/***************************************************************************
 *   Copyright (C) 2005 by Tim Sutton                                      *
 *   tim@linfiniti.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.                                   *
 ***************************************************************************/
/* $Id$ */
#include "qgsprojectionselector.h"

//standard includes
#include <iostream>
#include <cassert>
#include <sqlite3.h>
#include <cstdlib>

//qgis includes
#include "qgscsexception.h"
#include "qgsconfig.h"
#include <qgis.h> //magick numbers here

//qt includes
#include <qapplication.h>
#include <qfile.h>
#include <qtextedit.h>
#include <qbuttongroup.h>
#include <qlineedit.h>
#include <qmessagebox.h>
#include <qregexp.h>
#include <qprogressdialog.h>
#include <qfileinfo.h>
#include <qdir.h>
#include <qtextstream.h>
#include <qstring.h>
#include <qradiobutton.h>
//gdal and ogr includes
// XXX DO WE NEED THESE?
#include <ogr_api.h>
#include <ogr_spatialref.h>
#include <cpl_error.h>


QgsProjectionSelector::QgsProjectionSelector( QWidget* parent , const char* name , WFlags fl  )
    : QgsProjectionSelectorBase( parent, "Projection Selector", fl )
{
  // Get the package data path and set the full path name to the sqlite3 spatial reference
  // database.
#if defined(Q_OS_MACX) || defined(WIN32)
  QString PKGDATAPATH = qApp->applicationDirPath() + "/share/qgis";
#endif
  mSrsDatabaseFileName = PKGDATAPATH;
  mSrsDatabaseFileName += "/resources/srs.db";
  // Populate the projection list view
  getUserProjList();
  getProjList();
}

QgsProjectionSelector::~QgsProjectionSelector()
{}
void QgsProjectionSelector::setSelectedSRSName(QString theSRSNAme)
{
  //get the srid given the wkt so we can pick the correct list item
#ifdef QGISDEBUG
  std::cout << "QgsProjectionSelector::setSelectedSRSName called with \n" << theSRSNAme << std::endl;
#endif
  //now delegate off to the rest of the work
  QListViewItemIterator myIterator (lstCoordinateSystems);
  while (myIterator.current())
  {
    if (myIterator.current()->text(0)==theSRSNAme)
    {
      lstCoordinateSystems->setCurrentItem(myIterator.current());
      lstCoordinateSystems->ensureItemVisible(myIterator.current());
      return;
    }
    ++myIterator;
  }
}

void QgsProjectionSelector::setSelectedSRSID(long theSRSID)
{
  QString mySRSIDString=QString::number(theSRSID);
  QListViewItemIterator myIterator (lstCoordinateSystems);
  while (myIterator.current())
  {
    if (myIterator.current()->text(1)==mySRSIDString)
    {
      lstCoordinateSystems->setCurrentItem(myIterator.current());
      lstCoordinateSystems->ensureItemVisible(myIterator.current());
      return;
    }
    ++myIterator;
  }

}

//note this line just returns the projection name!
QString QgsProjectionSelector::getSelectedName()
{
  // return the selected wkt name from the list view
  QListViewItem *lvi = lstCoordinateSystems->currentItem();
  if(lvi)
  {
    return lvi->text(0);
  }
  else
  {
    return QString::null;
  }
}
// Returns the whole proj4 string for the selected projection node
QString QgsProjectionSelector::getCurrentProj4String()
{
  // Only return the projection if there is a node in the tree
  // selected that has an srid. This prevents error if the user
  // selects a top-level node rather than an actual coordinate
  // system
  //
  // Get the selected node
  QListViewItem *myItem = lstCoordinateSystems->currentItem();
  if(myItem)
  {

    if(myItem->text(1).length() > 0)
    {
      QString myDatabaseFileName;
      QString mySrsId = myItem->text(1);

