/*
 * LumaQQ - Java QQ Client
 *
 * Copyright (C) 2004 luma < stubma@163.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

package com.blogool.ip;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteOrder;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;

/**
 * 
 * 
 * 用來讀取QQwry.dat文件，以根據ip獲得好友位置，QQwry.dat的格式是 一. 文件頭，共8字節 1. 第一個起始IP的絕對偏移， 4字節 2.
 * 最后一個起始IP的絕對偏移， 4字節 二. "結束地址/國家/區域"記錄區 四字節ip地址后跟的每一條記錄分成兩個部分 1. 國家記錄 2. 地區記錄
 * 但是地區記錄是不一定有的。而且國家記錄和地區記錄都有兩種形式 1. 以0結束的字符串 2. 4個字節，一個字節可能為0x1或0x2 a.
 * 為0x1時，表示在絕對偏移后還跟著一個區域的記錄，注意是絕對偏移之后，而不是這四個字節之后 b. 為0x2時，表示在絕對偏移后沒有區域記錄
 * 不管為0x1還是0x2，后三個字節都是實際國家名的文件內絕對偏移
 * 如果是地區記錄，0x1和0x2的含義不明，但是如果出現這兩個字節，也肯定是跟著3個字節偏移，如果不是 則為0結尾字符串 三.
 * "起始地址/結束地址偏移"記錄區 1. 每條記錄7字節，按照起始地址從小到大排列 a. 起始IP地址，4字節 b. 結束ip地址的絕對偏移，3字節
 * 
 * 注意，這個文件里的ip地址和所有的偏移量均采用little-endian格式，而java是采用 big-endian格式的，要注意轉換
 * 
 */
public class IPSeeker {
	/**
	 * 
	 * 
	 * 用來封裝ip相關信息，目前只有兩個字段，ip所在的國家和地區
	 * 
	 * 
	 * 
	 * 
	 * @author 馬若劼
	 */

	public static void main(String[] args) {
		IPSeeker ipseeker = IPSeeker.getInstance();
		String sip[] = { "60.177.69.138", "124.91.62.239", "124.91.62.239",
				"59.40.87.8", "221.222.73.88", "60.51.114.120",
				"222.212.223.146", "60.51.114.120", "60.51.114.120",
				"60.51.114.120", "60.51.114.120", "211.99.23.121",
				"58.45.85.107", "58.45.85.107", "121.32.94.204",
				"117.22.46.178", "218.19.2.195", "58.218.23.10",
				"58.218.23.10", "202.173.10.2", "60.178.167.241",
				"58.213.137.5", "58.38.165.221", "58.38.165.221",
				"61.150.15.25", "58.45.82.76", "218.8.200.210", "59.33.24.233",
				"60.176.240.196", "60.9.86.85", "60.51.114.120",
				"60.51.114.120", "125.120.155.45", "219.140.61.180",
				"219.140.61.180", "59.49.158.100", "59.49.158.100",
				"58.218.23.10", "221.220.25.54", "222.71.176.119",
				"220.168.115.124", "58.38.165.221", "218.3.251.246",
				"58.213.137.5", "218.3.251.246", "121.33.219.235",
				"222.130.195.225", "60.51.114.120", "218.3.251.246",
				"219.140.61.180", "219.140.61.180", "125.120.155.45",
				"60.9.97.186", "124.228.44.177", "218.19.2.195",
				"222.70.225.180", "58.38.165.221", "58.38.165.221",
				"60.168.67.99", "58.38.165.221", "58.38.165.221",
				"61.29.214.76", "220.234.156.254", "60.51.114.120",
				"60.51.114.120", "60.51.114.120", "222.168.148.111",
				"117.24.28.13", "59.49.158.100", "60.209.253.61",
				"61.150.15.83", "60.208.156.110", "124.227.192.131",
				"125.120.155.90", "218.83.58.250", "60.191.89.102",
				"222.71.176.119", "60.178.167.241", "60.208.111.203",
				"222.74.231.66", "58.221.253.118", "122.89.146.55",
				"60.51.114.120", "58.221.253.118", "59.49.158.100",
				"218.10.158.162", "220.160.38.98", "124.227.192.131",
				"219.245.44.214", "211.158.41.214", "219.245.44.185",
				"218.0.113.43", "211.158.41.214", "218.68.82.73",
				"125.120.144.14", "125.120.155.90", "60.171.169.251",
				"124.78.165.8", "124.78.165.8", "218.22.186.125" };
		for (int i = 0; i < sip.length; i++) {
			System.out.println(ipseeker.getAddress(sip[i]));
		}

