/**********************************************************************
 *
 * z3950proto.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 "z3950proto.h"
#include "comtypes.h"
#include "browsefilter.h"
#include "queryfilter.h"
#include "filter.h"
// z39.50 yaz stuff
#include <stdio.h> // for (FILE *) type for yyin and fopen.
// config file parsing stuff
#include "z3950cfg.h" // for reading in config files - 
// defines "struct z3950cfg *zserver_list" as the head of the list.

// note! yyin is hash-defined in z3950cfg.h to something else, to avoid
// name conflicts with "other" yyins.
extern FILE *yyin;
extern FILE *yyout; // redirect for `errors' (unmatched tokens in flex)

extern "C" {
  extern int zconfigparse();
}




z3950proto::z3950proto() {
  zserver_count=0;
}

z3950proto::~z3950proto() {
}

void z3950proto::add_server (z3950_server& zserver) {

  // append the new server
  zserver_count++;
  zservers.push_back(&zserver);
}

void z3950proto::read_config_file(const text_t &filename, const text_t &errf) {
  struct z3950cfg *here;
  struct z3950cfg *oldhere;
  z3950_server *zserver;
  ShortColInfo_t *tempinfo;

  //  FILE *errfile declared in z3950cfg.h, defined in zparse.y

  char *errf_str=errf.getcstr();
  if ((errfile=fopen(errf_str,"a"))==NULL) {
    // what do we do if we can't open the error file?
    // this means that errors will go to stderr, which may stuff up 
    // any cgi headers and the page.
    errfile=stderr;
  }
  delete errf_str;
  yyout=errfile;

  // zconfigparse() is defined in zparse.tab.c,
  // which is the bison output of zparse.y
  
  char *filename_str=filename.getcstr();
  yyin=fopen(filename_str,"r");
  if (yyin==NULL) {
    cerr << "Could not open "<<filename_str<<" for reading.\n";
    delete filename_str;
    return;
  }
  delete filename_str;
  zconfigparse();

  if (errfile!=stderr)
    fclose(errfile);

  // we now have the config files in the ptr zserver_list
  if (zserver_list==NULL)
    return; // no valid servers found in the config file - note that
  // the parser will have already spat out any errors.

  // now create z3950servers for each structure in server_list
  here=zserver_list;
  while (here!=NULL) {
    zserver=new z3950_server;
    tempinfo=new ShortColInfo_t;

    tempinfo->host.setcstr(here->hostname);
    tempinfo->port=here->port;
    tempinfo->name.setcstr(here->dbname);
    zserver->setInfo(tempinfo);
    zserver->setName(here->shortname);
    // now collection metadata.
    zserver->setMeta("collectionname",here->longname);
    if (here->icon!=NULL)
      zserver->setMeta("iconcollection",here->icon);
    if (here->smallicon!=NULL)
      zserver->setMeta("iconcollectionsmall",here->smallicon);
    
    /*    filterclass *filter = new filterclass ();
	  zserver->add_filter (filter);
	  browsefilterclass *browsefilter = new browsefilterclass();
	  zserver->add_filter (browsefilter);
	  queryfilterclass *queryfilter = new queryfilterclass();
	  zserver->add_filter (queryfilter);
    */

    // About list
    if (here->about!=NULL) {
      struct z3950aboutlist *about_here=here->about;
      struct z3950aboutlist *oldabout;

      while (about_here!=NULL) {
	// problem with default lang (null): can't add ("",..)
	if (about_here->lang==NULL)
	  zserver->addcfgAbout("en",about_here->text);
	else
	  zserver->addcfgAbout(about_here->lang, about_here->text);
	oldabout=about_here;
	about_here=about_here->next;
	free(oldabout->lang);
	free(oldabout->text);
	free(oldabout);
      }
    }

    oldhere=here;
    here=here->next;
    free(oldhere->shortname); // these 4 strings should all be non-NULL...
    free(oldhere->hostname);
    free(oldhere->dbname);
    free(oldhere->longname);
    if (oldhere->icon) free(oldhere->icon);     // these 2 may be NULL
    if (oldhere->smallicon) free(oldhere->smallicon);
    free(oldhere);

    add_server(*zserver);
  } // end of while loop.

