/*
 * Copyright 2011 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.internal.resource.local;

import org.gradle.api.Action;
import org.gradle.api.Transformer;
import org.gradle.api.internal.file.TemporaryFileProvider;
import org.gradle.internal.hash.HashUtil;

import java.io.File;
import java.util.Set;

public class GroupedAndNamedUniqueFileStore<K> implements FileStore<K>, FileStoreSearcher<K> {

    private PathKeyFileStore delegate;
    private final TemporaryFileProvider temporaryFileProvider;
    private final Transformer<String, K> grouper;
    private final Transformer<String, K> namer;


    public GroupedAndNamedUniqueFileStore(PathKeyFileStore delegate, TemporaryFileProvider temporaryFileProvider, Transformer<String, K> grouper, Transformer<String, K> namer) {
        this.delegate = delegate;
        this.temporaryFileProvider = temporaryFileProvider;
        this.grouper = grouper;
        this.namer = namer;
    }

    public LocallyAvailableResource move(K key, File source) {
        return delegate.move(toPath(key, getChecksum(source)), source);
    }

    public LocallyAvailableResource copy(K key, File source) {
        return delegate.copy(toPath(key, getChecksum(source)), source);
    }

    public Set<? extends LocallyAvailableResource> search(K key) {
        return delegate.search(toPath(key, "*"));
    }

    protected String toPath(K key, String checksumPart) {
        String group = grouper.transform(key);
        String name = namer.transform(key);

        return group + "/" + checksumPart + "/" + name;
    }

    private String getChecksum(File contentFile) {
        return HashUtil.createHash(contentFile, "SHA1").asHexString();
    }

    public File getTempFile() {
        return temporaryFileProvider.createTemporaryFile("filestore", "bin");
    }

    public void moveFilestore(File destination) {
        delegate.moveFilestore(destination);
    }

    public LocallyAvailableResource add(K key, Action<File> addAction) {
        //We cannot just delegate to the add method as we need the file content for checksum calculation here
        //and reexecuting the action isn't acceptable
        final File tempFile = getTempFile();
        addAction.execute(tempFile);
        final String groupedAndNamedKey = toPath(key, getChecksum(tempFile));
        return delegate.move(groupedAndNamedKey, tempFile);
    }
}
