/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.module.reporting.dataset.definition.evaluator;

import org.apache.commons.lang.time.StopWatch;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openmrs.Cohort;
import org.openmrs.annotation.Handler;
import org.openmrs.api.context.Context;
import org.openmrs.module.reporting.cohort.CohortUtil;
import org.openmrs.module.reporting.cohort.definition.AllPatientsCohortDefinition;
import org.openmrs.module.reporting.cohort.definition.CohortDefinition;
import org.openmrs.module.reporting.cohort.definition.service.CohortDefinitionService;
import org.openmrs.module.reporting.common.ObjectUtil;
import org.openmrs.module.reporting.data.DataUtil;
import org.openmrs.module.reporting.data.MappedData;
import org.openmrs.module.reporting.data.patient.EvaluatedPatientData;
import org.openmrs.module.reporting.data.patient.definition.PatientDataDefinition;
import org.openmrs.module.reporting.data.patient.service.PatientDataService;
import org.openmrs.module.reporting.dataset.DataSet;
import org.openmrs.module.reporting.dataset.DataSetColumn;
import org.openmrs.module.reporting.dataset.SimpleDataSet;
import org.openmrs.module.reporting.dataset.column.definition.RowPerObjectColumnDefinition;
import org.openmrs.module.reporting.dataset.definition.DataSetDefinition;
import org.openmrs.module.reporting.dataset.definition.PatientDataSetDefinition;
import org.openmrs.module.reporting.definition.DefinitionUtil;
import org.openmrs.module.reporting.evaluation.EvaluationContext;
import org.openmrs.module.reporting.evaluation.EvaluationException;
import org.openmrs.module.reporting.evaluation.parameter.Mapped;

/**
 * The logic that evaluates a {@link PatientDataSetDefinition} and produces an {@link DataSet}
 */
@Handler(supports=PatientDataSetDefinition.class)
public class PatientDataSetEvaluator implements DataSetEvaluator {

	protected Log log = LogFactory.getLog(this.getClass());

	/**
	 * Public constructor
	 */
	public PatientDataSetEvaluator() { }
	
	/**
	 * @see DataSetEvaluator#evaluate(DataSetDefinition, EvaluationContext)
	 */
	@SuppressWarnings("unchecked")
	public DataSet evaluate(DataSetDefinition dataSetDefinition, EvaluationContext context) throws EvaluationException {
		
		PatientDataSetDefinition dsd = (PatientDataSetDefinition) dataSetDefinition;
		context = ObjectUtil.nvl(context, new EvaluationContext());
		
		SimpleDataSet dataSet = new SimpleDataSet(dsd, context);
		dataSet.setSortCriteria(dsd.getSortCriteria());
		
		// Construct a new EvaluationContext based on the passed filters
		Cohort c = context.getBaseCohort();
		if (dsd.getRowFilters() != null) {
			for (Mapped<? extends CohortDefinition> q : dsd.getRowFilters()) {
				Cohort s = Context.getService(CohortDefinitionService.class).evaluate(q, context);
				c = CohortUtil.intersectNonNull(c, s);
			}
		}
		if (c == null) {
			c = Context.getService(CohortDefinitionService.class).evaluate(new AllPatientsCohortDefinition(), context);
		}
		
		EvaluationContext ec = context.shallowCopy();
		if (!CohortUtil.areEqual(ec.getBaseCohort(), c)) {
			ec.setBaseCohort(c);
		}

		// Evaluate each specified ColumnDefinition for all of the included rows and add these to the dataset
		for (RowPerObjectColumnDefinition cd : dsd.getColumnDefinitions()) {

			if (log.isDebugEnabled()) {
				log.debug("Evaluating column: " + cd.getName());
				log.debug("With Data Definition: " + DefinitionUtil.format(cd.getDataDefinition().getParameterizable()));
				log.debug("With Mappings: " + cd.getDataDefinition().getParameterMappings());
				log.debug("With Parameters: " + ec.getParameterValues());
			}
			StopWatch sw = new StopWatch();
			sw.start();

			MappedData<? extends PatientDataDefinition> dataDef = (MappedData<? extends PatientDataDefinition>) cd.getDataDefinition();
			EvaluatedPatientData data = Context.getService(PatientDataService.class).evaluate(dataDef, ec);

			for (Integer id : c.getMemberIds()) {
				for (DataSetColumn column : cd.getDataSetColumns()) {
					Object val = data.getData().get(id);
					val = DataUtil.convertData(val, dataDef.getConverters());
					dataSet.addColumnValue(id, column, val);
				}
			}

			sw.stop();
			if (log.isDebugEnabled()) {
				log.debug("Evaluated column. Duration: " + sw.toString());
			}
		}

		return dataSet;
	}
}