}

void z3950proto::configure (const text_t &/*key*/,
			    const text_tarray &/*cfgline*/) {
  // this is called for each line in the gsdlsite.cfg file
}


bool z3950proto::init (ostream &/*logout*/) {
  // set up tcp connection to server here?
  // we might also read in the config file here (instead of librarymain.cpp)

  // 

  // logout goes to initout.txt
  //  logout <<"zdebug:init:Number of z3950 servers: "<< zserver_count << "\n";
  //logout << "\t1st server name: " << zservers[0].getName().getcstr() << "\n";
  return true;

}

/*text_t z3950proto::get_protocol_name () {
  return "z3950proto";
}
*/

void z3950proto::get_collection_list (text_tarray &collist, 
				      comerror_t &/*err*/,
				      ostream &/*logout*/) {

  z3950_server_array::iterator here = zservers.begin();
  z3950_server_array::iterator end = zservers.end();
  while (here != end) {
    collist.push_back((*here)->getName());
    here++;
  }
}

void z3950proto::has_collection (const text_t &collection, bool &hascollection,
				 comerror_t &/*err*/, ostream &/*logout*/) {
  z3950_server_array::iterator here = zservers.begin();
  z3950_server_array::iterator end = zservers.end();
  while (here != end) {
    if((*here)->getName()==collection) {
      hascollection=true;
      return;
    }
    here++;
  }
  hascollection=false;
}

void z3950proto::ping (const text_t &/*collection*/, bool &wassuccess, 
		       comerror_t &/*err*/, ostream &/*logout*/) {
  // should we just ping the server, or actually create a connection
  // to the z39.50 server process on the machine ?
  wassuccess = true;
}

void z3950proto::get_collectinfo (const text_t &collection,
				  ColInfoResponse_t &collectinfo,
				  comerror_t &err, ostream &logout) {

  // set err to protocolError if something goes wrong...
  err=noError;

  z3950_server_array::iterator here = zservers.begin();
  z3950_server_array::iterator end = zservers.end();
  while (here != end) {
    if((*here)->getName()==collection) {
      break;
    }
    here++;
  }

  if (here==end) {
    err=protocolError;
    char *coll_str=collection.getcstr();
    logout << "z39.50: couldn't find collection" 
	   << coll_str
	   << endl;
    delete coll_str;
    return;
  }

  const ShortColInfo_t *colinfo=(*here)->getInfo();
  collectinfo.shortInfo.name=colinfo->name;
  collectinfo.shortInfo.host=colinfo->host;
  collectinfo.shortInfo.port=colinfo->port;

  collectinfo.isPublic=true;
  // don't use beta field
  /*collectinfo.isBeta=false;*/
  collectinfo.buildDate=1;
  // leave ccsCols empty (no cross-coll. searching - for now)
  /*collectinfo.ccsCols=(text_tarray);*/ //not like this!!!
  // This info is available from the config file -- johnmcp
  /*******collectinfo.languages.push_back("en");
	  collectinfo.languages.push_back("fr");********/
  collectinfo.numDocs=0;
  collectinfo.numWords=0;
  collectinfo.numBytes=0;
  // copy the text maps over.
  //  collectinfo.collectionmeta; // text_tmap
  collectinfo.collectionmeta=*((*here)->getMeta());
  collectinfo.format=*((*here)->getFormat()); //text_tmap
  /*    collectinfo.building; //text_tmap  */

  ////collectinfo.receptionist="z3950"; 
  /* for now... this is a url,  relative to .../cgi-bin.
     NOTE: if this is empty, it defaults to _gwcgi_?a=p&p=about&c=<colname>
  */
}

void z3950proto::get_filterinfo (const text_t &/*collection*/,
				 InfoFiltersResponse_t &response,
				 comerror_t &/*err*/, ostream &/*logout*/) {
  // we'll fake it here, and say we have set up some filters
  response.filterNames.insert("BrowseFilter");
  response.filterNames.insert("QueryFilter");
  response.filterNames.insert("NullFilter");

