package it.cavallium.strangedb.java.database;

import it.cavallium.strangedb.database.DatabaseCore;
import it.cavallium.strangedb.java.objects.EnhancedObject;
import it.cavallium.strangedb.functionalinterfaces.FunctionWithIO;

import java.io.IOException;
import java.nio.file.Path;

public class DatabaseJava extends DatabaseCore implements IDatabaseTools {
	private final IDatabaseTools databaseTools;
	private final DatabaseObjectsIO objectsIO;
	private EnhancedObject loadedRootObject;

	public DatabaseJava(Path dataFile, Path blocksMetaFile, Path referencesMetaFile) throws IOException {
		super(dataFile, blocksMetaFile, referencesMetaFile);
		this.databaseTools = this;
		this.objectsIO = new DatabaseObjectsIO(databaseTools, referencesIO);
	}

	@Override
	public synchronized void close() throws IOException {
		if (this.closed) {
			throw new IOException("The database has been already closed!");
		}
		this.objectsIO.setEnhancedObject(0, loadedRootObject);
		super.close();
	}

	public <T extends EnhancedObject> T loadRoot(FunctionWithIO<IDatabaseTools, T> ifAbsent) throws IOException {
		if (loadedRootObject != null) {
			throw new RuntimeException("Root already set!");
		}
		T root;
		if (referencesMetadata.getFirstFreeReference() > 0) {
			root = objectsIO.loadEnhancedObject(0);
		} else {
			if (objectsIO.newNullObject() != 0) {
				throw new IOException("Can't allocate root!");
			} else {
				root = ifAbsent.apply(DatabaseJava.this);
				objectsIO.setEnhancedObject(0, root);
			}
		}
		loadedRootObject = root;
		return root;
	}

	protected void registerClass(Class<?> type, int id) {
		this.objectsIO.registerClass(type, id);
	}

	@Override
	public void initializeEnhancedObject(EnhancedObject enhancedObject) throws IOException {
		this.objectsIO.getDataInitializer().initializeDbObject(enhancedObject);
	}

	@Override
	public IObjectsIO getObjectsIO() {
		return objectsIO;
	}

}