package net.sf.openrocket.file.rocksim.export;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.StringWriter;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;

import net.sf.openrocket.document.OpenRocketDocument;
import net.sf.openrocket.document.StorageOptions;
import net.sf.openrocket.file.RocketSaver;
import net.sf.openrocket.file.rocksim.RocksimCommonConstants;
import net.sf.openrocket.masscalc.BasicMassCalculator;
import net.sf.openrocket.masscalc.MassCalculator;
import net.sf.openrocket.rocketcomponent.Configuration;
import net.sf.openrocket.rocketcomponent.Rocket;
import net.sf.openrocket.rocketcomponent.Stage;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class is responsible for converting an OpenRocket design to a Rocksim design.
 */
public class RocksimSaver extends RocketSaver {
	
	/**
	 * The logger.
	 */
	private static final Logger log = LoggerFactory.getLogger(RocksimSaver.class);
	
	/**
	 * This method marshals an OpenRocketDocument (OR design) to Rocksim-compliant XML.
	 *
	 * @param doc the OR design
	 * @return Rocksim-compliant XML
	 */
	public String marshalToRocksim(OpenRocketDocument doc) {
		
		try {
			JAXBContext binder = JAXBContext.newInstance(RocksimDocumentDTO.class);
			Marshaller marshaller = binder.createMarshaller();
			marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
			marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
			StringWriter sw = new StringWriter();
			
			marshaller.marshal(toRocksimDocumentDTO(doc), sw);
			return sw.toString();
		} catch (Exception e) {
			log.error("Could not marshall a design to Rocksim format. " + e.getMessage());
		}
		
		return null;
	}
	
	@Override
	public void save(OutputStream dest, OpenRocketDocument doc, StorageOptions options) throws IOException {
		log.info("Saving .rkt file");
		
		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(dest, "UTF-8"));
		writer.write(marshalToRocksim(doc));
		writer.flush();
	}
	
	@Override
	public long estimateFileSize(OpenRocketDocument doc, StorageOptions options) {
		return marshalToRocksim(doc).length();
	}
	
	/**
	 * Root conversion method.  It iterates over all subcomponents.
	 *
	 * @param doc the OR design
	 * @return a corresponding Rocksim representation
	 */
	private RocksimDocumentDTO toRocksimDocumentDTO(OpenRocketDocument doc) {
		RocksimDocumentDTO rsd = new RocksimDocumentDTO();
		
		rsd.setDesign(toRocksimDesignDTO(doc.getRocket()));
		
		return rsd;
	}
	
	private RocksimDesignDTO toRocksimDesignDTO(Rocket rocket) {
		RocksimDesignDTO result = new RocksimDesignDTO();
		result.setDesign(toRocketDesignDTO(rocket));
		return result;
	}
	
	private RocketDesignDTO toRocketDesignDTO(Rocket rocket) {
		RocketDesignDTO result = new RocketDesignDTO();
		
		MassCalculator massCalc = new BasicMassCalculator();
		
		final Configuration configuration = new Configuration(rocket);
		final double cg = massCalc.getCG(configuration, MassCalculator.MassCalcType.NO_MOTORS).x *
				RocksimCommonConstants.ROCKSIM_TO_OPENROCKET_LENGTH;
		configuration.release();
		int stageCount = rocket.getStageCount();
		if (stageCount == 3) {
			result.setStage321CG(cg);
		} else if (stageCount == 2) {
			result.setStage32CG(cg);
		} else {
			result.setStage3CG(cg);
		}
		
		result.setName(rocket.getName());
		result.setStageCount(stageCount);
		if (stageCount > 0) {
			result.setStage3(toStageDTO(rocket.getChild(0).getStage(), result, 3));
		}
		if (stageCount > 1) {
			result.setStage2(toStageDTO(rocket.getChild(1).getStage(), result, 2));
		}
		if (stageCount > 2) {
			result.setStage1(toStageDTO(rocket.getChild(2).getStage(), result, 1));
		}
		//Set the last serial number element and reset it.
		result.setLastSerialNumber(BasePartDTO.getCurrentSerialNumber());
		BasePartDTO.resetCurrentSerialNumber();
		return result;
	}
	
	private StageDTO toStageDTO(Stage stage, RocketDesignDTO designDTO, int stageNumber) {
		return new StageDTO(stage, designDTO, stageNumber);
	}
	
}