/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.ml.timeseries.processor.interpolation;

import org.openimaj.ml.timeseries.TimeSeries;
import org.openimaj.ml.timeseries.processor.TimeSeriesProcessor;
import org.openimaj.ml.timeseries.processor.interpolation.util.TimeSpanUtils;
import org.openimaj.ml.timeseries.series.DoubleTimeSeries;

/**
 * Interpolate values of a time series. Useful for filling in missing values and
 * homogonising disperate sets of {@link TimeSeries} data
 *
 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
 *
 */
public abstract class TimeSeriesInterpolation implements TimeSeriesProcessor<double[], Double, DoubleTimeSeries> {

        private long[] times;

        /**
         * The processor's times are set to default, i.e. from min to max time in
         * steps of 1 long
         */
        public TimeSeriesInterpolation() {
                times = null;
        }

        /**
         * @param begin
         * @param end
         * @param delta
         */
        public TimeSeriesInterpolation(long begin, long end, long delta) {
                this.times = TimeSpanUtils.getTime(begin, end, delta);
        }

        /**
         * @param begin
         * @param steps
         * @param delta
         */
        public TimeSeriesInterpolation(long begin, int steps, long delta) {
                this.times = TimeSpanUtils.getTime(begin, steps, delta);
        }

        /**
         * @param begin
         *            the start of the new time series
         * @param end
         *            the end of the new time series
         * @param steps
         *            the steps between (begin = 0, end = 10, 6 steps will give 0,
         *            2, 4, 6, 8, 10
         */
        public TimeSeriesInterpolation(long begin, long end, int steps) {
                this.times = TimeSpanUtils.getTime(begin, end, steps);
        }

        /**
         * @param times
         *            the times used by the processor
         */
        public TimeSeriesInterpolation(long[] times) {
                this.times = times;
        }

        /**
         * Uses {@link #interpolate(DoubleTimeSeries, long[])} to return an
         * interpolation of the construction {@link TimeSeries} between the times at
         * the required interval
         * 
         * @param series
         * @param begin
         *            time to start
         * @param end
         *            time to end
         * @param delta
         *            the delta between time steps
         * @return {@link DoubleTimeSeries} instance interpolated from the
         *         construction {@link TimeSeries} instance
         */
        public DoubleTimeSeries interpolate(DoubleTimeSeries series, long begin, long end, long delta) {
                final long[] times = TimeSpanUtils.getTime(begin, end, delta);
                return interpolate(series, times);
        }

        /**
         * Uses {@link #interpolate(DoubleTimeSeries, long[])} to return an
         * interpolation of the construction {@link TimeSeries} from begin, for a
         * number of steps with a given delta between steps
         * 
         * @param series
         * @param begin
         * @param steps
         * @param delta
         * @return {@link DoubleTimeSeries} instance interpolated from the
         *         construction {@link TimeSeries} instance
         */
        public DoubleTimeSeries interpolate(DoubleTimeSeries series, long begin, int steps, long delta) {
                final long[] times = TimeSpanUtils.getTime(begin, steps, delta);
                return interpolate(series, times);
        }

        /**
         * Uses {@link #interpolate(DoubleTimeSeries,long[])} to return an
         * interpolation of the construction {@link TimeSeries} from begin, until
         * end with a delta which means that there are splits time instances
         * 
         * @param series
         * @param begin
         * @param end
         * @param splits
         * @return {@link DoubleTimeSeries} instance interpolated from the
         *         construction {@link TimeSeries} instance
         */
        public DoubleTimeSeries interpolate(DoubleTimeSeries series, long begin, long end, int splits) {
                final long[] times = TimeSpanUtils.getTime(begin, end, splits);
                return interpolate(series, times);
        }

        /**
         * @param series
         * @return a new {@link DoubleTimeSeries} interpolated with times provided
         *         in the constructor
         */
        public DoubleTimeSeries interpolate(DoubleTimeSeries series) {
                return interpolate(series, this.times);
        }

        /**
         * @param series
         * @param times
         *            might be null, therefore some "defualt" time step should be
         *            used
         * @return {@link DoubleTimeSeries} instance interpolated from the
         *         construction {@link TimeSeries} instance
         */
        public abstract DoubleTimeSeries interpolate(DoubleTimeSeries series, long[] times);

        @Override
        public void process(DoubleTimeSeries ts) {
                ts.internalAssign(this.interpolate(ts, times));
        }
}