source: trunk/gsdl/src/recpt/z3950server.cpp@ 1371

/**********************************************************************
 *
 * z3950server.cpp --
 * Copyright (C) 2000  The New Zealand Digital Library Project
 *
 * A component of the Greenstone digital library software
 * from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *********************************************************************/

#include "z3950server.h"
#include "comtypes.h"
#include <stdio.h>
// z39.50 yaz stuff

extern "C" {
#include "yaz/yaz_zclient.h"
}

/*** 
     each z39.50 server+database pair is a GSDL collection.
***/

z3950_server::z3950_server() {
  info=NULL;
  connected=false;
  titles=NULL;
  // for now, assume that all records will have text associated with them.
  meta["hastxt"]="1";
  // for now, assume we don't want ANY DocumentButtons.
  format["DocumentButtons"]="";
}

z3950_server::~z3950_server() {
}

void z3950_server::setMeta(const text_t &key, const text_t &value) {
  meta[key]=value;
}

void z3950_server::setName(const text_t &newname) {
  title=newname;
  meta["collectionname"]=newname;
}

void z3950_server::addcfgAbout(const text_t &lang, const text_t &abouttext) {
    about[lang]=abouttext;
}

bool z3950_server::getcfgAbout(const text_t &lang, text_t &abouttxt) {
  text_tmap::iterator it;
  it=about.find(lang);
  if (it==about.end()) return (false);
  abouttxt=((*it).second);
  return (true);
}


// now functions that actually talk over the tcp connection.

// create a tcp connection to the associated target. Currently, this will
// re-initialise if we are already connected.
bool z3950_server::connect() {
  text_t server_and_port;
  char *zserverinfo;

  server_and_port=info->host+":"+info->port;
  // remember that info.name is the database name

  z_initialize();

  if (z_cmd_open(server_and_port.getcstr(),info->name.getcstr())==1)
    // we got a connection error
    return false;

  // get initialisation response.
  z_getnextAPDU();
  zserverinfo=z_get_initResponse();
  if (zserverinfo!=NULL) {
    z_initstr.appendcstr(zserverinfo);
  }
  free(zserverinfo);

  connected=true;
  return true;
}

void z3950_server::parseQuery(const text_t &query, 
                  const text_t &fields,
                  text_t &parsed_query) {
  /****** FIXME *****/
  // We need to format the query string into RPN - 
  // by just passing it like this, it will only work for simple queries.
  // This will require us to actually come up with a query syntax and 
  // a parser. For now, we'll just do an "AND" query for all terms

  // we need to count number of terms separated by a space
  char *ptr=query.getcstr();
  int strlength=strlen(ptr);
  bool inword=false;
  int num_terms=0;
  for (int i=0;i<strlength;i++) {
    if (*(ptr+i)!=' ') {
      if (inword==false) {
    inword=true;
    num_terms++;
      }
    }
    else { // ptr+i is a space
      inword=false;
      }
  }
  
  // set the field(s) to search on - main ones (that I've found) include:
  //  1016  => Any
  //  1     => (Personal) Name
  //  4     => Title
  //  21    => Subject Heading
  //  45    => Subject precis
  // Note I have no idea how these actually work - I think some servers
  // only have limited fields, and map all subject-type requests into that
  // subject field, etc.

  parsed_query="@attr 1=";
  if (fields==".author")
    parsed_query+="1 ";
  else if (fields==".title")
    parsed_query+="4 ";
  else // fields==".any"
    parsed_query+="1016 ";

  // append "@and" for each term after the first
  for (int i=1;i<num_terms;i++)
    parsed_query+="@and ";
  // append the actual query
  parsed_query+=query;

}

text_tarray *z3950_server::getrecordTitles(const text_t &query, 
                       const text_t &fields,
                       int first, int count,
                       int *nummatches, comerror_t &err) {
  char **c_str_titles;
  int i;
  int last;
  if (titles!=NULL) delete (titles);
  titles=new text_tarray;

