/**********************************************************************
 *
 * source.cpp -- 
 * Copyright (C) 1999  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 "source.h"
#include "colservertools.h"
#include "fileutil.h"
#include "OIDtools.h"
#include <assert.h>


sourceclass::sourceclass ()
{
  db_ptr = NULL;
  oaidb_ptr = NULL;
  textsearchptr = NULL;
  classname = "source";
}

sourceclass::~sourceclass ()
{
  if (db_ptr != NULL) delete db_ptr;
  if (textsearchptr != NULL) delete textsearchptr;

  // http://stackoverflow.com/questions/677620/do-i-need-to-explicitly-call-the-base-virtual-destructor
  // Answer: "No, destructors are called automatically [by the derived destructor] in the reverse
  // order of construction. (Base classes last). Do not call base class destructors."
  // The link also explains why the destructors should be declared as virtual in the header files.

  // now delete the oaidb object pointed to by the oaidb_ptr too
  if (oaidb_ptr != NULL) delete oaidb_ptr;
  oaidb_ptr = NULL;
}

// configure should be called once for each configuration line
void sourceclass::configure (const text_t &key, const text_tarray &cfgline)
{
  if (cfgline.size() >= 1) {
    const text_t &value = cfgline[0];

    if (key == "collection") collection = value;
    else if (key == "collectdir") collectdir = value;
    else if (key == "gsdlhome") gsdlhome = value;
    else if (key == "collecthome") collecthome = value;
    else if (key == "gdbmhome") dbhome = value;
  }

  if (key == "indexmap") {
    indexmap.importmap (cfgline);

  } else if (key == "defaultindex") {
    indexmap.from2to (cfgline[0], defaultindex);

  } else if (key == "subcollectionmap") {
    subcollectionmap.importmap (cfgline);

  } else if (key == "defaultsubcollection") {
    subcollectionmap.from2to (cfgline[0], defaultsubcollection);

  } else if (key == "languagemap") {
    languagemap.importmap (cfgline);

  } else if (key == "defaultlanguage") {
    languagemap.from2to (cfgline[0], defaultlanguage);
  } else if (key == "indexstem") {
    indexstem = cfgline[0];
  }
}


// init should be called after all the configuration is done but
// before any other methods are called
bool sourceclass::init (ostream &logout)
{
  outconvertclass text_t2ascii;
  
  if (collecthome.empty()) collecthome = filename_cat(gsdlhome,"collect");
  if (dbhome.empty()) dbhome = gsdlhome;

  if (defaultindex.empty()) {
    // use first index in map as default if no default is set explicitly
    text_tarray toarray;
    indexmap.gettoarray(toarray);
    if (toarray.size()) {
      defaultindex = toarray[0];
    }
  }

  if (defaultsubcollection.empty()) {
    // use first subcollection in map as default if no default is set explicitly
    text_tarray toarray;
    subcollectionmap.gettoarray(toarray);
    if (toarray.size()) {
      defaultsubcollection = toarray[0];
    }
  }

  if (defaultlanguage.empty()) {
    // use first language in map as default if no default is set explicitly
    text_tarray toarray;
    languagemap.gettoarray(toarray);
    if (toarray.size()) {
      defaultlanguage = toarray[0];
    }
  }
  
  // get the collection directory name
  if (collectdir.empty()) {
    collectdir = filename_cat (collecthome, collection);
  }

  if (db_ptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
	   << "configuration error: queryfilter contains a null dbclass\n\n";
    return false;
  }

