/*-
 * Copyright 2015, 2016 Diamond Light Source Ltd.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */

package org.eclipse.january.dataset;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateDatasetImpl extends StringDataset implements DateDataset {
        // pin UID to base class
        private static final long serialVersionUID = Dataset.serialVersionUID;

        private static final SimpleDateFormat ISO8601_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
        
        static DateDatasetImpl createFromObject(final Object obj) {
                final DateDatasetImpl result = new DateDatasetImpl();
                result.shape = ShapeUtils.getShapeFromObject(obj);
                result.size = ShapeUtils.calcSize(result.shape);
                result.odata = result.data = createArray(result.size);
                
                final int[] pos = new int[result.shape.length];
                result.fillData(obj, 0, pos);
                
                return result;
        }

        /**
         * Create a null dataset
         */
        DateDatasetImpl() {
                super();
        }

        DateDatasetImpl(final int... shape) {
                super(shape);
        }

        DateDatasetImpl(final Date[] data, int... shape) {
                super(datesToStrings(data), shape);
        }

        @Override
        public int getDType() {
                return DATE;
        }

        private static String[] datesToStrings(final Date[] dates) {
                final String[] dateStrings = new String[dates.length];
                for (int i = 0; i < dates.length; i++) {
                        dateStrings[i] = dateToString(dates[i]);
                }
                
                return dateStrings;
        }
        
        private static String dateToString(final Date date) {
                if (date != null) {
                        return ISO8601_DATE_FORMAT.format(date);
                }
                
                return null;
        }
        
        private static String objectToDateString(final Object obj) {
                if (obj instanceof Date) {
                        return dateToString((Date) obj);
                } else if (obj instanceof Dataset) {
                        Dataset dataset = (Dataset) obj;
                        if (dataset.getSize() != 1) {
                                logger.error("Given dataset must only have one item");
                                throw new IllegalArgumentException("Given dataset must have only one item");
                        }
                        
                        return objectToDateString(dataset.getObjectAbs(dataset.getOffset()));
                } else if (obj instanceof IDataset) {
                        IDataset dataset = (IDataset) obj;
                        if (dataset.getSize() != 1) {
                                logger.error("Given dataset must only have one item");
                                throw new IllegalArgumentException("Given dataset must have only one item");
                        }
                        return objectToDateString(dataset.getObject(new int[dataset.getRank()]));
                } else {
                        logger.error("Argument is of unsupported class");
                        throw new IllegalArgumentException("Argument is of unsupported class");
                }
        }
        
        private static Date stringToDate(final String dateAsString) {
                if (dateAsString != null) {
                        try {
                                return ISO8601_DATE_FORMAT.parse(dateAsString);
                        } catch (ParseException e) {
                                // fall through to return null
                                logger.error("Could not parse datetime: " + dateAsString);
                        }
                }
                
                return null;
        }
        
        @Override
        public Date getDate() {
                final String dateAsString = super.getString();
                return stringToDate(dateAsString);
        }

        @Override
        public Date getDate(int i) {
                final String dateAsString = super.getString(i);
                return stringToDate(dateAsString);
        }

        @Override
        public Date getDate(int i, int j) {
                final String dateAsString = super.getString(i, j);
                return stringToDate(dateAsString);
        }

        @Override
        public Date getDate(int... pos) {
                final String dateAsString = super.getString(pos);
                return stringToDate(dateAsString);
        }

        @Override
        public Date getDateAbs(int index) {
                final String dateAsString = super.getStringAbs(index);
                if (dateAsString != null) {
                        return stringToDate(dateAsString);
                }
                
                return null;
        }
        
        @Override
        public void setItemDirect(final int dindex, final int sindex, final Object src) {
                if (src instanceof String[]) {
                        super.setItemDirect(dindex, sindex, src);
                } else if (src instanceof Date[]) {
                        String[] datesAsStrings = datesToStrings((Date[]) src);
                        data[dindex] = datesAsStrings[sindex];
                } else {
                        logger.error("Argument is of unsupported class");
                        throw new IllegalArgumentException("Argument is of unsupported class");
                }
        }

        public void setAbs(final int index, final Date date) {
                data[index] = dateToString(date);
                setDirty();
        }
        
        /**
         * @since 2.0
         */
        public void setItem(final Date value) {
                setAbs(getFirst1DIndex(), value);
        }
        
        public void setItem(final Date value, final int i) {
                setAbs(get1DIndex(i), value);
        }
        
        public void setItem(final Date value, final int i, final int j) {
                setAbs(get1DIndex(i, j), value);
        }
        
        public void setItem(final Date value, final int... pos) {
                setAbs(get1DIndex(pos), value);
        }

        @Override
        public void set(final Object obj) {
                setItem(objectToDateString(obj));
        }

        @Override
        public void set(final Object obj, final int i) {
                setItem(objectToDateString(obj), i);
        }

        @Override
        public void set(final Object obj, final int i, final int j) {
                setItem(objectToDateString(obj), i, j);
        }
        
        @Override
        public void set(final Object obj, int... pos) {
                if (pos == null || (pos.length == 0 && shape.length > 0)) {
                        pos = new int[shape.length];
                }
                
                setItem(objectToDateString(obj), pos);
        }
        
        @Override
        public StringDatasetBase sort(Integer axis) {
                // Note yet supported.
                // TODO: this method will be inefficient as we store dates formatted as strings
                throw new UnsupportedOperationException("Cannot sort dataset");
        }

}