      std::cout << " QgsProjectionSelector::getCurrentProj4String :  mySrsId = " << mySrsId << std::endl;
      std::cout << " QgsProjectionSelector::getCurrentProj4String :  USER_PROJECTION_START_ID = " << USER_PROJECTION_START_ID << std::endl;
      //
      // Determine if this is a user projection or a system on
      // user projection defs all have srs_id >= 100000
      //
      if (mySrsId.toLong() >= USER_PROJECTION_START_ID)
      {
        myDatabaseFileName = QDir::homeDirPath () + "/.qgis/qgis.db";
        QFileInfo myFileInfo;
        myFileInfo.setFile(myDatabaseFileName);
        if ( !myFileInfo.exists( ) ) //its unlikely that this condition will ever be reached
        {
          std::cout << " QgsProjectionSelector::getCurrentProj4String :  users qgis.db not found" << std::endl;
          return NULL;
        }
      }
      else //must be  a system projection then
      {
        myDatabaseFileName =  mSrsDatabaseFileName;
      }
      std::cout << "QgsProjectionSelector::getCurrentProj4String db = " << myDatabaseFileName << std::endl;


      sqlite3 *db;
      char *zErrMsg = 0;
      int rc;
      rc = sqlite3_open(myDatabaseFileName, &db);
      if(rc)
      {
        std::cout <<  "Can't open database: " <<  sqlite3_errmsg(db) << std::endl;
        // XXX This will likely never happen since on open, sqlite creates the
        //     database if it does not exist.
        assert(rc == 0);
      }
      // prepare the sql statement
      const char *pzTail;
      sqlite3_stmt *ppStmt;
      char *pzErrmsg;
      QString sql = "select parameters from tbl_srs where srs_id = ";
      sql += mySrsId;
#ifdef QGISDEBUG
      std::cout << "Selection sql : " << sql << std::endl;
#endif

      rc = sqlite3_prepare(db, (const char *)sql, sql.length(), &ppStmt, &pzTail);
      // XXX Need to free memory from the error msg if one is set
      QString myProjString;
      if(rc == SQLITE_OK)
      {
        if(sqlite3_step(ppStmt) == SQLITE_ROW)
        {
          myProjString = (char*)sqlite3_column_text(ppStmt, 0);
        }
      }
      // close the statement
      sqlite3_finalize(ppStmt);
      // close the database
      sqlite3_close(db);
#ifdef QGISDEBUG
      std::cout << "Item selected : " << myItem->text(0) << std::endl;
      std::cout << "Item selected full string : " << myProjString << std::endl;
#endif
      assert(myProjString.length() > 0);
      return myProjString;
    }
    else
    {
      // No node is selected, return null
      return NULL;
    }
  }
  else
  {
    // No node is selected, return null
    return NULL;
  }

}

long QgsProjectionSelector::getCurrentSRID()
{
  // Only return the projection if there is a node in the tree
  // selected that has an srid. This prevents error if the user
  // selects a top-level node rather than an actual coordinate
  // system
  //
  // Get the selected node
  QListViewItem *lvi = lstCoordinateSystems->currentItem();
  if(lvi)
  {
    // Make sure the selected node is a srs and not a top-level projection node
    std::cout << lvi->text(1) << std::endl;
    if(lvi->text(1).length() > 0)
    {
      QString myDatabaseFileName;
      //
      // Determine if this is a user projection or a system on
      // user projection defs all have srs_id >= 100000
      //
      if (lvi->text(1).toLong() >= USER_PROJECTION_START_ID)
      {
        myDatabaseFileName = QDir::homeDirPath () + "/.qgis/qgis.db";
        QFileInfo myFileInfo;
        myFileInfo.setFile(myDatabaseFileName);
        if ( !myFileInfo.exists( ) )
        {
          std::cout << " QgsSpatialRefSys::createFromSrid failed :  users qgis.db not found" << std::endl;
          return NULL;
        }
      }
      else //must be  a system projection then
      {
        myDatabaseFileName=mSrsDatabaseFileName;
      }
      //
      // set up the database
      // XXX We could probabaly hold the database open for the life of this object,
      // assuming that it will never be used anywhere else. Given the low overhead,
      // opening it each time seems to be a reasonable approach at this time.
      sqlite3 *db;
      char *zErrMsg = 0;
      int rc;
      rc = sqlite3_open(myDatabaseFileName, &db);
      if(rc)
      {
        std::cout <<  "Can't open database: " <<  sqlite3_errmsg(db) << std::endl;
        // XXX This will likely never happen since on open, sqlite creates the
        //     database if it does not exist.
        assert(rc == 0);
      }
      // prepare the sql statement
      const char *pzTail;
      sqlite3_stmt *ppStmt;
      char *pzErrmsg;
      QString sql = "select srid from tbl_srs where srs_id = ";
      sql += lvi->text(1);