  // get the filename for the database and make sure it exists
  if (indexstem.empty()) {
    indexstem = collection;
  }
  db_filename = resolve_db_filename(gsdlhome, dbhome, collecthome, collection,
				    indexstem, db_ptr->getfileextension());
  if (!file_exists(db_filename)) {
    logout << text_t2ascii
	   << "warning: database \"" << db_filename << "\" does not exist\n\n";
    // return false;
  }
  
  oaidb_filename = resolve_oaidb_filename(gsdlhome, dbhome, collecthome, collection,
					  oaidb_ptr->getfileextension());

  return true;
}


// translate_OID translates OIDs using ".pr", ."fc" etc.
bool sourceclass::translate_OID (const text_t &OIDin, text_t &OIDout, 
				 comerror_t &err, ostream &logout)
{
  outconvertclass text_t2ascii;

  err = noError;
  if (db_ptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
	   << "configuration error: " << classname << " contains a null dbclass\n\n";
    err = configurationError;
    return true;
  }

  // open the database
  db_ptr->setlogout(&logout);
  if (!db_ptr->opendatabase (db_filename, DB_READER, 100, false)) {
    // most likely a system problem (we have already checked that the database exists)
    logout << text_t2ascii
	   << "system problem: open on database \"" << db_filename << "\" failed\n\n";
    err = systemProblem;
    return true;
  }

  infodbclass info;
  OIDout = db_ptr->translate_OID (OIDin, info);
  db_ptr->closedatabase();  // Important that local library doesn't leave any files open
  return true;
}

// get_oai_metadata fills out the oai metadata from oaidb if possible
// if it is not responsible for the given OID then it will return false.
bool sourceclass::get_oai_metadata (const text_t &requestParams, const text_t &refParams, 
				bool getParents, const text_tset &fields, 
				const text_t &OID, text_t &deleted_status, MetadataInfo_tmap &metadata, 
				comerror_t &err, ostream &logout)
{
  outconvertclass text_t2ascii;
  metadata.erase(metadata.begin(), metadata.end());
  err = noError;

  //logout << text_t2ascii << "sourceclass::get_oai_meta for OID: " << OID << "\n";   

// ONLY if we're doing any OAI stuff (FROAI will be set then) will we even be in here
// So next try to open the oai-inf db if it exists for this collection
  if (!file_exists(oaidb_filename)) { // if the oaidb file doesn't even exist, let's not bother with oaidb
    
    logout << text_t2ascii
	   << "warning: collection's oai-inf database \"" << oaidb_filename << "\" does not exist\n\n";    
    return false;
    
  } else { // let's try opening the oaidb file
    oaidb_ptr->setlogout(&logout);
    if (!oaidb_ptr->opendatabase (oaidb_filename, DB_READER, 100, false)) {
      // most likely a system problem (we have already checked that the database exists just above)
      logout << text_t2ascii
	     << "system problem: open on database \""
	     << oaidb_filename << "\" failed\n\n";
      err = systemProblem;
      return false;
    } // now we've opened the oai-inf db file successfully
  }

  // get the metadata (deleted status, timestamp, datestamp) for OID, and pushback onto the metadata array
  infodbclass oai_info;
  if (!oaidb_ptr->getinfo(OID, oai_info)) { // OID not found in oai_inf db
    logout << text_t2ascii
	     << "warning: lookup for OID \"" << OID
	     << "\" in etc/oai-inf db failed when getting metadata (in sourceclass source.cpp).\n\n";
    
    return false; 
  } else {
    //logout << text_t2ascii << "@@@@ getting metadata for OID \"" << OID << "\" from etc/oai-inf db.\n\n";
    //logout << text_t2ascii << "@@@@ timestamp: " << oai_info["timestamp"] << "\n\n";

    metadata["oaiinf.status"].isRef = false;
    metadata["oaiinf.status"].values.push_back(oai_info["status"]);
    metadata["oaiinf.timestamp"].isRef = false;
    metadata["oaiinf.timestamp"].values.push_back(oai_info["timestamp"]);
    metadata["oaiinf.datestamp"].isRef = false;
    metadata["oaiinf.datestamp"].values.push_back(oai_info["datestamp"]);

    deleted_status = oai_info["status"];
  }

   // we're done with oai-inf db

  oaidb_ptr->closedatabase(); // don't leave files open

  return true;
}


// get_metadata fills out the metadata if possible, if it is not responsible
// for the given OID then it will return false.
bool sourceclass::get_metadata (const text_t &requestParams, const text_t &refParams, 
				bool getParents, const text_tset &fields, 
				const text_t &OID, MetadataInfo_tmap &metadata, 
				comerror_t &err, ostream &logout, bool append)
{
  outconvertclass text_t2ascii;

  if(!append) {
    metadata.erase(metadata.begin(), metadata.end());
  }

  err = noError;
  if (db_ptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
	   << "configuration error: " << classname <<" contains a null dbclass\n\n";
    err = configurationError;
    return true;
  }

