/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.elasticsearch.test.rest.yaml.section;

import org.apache.logging.log4j.Logger;
import org.elasticsearch.common.collect.Tuple;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.xcontent.XContentLocation;
import org.elasticsearch.common.xcontent.XContentParser;

import java.io.IOException;

import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.lessThan;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;

/**
 * Represents a lt assert section:
 *
 *  - lt:    { fields._ttl: 20000}
 *
 */
public class LessThanAssertion extends Assertion {
    public static LessThanAssertion parse(XContentParser parser) throws IOException {
        XContentLocation location = parser.getTokenLocation();
        Tuple<String,Object> stringObjectTuple = ParserUtils.parseTuple(parser);
        if (false == stringObjectTuple.v2() instanceof Comparable) {
            throw new IllegalArgumentException("lt section can only be used with objects that support natural ordering, found "
                    + stringObjectTuple.v2().getClass().getSimpleName());
        }
        return new LessThanAssertion(location, stringObjectTuple.v1(), stringObjectTuple.v2());
    }

    private static final Logger logger = Loggers.getLogger(LessThanAssertion.class);

    public LessThanAssertion(XContentLocation location, String field, Object expectedValue) {
        super(location, field, expectedValue);
    }

    @Override
    protected void doAssert(Object actualValue, Object expectedValue) {
        logger.trace("assert that [{}] is less than [{}] (field: [{}])", actualValue, expectedValue, getField());
        assertThat("value of [" + getField() + "] is not comparable (got [" + safeClass(actualValue) + "])",
                actualValue, instanceOf(Comparable.class));
        assertThat("expected value of [" + getField() + "] is not comparable (got [" + expectedValue.getClass() + "])",
                expectedValue, instanceOf(Comparable.class));
        try {
            assertThat(errorMessage(), (Comparable) actualValue, lessThan((Comparable) expectedValue));
        } catch (ClassCastException e) {
            fail("cast error while checking (" + errorMessage() + "): " + e);
        }
    }

    private String errorMessage() {
        return "field [" + getField() + "] is not less than [" + getExpectedValue() + "]";
    }
}
