/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * 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 com.android.tradefed.result;

import com.android.tradefed.util.FileUtil;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * A {@link InputStreamSource} that takes an input file.
 *
 * <p>Caller is responsible for deleting the file
 */
public class FileInputStreamSource implements InputStreamSource {

    private final File mFile;
    private boolean mIsCancelled = false;
    private boolean mDeleteOnCancel = false;

    public FileInputStreamSource(File file) {
        mFile = file;
    }

    /**
     * Ctor
     *
     * @param file {@link File} containing the data to be streamed
     * @param deleteFileOnCancel if true, the file associated will be deleted when {@link #close()}
     *     is called
     */
    public FileInputStreamSource(File file, boolean deleteFileOnCancel) {
        mFile = file;
        mDeleteOnCancel = deleteFileOnCancel;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public synchronized InputStream createInputStream() {
        if (mIsCancelled) {
            return null;
        }
        try {
            return new FileInputStream(mFile);
        } catch (IOException e) {
            return null;
        }
    }

    /** {@inheritDoc} */
    @Override
    public synchronized void close() {
        mIsCancelled = true;
        if (mDeleteOnCancel) {
            cleanFile();
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public long size() {
        return mFile.length();
    }

    /**
     * Convenience method to delete the file associated with the FileInputStreamSource. Not safe.
     */
    public void cleanFile() {
        FileUtil.deleteFile(mFile);
    }

    /**
     * Returns the underlying file. File is not guarantee to exists anymore once the stream is
     * closed.
     */
    public File getFile() {
        return mFile;
    }
}