package org.awesky.webapp.utils;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Random;

import javax.servlet.http.HttpServletRequest;

import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;

public class CommonUtils {
	/**
	 * 判断变量是否为空
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isEmpty(String s) {
		if (null == s || "".equals(s) || "".equals(s.trim()) || "null".equalsIgnoreCase(s)) {
			return true;
		} else {
			return false;
		}
	}
	
	/**
	 * 使用率计算
	 */
	public static String fromUsage(long free, long total) {
		Double d = new BigDecimal(free * 100 / total).setScale(1, BigDecimal.ROUND_HALF_UP).doubleValue();
		return String.valueOf(d);
	}
	
	/**
	 * 返回当前时间 格式:yyyy-MM-dd hh:mm:ss
	 */
	public static String fromDateH(){
		DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
		return format1.format(new Date());
	}
	
	/**
	 * 返回当前时间 格式:yyyy-MM-dd
	 */
	public static String fromDateY(){
		DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
		return format1.format(new Date());
	}
	
	/**
	 * 用来去掉List中空值和相同项的。
	 */
	public static List<String> removeSameItem(List<String> list) {
		List<String> difList = new ArrayList<String>();
		for (String t : list) {
			if (t != null && !difList.contains(t)) {
				difList.add(t);
			}
		}
		return difList;
	}

	/**
	 * 返回用户的IP地址
	 */
	public static String toIpAddr(HttpServletRequest request) {
		String ip = request.getHeader("x-forwarded-for");
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("Proxy-Client-IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("WL-Proxy-Client-IP");
		}
		if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
		}
		return ip;
	}

	/**
	 * 传入原图名称,,获得一个以时间格式的新名称
	 */
	public static String generateFileName(String fileName) {
		DateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
		String formatDate = format.format(new Date());
		int random = new Random().nextInt(10000);
		int position = fileName.lastIndexOf(".");
		String extension = fileName.substring(position);
		return formatDate + random + extension;
	}

	/**
	 * 取得html网页内容 UTF8编码
	 * @param urlStr
	 *            网络地址
	 */
	public static String getInputHtmlUTF8(String urlStr) {
		URL url = null;
		try {
			url = new URL(urlStr);
			HttpURLConnection httpsURLConnection = (HttpURLConnection) url.openConnection();

			httpsURLConnection.setRequestMethod("GET");
			httpsURLConnection.setConnectTimeout(5 * 1000);
			httpsURLConnection.connect();
			if (httpsURLConnection.getResponseCode() == 200) {
				// 通过输入流获取网络图片
				InputStream inputStream = httpsURLConnection.getInputStream();
				String data = readHtml(inputStream, "UTF-8");
				inputStream.close();
				return data;
			}
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}

		return null;

	}

	/**
	 * 取得html网页内容 GBK编码
	 * @param urlStr
	 *            网络地址
	 */
	public static String getInputHtmlGBK(String urlStr) {
		URL url = null;
		try {
			url = new URL(urlStr);
			HttpURLConnection httpsURLConnection = (HttpURLConnection) url.openConnection();

			httpsURLConnection.setRequestMethod("GET");
			httpsURLConnection.setConnectTimeout(5 * 1000);
			httpsURLConnection.connect();
			if (httpsURLConnection.getResponseCode() == 200) {
				// 通过输入流获取网络图片
				InputStream inputStream = httpsURLConnection.getInputStream();
				String data = readHtml(inputStream, "GBK");
				inputStream.close();
				return data;
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}

		return null;

	}

	/**
	 * @param uncode
	 *            编码 GBK 或 UTF-8
	 */
	public static String readHtml(InputStream inputStream, String uncode) throws Exception {
		InputStreamReader input = new InputStreamReader(inputStream, uncode);
		BufferedReader bufReader = new BufferedReader(input);
		String line = "";
		StringBuilder contentBuf = new StringBuilder();
		while ((line = bufReader.readLine()) != null) {
			contentBuf.append(line);
		}
		return contentBuf.toString();
	}

	/**
	 * @return 返回资源的二进制数据 @
	 */
	public static byte[] readInputStream(InputStream inputStream) {

		// 定义一个输出流向内存输出数据
		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
		// 定义一个缓冲区
		byte[] buffer = new byte[1024];
		// 读取数据长度
		int len = 0;
		// 当取得完数据后会返回一个-1
		try {
			while ((len = inputStream.read(buffer)) != -1) {
				// 把缓冲区的数据 写到输出流里面
				byteArrayOutputStream.write(buffer, 0, len);
			}
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		} finally {
			try {
				byteArrayOutputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
				return null;
			}
		}

		// 得到数据后返回
		return byteArrayOutputStream.toByteArray();

	}

	/**
	 * 获取当前认证通过的用户名
	 * @return
	 */
	public static String getAuthenticatedUsername() { 
	    String username = null; 
	    Object principal = SecurityContextHolder.getContext() 
	        .getAuthentication().getPrincipal(); 
	    if (principal instanceof UserDetails) { 
	        username = ((UserDetails) principal).getUsername(); 
	    } else { 
	        username = principal.toString(); 
	    } 
	    return username; 
	 }

}