/*
 ***************************************************************************************
 *  Copyright (C) 2006 EsperTech, Inc. All rights reserved.                            *
 *  http://www.espertech.com/esper                                                     *
 *  http://www.espertech.com                                                           *
 *  ---------------------------------------------------------------------------------- *
 *  The software in this package is published under the terms of the GPL license       *
 *  a copy of which has been included with this distribution in the license.txt file.  *
 ***************************************************************************************
 */
package com.espertech.esper.filter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.IdentityHashMap;
import java.util.TreeMap;
import java.util.concurrent.locks.ReadWriteLock;

/**
 * Index for filter parameter constants for the range operators (range open/closed/half).
 * The implementation is based on the SortedMap implementation of TreeMap and stores only expression
 * parameter values of type DoubleRange.
 */
public abstract class FilterParamIndexDoubleRangeBase extends FilterParamIndexLookupableBase {
    protected final TreeMap<DoubleRange, EventEvaluator> ranges;
    private final IdentityHashMap<DoubleRange, EventEvaluator> rangesNullEndpoints;
    private final ReadWriteLock rangesRWLock;

    protected double largestRangeValueDouble = Double.MIN_VALUE;

    protected FilterParamIndexDoubleRangeBase(FilterSpecLookupable lookupable, ReadWriteLock readWriteLock, FilterOperator filterOperator) {
        super(filterOperator, lookupable);

        ranges = new TreeMap<DoubleRange, EventEvaluator>(new DoubleRangeComparator());
        rangesNullEndpoints = new IdentityHashMap<DoubleRange, EventEvaluator>();
        rangesRWLock = readWriteLock;
    }

    public final EventEvaluator get(Object expressionValue) {
        if (!(expressionValue instanceof DoubleRange)) {
            throw new IllegalArgumentException("Supplied expressionValue must be of type DoubleRange");
        }

        DoubleRange range = (DoubleRange) expressionValue;
        if ((range.getMax() == null) || (range.getMin() == null)) {
            return rangesNullEndpoints.get(range);
        }

        return ranges.get(range);
    }

    public final void put(Object expressionValue, EventEvaluator matcher) {
        if (!(expressionValue instanceof DoubleRange)) {
            throw new IllegalArgumentException("Supplied expressionValue must be of type DoubleRange");
        }

        DoubleRange range = (DoubleRange) expressionValue;
        if ((range.getMax() == null) || (range.getMin() == null)) {
            rangesNullEndpoints.put(range, matcher);     // endpoints null - we don't enter
            return;
        }

        if (Math.abs(range.getMax() - range.getMin()) > largestRangeValueDouble) {
            largestRangeValueDouble = Math.abs(range.getMax() - range.getMin());
        }

        ranges.put(range, matcher);
    }

    public final void remove(Object filterConstant) {
        DoubleRange range = (DoubleRange) filterConstant;

        if ((range.getMax() == null) || (range.getMin() == null)) {
            rangesNullEndpoints.remove(range);
            return;
        }
        ranges.remove(range);
    }

    public final int sizeExpensive() {
        return ranges.size();
    }

    public boolean isEmpty() {
        return ranges.isEmpty();
    }

    public final ReadWriteLock getReadWriteLock() {
        return rangesRWLock;
    }

    private static final Logger log = LoggerFactory.getLogger(FilterParamIndexDoubleRangeBase.class);
}