}

void z3950proto::get_filteroptions (const text_t &/*collection*/,
				    const InfoFilterOptionsRequest_t &/*req*/,
				    InfoFilterOptionsResponse_t &response, 
				    comerror_t &err, ostream &/*logout*/) {
  // for now, assume all servers have the same characteristics
  /*  if (request.filterName=="QueryFilter") { } 
      else if (request.filterName=="BrowseFilter") { } 
      else if (request.filterName=="NullFilter") {  } */
  response.filterOptions["Index"].type=FilterOption_t::stringt;
  response.filterOptions["Index"].repeatable=FilterOption_t::onePerQuery;
  response.filterOptions["Index"].defaultValue="any";
  response.filterOptions["Index"].validValues.push_back(".any");
  response.filterOptions["Index"].validValues.push_back(".title");
  response.filterOptions["Index"].validValues.push_back(".author");
  // and maybe ["Language"] option as well?
  err=noError;
}

void z3950proto::filter (const text_t &collection,
			 FilterRequest_t &request,
			 FilterResponse_t &response,
			 comerror_t &err, ostream &logout) {
  // this function is called when:
  //  *  creating the title page,(looking for iconcoll* & collectname metadata)
  //  *  creating the about page (looking for "Title" metadata)
  //  * doing the query - (note that a request for metadata comes first, then
  // filterOptions = FRmetadata | FROID | FRtermFreq (64+4+1)

  // metadata-only requests have filterName="NullFilter", else "QueryFilter".
  // For the title page, we should not create a connection to the target
  // (target means the actual z39.50 server, origin means us), but
  // for the about page and query pages, we need to get information from the
  // origin. (eg for the about page, we will print out some info such as ID,
  // name and version.

  // cerr now goes to errout.txt in etc directory
  err=noError;

  // get relevant "collection"
  z3950_server_array::iterator zserver = zservers.begin();
  z3950_server_array::iterator zend = zservers.end();
  while (zserver != zend) {
    if((*zserver)->getName()==collection) {
      break;
    }
    zserver++;
  }
  // now have collection in zserver.
  
  ColInfoResponse_t info;
  ResultDocInfo_t *docInfo;
  
  // leave response.termInfo empty
  // response.termInfo.push_back(""); ??????? (should be empty if not req.)

