package org.litesoft.language.server;

import java.io.*;
import java.util.*;

/**
 * Like Properties.java but simplified to only use natural lines and equals separators. And also supporting quoted values and only limited Key Forms Dotted Constrained Ascii Identifier (See Key).
 * Only supports # comments (as only the first non-whitespace character in a line)
 * Leading and trailing whitespace is not preserved on save.
 */
public class SimplePropertyFileAccessorImpl implements SimplePropertyFileAccessor
{

    private TextFileAccessor mPropertyFile;

    /**
     * @return Keys in the order they were stored!
     */
    @Override
    public @NotNull @Immutable List<String> getKeys()
    {
        return Collections.unmodifiableList( new ArrayList<>( mOrderedKeyValues.keySet() ) );
    }

    @Override
    public @Nullable String getProperty( String pKey )
    {
        return null;
    }

    /**
     * Writes all the properties to a properties file retaining the order of the properties as they were read and retaining any comments as they were read as well.
     *
     * @throws IOException
     */
    @Override
    public void save()
            throws IOException
    {
        mPropertyFile.write( mLineTracker.toLines() );
    }

    public SimplePropertyFileAccessorImpl( TextFileAccessor pPropertyFile )
            throws IOException
    {
        mPropertyFile = pPropertyFile;
        mLineTracker = new LineTracker( mPropertyFile.read(), mOrderedKeyValues );
    }

    public SimplePropertyFileAccessorImpl( File pPropertyFile )
            throws IOException
    {
        this( new TextFileAccessorImpl( pPropertyFile ) );
    }

    private Map<String, String> mOrderedKeyValues = new LinkedHashMap<>();
    private LineTracker mLineTracker;

    private static class LineTracker
    {
        private Object[] mLines;

        public LineTracker( String[] pLines, Map<String, String> pKeyValues )
        {
            mLines = new Object[pLines.length];
            for ( int i = 0; i < pLines.length; i++ )
            {
                String zLine = pLines[i].trim();
                if ( zLine.length() == 0 || zLine.startsWith( "#" ) )
                {
                    mLines[i] = zLine;
                }
                else
                {
                    Entry zEntry = Entry.parse( zLine );
                    if ( zEntry == null )
                    {
                        throw new IllegalArgumentException( "Bad Line in Property File at: " + i );
                    }
                    mLines[i] = zEntry;
                    pKeyValues.put( zEntry.getKey(), zEntry.getValue() );
                }
            }
        }

        public String[] toLines()
        {
            String[] zLines = new String[mLines.length];
            for ( int i = 0; i < mLines.length; i++ )
            {
                zLines[i] = mLines[i].toString();
            }
            return zLines;
        }
    }

    private static class Entry
    {

        private String mKey;
        private String mValue;

        public static Entry parse( String pLine )
        {
            // TODO: XXX
            return null;
        }

        public String getKey()
        {
            return mKey;
        }

        public String getValue()
        {
            return mValue;
        }
    }
}