	}

	private class IPLocation {
		public String country;

		public String area;

		public IPLocation() {
			country = area = "";
		}

		public IPLocation getCopy() {
			IPLocation ret = new IPLocation();
			ret.country = country;
			ret.area = area;
			return ret;
		}
	}

	private static final String IP_FILE = IPSeeker.class.getResource(
			"QQWry.dat").toString().substring(5);

	// 一些固定常量，比如記錄長度等等
	private static final int IP_RECORD_LENGTH = 7;

	private static final byte AREA_FOLLOWED = 0x01;

	private static final byte NO_AREA = 0x2;

	// 用來做為cache，查詢一個ip時首先查看cache，以減少不必要的重復查找
	private Hashtable ipCache;

	// 隨機文件訪問類
	private RandomAccessFile ipFile;

	// 內存映射文件
	private MappedByteBuffer mbb;

	// 單一模式實例
	private static IPSeeker instance = new IPSeeker();

	// 起始地區的開始和結束的絕對偏移
	private long ipBegin, ipEnd;

	// 為提高效率而采用的臨時變量
	private IPLocation loc;

	private byte[] buf;

	private byte[] b4;

	private byte[] b3;

	/**
	 * 私有構造函數
	 */
	private IPSeeker() {
		ipCache = new Hashtable();
		loc = new IPLocation();
		buf = new byte[100];
		b4 = new byte[4];
		b3 = new byte[3];
		try {
			ipFile = new RandomAccessFile(IP_FILE, "r");
		} catch (FileNotFoundException e) {
			System.out.println(IPSeeker.class.getResource("QQWry.dat")
					.toString());
			System.out.println(IP_FILE);
			System.out.println("IP地址信息文件沒有找到，IP顯示功能將無法使用");
			ipFile = null;
		}
		// 如果打開文件成功，讀取文件頭信息
		if (ipFile != null) {
			try {
				ipBegin = readLong4(0);
				ipEnd = readLong4(4);
				if (ipBegin == -1 || ipEnd == -1) {
					ipFile.close();
					ipFile = null;
				}
			} catch (IOException e) {
				System.out.println("IP地址信息文件格式有錯誤，IP顯示功能將無法使用");
				ipFile = null;
			}
		}
	}

	/**
	 * @return 單一實例
	 */
	public static IPSeeker getInstance() {
		return instance;
	}

	/**
	 * 給定一個地點的不完全名字，得到一系列包含s子串的IP范圍記錄
	 * 
	 * @param s
	 *            地點子串
	 * @return 包含IPEntry類型的List
	 */
	public List getIPEntriesDebug(String s) {
		List ret = new ArrayList();
		long endOffset = ipEnd + 4;
		for (long offset = ipBegin + 4; offset <= endOffset; offset += IP_RECORD_LENGTH) {
			// 讀取結束IP偏移
			long temp = readLong3(offset);
			// 如果temp不等于-1，讀取IP的地點信息
			if (temp != -1) {
				IPLocation loc = getIPLocation(temp);
				// 判斷是否這個地點里面包含了s子串，如果包含了，添加這個記錄到List中，如果沒有，繼續
				if (loc.country.indexOf(s) != -1 || loc.area.indexOf(s) != -1) {
					IPEntry entry = new IPEntry();
					entry.country = loc.country;
					entry.area = loc.area;
					// 得到起始IP
					readIP(offset - 4, b4);
					entry.beginIp = Utils.getIpStringFromBytes(b4);
					// 得到結束IP
					readIP(temp, b4);
					entry.endIp = Utils.getIpStringFromBytes(b4);
					// 添加該記錄
					ret.add(entry);
				}
			}
		}
		return ret;
	}

