//
// Synonym.cc
//
// Synonym: A fuzzy matching algorithm to create a database of related words
//          (or misspellings) that should be searched together.
//
// Part of the ht://Dig package   <http://www.htdig.org/>
// Copyright (c) 1995-2004 The ht://Dig Group
// For copyright details, see the file COPYING in your distribution
// or the GNU Library General Public License (LGPL) version 2 or later 
// <http://www.gnu.org/copyleft/lgpl.html>
//
// $Id: Synonym.cc,v 1.16 2004/05/28 13:15:20 lha Exp $
//

#ifdef HAVE_CONFIG_H
#include "htconfig.h"
#endif /* HAVE_CONFIG_H */

#include <fcntl.h>

#include "Synonym.h"
#include "htfuzzy.h"
#include "List.h"
#include "StringList.h"
#include "HtConfiguration.h"

#include "filecopy.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>

#ifdef HAVE_STD
#include <fstream>
#ifdef HAVE_NAMESPACES
using namespace std;
#endif
#else
#include <fstream.h>
#endif /* HAVE_STD */

//*****************************************************************************
Synonym::Synonym(const HtConfiguration& config_arg) :
  Fuzzy(config_arg)
{
    name = "synonyms";
    db = 0;
}


//*****************************************************************************
Synonym::~Synonym()
{
    if (db)
    {
        db->Close();
        delete db;
        db = 0;
    }
}


//*****************************************************************************
int
Synonym::createDB(const HtConfiguration &config)
{
    String      tmpdir = getenv("TMPDIR");
    String 	dbFile;

#if defined(LIBHTDIG) || defined(LIBHTDIGPHP) || defined(_MSC_VER) //WIN32
    int ret = -1;
    char * source = NULL;
    char * dest = NULL;
#endif

    if (tmpdir.length())
      dbFile = tmpdir;
    else
      dbFile = "/tmp";

    dbFile << "/synonyms.db";

    char	input[1000];
    FILE	*fl;
	
    const String sourceFile = config["synonym_dictionary"];

    fl = fopen(sourceFile, "r");
    if (fl == NULL)
    {
	cout << "htfuzzy/synonyms: unable to open " << sourceFile << endl;
	cout << "htfuzzy/synonyms: Use the 'synonym_dictionary' attribute\n";
	cout << "htfuzzy/synonyms: to specify the file that contains the synonyms\n";
	return NOTOK;
    }

    Database	*db = Database::getDatabaseInstance(DB_HASH);

    if (db->OpenReadWrite(dbFile.get(), 0664) == NOTOK)
    {
	delete db;
	db = 0;
	return NOTOK;
    }

    String	data;
    String	word;
    int		count = 0;
    while (fgets(input, sizeof(input), fl))
    {
	StringList	sl(input, " \t\r\n");
	if (sl.Count() < 2)
	{		// Avoid segfault caused by calling Database::Put()
	    if (debug)	// with negative length for data field
	    {
		cout<<"htfuzzy/synonyms: Rejected line with less than 2 words: "
		     << input << endl;
		cout.flush();
	    }
	    continue;
	}
	for (int i = 0; i < sl.Count(); i++)
	{
	    data = 0;
	    for (int j = 0; j < sl.Count(); j++)
	    {
		if (i != j)
		    data << sl[j] << ' ';
	    }
	    word = sl[i];
	    word.lowercase();
	    data.lowercase();
	    db->Put(word, String(data.get(), data.length() - 1));
	    if (debug && (count % 10) == 0)
	    {
                cout << "htfuzzy/synonyms: " << count << ' ' << word << "\n";
		cout.flush();
	    }
	    count++;
	}
    }
    fclose(fl);
    db->Close();
    delete db;

#if defined(LIBHTDIG) || defined(LIBHTDIGPHP) || defined(_MSC_VER) //WIN32
    
    //Uses file_copy function - works on Unix/Linux & WinNT
    source = dbFile.get();
    dest = (char *)config["synonym_db"].get();

    //Attempt rename, if fail attempt copy & delete.
    ret = rename(source, dest);
    if (ret < 0)
    {
        ret = file_copy(source, dest, FILECOPY_OVERWRITE_ON);
        if (ret == TRUE)
            unlink(source);
        else
            return NOTOK;
    }

    if (debug)
    {
        cout << "htfuzzy/synonyms: " << count << ' ' << word << "\n";
        cout << "htfuzzy/synonyms: Done.\n";
    }

#else //This code uses a system call - Phase this out

    struct stat stat_buf;
    String mv("mv");	// assume it's in the PATH if predefined setting fails
    if ((stat(MV, &stat_buf) != -1) && S_ISREG(stat_buf.st_mode))
	mv = MV;
    system(form("%s %s %s",
		mv.get(), dbFile.get(), config["synonym_db"].get()));

#endif

    return OK;
}


//*****************************************************************************
int
Synonym::openIndex()
{
    const String	dbFile = config["synonym_db"];
	
    if (db)
    {
        db->Close();
        delete db;
        db = 0;
    }
    db = Database::getDatabaseInstance(DB_HASH);
    if (db->OpenRead(dbFile) == NOTOK)
    {
	delete db;
	db = 0;
	return NOTOK;
    }
    return OK;
}


//*****************************************************************************
void
Synonym::getWords(char *originalWord, List &words)
{
    String	data;
    String	stripped = originalWord;
    HtStripPunctuation(stripped);

    if (db && db->Get(stripped, data) == OK)
    {
	char	*token = strtok(data.get(), " ");
	while (token)
	{
	    words.Add(new String(token));
	    token = strtok(0, " ");
	}
    }
}