#ifdef QGISDEBUG
      std::cout << "Finding selected srid using : " <<  sql << std::endl;
#endif
      rc = sqlite3_prepare(db, (const char *)sql, sql.length(), &ppStmt, &pzTail);
      // XXX Need to free memory from the error msg if one is set
      QString mySrid;
      if(rc == SQLITE_OK)
      {
        // get the first row of the result set
        if(sqlite3_step(ppStmt) == SQLITE_ROW)
        {
          // get the wkt
          mySrid = (char*)sqlite3_column_text(ppStmt, 0);
        }
      }
      // close the statement
      sqlite3_finalize(ppStmt);
      // close the database
      sqlite3_close(db);
      // return the srs wkt
      return mySrid.toLong();
    }
  }
  else
  {
    // No node is selected, return null
    return NULL;
  }

}

long QgsProjectionSelector::getCurrentSRSID()
{
  if(lstCoordinateSystems->currentItem()->text(1).length() > 0)
  {
    return lstCoordinateSystems->currentItem()->text(1).toLong();
  }
  else
  {
    return NULL;
  }
}

void QgsProjectionSelector::getUserProjList()
{
#ifdef QGISDEBUG
  std::cout << "Fetching user projection list..." << std::endl;
#endif
  // User defined coordinate system node
  mUserProjList = new QListViewItem(lstCoordinateSystems,"User Defined Coordinate System");
  //determine where the user proj database lives for this user. If none is found an empty
  //now only will be shown
  QString myQGisSettingsDir = QDir::homeDirPath () + "/.qgis/";
  // first we look for ~/.qgis/qgis.db
  // if it doesnt exist we copy it in from the global resources dir
  QFileInfo myFileInfo;
  myFileInfo.setFile(myQGisSettingsDir+"qgis.db");
  //return straight away if the user has not created any custom projections
  if ( !myFileInfo.exists( ) )
  {
#ifdef QGISDEBUG
    std::cout << "Users qgis.db not found...skipping" << std::endl;
#endif
    return;
  }

  sqlite3      *myDatabase;
  char         *myErrorMessage = 0;
  const char   *myTail;
  sqlite3_stmt *myPreparedStatement;
  int           myResult;
  //check the db is available
  myResult = sqlite3_open(QString(myQGisSettingsDir+"qgis.db").latin1(), &myDatabase);
  if(myResult)
  {
    std::cout <<  "Can't open database: " <<  sqlite3_errmsg(myDatabase) << std::endl;
    // XXX This will likely never happen since on open, sqlite creates the
    //     database if it does not exist. But we checked earlier for its existance
    //     and aborted in that case. This is because we may be runnig from read only
    //     media such as live cd and dont want to force trying to create a db.
    assert(myResult == 0);
  }

  // Set up the query to retreive the projection information needed to populate the list
  QString mySql = "select description,srs_id,is_geo, name,parameters from vw_srs";
#ifdef QGISDEBUG
  std::cout << "User projection list sql" << mySql << std::endl;
#endif
  myResult = sqlite3_prepare(myDatabase, (const char *)mySql, mySql.length(), &myPreparedStatement, &myTail);
  // XXX Need to free memory from the error msg if one is set
  if(myResult == SQLITE_OK)
  {
    QListViewItem *newItem;
    while(sqlite3_step(myPreparedStatement) == SQLITE_ROW)
    {
      newItem = new QListViewItem(mUserProjList, (char *)sqlite3_column_text(myPreparedStatement,0));
      // display the qgis srs_id in the second column of the list view
      newItem->setText(1,(char *)sqlite3_column_text(myPreparedStatement, 1));
    }
  }
  // close the sqlite3 statement
  sqlite3_finalize(myPreparedStatement);
  sqlite3_close(myDatabase);
}

void QgsProjectionSelector::getProjList()
{
  // Create the top-level nodes for the list view of projections
  //
  // Geographic coordinate system node
  mGeoList = new QListViewItem(lstCoordinateSystems,"Geographic Coordinate System");
  // Projected coordinate system node
  mProjList = new QListViewItem(lstCoordinateSystems,"Projected Coordinate System");

  //bail out in case the projections db does not exist
  //this is neccessary in case the pc is running linux with a
  //read only filesystem because otherwise sqlite will try
  //to create the db file on the fly

  QFileInfo myFileInfo;
  myFileInfo.setFile(mSrsDatabaseFileName);
  if ( !myFileInfo.exists( ) )
  {
    return;
  }

