#include "postgres.h"
#include "executor/spi.h"    
#include "commands/trigger.h" 

#include "postgres.h"
#include "executor/spi.h"       /* this is what you need to work with SPI */
#include "commands/trigger.h"   /* ... and triggers */

static char * get_column_name(int attrelid, int col_num, char *result)
{
  int ret; 
  char query[ 256 ];
  
  sprintf(query,"select attname from pg_attribute  where attrelid=%d and attnum=%d",attrelid, col_num);
  
  ret = SPI_exec(query,  1 );
  return SPI_getvalue(SPI_tuptable->vals[ 0 ], SPI_tuptable->tupdesc,  1 );
}

extern Datum trigf(PG_FUNCTION_ARGS);

PG_FUNCTION_INFO_V1(trigf);

Datum
trigf(PG_FUNCTION_ARGS)
{
    TriggerData *trigdata = (TriggerData *) fcinfo->context;
    TupleDesc   tupdesc;
    HeapTuple   rettuple;
    char       *when;
    bool        checknull = false;
    bool        isnull;
    int         ret, i;
    enum {UPDATE, DELETE, INSERT} state; 

    /* make sure it's called as a trigger at all */
    if (!CALLED_AS_TRIGGER(fcinfo))
        elog(ERROR, "trigf: not called by trigger manager");

    /* tuple to return to executor */
    if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
    {
        state= UPDATE;
        rettuple = trigdata->tg_newtuple;
    }
    else
        rettuple = trigdata->tg_trigtuple;

    /* check for null values */
    if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
    {
      state = DELETE;
    }

    if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
    {
      state = INSERT;
    }

    tupdesc = trigdata->tg_relation->rd_att;

    /* connect to SPI manager */
    if ((ret = SPI_connect()) < 0)
        elog(ERROR, "trigf (fired %s): SPI_connect returned %d", when, ret);

    
    char *relation_name = SPI_getrelname(trigdata->tg_relation);
    char *schema_name = SPI_getnspname(trigdata->tg_relation);
    /* Should be pfreed at the end */

    elog (INFO, "XXX TABLE %s", name);
//    elog (INFO, "xxx %s", get_column_name(trigdata->tg_relation->rd_id,2,""));
    
    char *buf, *p, *p1;
    int len, buf_len=100;
    buf=palloc(100);
    buf[0]=0;
    buf[1]=0;
    char pgnull[1]={0};
    if (state==DELETE)
    {
      elog (INFO, "XXX DELETE");
      buf[0]='(';
      buf_len=1;
      for(i = 1; i <= tupdesc->natts;i++)
      {
        p=SPI_getvalue(trigdata->tg_trigtuple,tupdesc,i);
        len=strlen(p);
        buf=repalloc(buf,len+buf_len+1);
        if (i!=1) strcat(buf,",");
        strcat(buf,p);
        buf_len+=len+1;
      }
      strcat(buf,")");
      elog (INFO, "XXX %s", buf);
    }
    else if (state==UPDATE)
    {
      elog (INFO, "XXX UPDATE");
      /*
      for(i=1;i<=tupdesc->natts;i++)
      {
        p=SPI_getvalue(trigdata->tg_trigtuple,tupdesc,i);
        p1=SPI_getvalue(trigdata->tg_newtuple,tupdesc,i);
        /*if (strcmp(p,p1))
        {
          elog(INFO, "CHANGE (column %s): %s -> %s", get_column_name(trigdata->tg_relation->rd_id,2,""), p, p1);
        }
        */
        buf[0]='(';
      buf_len=1;
      
      for(i = 1; i <= tupdesc->natts;i++)
      {
        p=SPI_getvalue(trigdata->tg_trigtuple,tupdesc,i);
        if (p==0) {p=pgnull;}        
        len=strlen(p);
        buf=repalloc(buf,len+buf_len+1);
        if (i!=1) strcat(buf,",");
        strcat(buf,p);
        buf_len+=len+1;
      }
      strcat(buf,")");
      elog (INFO, "XXX %s", buf);

        buf[0]='(';
        buf[1]=0;
      buf_len=1;
      for(i = 1; i <= tupdesc->natts;i++)
      {
        p=SPI_getvalue(trigdata->tg_newtuple,tupdesc,i);
        if (p==0) {p=pgnull;}
        len=strlen(p);
        buf=repalloc(buf,len+buf_len+1);
        if (i!=1) strcat(buf,",");
        strcat(buf,p);
        buf_len+=len+1;
      }
      strcat(buf,")");
      elog (INFO,"XXX ->>> %s", buf);        
      /*}*/
      
    }
    else if (state==INSERT)
    {
      elog (INFO, "XXX INSERT");
      buf[0]='(';
      buf_len=1;
      for(i = 1; i <= tupdesc->natts;i++)
      {
        p=SPI_getvalue(trigdata->tg_trigtuple,tupdesc,i);
        if (p==0) {p=pgnull;}
        len=strlen(p);
        buf=repalloc(buf,len+buf_len+1);
        if (i!=1) strcat(buf,",");
        strcat(buf,p);
        buf_len+=len+1;
      }
      strcat(buf,")");
      elog (INFO, "XXX %s", buf);
    }    

//    elog(NOTICE, "XXXX %s",ss);
/*
    ss[0]=0;
    if (trigdata->tg_newtuple!=NULL)
    for(i=1;i<=tupdesc->natts;i++)
    {
      strcat(ss,SPI_getvalue(trigdata->tg_newtuple,tupdesc,i));
    }
    elog(NOTICE, "YYYY %s",ss);
*/

//    SPI_finish();
//    char query[ 256 ];
//    sprintf(query,"SELECT relname FROM pg_class where reltype=%d",trigdata->tg_relation->rd_id);

//    ret = SPI_exec(query,  1 );


/*
    if (ret < 0)
        elog(NOTICE, "trigf (fired %s): SPI_exec returned %d", when, ret);

    char *query1 = SPI_getvalue(SPI_tuptable->vals[0],
                                    SPI_tuptable->tupdesc,
                                    1);

    elog (INFO, "table %s", query1);
*/

//      ret=SPI_execute("INSERT INTO foo VALUES (1)", false,  1 );
//elog(INFO,"%d",ret==SPI_OK_INSERT);


    SPI_finish();

/*
    if (checknull)
    {
        SPI_getbinval(rettuple, tupdesc, 1, &isnull);
        if (isnull)
            rettuple = NULL;
    }
*/
    return PointerGetDatum(rettuple);
}