/*
 * Copyright 2013 the original author or authors.
 *
 * 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 org.gradle.api.internal.artifacts.ivyservice.ivyresolve.strategy;

import org.gradle.api.artifacts.ComponentMetadata;

public class LatestVersionSelector extends AbstractStringVersionSelector implements LockingAwareSelector {
    private final String selectorStatus;

    public LatestVersionSelector(String selector) {
        super(selector);
        selectorStatus = selector.substring("latest.".length());
    }

    public String getSelectorStatus() {
        return selectorStatus;
    }

    public boolean isDynamic() {
        return true;
    }

    public boolean requiresMetadata() {
        return true;
    }

    public boolean matchesUniqueVersion() {
        return true;
    }

    public boolean accept(String candidate) {
        throw new UnsupportedOperationException("accept(String)");
    }

    public boolean accept(ComponentMetadata candidate) {
        int selectorStatusIndex = candidate.getStatusScheme().indexOf(selectorStatus);
        int candidateStatusIndex = candidate.getStatusScheme().indexOf(candidate.getStatus());
        return selectorStatusIndex >=0 && selectorStatusIndex <= candidateStatusIndex;
    }

    @Override
    public boolean canShortCircuitWhenVersionAlreadyPreselected() {
        return false;
    }

    public VersionSelector forLocking() {
        return new LockingAwareLatestVersionSelector(getSelector());
    }

    private static class LockingAwareLatestVersionSelector extends LatestVersionSelector {
        private LockingAwareLatestVersionSelector(String selector) {
            super(selector);
        }

        @Override
        public boolean accept(String candidate) {
            // This is not right, we should really call accept with ComponentMetadata because
            // we need to check if the status of the candidate is matching. However, this is
            // only used in the context of dependency locking, and this method will only be
            // called with a candidate which is assumed to pass the test.
            return true;
        }

        @Override
        public boolean matchesUniqueVersion() {
            return false;
        }

        @Override
        public boolean canShortCircuitWhenVersionAlreadyPreselected() {
            return true;
        }
    }
}