  // open the database containing the spatial reference data
  sqlite3 *db;
  char *zErrMsg = 0;
  int rc;
  rc = sqlite3_open(mSrsDatabaseFileName, &db);
  if(rc)
  {
    std::cout <<  "Can't open database: " <<  sqlite3_errmsg(db) << std::endl;
    // XXX This will likely never happen since on open, sqlite creates the
    //     database if it does not exist.
    assert(rc == 0);
  }
  // prepare the sql statement
  const char *pzTail;
  sqlite3_stmt *ppStmt;
  char *pzErrmsg;
  // get total count of records in the projection table
  QString sql = "select count(*) from tbl_srs";

  rc = sqlite3_prepare(db, sql, sql.length(), &ppStmt, &pzTail);
  assert(rc == SQLITE_OK);
  sqlite3_step(ppStmt);
  // Set the max for the progress dialog to the number of entries in the srs_name table
  int myEntriesCount = sqlite3_column_int(ppStmt, 0);
#ifdef QGISDEBUG
  std::cout << "Projection entries found in srs.db: " << myEntriesCount << std::endl;
#endif
  sqlite3_finalize(ppStmt);

  // Set up the query to retreive the projection information needed to populate the list
  //note I am giving the full field names for clarity here and in case someown
  //changes the underlying view TS
  sql = "select description,srs_id,is_geo, name,parameters from vw_srs";
#ifdef QGISDEBUG
  std::cout << "SQL for projection list:\n" << sql << std::endl;
#endif
  rc = sqlite3_prepare(db, (const char *)sql, sql.length(), &ppStmt, &pzTail);
  // XXX Need to free memory from the error msg if one is set
  if(rc == SQLITE_OK)
  {
#ifdef QGISDEBUG
    std::cout << "SQL for projection list executed ok..."  << std::endl;
#endif

    QListViewItem *newItem;
    // set up the progress dialog
    int myProgress = 1;
    QProgressDialog myProgressBar( "Building Projections List...", 0, myEntriesCount,
                                   this, "progress", TRUE );
    // set initial value to 1
    myProgressBar.setProgress(myProgress);
    while(sqlite3_step(ppStmt) == SQLITE_ROW)
    {
      // only update the progress dialog every 10 records
      if((myProgress++ % 10) == 0)
      {
        myProgressBar.setProgress(myProgress++);
      }
      // check to see if the srs is geographic
      int isGeo = sqlite3_column_int(ppStmt, 2);
      if(isGeo)
      {
        // this is a geographic coordinate system
        // Add it to the tree
        newItem = new QListViewItem(mGeoList, (char *)sqlite3_column_text(ppStmt,0));

        // display the qgis srs_id in the second column of the list view
        newItem->setText(1,(char *)sqlite3_column_text(ppStmt, 1));
      }
      else
      {
        // This is a projected srs

        QListViewItem *node;
        // Fine the node for this type and add the projection to it
        // If the node doesn't exist, create it
        node = lstCoordinateSystems->findItem(QString((char*)sqlite3_column_text(ppStmt, 3)),0);
        if(node == 0)
        {
          // the node doesn't exist -- create it
          node = new QListViewItem(mProjList, (char*)sqlite3_column_text(ppStmt, 3));
        }

        // add the item, setting the projection name in the first column of the list view
        newItem = new QListViewItem(node, (char *)sqlite3_column_text(ppStmt,0));
        // set the srs_id in the second column on the list view
        newItem->setText(1,(char *)sqlite3_column_text(ppStmt, 1));
      }
      //Only enable thse lines temporarily if you want to generate a script
      //to update proj an ellipoid fields in the srs.db
      //updateProjAndEllipsoidAcronyms(QString((char *)sqlite3_column_text(ppStmt, 1)).toLong(),
      //                               QString((char *)sqlite3_column_text(ppStmt, 4)))  ;
    }
    // update the progress bar to 100% -- just for eye candy purposes (some people hate to
    // see a progress dialog end at 99%)
    myProgressBar.setProgress(myEntriesCount);
  }
  // close the sqlite3 statement
  sqlite3_finalize(ppStmt);
  // close the database
  sqlite3_close(db);
}

