package froala.editor.service;

import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.pdfbox.rendering.PDFRenderer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import froala.editor.utils.FileUtil;

/**
 * 다중 쓰레드 파일 업로드
 *
 * @since 2020. 8. 29.
 * @author 임종호
 *
 *         <PRE>
 * -----------------------
 * 개정이력
 * 2020. 8. 29. 임종호 : 최초작성
 *         </PRE>
 */
public class ParallelExcutorService {

	private static final Logger LOGGER = LoggerFactory.getLogger(ParallelExcutorService.class);
//	private final int maxCore = Runtime.getRuntime().availableProcessors();
//	private final ExecutorService executor = Executors.newFixedThreadPool(maxCore);
	private final ExecutorService executor = Executors.newCachedThreadPool();
	private final BlockingQueue<String> queue = new ArrayBlockingQueue<>(10);

	public ParallelExcutorService() {
	}

	/**
	 * start : 시작번호, repeat : 반복횟수, max : pdf파일 최대번호, pdfRenderer : PDFBox 객체,
	 * returnFileRoute : 이미지 파일저장경로
	 *
	 * @Author : 임종호
	 * @Date : 2020. 8. 29.
	 * @Method Name : submit
	 * @return : void
	 */
	public void pdfSubmit(String job, int start, int repeat, int max, PDFRenderer pdfRenderer, String returnFileRoute) {
		executor.submit(() -> {
			for (int i = start; i < repeat * 3 + start;) {
				int fileIndex = i + 1;
				if (max < fileIndex) {
					break;
				}
				String imgFileName = returnFileRoute + '_' + fileIndex + ".png";
				java.io.File existCheck2 = new java.io.File(imgFileName);
				if (!existCheck2.exists()) {
					// 순회하며 이미지로 변환 처리
					FileUtil.pdfImageWrite(pdfRenderer, i, imgFileName);
				}
				i += repeat;
			}
			String threadName = Thread.currentThread().getName();
			String result = job + ", " + threadName;
			try {
				queue.put(result);
			} catch (InterruptedException e) {
				Thread.currentThread().interrupt();
			}
		});
	}

	public String take() {
		try {
			return queue.take();
		} catch (InterruptedException e) {
			Thread.currentThread().interrupt();
			throw new IllegalStateException(e);
		}
	}

	public void close() {
		List<Runnable> unfinishedTasks = executor.shutdownNow();
		if (!unfinishedTasks.isEmpty()) {
			LOGGER.error("Not all tasks finished before calling close: " + unfinishedTasks.size());
		}
	}
}