package org.gcube.vremanagement.vremodeler.resources.handlers;

import java.sql.ResultSet;

import org.gcube.common.core.utils.logging.GCUBELog;
import org.gcube.vremanagement.vremodeler.db.DBInterface;
import org.gcube.vremanagement.vremodeler.resources.MFRelationNative;
import org.gcube.vremanagement.vremodeler.resources.MetadataFormat;

public class MetadataFormatHandler implements ResourceHandler<MetadataFormat> {

	private static GCUBELog logger= new GCUBELog(MetadataFormatHandler.class);
	
	private static final  String nameFieldDb="NAME";
	private static final  String schemaFieldDb="SCHEMAURI";
	private static final  String languageFieldDb="LANGUAGE";
	
	public static final String tableName="METADATAFORMAT";
	
	private String relatedMCollectionID;
	
	public MetadataFormatHandler(String relatedMCollectionId){
		this.relatedMCollectionID= relatedMCollectionId;
	}
		
	public void add(MetadataFormat resource) throws Exception {
		String id;
		if ((id=exists(resource))!=null){
			new NativeMetadataFormatHandler().add(new MFRelationNative(this.relatedMCollectionID, id));
		}else{
			DBInterface.connect();
			DBInterface.insertIntoListable(tableName, resource); 
			new NativeMetadataFormatHandler().add(new MFRelationNative(this.relatedMCollectionID, resource.getId()));
		}
	}

	public void drop(String resourceId) throws Exception {
		// TODO Auto-generated method stub
	}

	public void initialize() throws Exception {}
	
	
	/**
	 * this method returns the id of the MetadataFormat if this metadataFormat exists, null otherwise
	 */
	private static String exists(MetadataFormat metadataFormat) throws Exception{
		DBInterface.connect();
		ResultSet result;
		if (metadataFormat.getLanguage().compareTo(MetadataFormat.ANY_LANGUAGE)==0){
			result=DBInterface.queryDB("SELECT ID from "+tableName+" WHERE "+nameFieldDb+"='"+metadataFormat.getName()+"' AND "+schemaFieldDb+"='"+metadataFormat.getSchemaURI()+"'");
		}else
			result=DBInterface.queryDB("SELECT ID from "+tableName+" WHERE "+nameFieldDb+"='"+metadataFormat.getName()+"' AND "+schemaFieldDb+"='"+metadataFormat.getSchemaURI()+"' AND ("+languageFieldDb+"='"+MetadataFormat.ANY_LANGUAGE+"' OR "+languageFieldDb+"='"+metadataFormat.getLanguage()+"')");
		if (result.next()) {
			logger.trace("the metadataFormat already exists");
			return result.getString(1);
		}else return null;
	}

}