//this is a little helper function to populate the (well give you a sql script to populate)
//the projection_acronym and ellipsoid_acronym fields in the srs.db backend
//To cause it to be run, uncomment or add the line:
//      updateProjAndEllipsoidAcronyms(QString((char *)sqlite3_column_text(ppStmt, 1)).toLong(),
//                                     QString((char *)sqlite3_column_text(ppStmt, 4)))  ;
//to the above method. NOTE it will cause a huge slow down in population of the proj selector dialog so
//remember to disable it again!
void QgsProjectionSelector::updateProjAndEllipsoidAcronyms(int theSrsid,QString theProj4String)
{


  //temporary hack
  QFile myFile( "/tmp/srs_updates.sql" );
  myFile.open(  IO_WriteOnly | IO_Append );
  QTextStream myStream( &myFile );






  QRegExp myProjRegExp( "proj=[a-zA-Z]* " );
  int myStart= 0;
  int myLength=0;
  myStart = myProjRegExp.search(theProj4String, myStart);
  QString myProjectionAcronym;
  if (myStart==-1)
  {
    std::cout << "proj string supplied has no +proj argument" << std::endl;
    myProjectionAcronym = "";
  }
  else
  {
    myLength = myProjRegExp.matchedLength();
    myProjectionAcronym = theProj4String.mid(myStart+PROJ_PREFIX_LEN,myLength-(PROJ_PREFIX_LEN+1));//+1 for space
  }


  QRegExp myEllipseRegExp( "ellps=[a-zA-Z0-9\-]* " );
  myStart= 0;
  myLength=0;
  myStart = myEllipseRegExp.search(theProj4String, myStart);
  QString myEllipsoidAcronym;
  if (myStart==-1)
  {
    std::cout << "proj string supplied has no +ellps argument" << std::endl;
    myEllipsoidAcronym="";
  }
  else
  {
    myLength = myEllipseRegExp.matchedLength();
    myEllipsoidAcronym = theProj4String.mid(myStart+ELLPS_PREFIX_LEN,myLength-(ELLPS_PREFIX_LEN+1));
  }


  //now create the update statement
  QString mySql = "update tbl_srs set projection_acronym='" + myProjectionAcronym +
                  "', ellipsoid_acronym='" + myEllipsoidAcronym + "' where " +
                  "srs_id=" + QString::number(theSrsid)+";";


  //tmporary hack
  myStream << mySql << "\n";
  myFile.close();
  //std::cout

}

// New coordinate system selected from the list
void QgsProjectionSelector::coordinateSystemSelected( QListViewItem * theItem )
{
      QString myProjString = getCurrentProj4String();
      if (myProjString)
      {
        teProjection->setText(myProjString);
      }
}

void QgsProjectionSelector::pbnFind_clicked()
{

#ifdef QGISDEBUG
  std::cout << "pbnFind..." << std::endl;
#endif


  sqlite3      *myDatabase;
  char         *myErrorMessage = 0;
  const char   *myTail;
  sqlite3_stmt *myPreparedStatement;
  int           myResult;
  //check the db is available
  myResult = sqlite3_open(mSrsDatabaseFileName, &myDatabase);
  if(myResult)
  {
    std::cout <<  "Can't open database: " <<  sqlite3_errmsg(myDatabase) << std::endl;
    // XXX This will likely never happen since on open, sqlite creates the
    //     database if it does not exist. But we checked earlier for its existance
    //     and aborted in that case. This is because we may be runnig from read only
    //     media such as live cd and dont want to force trying to create a db.
    assert(myResult == 0);
  }

  // Set up the query to retreive the projection information needed to populate the list
  QString mySql;
  if (radSRID->isChecked())
  {
    mySql= "select srs_id from tbl_srs where srid=" + leSearch->text();
  }
  else
  {
    mySql= "select srs_id from tbl_srs where epsg=" + leSearch->text();
  }
#ifdef QGISDEBUG
  std::cout << " Search sql" << mySql << std::endl;
#endif
  myResult = sqlite3_prepare(myDatabase, (const char *)mySql, mySql.length(), &myPreparedStatement, &myTail);
  // XXX Need to free memory from the error msg if one is set
  if(myResult == SQLITE_OK)
  {
    sqlite3_step(myPreparedStatement);
    QString mySrsId((char *)sqlite3_column_text(myPreparedStatement, 0));
    setSelectedSRSID(mySrsId.toLong());
  }
  // close the sqlite3 statement
  sqlite3_finalize(myPreparedStatement);
  sqlite3_close(myDatabase);

}