/*
** Title:          Business
** SCCSid:         %W% %E% %U%
** CCid:           %W% %E% %U%
** Author:         Informix Software, Inc.
** Created:        06/11/1998 14:49
** Description:    This is the generated 'C' file for the Business DataBlade.
** Comments:       Generated for project Business.3.6
*/

/*
**  The following is placed here to insure
**  that name "mangling" does not occur.
*/
#ifdef __cplusplus

extern "C"
{

#endif

/* Standard library includes. */
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>

/* Used by Informix GLS routines. */
#include <ifxgls.h>

/* Include when accessing the Informix API. */
#include <mi.h>

/* This is the project include file. */
#include "Business.h"
#include <math.h>

/*
 *  The AMORT_STATE structure holds the state of a loan's amortization
 *  across iterations.  We store this structure in the MI_FP_FUNCSTATE
 *  entry in the MI_FPARAM for the set-valued function LoanAmortization.
 */

typedef struct
{
	int	numyears;
	int	iter;
	mi_real	amount;
	mi_real	balance;
	mi_real	interest_rate;
	mi_real	payment;
} AMORT_STATE;

/* {{FUNCTION(594117f1-5f4c-11d0-93a5-00a0c9202325) (MergeSection) */

/****************************************************************
**
** Function name:
**
**	PresentValue
**
** Description:
**
** Special Comments:
**
**	Entrypoint for the SQL routine ExmPV (real,integer,real) returns real.
**
** Parameters:
**
** Return value:
**
**	mi_real
**
** History:
**
**	06/30/1998 - Generated by BladeSmith Version 3.60.630  .
**
** Identification:
**
** NOTE:
**
**	BladeSmith will add and remove parameters from the function
**	prototype, and will generate tracing calls.  ONLY EDIT code
**	in blocks marked  Your_<section>.  Any other  modifications
**	will require manual merging.
**
*****************************************************************
*/
UDREXPORT mi_real *PresentValue
(

mi_real *               amount,

mi_integer              numyears,

mi_real *               interest_rate,
MI_FPARAM *             Gen_fparam        /* Standard info - see DBDK docs.*/
)
{
	mi_real*        Gen_RetVal;       /* The return value. */
	MI_CONNECTION * Gen_Con;          /* The connection handle. */
	/* ------ {{Your_Declarations (PreserveSection) BEGIN ------ */
	double			pv;

	/* ------ }}Your_Declarations (#0000) END ------ */

	/* Use the NULL connection. */
	Gen_Con = NULL;

	/* ------ {{Your_Code (PreserveSection) BEGIN ------ */
	/*
	** Write to the trace file indicating
	** that PresentValue has been called.
	*/
	DBDK_TRACE_ENTER( "PresentValue" );

	/* simple sanity checks */
	if( (*amount < 0.0) || (numyears < 0) || (*interest_rate < 0) )
	{
		mi_db_error_raise( Gen_Con, MI_SQL, "UE001",
			 "FUNCT%s", "PresentValue", (mi_integer)NULL);
		/* not reached */
        }

	/* compute the present value of the loan */
	pv  = *amount / pow((double) (1.0f + *interest_rate/100.0f),
			    (double) numyears);

	/* allocate return value */
	Gen_RetVal = (mi_real *) mi_alloc(sizeof(mi_real));
	*Gen_RetVal = (mi_real) pv;

	/*
	** Write to the trace file indicating
	** that PresentValue has successfully exited.
	*/
	DBDK_TRACE_EXIT( "PresentValue" );

	/* ------ }}Your_Code (#B4PS) END ------ */


	/* Return the function's return value. */
	return Gen_RetVal;
}
/* }}FUNCTION (#6V87I8P7) */


/* {{FUNCTION(edf2f7a0-8384-11d0-93b2-00a0c9202325) (MergeSection) */

/****************************************************************
**
** Function name:
**
**	LoanAmortization
**
** Description:
**
**	This  function  is an iterator function.   As such,  it  must  be
**	registered using SQL as an iterator function:
**
**	     create function ExmAmortize( args )
**	      	returns MI_ROW
**	       	with
**	       	(
**	              	iterator
**	       	)
**	       	external name "yourpath/Business.bld(LoanAmortization)"
**	       	language C
**	     end function;
**
**	Iterator functions are called with state information.   There are
**	three  states:  SET_INIT,  SET_RETONE,  and SET_END.   This state
**	information  is  passed  in via the Gen_fparam  argument  to  the
**	function  and placed in Gen_IteratorState.   During the  SET_INIT
**	state,   the   iterator  function  must  perform   any   required
**	initialization.   Typically, this means allocating memory to hold
**	any  information  that  is needed across calls to  the  function.
**	This  allocated  memory must be stored back  into  Gen_fparam  by
**	calling  mi_fp_setfuncstate  and  can  be  retrieved  by  calling
**	mi_fp_funcstate.  Values passed back from this state are ignored.
**
**	Following  initialization,  the function is repeatedly called  in
**	the SET_RETONE state.   The return value returned from this state
**	is  passed back to the user.   The function is called  repeatedly
**	until  the  iterator function signals that no more data is to  be
**	passed back.  The iterator function *MUST* call:
**
**		mi_fp_setisdone( Gen_fparam, MI_TRUE );
**
**	to conclude looping.   Failing to call this function will  result
**	in infinite looping!
**
**	Finally, the iterator function is called in the SET_END state and
**	the  function  is given a chance to perform any cleanup  that  is
**	required.  Values passed back from this state are ignored.
**
**	N.B.: If mi_db_error_raise is called during the processing of the
**	iterator function,  the function  is not  called in  the  SET_END
**	state. Resources allocated using mi_dalloc on a PER_COMMAND basis
**	are freed for you but all other resources should be  freed before
**	calling mi_db_error_raise.
**
**
** Special Comments:
**
**	Entrypoint for the SQL routine ExmAmortize (real,integer,real) returns ExmLoanAmortResult.
**
** Parameters:
**
** Return value:
**
**	MI_ROW
**
** History:
**
**	06/30/1998 - Generated by BladeSmith Version 3.60.630  .
**
** Identification:
**
** NOTE:
**
**	BladeSmith will add and remove parameters from the function
**	prototype, and will generate tracing calls.  ONLY EDIT code
**	in blocks marked  Your_<section>.  Any other  modifications
**	will require manual merging.
**
*****************************************************************
*/
UDREXPORT MI_ROW * LoanAmortization
(

