package com.imyeyu.compress;

import com.imyeyu.io.IO;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;

/**
 * Zip 解压器
 *
 * @author 夜雨
 * @version 2024-06-30 19:47
 */
public class ZipDecompressor extends Decompressor {

	@Override
	public void run(File fromFile, String toPath) throws Exception {
		initByteProgress(readTotalSize(fromFile));
		try {
			super.run(fromFile, toPath);
		} finally {
			resetProgress();
		}
	}

	@Override
	public void run(InputStream fromStream, String toPath) throws Exception {
		try (ZipInputStream zipInputStream = new ZipInputStream(nonClosing(fromStream))) {
			ZipEntry entry;
			boolean processed = false;
			while ((entry = zipInputStream.getNextEntry()) != null) {
				String path = IO.fitPath(toPath) + entry.getName();
				if (entry.isDirectory()) {
					IO.dir(path);
				} else {
					File toFile = IO.file(path);
					try (OutputStream outputStream = IO.getOutputStream(toFile)) {
						transfer(zipInputStream, outputStream);
						outputStream.flush();
					}
					handleFile(toFile);
					processed = true;
				}
				zipInputStream.closeEntry();
			}
			if (processed) {
				finishProgress();
			}
		}
	}

	/**
	 * 读取压缩包解压总字节数
	 *
	 * @param fromFile 压缩文件
	 * @return 总字节数，未知时返回 -1
	 * @throws Exception 读取失败
	 */
	private long readTotalSize(File fromFile) throws Exception {
		long totalSize = 0L;
		try (ZipFile zipFile = new ZipFile(fromFile)) {
			Enumeration<? extends ZipEntry> entries = zipFile.entries();
			while (entries.hasMoreElements()) {
				ZipEntry entry = entries.nextElement();
				if (entry.isDirectory()) {
					continue;
				}
				long size = entry.getSize();
				if (size < 0L) {
					return -1L;
				}
				totalSize += size;
			}
		}
		return totalSize;
	}
}