/*
 * 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.file.copy;

import org.gradle.api.file.DuplicateFileCopyingException;
import org.gradle.api.file.DuplicatesStrategy;
import org.gradle.api.file.RelativePath;
import org.gradle.api.internal.file.CopyActionProcessingStreamAction;
import org.gradle.api.tasks.WorkResult;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.HashSet;
import java.util.Set;

public class DuplicateHandlingCopyActionDecorator implements CopyAction {

    private final static Logger LOGGER = LoggerFactory.getLogger(DuplicateHandlingCopyActionDecorator.class);
    private final CopyAction delegate;

    public DuplicateHandlingCopyActionDecorator(CopyAction delegate) {
        this.delegate = delegate;
    }

    public WorkResult execute(final CopyActionProcessingStream stream) {
        final Set<RelativePath> visitedFiles = new HashSet<RelativePath>();

        return delegate.execute(new CopyActionProcessingStream() {
            public void process(final CopyActionProcessingStreamAction action) {
                stream.process(new CopyActionProcessingStreamAction() {
                    public void processFile(FileCopyDetailsInternal details) {
                        if (!details.isDirectory()) {
                            DuplicatesStrategy strategy = details.getDuplicatesStrategy();

                            if (!visitedFiles.add(details.getRelativePath())) {
                                if (strategy == DuplicatesStrategy.EXCLUDE) {
                                    return;
                                } else if (strategy == DuplicatesStrategy.FAIL) {
                                    throw new DuplicateFileCopyingException(String.format("Encountered duplicate path \"%s\" during copy operation configured with DuplicatesStrategy.FAIL", details.getRelativePath()));
                                } else if (strategy == DuplicatesStrategy.WARN) {
                                    LOGGER.warn("Encountered duplicate path \"{}\" during copy operation configured with DuplicatesStrategy.WARN", details.getRelativePath());
                                }
                            }
                        }

                        action.processFile(details);
                    }
                });
            }
        });
    }
}
