasNext(); ) {
            String option = i.next();
            buffer.append( option.length() > 1 ? DOUBLE_HYPHEN : HYPHEN );
            buffer.append( option );

            if ( i.hasNext() )
                buffer.append( ", " );
        }

        maybeAppendOptionInfo( buffer, descriptor );

        return buffer.toString();
    }

    private void maybeAppendOptionInfo( StringBuilder buffer, OptionDescriptor descriptor ) {
        String indicator = extractTypeIndicator( descriptor );
        String description = descriptor.argumentDescription();
        if ( indicator != null || !isNullOrEmpty( description ) )
            appendOptionHelp( buffer, indicator, description, descriptor.requiresArgument() );
    }

    private String extractTypeIndicator( OptionDescriptor descriptor ) {
        String indicator = descriptor.argumentTypeIndicator();

        if ( !isNullOrEmpty( indicator ) && !String.class.getName().equals( indicator ) )
            return shortNameOf( indicator );

        return null;
    }

    private void appendOptionHelp( StringBuilder buffer, String typeIndicator, String description, boolean required ) {
        if ( required )
            appendTypeIndicator( buffer, typeIndicator, description, '<', '>' );
        else
            appendTypeIndicator( buffer, typeIndicator, description, '[', ']' );
    }

    private void appendTypeIndicator( StringBuilder buffer, String typeIndicator, String description,
                                      char start, char end ) {
        buffer.append( ' ' ).append( start );
        if ( typeIndicator != null )
            buffer.append( typeIndicator );

        if ( !Strings.isNullOrEmpty( description ) ) {
            if ( typeIndicator != null )
                buffer.append( ": " );

            buffer.append( description );
        }

        buffer.append( end );
    }

    private String createDescriptionDisplay( OptionDescriptor descriptor ) {
        List<?> defaultValues = descriptor.defaultValues();
        if ( defaultValues.isEmpty() )
            return descriptor.description();

        String defaultValuesDisplay = createDefaultValuesDisplay( defaultValues );
        return ( descriptor.description() + ' ' + surround( "default: " + defaultValuesDisplay, '(', ')' ) ).trim();
    }

    private String createDefaultValuesDisplay( List<?> defaultValues ) {
        return defaultValues.size() == 1 ? defaultValues.get( 0 ).toString() : defaultValues.toString();
    }

    private void fitRowsToWidth() {
        nonOptionRows.fitToWidth();
        optionRows.fitToWidth();
    }
}