package test;

import org.junit.Assert;
import org.junit.Test;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class TestQueryStatsComparator {

    @Test
    public void test() {

        long[] testData = {
                0, 0, 0, 1444225382010l, 0, 1444225382011l, 0, 1444225382012l, 0, 1444225382056l, 0,
                1444225382014l, 0, 1444225382015l, 0, 1444225382016l, 0, 0, 1444225382017l, 0, 1444225678350l, 0,
                1444225680397l, 0, 1444225382018l, 1444225382019l, 1444225382020l, 0, 1444225382021l, 0, 1444225382022l, 1444225382023l

        };

        List<QueryStats> stats = new ArrayList<>();

        for (int i = 0; i < testData.length; i++) {
            QueryStats qs = new QueryStats(String.valueOf(i), testData[i]);
            stats.add(qs);
        }

        try {
            Collections.sort(stats, new QueryStatsComparator());
        } catch (IllegalArgumentException e) {
            Assert.fail(e.getMessage());
        }
    }

    private static class QueryStatsComparator implements Comparator<QueryStats> {

        @Override
        public int compare(QueryStats stats1, QueryStats stats2) {
            if (stats1.lastInvocation == 0) return 1;
            if (stats2.lastInvocation == 0) return -1;

            long result = stats1.lastInvocation - stats2.lastInvocation;
            if (result > 0) {
                return 1;
            } else if (result == 0) {
                return 0;
            } else {
                return -1;
            }
        }
    }

    private static class QueryStats {

        private final long lastInvocation;
        private final String query;

        public QueryStats(String query, long lastInvocation) {
            this.query = query;
            this.lastInvocation = lastInvocation;
        }

        @Override
        public int hashCode() {
            return query.hashCode();
        }

        @Override
        public boolean equals(Object other) {
            if (other instanceof QueryStats) {
                QueryStats qs = (QueryStats) other;
                return qs.query.equals(this.query);
            }
            return false;
        }
    }

}