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/*
 * Licensed 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 io.trino.matching.pattern;

import io.trino.matching.Captures;
import io.trino.matching.Match;
import io.trino.matching.Pattern;
import io.trino.matching.PatternVisitor;

import java.util.Optional;
import java.util.stream.Stream;

import static java.util.Objects.requireNonNull;

public class EqualsPattern
        extends Pattern
{
    private final T expectedValue;

    public EqualsPattern(T expectedValue, Optional> previous)
    {
        super(previous);
        this.expectedValue = requireNonNull(expectedValue, "expectedValue can't be null. Use isNull() pattern instead.");
    }

    public T expectedValue()
    {
        return expectedValue;
    }

    @Override
    public  Stream accept(Object object, Captures captures, C context)
    {
        return Stream.of(Match.of(captures))
                .filter(match -> expectedValue.equals(object));
    }

    @Override
    public void accept(PatternVisitor patternVisitor)
    {
        patternVisitor.visitEquals(this);
    }
}