/**
 * 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.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openmrs.Obs;
import org.openmrs.annotation.Handler;
import org.openmrs.module.reporting.common.BeanPropertyComparator;
import org.openmrs.module.reporting.common.ObjectCounter;
import org.openmrs.module.reporting.common.ObjectUtil;
import org.openmrs.module.reporting.data.converter.ObsValueConverter;
import org.openmrs.module.reporting.data.encounter.definition.ObsForEncounterDataDefinition;
import org.openmrs.module.reporting.data.encounter.library.BuiltInEncounterDataLibrary;
import org.openmrs.module.reporting.dataset.DataSet;
import org.openmrs.module.reporting.dataset.DataSetColumn;
import org.openmrs.module.reporting.dataset.DataSetRow;
import org.openmrs.module.reporting.dataset.SimpleDataSet;
import org.openmrs.module.reporting.dataset.definition.DataSetDefinition;
import org.openmrs.module.reporting.dataset.definition.EncounterAndObsDataSetDefinition;
import org.openmrs.module.reporting.evaluation.EvaluationContext;
import org.openmrs.module.reporting.evaluation.EvaluationException;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * The logic that evaluates a {@link EncounterAndObsDataSetDefinition} and produces an {@link DataSet}
 * @see EncounterAndObsDataSetDefinition
 */
@Handler(supports = { EncounterAndObsDataSetDefinition.class }, order = 25)
public class EncounterAndObsDataSetEvaluator extends EncounterDataSetEvaluator {

	protected static final Log log = LogFactory.getLog(EncounterAndObsDataSetEvaluator.class);

	@Autowired
	BuiltInEncounterDataLibrary encounterData;

	/**
	 * @see DataSetEvaluator#evaluate(DataSetDefinition, EvaluationContext)
	 * @should evaluate an EncounterAndObsDataSetDefinition
	 */
	public DataSet evaluate(DataSetDefinition dataSetDefinition, EvaluationContext context) throws EvaluationException {

		EncounterAndObsDataSetDefinition dsd = (EncounterAndObsDataSetDefinition) dataSetDefinition;

		// If no specific columns definitions are specified, use some defaults
		if (dsd.getColumnDefinitions().isEmpty()) {
			dsd.addColumn("ENCOUNTER_ID", encounterData.getEncounterId(), "");
			dsd.addColumn("PATIENT_ID", encounterData.getPatientId(), "");
			dsd.addColumn("ENCOUNTER_TYPE", encounterData.getEncounterTypeName(), "");
			dsd.addColumn("ENCOUNTER_DATETIME", encounterData.getEncounterDatetime(), "");
			dsd.addColumn("LOCATION", encounterData.getLocationName(), "");
		}

		// Add all Obs for each encounter
		ObsForEncounterDataDefinition allObs = new ObsForEncounterDataDefinition();
		allObs.setSingleObs(false);
		dsd.addColumn("OBS", allObs, "");

		// Produce the core starting data set for encounter data
		SimpleDataSet data = (SimpleDataSet) super.evaluate(dsd, context);

		// Determine all necessary column headers and get necessary obs data to populate these
		Map<String, DataSetColumn> obsColumnMap = new HashMap<String, DataSetColumn>();
		ObsValueConverter obsValueConverter = new ObsValueConverter();

		// Get the maximum number of occurrences for each Obs column, to determine which need to have sequence numbers appended
		Map<String, Integer> maxNumForKey = new HashMap<String, Integer>();

		for (DataSetRow row : data.getRows()) {
			List<Obs> obsList = (List<Obs>)row.getColumnValue("OBS");

			if (obsList != null) {
				ObjectCounter<String> currentNumForKey = new ObjectCounter<String>();
				for (Obs obs : obsList) {
					String key = getObsKey(obs);
					if (key != null) {
						currentNumForKey.increment(key);
					}
				}

				for (Map.Entry<String, Integer> e : currentNumForKey.getAllObjectCounts().entrySet()) {
					Integer existing = maxNumForKey.get(e.getKey());
					if (existing == null || (existing < e.getValue())) {
						maxNumForKey.put(e.getKey(), e.getValue());
					}
				}
			}
		}

		// Add the Obs values to each dataset row
		for (DataSetRow row : data.getRows()) {
			List<Obs> obsList = (List<Obs>)row.getColumnValue("OBS");

			if (obsList != null) {
				ObjectCounter<String> currentNumForKey = new ObjectCounter<String>();
				for (Obs obs : obsList) {
					String key = getObsKey(obs);
					if (key != null) {
						int num = currentNumForKey.increment(key);
						String columnName = ObjectUtil.format(obs.getConcept()).replaceAll("\\s", "_").replaceAll("-", "_").toUpperCase();
						if (maxNumForKey.get(key) > 1) {
							columnName = columnName + "_" + num;
						}
						DataSetColumn obsColumn = obsColumnMap.get(columnName);
						if (obsColumn == null) {
							obsColumn = new DataSetColumn(columnName, columnName, Object.class);
							obsColumnMap.put(columnName, obsColumn);
						}
						row.addColumnValue(obsColumn, obsValueConverter.convert(obs));
					}
				}
			}

			row.removeColumn("OBS");
		}
		data.getMetaData().removeColumn("OBS");

		// Sort the obs columns by name, and add to metadata
		List<DataSetColumn> obsColumns = new ArrayList<DataSetColumn>(obsColumnMap.values());
		Collections.sort(obsColumns, new BeanPropertyComparator("name"));
		data.getMetaData().getColumns().addAll(obsColumns);

		return data;
	}

	protected String getObsKey(Obs obs) {
		if (obs.isObsGrouping()) {
			return null;
		}
		StringBuilder key = new StringBuilder(obs.getConcept().getConceptId().toString());
		for (Obs toCheck = obs.getObsGroup(); toCheck != null; toCheck = toCheck.getObsGroup() ) {
			key.append("_").append(toCheck.getConcept().getConceptId());
		}
		return key.toString();
	}
}