	/**
	 * 給定一個地點的不完全名字，得到一系列包含s子串的IP范圍記錄
	 * 
	 * @param s
	 *            地點子串
	 * @return 包含IPEntry類型的List
	 */
	public List getIPEntries(String s) {
		List ret = new ArrayList();
		try {
			// 映射IP信息文件到內存中
			if (mbb == null) {
				FileChannel fc = ipFile.getChannel();
				mbb = fc.map(FileChannel.MapMode.READ_ONLY, 0, ipFile.length());
				mbb.order(ByteOrder.LITTLE_ENDIAN);
			}
			int endOffset = (int) ipEnd;
			for (int offset = (int) ipBegin + 4; offset <= endOffset; offset += IP_RECORD_LENGTH) {
				int temp = readInt3(offset);
				if (temp != -1) {
					IPLocation loc = getIPLocation(temp);
					// 判斷是否這個地點里面包含了s子串，如果包含了，添加這個記錄到List中，如果沒有，繼續
					if (loc.country.indexOf(s) != -1
							|| loc.area.indexOf(s) != -1) {
						IPEntry entry = new IPEntry();
						entry.country = loc.country;
						entry.area = loc.area;
						// 得到起始IP
						readIP(offset - 4, b4);
						entry.beginIp = Utils.getIpStringFromBytes(b4);
						// 得到結束IP
						readIP(temp, b4);
						entry.endIp = Utils.getIpStringFromBytes(b4);
						// 添加該記錄
						ret.add(entry);
					}
				}
			}
		} catch (IOException e) {
			System.out.println(e.getMessage());
		}
		return ret;
	}

	/**
	 * 從內存映射文件的offset位置開始的3個字節讀取一個int
	 * 
	 * @param offset
	 * @return
	 */
	private int readInt3(int offset) {
		mbb.position(offset);
		return mbb.getInt() & 0x00FFFFFF;
	}

	/**
	 * 從內存映射文件的當前位置開始的3個字節讀取一個int
	 * 
	 * @return
	 */
	private int readInt3() {
		return mbb.getInt() & 0x00FFFFFF;
	}

	/**
	 * 根據IP得到國家名
	 * 
	 * @param ip
	 *            ip的字節數組形式
	 * @return 國家名字符串
	 */
	public String getCountry(byte[] ip) {
		// 檢查ip地址文件是否正常
		if (ipFile == null)
			return "錯誤的IP數據庫文件";
		// 保存ip，轉換ip字節數組為字符串形式
		String ipStr = Utils.getIpStringFromBytes(ip);
		// 先檢查cache中是否已經包含有這個ip的結果，沒有再搜索文件
		if (ipCache.containsKey(ipStr)) {
			IPLocation loc = (IPLocation) ipCache.get(ipStr);
			return loc.country;
		} else {
			IPLocation loc = getIPLocation(ip);
			ipCache.put(ipStr, loc.getCopy());
			return loc.country;
		}
	}

	/**
	 * 根據IP得到國家名
	 * 
	 * @param ip
	 *            IP的字符串形式
	 * @return 國家名字符串
	 */
	public String getCountry(String ip) {
		return getCountry(Utils.getIpByteArrayFromString(ip));
	}

	/**
	 * 根據IP得到地區名
	 * 
	 * @param ip
	 *            ip的字節數組形式
	 * @return 地區名字符串
	 */
	public String getArea(byte[] ip) {
		// 檢查ip地址文件是否正常
		if (ipFile == null)
			return "錯誤的IP數據庫文件";
		// 保存ip，轉換ip字節數組為字符串形式
		String ipStr = Utils.getIpStringFromBytes(ip);
		// 先檢查cache中是否已經包含有這個ip的結果，沒有再搜索文件
		if (ipCache.containsKey(ipStr)) {
			IPLocation loc = (IPLocation) ipCache.get(ipStr);
			return loc.area;
		} else {
			IPLocation loc = getIPLocation(ip);
			ipCache.put(ipStr, loc.getCopy());
			return loc.area;
		}
	}

	/**
	 * 根據IP得到地區名
	 * 
	 * @param ip
	 *            IP的字符串形式
	 * @return 地區名字符串
	 */
	public String getArea(String ip) {
		return getArea(Utils.getIpByteArrayFromString(ip));
	}

	/**
	 * 根據ip搜索ip信息文件，得到IPLocation結構，所搜索的ip參數從類成員ip中得到
	 * 
	 * @param ip
	 *            要查詢的IP
	 * @return IPLocation結構
	 */
	private IPLocation getIPLocation(byte[] ip) {
		IPLocation info = null;
		long offset = locateIP(ip);
		if (offset != -1)
			info = getIPLocation(offset);
		if (info == null) {
			info = new IPLocation();
			info.country = "未知國家";
			info.area = "未知地區";
		}