  // open the database
  db_ptr->setlogout(&logout);
  if (!db_ptr->opendatabase (db_filename, DB_READER, 100, false)) {
    // most likely a system problem (we have already checked that the database exists)
    logout << text_t2ascii
	   << "system problem: open on database \"" << db_filename << "\" failed\n\n";
    err = systemProblem;
    return true;
  }

  // get the metadata - if getParents is set we need to get 
  // info for all parents of OID as well as OID
  vector<infodbclass> info_array;
  text_tarray OIDs;
  if (getParents) get_parents_array (OID, OIDs);
  OIDs.push_back (OID);

  text_tarray::const_iterator this_OID = OIDs.begin();
  text_tarray::const_iterator end_OID = OIDs.end();

  while (this_OID != end_OID) {
    infodbclass info;
    if (!db_ptr->getinfo(*this_OID, info)) return false;

    // adjust the metadata
    text_t &contains = info["contains"];
    if (contains.empty()) info["haschildren"] = 0;
    else info["haschildren"] = 1;
    //contains.clear();

    info_array.push_back(info);
    ++this_OID;
  }

  // if fields set is empty we want to get all available metadata
  text_tset tfields = fields;
  if (tfields.empty() && !info_array.empty()) {
    infodbclass::iterator t_info = info_array[0].begin(); 
    infodbclass::iterator e_info = info_array[0].end(); 
    while (t_info != e_info) {
      if ((*t_info).first != "contains")
	tfields.insert ((*t_info).first);
      ++t_info;
    }
    tfields.insert ("hasnext");
    tfields.insert ("hasprevious");
  }
    
  // collect together the metadata
  bool donenextprevtest = false;
  bool hasnext=false, hasprevious=false;
  MetadataInfo_t this_metadata;
  text_tarray *pos_metadata;
  text_tset::const_iterator fields_here = tfields.begin();
  text_tset::const_iterator fields_end = tfields.end();

  while (fields_here != fields_end) {
    this_metadata.clear();
    this_metadata.isRef = false;

    vector<infodbclass>::reverse_iterator this_info = info_array.rbegin(); 
    vector<infodbclass>::reverse_iterator end_info = info_array.rend(); 
    MetadataInfo_t *tmetaptr = &this_metadata;
    while (this_info != end_info) {

      pos_metadata = (*this_info).getmultinfo(*fields_here);
      if ((*fields_here == "hasnext" || *fields_here == "hasprevious")) {
	
	// collect metadata
	if (!donenextprevtest) {
	  donenextprevtest = true;
	  
	  // cache parent contents array
	  text_t thisparent = get_parent (OID);
	  if (!thisparent.empty()) {
	    if (thisparent != parentOID) {
	      parentOID = thisparent;
	      parentcontents.erase(parentcontents.begin(), parentcontents.end());
	      if (db_ptr->getinfo(parentOID, parentinfo)) {
		text_t &parentinfocontains = parentinfo["contains"];
		if (!parentinfocontains.empty())
		  splitchar (parentinfocontains.begin(), parentinfocontains.end(), 
			     ';', parentcontents);
	      }
	    }
	    
	    // do tests
	    text_tarray::const_iterator parentcontents_here = parentcontents.begin();
	    text_tarray::const_iterator parentcontents_end = parentcontents.end();
	    text_t shrunk_OID = OID;
	    shrink_parent (shrunk_OID);
	    while (parentcontents_here != parentcontents_end) {
	      if (*parentcontents_here == shrunk_OID) {
		if (parentcontents_here == parentcontents.begin()) hasprevious = false;
		else hasprevious = true;
		
