/* Copyright (c) 2005 Ricebridge. All Rights Reserved.
 *
 * This file is available under the terms and conditions of the
 * Ricebridge "Open Source API" policy; Ricebridge grants use of this
 * copyrighted work under the terms of a BSD-style license only. See
 * http://www.opensource.org/licenses/bsd-license.php for more
 * information.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 *  - Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following
 *  disclaimer in the documentation and/or other materials provided
 *  with the distribution.
 *
 *  - Neither the name of the Ricebridge nor the names of its
 *  contributors may be used to endorse or promote products derived
 *  from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.  
 */


import com.ricebridge.csvman.CsvManager;

import java.io.*;
import java.sql.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;


/** Full source code for MaxMindManager class. 
 *    Please note that the code in this class does include
 *  error handling functionality. You will need to add this if 
 *  you intend to use this code in a production environment.
 */
public class MaxMindManager {

  public static final ArrayList sProxyHeaders = new ArrayList();

  static {
    sProxyHeaders.add("HTTP_X_FORWARDED_FOR");
    sProxyHeaders.add("HTTP_FORWARDED");
    sProxyHeaders.add("HTTP_CLIENT_IP");    
  }


  // public methods

  /** Insert records from a CSV file. 
   *  @param pDataFile CSV text file from MaxMind
   *  @param pConnection database connection
   */
  public void insert( File pDataFile, Connection pConnection ) throws Exception {
    CsvManager      csvman = new CsvManager();
    MaxMindInserter mmi    = new MaxMindInserter( pConnection );
    csvman.load( pDataFile, mmi );
  }


  /** Update records from a CSV file. 
   *  @param pDataFile new CSV text file from MaxMind
   *  @param pConnection database connection
   */
  public void update( File pDataFile, Connection pConnection ) throws Exception {
    int                 numlines = (int) pDataFile.length()/64;
    CsvManager          csvman   = new CsvManager();
    MaxMindLineListener mmll     = new MaxMindLineListener( numlines );
    csvman.load( pDataFile, mmll );

    String    countq      = "SELECT COUNT(*) FROM IPLookup";
    String    dataq       = "SELECT BeginIPNum, EndIPNum, CountryCode FROM IPLookup ORDER BY BeginIPNum";
    int       recI        = 0;
    long[]    old_range   = null;
    short[]   old_country = null;
    Statement st          = pConnection.createStatement();
    ResultSet rs          = st.executeQuery( countq );
    rs.next();
    int numrecords = rs.getInt(1);
    rs.close();
    st.close();

    st = pConnection.createStatement();
    rs = st.executeQuery( dataq );

    old_range   = new long[numrecords];
    old_country = new short[numrecords];
    while( rs.next() ) {
      old_range[recI]   = (rs.getLong(1) << 32) | rs.getLong(2);
      old_country[recI] = rs.getShort(3);
      recI++;
    }
    rs.close();
    st.close();
    
    ArrayList newrecs = new ArrayList();
    ArrayList oldrecs = new ArrayList();
    compare( mmll.getRanges(), mmll.getCountries(), mmll.getNumLines(),
             old_range, old_country, recI, 
             newrecs, oldrecs );

    insertRecords( newrecs, pConnection );
    deleteRecords( oldrecs, pConnection );
  }


  /** Insert records into database
   *  @param pRecords list of records
   *  @param pConnection database connection
   */
  public void insertRecords( List pRecords, Connection pConnection ) throws Exception {
    String insertq = new String( "INSERT INTO IPLookup VALUES (?,?,?)" );
    PreparedStatement st = pConnection.prepareStatement( insertq );
      
    for( Iterator rI = pRecords.iterator(); rI.hasNext(); ) {
      Record r = (Record) rI.next();
      st.setLong(  1, r.iStart );
      st.setLong(  2, r.iEnd );
      st.setShort( 3, r.iCountry );
      st.executeUpdate();
    }

    st.close();
  }


  /** Delete records from database
   *  @param pRecords list of records
   *  @param pConnection database connection
   */
  public void deleteRecords( List pRecords, Connection pConnection ) throws Exception {
    String deleteq = new String( "DELETE FROM IPLookup WHERE BeginIPNum = ? AND EndIPNum = ? AND CountryCode = ?" );
    PreparedStatement st = pConnection.prepareStatement( deleteq );
      
    for( Iterator rI = pRecords.iterator(); rI.hasNext(); ) {
      Record r = (Record) rI.next();
      st.setLong(  1, r.iStart );
      st.setLong(  2, r.iEnd );
      st.setShort( 3, r.iCountry );
      st.executeUpdate();
    }

    st.close();
  }


  /** Find Country Code from HTTP Request
   *  @param pRecords HTTP request
   *  @param pConnection database connection
   */
  public String findCountry( HttpServletRequest pRequest, Connection pConnection ) throws Exception {
    String ipaddr = getIPAddress( pRequest );
    return findCountry( ipaddr, pConnection );
  }