  /* check if connected */
  if (connected==false) 
    if (connect()==false) {
      // we could not connect.
      err=protocolError;
      return (NULL);
    }
  

  text_t expanded_query="";
  parseQuery(query,fields,expanded_query);

  // following functions defined in yaz_zclient.c
  *nummatches=z_cmd_dosearch(expanded_query.getcstr()); // returns # found, -1 on err.
  if (*nummatches<=0) {
    if (*nummatches==0) {
      // no matches
      return (NULL);
    } else  if (*nummatches==-1) {
      // prefix query error
      err=protocolError;
      return (NULL);
    }  else if (*nummatches==-2) {
      // sendsearchRequest not answered by searchResponse
      err=protocolError;
      return (NULL);
    }
  }
  // could do a sort eventually, eg on date, title, etc.
  // (non-existent function)    z_sort(field, asc|desc);
  /* min of (count, first + (*nummatches) ) */
  // z_getrecordTitles ( first, howmany )
  c_str_titles=z_getrecordTitles(first,min(count,*nummatches-first+1));
  if (c_str_titles==NULL) {
    // an error occurred. we need a logout/err as an arg
    return (NULL);
  }
  if (c_str_titles[0]==0) {
    // no matches.
    return (NULL);
  }
  last=(int)c_str_titles[0];
  for (i=1;i<=last;i++) {
    titles->push_back(c_str_titles[i]);
    free(c_str_titles[i]);
  }
  free(c_str_titles);
  return (titles);
  
}

bool z3950_server::getfullrecord(const text_t &query, const text_t &fields,
                 const int ID, 
                 text_t &rettitle, 
                 text_t &rettext, comerror_t &err) {
  if (connected==false) {
    if (connect()==false) {
      // error connecting...
      err=protocolError;
      return (false);
    }
    // since we have just re-connected, we need to do the
    // query again.

    text_t expanded_query="";
    parseQuery(query,fields,expanded_query);

    int returned=z_cmd_dosearch(expanded_query.getcstr());
    if (returned<=0) {
      // 0 => none.
      // <0 => error
      err=protocolError;
      return (false);
    }
  }

  if (rettitle!="unneeded") {
    char **c_str_titles;
    //int dummy;
    c_str_titles=z_getrecordTitles(ID,1); // check this return value.
    if (c_str_titles!=NULL && (int)c_str_titles[0]==1) {
      rettitle.setcstr(c_str_titles[1]); // and check this 
      free (c_str_titles);
      // rettitle="Dummy Title";
    } else {
      // we didn't get something....
      rettitle="Nothing Returned...";
    }
  }

  if (rettext!="unneeded") {
    // get the text
    rettext.setcstr(z_getfullRecord(ID));
  }
  return (true);
  }

text_t &z3950_server::getzAbout() {
  text_t zserverresp;

  // Assume we have not yet connected, so that must be done here.
  if (connected==true)
    return (z_initstr);
  
  // we need to create the tcp connection to the target (server)  
  //  z_initstr=new text_t;
  
  if (connect()==false) {
    z_initstr.setcstr("<H2>Server offline</H2>Error - could not connect to server <B>");
    z_initstr += info->host.getcstr();
    z_initstr += "</B> on port ";
    z_initstr += info->port;
    z_initstr += "\n";
    return (z_initstr);
  }
  
  // z_initstr currently contains the target's response. We want to
  // PREPEND the following information.
  zserverresp=z_initstr;
  z_initstr="Internet server: <b>";
  z_initstr+=info->host;
  z_initstr+="</b> on port ";
  z_initstr+=info->port;
  z_initstr+=".<br>\n";
  z_initstr+=zserverresp;

  // should close /******* WHAT IF DOING A QUERY!??!?!? ********/
  // z_cmd_close(0);
  // connected=false;
  return (z_initstr);
}