/**
 * AnalyzerBeans
 * Copyright (C) 2014 Neopost - Customer Information Management
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.eobjects.analyzer.descriptors;

import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Set;
import java.util.TreeSet;

import org.eobjects.analyzer.beans.api.Distributed;
import org.eobjects.analyzer.beans.api.NoAnalyzerResultReducer;
import org.eobjects.analyzer.result.AnalyzerResult;
import org.eobjects.analyzer.result.AnalyzerResultReducer;
import org.eobjects.analyzer.result.Metric;
import org.eobjects.analyzer.util.ReflectionUtils;

/**
 * Default {@link ResultDescriptor} implementation which can be used stand-alone
 * or as a delegate for e.g. an {@link AnalyzerBeanDescriptor} implementation.
 */
final class ResultDescriptorImpl implements ResultDescriptor {

    private static final long serialVersionUID = 1L;

    private final Class<? extends AnalyzerResult> _resultClass;
    private final Set<MetricDescriptor> _metrics;

    public ResultDescriptorImpl(Class<? extends AnalyzerResult> resultClass) {
        _resultClass = resultClass;

        Method[] metricMethods = ReflectionUtils.getMethods(resultClass, Metric.class);
        _metrics = new TreeSet<MetricDescriptor>();
        for (Method method : metricMethods) {
            MetricDescriptor metric = new MetricDescriptorImpl(resultClass, method);
            _metrics.add(metric);
        }
    }

    @Override
    public Class<? extends AnalyzerResult> getResultClass() {
        return _resultClass;
    }

    @Override
    public MetricDescriptor getResultMetric(String name) {
        if (name == null) {
            return null;
        }

        for (MetricDescriptor metric : _metrics) {
            if (name.equals(metric.getName())) {
                return metric;
            }
        }

        // second try - case insensitive
        for (MetricDescriptor metric : _metrics) {
            if (name.equalsIgnoreCase(metric.getName())) {
                return metric;
            }
        }
        return null;
    }

    @Override
    public Set<MetricDescriptor> getResultMetrics() {
        if (_metrics == null) {
            // can happen with deserialized instances only
            return Collections.emptySet();
        }
        return Collections.unmodifiableSet(_metrics);
    }

    @Override
    public Class<? extends AnalyzerResultReducer<?>> getResultReducerClass() {
        final Distributed distributedResult = ReflectionUtils.getAnnotation(getResultClass(), Distributed.class);
        if (distributedResult != null) {
            if (!distributedResult.value()) {
                return null;
            }
            final Class<? extends AnalyzerResultReducer<?>> reducer = distributedResult.reducer();
            if (reducer != null && reducer != NoAnalyzerResultReducer.class) {
                return reducer;
            }
        }
        return null;
    }

}