/* @(#)validate_schema.c	2.1 93/05/18 */
 
/******************************************************************************/
/* function    : validate_schema.c                                            */
/*                                                                            */
/* subsystem   : chgen                                                        */
/*                                                                            */
/* input       : <none> (accesses tt and ta structures)                       */
/*                                                                            */
/* output      : <none> (error messages)                                      */
/*                                                                            */
/* returns     : void (exits upon fatal errors)                               */
/*                                                                            */
/* author      : Steve Smith / Craig Smith                                    */
/*                                                                            */
/* created     : July, 1991                                                   */
/*                                                                            */
/* revisions   : 93s5232:  changed code to incorporate integer keys:          */
/*               strn(cmp/cpy) funcs need to use hcg_abbr_size, error         */
/*               messages need to output hcg_abbr_size chars from key.        */
/*                                                                            */
/* description : This routine will traverse the tt and ta structures, looking */
/*               for various error and warning conditions.  The conditions    */
/*               detected are:                                                */
/*                 - duplicate table names                                    */
/*                 - duplicate filed names (within each table)                */
/*                 - forward references (fkey to table defined later in file) */
/*                 - undefined references (fkey to unknown table)             */
/*                                                                            */
/******************************************************************************/


#include <stdio.h>
#include <ctype.h>
#include "chgen_define.h"
#include "chgen_externs.h"

/*
 *	This function performs some basic validations on the schema
 *	which is now loaded into the internal tt/ta lists.
 */
void validate_schema()
{
	static char rcsid[] = "$Id: validate_schema.c,v 1.2.4.1 1999/05/04 17:00:25 jkarner Exp $";
int num_errors = 0;
int found_reference;
int found_after;
char temp_string[ABBREV_NAME_LENGTH];

  /*********************************************************/
  /* Search for duplicate table names.                     */
  /*********************************************************/
  tt_curr = tt;
  while (tt_curr != NULL)
   {

     tt_tmp = tt_curr->next_ptr;
     while (tt_tmp != NULL)
      {
       if (strcmp(tt_curr->TTabbr,tt_tmp->TTabbr) == 0)
        {
         printf("CHGEN-F-DUPTBLID, duplicate table-id (%s) found in schema\n",tt_curr->TTabbr);
         num_errors++;
        }
       if (strcmp(tt_curr->TableName,tt_tmp->TableName) == 0)
        {
         printf("CHGEN-F-DUPTBLNAME, duplicate table-name (%s) found in schema\n",tt_curr->TableName);
         num_errors++;
        }
       tt_tmp = tt_tmp->next_ptr;
      }
     tt_curr = tt_curr->next_ptr;
   }

  /*********************************************************/
  /* For each table, check for duplicate field names.      */
  /*********************************************************/
  tt_curr = tt;
  while (tt_curr != NULL)
   {

     ta_curr = tt_curr->ta_ptr;
     while (ta_curr != NULL)
      {

       ta_tmp = ta_curr->next_ptr;
       while (ta_tmp != NULL)
        {
         if (strcmp(ta_curr->FieldName,ta_tmp->FieldName) == 0)
          {
           printf("CHGEN-F-DUPTBLID, duplicate field-name (%s) found in table %s (%s)\n",
                  ta_curr->FieldName,tt_curr->TableName,tt_curr->TTabbr);
           num_errors++;
          }
         ta_tmp = ta_tmp->next_ptr;
        }
       ta_curr = ta_curr->next_ptr;
      }
     tt_curr = tt_curr->next_ptr;
   }

  /*********************************************************/
  /* For each table, check for forward references.         */
  /* to do this, loop over tables, and within each, loop   */
  /* over its fields.  If a field is a foreign key (but    */
  /* not the primary key), then search the list of tables  */
  /* for it.  If it is found before this table, ok.  if it */
  /* is found after this table its a forward reference.    */
  /* If it is not found at all, its a reference to an      */
  /* unknown table.                                        */
  /*********************************************************/
  tt_curr = tt;
  while (tt_curr != NULL)
   {

     ta_curr = tt_curr->ta_ptr;
     while (ta_curr != NULL)
      {

       if ((ta_curr != tt_curr->ta_ptr) &&
           (ta_curr->IsKey) &&
           (strncmp(ta_curr->FieldName,tt_curr->TTabbr,hcg_abbr_size) != 0)) 
         /* its a foreign key to some other table */
        {
         found_reference = 0;
         found_after     = 0;
         tt_tmp = tt;
         while (tt_tmp != NULL)
          {
           if ((tt_curr == tt_tmp) && (!found_reference))
             found_after = 1;
           if (strncmp(ta_curr->FieldName,tt_tmp->TTabbr,hcg_abbr_size) == 0)
            {
             found_reference = 1;
             break;
            }
           tt_tmp = tt_tmp->next_ptr;
          }

         if (!found_reference)
          {
	   strncpy_null(temp_string, ta_curr->FieldName, hcg_abbr_size);
           printf("CHGEN-F-UNKNOWNTABLEREF, unknown table %s referenced as a foreign key (%s) in table %s (%s)\n",
                  temp_string,ta_curr->FieldName,tt_curr->TableName,tt_curr->TTabbr);
           num_errors++;
          }
         else
         if (found_after)
          {
           if (!cli_quiet)
             printf("CHGEN-I-FORWARDREF, forward reference to table %s (%s) found in table %s (%s) via foreign key field %s\n",
                    tt_tmp->TableName,tt_tmp->TTabbr,tt_curr->TableName,tt_curr->TTabbr,ta_curr->FieldName);
          }

        } /* its a foreign key */

       ta_curr = ta_curr->next_ptr;
      }
     tt_curr = tt_curr->next_ptr;
   }

  if (num_errors > 0)
   exit(1);

  return;
}