  // See if this is for a query action
  if (request.filterName=="QueryFilter") {
    /* Sample OptionValue pairs
      `StartResults'=`1'
      `EndResults'=`20'
      `Term'=`firstword secondword' (term is just whatever the user typed in)
      `QueryType'=`ranked' => 'OR' (cgiarg t=1)
      `QueryType' = `boolean' => 'AND' (cgiarg t=0)
      `Casefold'=`true'
      `Stem'=`false'
      `Maxdocs'=`50'
     */
    // go through options
    text_t opt_term;            // the term(s) that the user entered 
    text_t opt_fields;          // which fields to search on
    int opt_start=1, opt_end=20; // default values
    int nummatches=0, maxdocs=50; // default values
    OptionValue_tarray::iterator ov_here=request.filterOptions.begin();
    OptionValue_tarray::iterator ov_end=request.filterOptions.end();
    while (ov_here != ov_end) {
      // cerr << "OV pair: `" << ov_here->name.getcstr() << "'=`" 
      //      << ov_here->value.getcstr() << "'\n";
      if (ov_here->name=="Term") 
	{
	  opt_term=ov_here->value;
	} else if (ov_here->name=="Index") 
	  {
	    opt_fields=ov_here->value;
	  } else if (ov_here->name=="StartResults") 
	    {
	      opt_start=ov_here->value.getint();
	    } else if (ov_here->name=="EndResults") 
	      {
		opt_end=ov_here->value.getint();
	      } else if (ov_here->name=="Maxdocs") 
		{
		  maxdocs=ov_here->value.getint();
		} 
      ov_here++;
    }
    err=noError;
    text_tarray *titles=(*zserver)->getrecordTitles(opt_term,
						    opt_fields,
						    opt_start, // first to get
						    opt_end-opt_start, //count
						    &nummatches,err);
    if (err!=noError) {
      // can we return an err msg in a response, or just use
      // the more drastic Greenstone error mechanism?
      docInfo=new ResultDocInfo_t;
      response.docInfo.push_back(*docInfo);
      docInfo->metadata["Title"].values.push_back("Error - query err?");
      logout << "\nz3950 filter query: error connecting to server\n";
      // for now, DON'T use GSDL protocol err.
      err=noError;
      return;
    }
    // check if (titles==NULL) - only happens on error?
    if (nummatches>0) {
      text_tarray::iterator titles_here=titles->begin();
      text_tarray::iterator titles_end=titles->end();
      int counter=1;
      while (titles_here!=titles_end) {
	docInfo=new ResultDocInfo_t; 
	docInfo->metadata["Title"].values.push_back(*titles_here);
	docInfo->result_num=counter;
	// we need to give some OID, so we'll just use counter for now...
	// make it the number into the whole possible retrieved set.
	docInfo->OID=counter+opt_start-1;
	response.docInfo.push_back(*docInfo);
	counter++;
	titles_here++;
      }
    }

    if (request.filterResultOptions & FRtermFreq) {
      if (nummatches>maxdocs) {
      	response.numDocs=maxdocs; // eg "more than 50" (if Maxdocs==50)
	response.isApprox=MoreThan;
      } else {
	response.numDocs=nummatches; // eg "36 documents"
	response.isApprox=Exact; // Exact | Approximate | MoreThan
      }
    } // end of if (... & FRtermFreq)
    
  } // end of if (... & FROID)
  else {
    // this wasn't a query action

    if (request.filterOptions.size()>0 &&
	request.filterOptions[0].name=="ParentNode") {
      // don't want to return anything
      return;
      /*    } else if (request.docSet.size() &&
	    request.docSet[0]!="collection") {
	    // documentaction
	    // if docSet is not empty, it is either "collection", or an array
	    // of OIDs 
	    docInfo=new ResultDocInfo_t;
	    response.docInfo.push_back(*docInfo);
      */
    } else {
      // in case we need to return only metadata
      docInfo=new ResultDocInfo_t;
      response.docInfo.push_back(*docInfo); 
    }
  }

  // Fill in metadata for each response.docInfo (if wanted)
  if (request.filterResultOptions & FRmetadata) {
    get_collectinfo (collection, info, err, logout);
    // should check err returned here....

    // get the Query out of the filterOptions.
    text_t query="";
    text_t field="";
    OptionValue_tarray::iterator opt_here=request.filterOptions.begin();
    OptionValue_tarray::iterator opt_end=request.filterOptions.end();
    while (opt_here!=opt_end) {
      if (opt_here->name=="Query") {
	query=opt_here->value;
	if (field!="") break; // break from loop if we've got both
      } else if (opt_here->name=="Index") {
	field=opt_here->value;
	if (query!="") break; // break from loop if we've got both
      }
      opt_here++;
    }

    if (!request.fields.empty()) {
      // loop on each document being returned
      ResultDocInfo_tarray::iterator docs_here=response.docInfo.begin();
      ResultDocInfo_tarray::iterator docs_end=response.docInfo.end();
      while (docs_here!=docs_end) {
	
