package froala.editor.video;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.io.RandomAccessFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import froala.editor.utils.view.VideoView;

/**
 * 동영상 스트리밍 유틸
 * @since 2021. 6. 18.
 * @author 임종호
 * <PRE>
 * -----------------------
 * 개정이력
 * 2021. 6. 18. 임종호 : 최초작성
 * </PRE>
 */
public class StreamingUtil {
	private final static Logger LOGGER = LoggerFactory.getLogger(VideoView.class);

	public void streaming(File file, HttpServletRequest request, HttpServletResponse response, OutputStream out)
			throws IOException {
		StreamingResponse streamingResponse = new StreamingResponse();
		Range range = streamingResponse.write(file, request, response);
		copyStreaming(file, out, range);
	}

	private void copyStreaming(File file, OutputStream output, Range range) {
		RandomAccessFile randomFile = null;
		long partSize = range.getPartSize();
		try {
			randomFile = new RandomAccessFile(file, "r");
			randomFile.seek(range.getStart());
			byte[] buf = new byte[StreamingResponse.DEFAULT_BUFFER_SIZE];
			do {
				int block = 0;
				if (partSize > StreamingResponse.DEFAULT_BUFFER_SIZE) {
					block = StreamingResponse.DEFAULT_BUFFER_SIZE;
				} else {
					block = (int) partSize;
				}
				int len = randomFile.read(buf, 0, block);
				output.write(buf, 0, len);
				output.flush();
				partSize -= block;
			} while (partSize > 0);
		} catch (IOException e) {
			LOGGER.error("User canceled streaming request {}", e.getCause().getMessage());
		} finally {
			IOUtils.closeQuietly(randomFile);
		}
	}
}