package org.litesoft.orsup;

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

import org.litesoft.util.*;
import org.litesoft.exceptions.*;

public class DataLoader
{
    public static final DataLoader INSTANCE = new DataLoader();

    private static final String LOAD_DATA_PATH = System.getProperty( "LoadDataPath" );
    private static final String LOAD_DATA_DIR_PARENT_PATH = System.getProperty( "LoadDataDirParentPath", "../webapps/LoadData" );
    private static final String LOAD_DATA_SUB_DIR = System.getProperty( "LoadDataSubDir", "Default" );
    private static final String LOAD_DEMO_DATA_PATH = LOAD_DATA_DIR_PARENT_PATH + "/Demo";

    public void loadData()
    {
        String zLoadDataPath = LOAD_DATA_PATH;
        if ( zLoadDataPath == null )
        {
            zLoadDataPath = LOAD_DATA_DIR_PARENT_PATH + "/" + LOAD_DATA_SUB_DIR;
        }
        loadDataFrom( zLoadDataPath );
    }

    public void loadDataFrom( String zLoadDataPath )
    {
        try
        {
            File zLoadDir = new File( zLoadDataPath );
            String[] zFilesToLoad = getFileNames( zLoadDir );
            DB_Import.importCSV( zLoadDir, zFilesToLoad );
        }
        catch ( IOException e )
        {
            throw new RuntimeException( e );
        }
    }

    public void loadDemoData()
    {
        synchronized ( LOAD_DEMO_DATA_PATH )
        {
            if ( mCSVtoMemo == null )
            {
                mCSVtoMemo = loadDemoDataMemo();
            }
        }
        loadMemoDemoData( mCSVtoMemo );
    }

    private Object mCSVtoMemo = null;

    private Object loadDemoDataMemo()
    {
        try
        {
            File zLoadDir = new File( LOAD_DEMO_DATA_PATH );
            String[] zFilesToLoad = getFileNames( zLoadDir );
            return DB_Import.importCSVtoMemo( FileUtils.filesToReaders( zLoadDir, zFilesToLoad ) );
        }
        catch ( IOException e )
        {
            throw new RuntimeException( e );
        }
    }

    private void loadMemoDemoData( Object pCSVtoMemo )
    {
        try
        {
            File zLoadDir = new File( LOAD_DEMO_DATA_PATH );
            DB_Import.importCSVfromMemo( zLoadDir, pCSVtoMemo );
        }
        catch ( IOException e )
        {
            throw new RuntimeException( e );
        }
    }

    private String[] getFileNames( File pLoadDir )
    {
        FilenameFilter zCSV_FilesFilter = FileUtils.createFileNameFilter( Utils.parseChar( "*.csv", '*' ) );
        String[] zFilesToLoad = pLoadDir.list( zCSV_FilesFilter );
        if ( Utils.isNullOrEmpty( zFilesToLoad ) )
        {
            throw new DisplayableRuntimeException( "No Load Data Files at: " + pLoadDir.getAbsolutePath() );
        }
        Arrays.sort( zFilesToLoad );
        return zFilesToLoad;
    }
}