	// loop on all the metadata fields in request.fields (type text_tset)
	text_tset::iterator fields_here=request.fields.begin();
	text_tset::iterator fields_end=request.fields.end();
	text_tmap::iterator it;
	while (fields_here!=fields_end) {
	  it=info.collectionmeta.find(*fields_here);
	  if (it!=info.collectionmeta.end())
	    docs_here->metadata[*fields_here].values.push_back((*it).second);
	  else if (*fields_here=="Title" && !request.docSet.empty()) { 
	    // We only do this for a document action.
	    // (This comes through as a NullQuery).
	    // hopefully docSet is only not empty for documentaction...
	    text_t doctitle;
	    int i;
	    // check that docSet isn't empty first!!!!!!
	    i=request.docSet[0].getint();
	    text_t doctext="unneeded";
	    (*zserver)->getfullrecord(query, field, i, doctitle, doctext, err);
	    // check err value!
	    docs_here->metadata["Title"].values.push_back(doctitle);	    
	  } else {
	    docs_here->metadata[*fields_here].values.push_back("");
	    /////// cerr << " (not found)";
	  }
	  fields_here++;
	} // end of inner while loop
	docs_here++;
      } // end of outer while loop
    } // end of if (!request.fields.empty())

    else { // request.fields empty: return all metadata for about page or query
      // we'll only put it in the first docInfo.
      text_tmap::iterator colmeta_here=info.collectionmeta.begin();
      text_tmap::iterator colmeta_end=info.collectionmeta.end();
      while (colmeta_here!=colmeta_end) {
	response.docInfo[0].metadata[(*colmeta_here).first].
	  values.push_back((*colmeta_here).second);
	colmeta_here++;
      }

      // check if "collectionextra" metadata is set. If it isn't, we should
      // create connection to target to get it.
      if (info.collectionmeta.find("collectionextra")==colmeta_end) {
	// it hasn't been set yet...
	text_t abouttext="<B>Server Online</B><br>\n";
	abouttext+=(*zserver)->getzAbout();
	// add in the "About" text we read in from config file.
	// how do we incorporate multi-lingual metadata?
	abouttext+="<P>\n";
	text_t tmpabout;

	if ((*zserver)->getcfgAbout("en", tmpabout)==true)
	  abouttext+=tmpabout;

	(*zserver)->setMeta("collectionextra",abouttext);
	response.docInfo[0].metadata["collectionextra"].values.push_back(abouttext);
      }
    } // end of else

    // do indices' names, regardless of whether asked for or not...
    if (!response.docInfo.empty()) {
     response.docInfo[0].metadata[".author"].values.push_back("author fields");
      response.docInfo[0].metadata[".title"].values.push_back("title fields");
      response.docInfo[0].metadata[".any"].values.push_back("any fields");
    }
  } //end of  if (... & FRmetadata) ...
}



void z3950proto::get_document (const text_t &collection,
			       const DocumentRequest_t &request,
			       DocumentResponse_t &response,
			       comerror_t &err, ostream &logout) {

  err=noError;

  // get relevant "collection"
  z3950_server_array::iterator zserver = zservers.begin();
  z3950_server_array::iterator zend = zservers.end();
  while (zserver != zend) {
    if((*zserver)->getName()==collection) {
      break;
    }
    zserver++;
  }
  // now have collection in zserver.

  /*  cout << "get document:\n\tOID: " << request.OID.getcstr()
      << "\n\tdocType: " << request.docType.getcstr()
      << "\n\tdocFormat: " << request.docFormat.getcstr() <<"\n";
  */

  /* docresponse consists of
     text_t response.doc */
  text_t title="unneeded";
  text_t doctext;
  text_t query; // this should not be needed, as we have already connected to 
  // get the  title....
  text_t field; // ditto...
  (*zserver)->getfullrecord(query,field,request.OID.getint(),
			    title,doctext,err);
  // check return value of above? (false=>not connected) 
  if (err==noError)
    response.doc=doctext;
  else {
    // could print out different messages based on error type....
    response.doc="<h2>Error</h2>There was an error while connecting to the ";
    response.doc+="z39.50 server (ie target). Most likely this was a \n";
    response.doc+="\"Connection Refused\" error.\n";

  }
  if (0) {
    err=protocolError;
    logout << "Some error\n";
  }
}