		++parentcontents_here;
		
		if (parentcontents_here == parentcontents.end()) hasnext = false;
		else hasnext = true;
		
		break;
	      }  
	      
	      ++parentcontents_here;
	    }
	 
	    // fill in metadata
	    if ((*fields_here == "hasnext" && hasnext) ||
		(*fields_here == "hasprevious" && hasprevious))
	      tmetaptr->values.push_back("1");
	    else
	      tmetaptr->values.push_back("0");
	  } else
	    tmetaptr->values.push_back("0");
	}
      }
      //else if (pos_metadata != NULL && *fields_here != "contains") {
      else if (pos_metadata != NULL) {
	tmetaptr->values = *pos_metadata;
      }
      else
	tmetaptr->values.push_back("");

      ++this_info;
      if (this_info != end_info) {
	tmetaptr->parent = new MetadataInfo_t();
	tmetaptr = tmetaptr->parent;
      }
    }
    metadata[*fields_here] = this_metadata;
    ++fields_here;
  }

  db_ptr->closedatabase();  // Important that local library doesn't leave any files open
  return true;
}

bool sourceclass::get_document (const text_t &OID, text_t &doc, 
				comerror_t &err, ostream &logout)
{
  outconvertclass text_t2ascii;

  err = noError;
  if (db_ptr == NULL) {
    // most likely a configuration problem
    logout << text_t2ascii 
	   << "configuration error: " << classname << " contains a null dbclass\n\n";
    err = configurationError;
    return true;
  }

  // open the database
  db_ptr->setlogout(&logout);
  if (!db_ptr->opendatabase (db_filename, DB_READER, 100, false)) {
    // most likely a system problem (we have already checked that the database exists)
    logout << text_t2ascii
	   << "system problem: open on database \"" << db_filename << "\" failed\n\n";
    err = systemProblem;
    return true;
  }

  text_t tOID = OID;
  if (needs_translating (OID)) 
    translate_OID (OID, tOID, err, logout);
  infodbclass info;
  if (!db_ptr->getinfo(tOID, info)) {
    db_ptr->closedatabase();  // Important that local library doesn't leave any files open
    return false;
  }
  
  if (info["hastxt"].getint() == 1) {
    int docnum = info["docnum"].getint();
    
    // set the collection directory
    textsearchptr->setcollectdir (collectdir);
    
    // get the text
    textsearchptr->docTargetDocument(defaultindex, defaultsubcollection,
				   defaultlanguage, collection, docnum, doc);    

    // remove the <Doc></Doc> and <Sec></Sec> tags
    doc.replace("<Doc>", "");
    doc.replace("</Doc>", "");
    doc.replace("<Sec>", "");
    doc.replace("</Sec>", "");
  }

  db_ptr->closedatabase();  // Important that local library doesn't leave any files open
  return true;
}

bool sourceclass::is_searchable(bool &issearchable, comerror_t &err, ostream &logout)
{
  err = noError;
  issearchable = false;

  text_tarray fromarray;
  indexmap.getfromarray(fromarray);
  if (fromarray.size() == 0) {
    return true;
  } else if (fromarray.size() == 1) {
    if (fromarray[0] == "dummy:text") {
      // always return true - issearchable is false here though
      return true;
    }
  }
  issearchable = true;
  return true;
}


bool operator==(const sourceptr &x, const sourceptr &y) {
  return (x.s == y.s);
}

bool operator<(const sourceptr &x, const sourceptr &y) {
  return (x.s < y.s);
}


// thesource remains the property of the calling code but
// should not be deleted until it is removed from this list.
void sourcelistclass::addsource (sourceclass *thesource) {
  // can't add a source that doesn't exist
  assert (thesource != NULL);
  if (thesource == NULL) return;

  sourceptr sp;
  sp.s = thesource;

  sourceptrs.push_back(sp);
}