// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.orsup;

import org.litesoft.commonfoundation.base.*;
import org.litesoft.commonfoundation.exceptions.*;
import org.litesoft.commonfoundation.typeutils.*;
import org.litesoft.configuration.*;
import org.litesoft.server.file.*;

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

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

    public static final String DEFAULT_LOAD_DATA_RELATIVE_DIR_PARENT_PATH = "LoadData";
    public static final String DEFAULT_LOAD_DATA_SUB_DIR_REGULAR = "Default";
    public static final String DEFAULT_LOAD_DATA_SUB_DIR_DEMO = "Demo";

    public static final String PROPERTY_LOAD_DATA_PATH = "LoadDataPath";
    public static final String PROPERTY_LOAD_DATA_DIR_PARENT_PATH = "LoadDataDirParentPath";
    public static final String PROPERTY_LOAD_DATA_SUB_DIR = "LoadDataSubDir";

    private String getSubDirPath( String pSubDir ) {
        String parent = ServerConfiguration.getPath( PROPERTY_LOAD_DATA_DIR_PARENT_PATH, DEFAULT_LOAD_DATA_RELATIVE_DIR_PARENT_PATH );
        return parent + "/" + pSubDir;
    }

    public void loadData() {
        String zLoadDataPath = ServerConfiguration.getPath( PROPERTY_LOAD_DATA_PATH, null );
        if ( zLoadDataPath == null ) {
            zLoadDataPath = getSubDirPath( Configuration.getString( PROPERTY_LOAD_DATA_SUB_DIR, DEFAULT_LOAD_DATA_SUB_DIR_REGULAR ) );
        }
        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 ( getClass() ) {
            if ( mCSVtoMemo == null ) {
                mCSVtoMemo = loadDemoDataMemo();
            }
        }
        loadMemoDemoData( mCSVtoMemo );
    }

    private Object mCSVtoMemo = null;

    private Object loadDemoDataMemo() {
        try {
            File zLoadDir = new File( getSubDirPath( DEFAULT_LOAD_DATA_SUB_DIR_DEMO ) );
            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( getSubDirPath( DEFAULT_LOAD_DATA_SUB_DIR_DEMO ) );
            DB_Import.importCSVfromMemo( zLoadDir, pCSVtoMemo );
        }
        catch ( IOException e ) {
            throw new RuntimeException( e );
        }
    }

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