/*=============================================================================#
 # Copyright (c) 2013, 2018 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.rj.services.util.dataaccess;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.statet.rj.data.RDataUtils;
import org.eclipse.statet.rj.data.RLanguage;
import org.eclipse.statet.rj.data.RObject;
import org.eclipse.statet.rj.data.RVector;
import org.eclipse.statet.rj.data.UnexpectedRDataException;
import org.eclipse.statet.rj.data.impl.DefaultRObjectFactory;
import org.eclipse.statet.rj.services.FQRObjectRef;
import org.eclipse.statet.rj.services.FunctionCall;
import org.eclipse.statet.rj.services.RService;


/**
 * Adapter interface to load R data in one- or two-dimensional fragments.
 * 
 * @param <TRObject> type of R object
 * @param <TFragmentObject> type of R object value fragments
 * @since 2.0 (provisional)
 */
public abstract class AbstractRDataAdapter<TRObject extends RObject, TFragmentObject extends RObject> {
	
	
	public static final int ROW_COUNT= 1 << 0;
	public static final int STORE_TYPE= 1 << 2;
	
	protected static final String API_R_PREFIX= "rj:::sda002"; //$NON-NLS-1$
	
	
	protected static void addXRef(final FunctionCall fcall, final FQRObjectRef ref) {
		fcall.add("x.env", ref.getEnv()); //$NON-NLS-1$
		fcall.add("x.expr", DefaultRObjectFactory.INSTANCE.createExpression( //$NON-NLS-1$
				"x.env$" + ((RLanguage) ref.getName()).getSource() )); //$NON-NLS-1$
	}
	
	
	public abstract TRObject validate(RObject rObject)
			throws UnexpectedRDataException;
	public abstract TRObject validate(RObject rObject, TRObject referenceObject, int flags)
			throws UnexpectedRDataException;
	
	public abstract long getRowCount(TRObject rObject);
	public abstract long getColumnCount(TRObject rObject);
	
	
	public void check(final FQRObjectRef ref, final TRObject referenceObject,
			final RService r, final IProgressMonitor monitor) throws CoreException,
			UnexpectedRDataException {
		final RObject result;
		{	final FunctionCall fcall= r.createFunctionCall(API_R_PREFIX + ".checkDataStruct"); //$NON-NLS-1$
			addXRef(fcall, ref);
			fcall.addChar("xClass1", referenceObject.getRClassName()); //$NON-NLS-1$
			fcall.add("xDim", DefaultRObjectFactory.INSTANCE.createNumVector(new double[] { //$NON-NLS-1$
					getRowCount(referenceObject),
					getColumnCount(referenceObject),
			}));
			result= fcall.evalData(monitor);
		}
		if (RDataUtils.checkSingleLogiValue(result) == false) {
			throw new UnexpectedRDataException("It seems something changed.");
		}
	}
	
	public TFragmentObject loadData(final FQRObjectRef ref, final TRObject referenceObject,
			final LazyRStore.Fragment<TFragmentObject> fragment, final String rowMapping,
			final RService r,
			final IProgressMonitor monitor) throws CoreException, UnexpectedRDataException {
		final RObject fragmentObject;
		{	final FunctionCall fcall= r.createFunctionCall(getLoadDataFName());
			addXRef(fcall, ref);
			fcall.add("idxs", DefaultRObjectFactory.INSTANCE.createNumVector(new double[] { //$NON-NLS-1$
					fragment.getRowBeginIdx() + 1,
					fragment.getRowEndIdx(),
					fragment.getColumnBeginIdx() + 1,
					fragment.getColumnEndIdx(),
			}));
			if (rowMapping != null) {
				fcall.addChar("rowMapping", rowMapping); //$NON-NLS-1$
			}
			
			fragmentObject= fcall.evalData(monitor);
		}
		
		return validateData(fragmentObject, referenceObject, fragment);
	}
	
	protected abstract String getLoadDataFName();
	
	protected abstract TFragmentObject validateData(RObject rObject, TRObject referenceObject,
			LazyRStore.Fragment<TFragmentObject> fragment)
			throws UnexpectedRDataException;
	
	public void setData(final FQRObjectRef ref, final TRObject referenceObject,
			final RDataAssignment assignment, final String rowMapping,
			final RService r,
			final IProgressMonitor monitor) throws CoreException, UnexpectedRDataException {
		{	final FunctionCall fcall= r.createFunctionCall(getSetDataFName());
			addXRef(fcall, ref);
			fcall.add("idxs", DefaultRObjectFactory.INSTANCE.createNumVector(new double[] { //$NON-NLS-1$
					assignment.getRowBeginIdx() + 1,
					assignment.getRowEndIdx(),
					assignment.getColumnBeginIdx() + 1,
					assignment.getColumnEndIdx(),
			}));
			if (rowMapping != null) {
				fcall.addChar("rowMapping", rowMapping); //$NON-NLS-1$
			}
			fcall.add("values", DefaultRObjectFactory.INSTANCE.createVector( //$NON-NLS-1$
					assignment.getData() ));
			
			fcall.evalVoid(monitor);
		}
	}
	
	protected abstract String getSetDataFName();
	
	public RVector<?> loadRowNames(final FQRObjectRef ref, final TRObject referenceObject,
			final LazyRStore.Fragment<RVector<?>> fragment, final String rowMapping,
			final RService r, final IProgressMonitor monitor) throws CoreException,
			UnexpectedRDataException {
		final RObject fragmentObject;
		{	final FunctionCall fcall= r.createFunctionCall(getLoadRowNamesFName());
			addXRef(fcall, ref);
			fcall.add("idxs", DefaultRObjectFactory.INSTANCE.createNumVector(new double[] { //$NON-NLS-1$
					fragment.getRowBeginIdx() + 1,
					fragment.getRowEndIdx(),
			}));
			if (rowMapping != null) {
				fcall.addChar("rowMapping", rowMapping); //$NON-NLS-1$
			}
			
			fragmentObject= fcall.evalData(monitor);
		}
		
		return validateRowNames(fragmentObject, referenceObject, fragment);
	}
	
	protected abstract String getLoadRowNamesFName();
	
	protected RVector<?> validateRowNames(final RObject rObject, final TRObject referenceObject,
			final LazyRStore.Fragment<RVector<?>> fragment)
			throws UnexpectedRDataException {
		if (rObject.getRObjectType() == RObject.TYPE_NULL) {
			return null;
		}
		
		final RVector<?> vector= RDataUtils.checkRVector(rObject);
		RDataUtils.checkLengthEqual(vector.getData(), fragment.getRowCount());
		
		return vector;
	}
	
}