package org.litesoft.configuration;

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

import org.litesoft.util.*;

public class ConfigAccessorFactoryProperties implements ConfigAccessorFactory
{
    public static final ConfigAccessorFactory INSTANCE = new ConfigAccessorFactoryProperties();

    private ConfigAccessorFactoryProperties()
    {
    }

    public ConfigDataAccessor create( String pLoadedFromDirectory, String pLoadedFromName, InputStream pInputStream )
            throws IOException
    {
        Utils.assertNotNull( "LoadedFromDirectory", pLoadedFromDirectory );
        Utils.assertNotNull( "LoadedFromName", pLoadedFromName );
        Utils.assertNotNull( "InputStream", pInputStream );
        Properties props = new Properties();
        props.load( pInputStream );

        return new ConfigDataAccessorImpl( pLoadedFromDirectory, pLoadedFromName, props );
    }

    private static class ConfigDataAccessorImpl implements ConfigDataAccessor
    {
        private String mLoadedFromDirectory;
        private String mLoadedFromName;
        private Properties mProperties;

        public ConfigDataAccessorImpl( String pLoadedFromDirectory, String pLoadedFromName, Properties pProperties )
        {
            mLoadedFromDirectory = pLoadedFromDirectory;
            mLoadedFromName = pLoadedFromName;
            mProperties = pProperties;
        }

        public String loadedFrom()
        {
            return mLoadedFromName + " from '" + loadedFromDirectory() + "'";
        }

        public String loadedFromDirectory()
        {
            return mLoadedFromDirectory;
        }

        /**
         * All implementations MUST support RUN level, but may not support other levels
         *
         * @return an array with at least 1 (RUN) entry
         */
        public Level[] getSetableSupportedLevels()
        {
            return new Level[]{Level.RUN};
        }

        /**
         * All implementations MUST support RUN level, but may not support other levels
         *
         * @param pLevel null interpreted as RUN
         * @param pKey   not null or empty
         * @param pValue null means remove
         *
         * @throws UnsupportedOperationException if requested level not supported
         */
        public void setKeyValue( Level pLevel, String pKey, String pValue )
                throws UnsupportedOperationException
        {
            if ( !Level.RUN.equals( Utils.deNull( pLevel, Level.RUN ) ) )
            {
                throw new UnsupportedOperationException( "setKeyValue for Level '" + pLevel + "' not supported" );
            }
            pKey = Utils.assertNotNullNotEmpty( "Key", pKey );
            if ( pValue == null )
            {
                mProperties.remove( pKey );
            }
            else
            {
                mProperties.put( pKey, pValue );
            }
        }

        public String[] getAllKeys()
        {
            List<String> keys = new ArrayList<String>();
            for ( Object key : mProperties.keySet() )
            {
                if ( key instanceof String )
                {
                    keys.add( (String) key );
                }
            }
            return keys.toArray( new String[keys.size()] );
        }

        /**
         * @param pKey not null or empty
         *
         * @return null if not found or value associated with key
         */
        public String getString( String pKey )
        {
            Object o = mProperties.get( Utils.assertNotNullNotEmpty( "Key", pKey ) );
            return (o == null) ? null : o.toString();
        }
    }
}