#include "executor/spi.h"

#include "fmgr.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "storage/ipc.h"
#include "utils/date.h"
#include "utils/memutils.h"
#include "utils/syscache.h"



#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

/*

CREATE OR REPLACE FUNCTION vpc() RETURNS setof record
	AS 'plbsh.dll', 'vpc' LANGUAGE 'C';

SELECT * FROM vpc() AS T(a INT, b TEXT);

SELECT * FROM vpc() AS T(a INT, b TEXT) LIMIT 1;

*/
extern Datum vpc(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(vpc);
Datum vpc(PG_FUNCTION_ARGS)
{
	ReturnSetInfo* rsinfo;
	FuncCallContext *funcctx;
	int current = 0;

	rsinfo = (ReturnSetInfo*) fcinfo->resultinfo;
	if (!rsinfo)
		ereport(ERROR, (errmsg("Invalid ReturnSetInfo in SRF")));
	if (!(rsinfo->allowedModes & SFRM_ValuePerCall))
		ereport(ERROR, (errmsg("Function must support returning a SETOF composite type in SFRM_ValuePerCall mode")));

	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext oldcontext;

		funcctx = SRF_FIRSTCALL_INIT();
		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		funcctx->attinmeta = TupleDescGetAttInMetadata(rsinfo->expectedDesc);
		funcctx->user_fctx = (void*)(int*)palloc(sizeof(int));
		*((int*)funcctx->user_fctx) = 0;

		MemoryContextSwitchTo(oldcontext);
	}

	rsinfo->returnMode = SFRM_ValuePerCall;
	rsinfo->setDesc = rsinfo->expectedDesc;

	funcctx = SRF_PERCALL_SETUP();
	current = *((int*)funcctx->user_fctx);
	ereport(WARNING, (errmsg("## Call#%d", current)));
	if(current >= 10)
	{
		ereport(WARNING, (errmsg("## Last Call")));
		SRF_RETURN_DONE(funcctx);
	}
	else
	{
		char buffer[100];
		char* values[2];
		HeapTuple tuple;
		Datum result;

		sprintf(buffer, "%d", current++);
		*((int*)funcctx->user_fctx) = current;
		values[0] = buffer;
		values[1] = buffer;

		tuple = BuildTupleFromCStrings(funcctx->attinmeta, values);
		result = TupleGetDatum(slot, tuple);

		ereport(WARNING, (errmsg("## (return)", current)));
		SRF_RETURN_NEXT(funcctx, result);
	}
}