/*-------------------------------------------------------------------------

 *

 * dict_simple.c

 *    Simple dictionary: just lowercase and check for stopword

 *

 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group

 *

 *

 * IDENTIFICATION

 *    src/backend/tsearch/dict_simple.c

 *

 *-------------------------------------------------------------------------

 */

#include "postgres.h"

#include "catalog/pg_collation_d.h"

#include "commands/defrem.h"

#include "tsearch/ts_public.h"

#include "utils/fmgrprotos.h"

#include "utils/formatting.h"

typedef struct

{

  StopList  stoplist;

  bool    accept;

} DictSimple;

Datum

dsimple_init(PG_FUNCTION_ARGS)

{

  List     *dictoptions = (List *) PG_GETARG_POINTER(0);

  DictSimple *d = (DictSimple *) palloc0(sizeof(DictSimple));

  bool    stoploaded = false,

        acceptloaded = false;

  ListCell   *l;

  d->accept = true;     /* default */

  foreach(l, dictoptions)

  {

    DefElem    *defel = (DefElem *) lfirst(l);

    if (strcmp(defel->defname, "stopwords") == 0)

    {

      if (stoploaded)

        ereport(ERROR,

            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

             errmsg("multiple StopWords parameters")));

      readstoplist(defGetString(defel), &d->stoplist, str_tolower);

      stoploaded = true;

    }

    else if (strcmp(defel->defname, "accept") == 0)

    {

      if (acceptloaded)

        ereport(ERROR,

            (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

             errmsg("multiple Accept parameters")));

      d->accept = defGetBoolean(defel);

      acceptloaded = true;

    }

    else

    {

      ereport(ERROR,

          (errcode(ERRCODE_INVALID_PARAMETER_VALUE),

           errmsg("unrecognized simple dictionary parameter: \"%s\"",

              defel->defname)));

    }

  }

  PG_RETURN_POINTER(d);

}

Datum

dsimple_lexize(PG_FUNCTION_ARGS)

{

  DictSimple *d = (DictSimple *) PG_GETARG_POINTER(0);

  char     *in = (char *) PG_GETARG_POINTER(1);

  int32   len = PG_GETARG_INT32(2);

  char     *txt;

  TSLexeme   *res;

  txt = str_tolower(in, len, DEFAULT_COLLATION_OID);

  if (*txt == '\0' || searchstoplist(&(d->stoplist), txt))

  {

    /* reject as stopword */

    pfree(txt);

    res = palloc0(sizeof(TSLexeme) * 2);

    PG_RETURN_POINTER(res);

  }

  else if (d->accept)

  {

    /* accept */

    res = palloc0(sizeof(TSLexeme) * 2);

    res[0].lexeme = txt;

    PG_RETURN_POINTER(res);

  }

  else

  {

    /* report as unrecognized */

    pfree(txt);

    PG_RETURN_POINTER(NULL);

  }

}