package ryancheng.example.progressbar;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
import android.os.Environment;

public class FTPManager {
	FTPClient ftpClient = null;

	public FTPManager() {
		ftpClient = new FTPClient();
	}

	// 連線到ftp伺服器
	public synchronized boolean connect() throws Exception {
		boolean bool = false;
		if (ftpClient.isConnected()) {//判斷是否已登陸
			ftpClient.disconnect();
		}
		ftpClient.setDataTimeout(20000);//設定連線超時時間
		ftpClient.setControlEncoding("utf-8");
		ftpClient.connect("ip地址", 埠);
		if (FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
			if (ftpClient.login("使用者名稱", "密碼")) {
				bool = true;
				System.out.println("ftp連線成功");
			}
		}
		return bool;
	}

	// 建立資料夾
	public boolean createDirectory(String path) throws Exception {
		boolean bool = false;
		String directory = path.substring(0, path.lastIndexOf("/") + 1);
		int start = 0;
		int end = 0;
		if (directory.startsWith("/")) {
			start = 1;
		}
		end = directory.indexOf("/", start);
		while (true) {
			String subDirectory = directory.substring(start, end);
			if (!ftpClient.changeWorkingDirectory(subDirectory)) {
				ftpClient.makeDirectory(subDirectory);
				ftpClient.changeWorkingDirectory(subDirectory);
				bool = true;
			}
			start = end + 1;
			end = directory.indexOf("/", start);
			if (end == -1) {
				break;
			}
		}
		return bool;
	}

	// 實現上傳檔案的功能
	public synchronized boolean uploadFile(String localPath, String serverPath)
			throws Exception {
		// 上傳檔案之前，先判斷本地檔案是否存在
		File localFile = new File(localPath);
		if (!localFile.exists()) {
			System.out.println("本地檔案不存在");
			return false;
		}
		System.out.println("本地檔案存在，名稱為：" + localFile.getName());
		createDirectory(serverPath); // 如果資料夾不存在，建立資料夾
		System.out.println("伺服器檔案存放路徑：" + serverPath + localFile.getName());
		String fileName = localFile.getName();
		// 如果本地檔案存在，伺服器檔案也在，上傳檔案，這個方法中也包括了斷點上傳
		long localSize = localFile.length(); // 本地檔案的長度
		FTPFile[] files = ftpClient.listFiles(fileName);
		long serverSize = 0;
		if (files.length == 0) {
			System.out.println("伺服器檔案不存在");
			serverSize = 0;
		} else {
			serverSize = files[0].getSize(); // 伺服器檔案的長度
		}
		if (localSize <= serverSize) {
			if (ftpClient.deleteFile(fileName)) {
				System.out.println("伺服器檔案存在,刪除檔案,開始重新上傳");
				serverSize = 0;
			}
		}
		RandomAccessFile raf = new RandomAccessFile(localFile, "r");
		// 進度
		long step = localSize / 100;
		long process = 0;
		long currentSize = 0;
		// 好了，正式開始上傳檔案
		ftpClient.enterLocalPassiveMode();
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		ftpClient.setRestartOffset(serverSize);
		raf.seek(serverSize);
		OutputStream output = ftpClient.appendFileStream(fileName);
		byte[] b = new byte[1024];
		int length = 0;
		while ((length = raf.read(b)) != -1) {
			output.write(b, 0, length);
			currentSize = currentSize + length;
			if (currentSize / step != process) {
				process = currentSize / step;
				if (process % 10 == 0) {
					System.out.println("上傳進度：" + process);
				}
			}
		}
		output.flush();
		output.close();
		raf.close();
		if (ftpClient.completePendingCommand()) {
			System.out.println("檔案上傳成功");
			return true;
		} else {
			System.out.println("檔案上傳失敗");
			return false;
		}
	}

	// 實現下載檔案功能，可實現斷點下載
	public synchronized boolean downloadFile(String localPath, String serverPath)
			throws Exception {
		// 先判斷伺服器檔案是否存在
		FTPFile[] files = ftpClient.listFiles(serverPath);
		if (files.length == 0) {
			System.out.println("伺服器檔案不存在");
			return false;
		}
		System.out.println("遠端檔案存在,名字為：" + files[0].getName());
		localPath = localPath + files[0].getName();
		// 接著判斷下載的檔案是否能斷點下載
		long serverSize = files[0].getSize(); // 獲取遠端檔案的長度
		File localFile = new File(localPath);
		long localSize = 0;
		if (localFile.exists()) {
			localSize = localFile.length(); // 如果本地檔案存在，獲取本地檔案的長度
			if (localSize >= serverSize) {
				System.out.println("檔案已經下載完了");
				File file = new File(localPath);
				file.delete();
				System.out.println("本地檔案存在，刪除成功，開始重新下載");
				return false;
			}
		}
		// 進度
		long step = serverSize / 100;
		long process = 0;
		long currentSize = 0;
		// 開始準備下載檔案
		ftpClient.enterLocalActiveMode();
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		OutputStream out = new FileOutputStream(localFile, true);
		ftpClient.setRestartOffset(localSize);
		InputStream input = ftpClient.retrieveFileStream(serverPath);
		byte[] b = new byte[1024];
		int length = 0;
		while ((length = input.read(b)) != -1) {
			out.write(b, 0, length);
			currentSize = currentSize + length;
			if (currentSize / step != process) {
				process = currentSize / step;
				if (process % 10 == 0) {
					System.out.println("下載進度：" + process);
				}
			}
		}
		out.flush();
		out.close();
		input.close();
		// 此方法是來確保流處理完畢，如果沒有此方法，可能會造成現程式死掉
		if (ftpClient.completePendingCommand()) {
			System.out.println("檔案下載成功");
			return true;
		} else {
			System.out.println("檔案下載失敗");
			return false;
		}
	}

	// 如果ftp上傳開啟，就關閉掉
	public void closeFTP() throws Exception {
		if (ftpClient.isConnected()) {
			ftpClient.disconnect();
		}
	}
}