  /** Find Country Code from IP Address
   *  @param pIPAddress IP Address in 255.255.255.255 form
   *  @param pConnection database connection
   */
  public String findCountry( String pIPAddress, Connection pConnection ) throws Exception {
    String[] quads = pIPAddress.split( "\\." );
    if( 4 != quads.length ) {
      throw new Exception( "invalid ip addr:'"+pIPAddress+"'" );
    }

    long ipnum 
      = (long)16777216*Long.parseLong(quads[0]) 
      + (long)65536*Long.parseLong(quads[1])  
      + (long)256*Long.parseLong(quads[2]) 
      + (long)1*Long.parseLong(quads[3]) 
      ;

    String cc  = "US"; // default
    String ipq = "SELECT CountryCode FROM IPLookup WHERE BeginIPNum <= "+ipnum+" AND "+ipnum+" <= EndIPNum";

    short ci = -1;
    Statement st = pConnection.createStatement();
    ResultSet rs = st.executeQuery( ipq );
    if( rs.next() ) {
      ci = rs.getShort(1);
    }
    rs.close();
    st.close();

    if( -1 != ci ) {
      cc = MaxMindDef.sCountry[ci];
    }
    
    return cc;
  }


  /** Compare new and old CSV records and extract new records to add and old records to delete
   *  @param pNewRanges    new start and end ip numbers
   *  @param pNewCountries new country codes
   *  @param pNewMax,      actual number of new records (array may be larger)
   *  @param pOldRanges,   old start and end ip numbers
   *  @param pOldCountries old country codes
   *  @param pOldMax,      actual number of old records
   *  @param pAdd,         list to add completely new records to 
   *  @param pDelete       list to add completely removed records to
   */
  public void compare( long[]  pNewRanges, 
                       short[] pNewCountries, 
                       int     pNewMax,
                       long[]  pOldRanges, 
                       short[] pOldCountries, 
                       int     pOldMax,
                       ArrayList pAdd, 
                       ArrayList pDelete ) {
    pAdd.clear();
    pDelete.clear();

    long[]  nr = pNewRanges;
    short[] nc = pNewCountries;
    long[]  or = pOldRanges;
    short[] oc = pOldCountries;
    int     nI = 0;
    int     oI = 0;
    int     nmax = pNewMax;
    int     omax = pOldMax;
    
    long  nrange;
    long  ns;
    long  ne;
    short nk;
    
    long  orange;
    long  os;
    long  oe;
    short ok;

    while( nI < nmax && oI < omax ) {
      nrange = nr[nI];
      ns = nrange >>> 32;
      ne = nrange & 0xFFFFFFFFL;
      nk = nc[nI];
      orange = or[oI];
      os = orange >>> 32;
      oe = orange & 0xFFFFFFFFL;
      ok = oc[oI];

      if( ns == os && ne == oe && nk == ok ) {
        nI++; oI++;
      }
      else if( ns < os 
               || ( ns == os && ne < oe )
               || ( ns == os && ne == oe && nk < ok ) ) {
        pAdd.add( new Record( ns, ne, nk ) );
        nI++;
      }
      else if( ns > os 
               || ( ns == os && ne > oe )
               || ( ns == os && ne == oe && nk > ok ) ) {
        pDelete.add( new Record( os, oe, ok ) );
        oI++;
      }
    }

    if( nI < nmax ) {
      for( ; nI < nmax; nI++ ) {
        nrange = nr[nI];
        ns = nrange >>> 32;
        ne = nrange & 0xFFFFFFFFL;
        nk = nc[nI];
        pAdd.add( new Record( ns, ne, nk ) );
      }
    }

    if( oI < omax ) {
      for( ; oI < omax; oI++ ) {
        orange = or[oI];
        os = orange >>> 32;
        oe = orange & 0xFFFFFFFFL;
        ok = oc[oI];
        pDelete.add( new Record( os, oe, ok ) );
      }
    }
  }


  /** Simplistic hard-coded method to open a database connection. */
  public Connection getConnection() throws Exception {
    DriverManager.registerDriver( new com.mysql.jdbc.Driver() );
    return DriverManager.getConnection( "jdbc:mysql://localhost/testdb", "testuser", "testpass" );
  }
  

  /** Parse IP Address String out of HTTP headers 
   *  @param pRequest HTTP request
   */
  public String getIPAddress( HttpServletRequest pRequest ) {
    String ipaddr = pRequest.getRemoteAddr();
    for( Iterator hIt = sProxyHeaders.iterator(); hIt.hasNext(); ) {
      String ph = (String) hIt.next();
      String v  = pRequest.getHeader( ph );
      if( null != ph && null != v && !"".equals( v ) ) {
        ipaddr = v;
        break;
      }
    }
    return ipaddr;
  }


  /** Internal class to hold start and end ip numbers and country code. */ 
  public static class Record {
    public Record( long pStart, long pEnd, short pCountry ) {
      iStart = pStart; iEnd = pEnd; iCountry = pCountry;
    }
    public long  iStart; 
    public long  iEnd;
    public short iCountry;

    public String toString() {
      return "s:"+iStart+",e:"+iEnd+",c:"+MaxMindDef.sCountry[iCountry];
    }
  }




}