mi_real *               amount,

mi_integer              num_years,

mi_real *               interest_rate,
MI_FPARAM *             Gen_fparam        /* Standard info - see DBDK docs.*/

)
{

	int             Gen_IteratorState;              /* This is the iteration state.   */
	MI_CONNECTION * Gen_Con;                        /* The current connection.        */
	MI_ROW *        Gen_RetVal = 0;                 /* LoanAmortization's return value.    */

	/* ------ {{Your_StateInfoDeclaration (PreserveSection) BEGIN ------ */

	AMORT_STATE *	input;
	mi_real			iter_interest;
	mi_real			iter_principal;
	mi_real			iter_balance;
	mi_real 		payment_factor;
	mi_integer 		i;
	void *			values[6];
	mi_boolean		nulls[6]; 
	MI_TYPEID *		typid;
	MI_ROW_DESC *	rowdesc;

	struct _StateInfo
	{
		MI_CONNECTION * Conn;      /* The current connection.               */
		void *          StateInfo; /* Private state information.            */
	} *				Gen_StateInfo; /* LoanAmortization's state information. */

	/* ------ }}Your_StateInfoDeclaration (#0JN8) END ------ */

	/* ------ {{Your_AutoVariable_Declarations (PreserveSection) BEGIN ------ */
	/* Initialize data members */
	Gen_RetVal = 0;
	input = (AMORT_STATE *) NULL;

	/* ------ }}Your_AutoVariable_Declarations (#0000) END ------ */

	/* Get the iteration state. */
	Gen_IteratorState = mi_fp_request( Gen_fparam );

	/*
	** Based  on the iteration  state,
	** calculate the iterator's return
	** value.
	*/
	switch( Gen_IteratorState )
	{
		case SET_INIT:			/* Initialize */

			/*
			** Get the current connection handle.
			** This connection handle is held in
			** the state information for the duration
			** of the running of LoanAmortization.
			*/
			Gen_Con = mi_open( NULL, NULL, NULL );

			/* Verify that the connection has been established. */
			if( Gen_Con == 0 )
			{
				/*
				** Opening the current connection has failed
				** so issue the following message and quit.
				**
				** 	"Connection has failed in LoanAmortization."
				*/
				DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG1, 10 );

				/* not reached */
			}


			/* ------ {{Your_InitializationCode (PreserveSection) BEGIN ------ */
			{
				/*
				** Write to the trace file indicating
				** that LoanAmortization has been called.
				*/
				DBDK_TRACE_ENTER( "LoanAmortization" );
			
				/*
				** Perform any required  initializa-
				** tion  for  the  iterator  function.  Any
				** state information must be allocated  and
				** registered here.
				*/

				/*
				** Allocate the  state  information.   Both
				** the   private  state   information   and
				** connection are stored here.
				*/
				Gen_StateInfo = (struct _StateInfo *)
								   mi_dalloc( sizeof( struct _StateInfo ), PER_COMMAND );
				if( Gen_StateInfo == NULL )
				{
					DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG2, 10 );
				}

				/* Save the connection. */
				Gen_StateInfo->Conn = Gen_Con;

				/*
				** Allocate  any  required  private
				** state information  here.  
				*/
				Gen_StateInfo->StateInfo = mi_dalloc(sizeof(AMORT_STATE), PER_COMMAND);
				if( Gen_StateInfo->StateInfo == NULL )
				{
					DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG2, 10 );
				}

				/* Register the private state info in Gen_fParam. */
				mi_fp_setfuncstate( Gen_fparam, Gen_StateInfo );

				/* 
				** Save private state information
				*/
				input = (AMORT_STATE *)Gen_StateInfo->StateInfo; 

				input->numyears = num_years;
				input->iter = 1;
				input->amount = *amount;
				input->interest_rate = *interest_rate;

				/* sanity check */
				if ((*amount < 0.0) 
					|| (num_years < 0)
		    			|| (*interest_rate < 0))
				{
					mi_db_error_raise(Gen_Con,
							  MI_SQL,"UE001",
							  "FUNCT%s", "LoanAmortization",
							  (char *) NULL);
				}

				payment_factor = 0.0f;

				for (i=1; i<=input->numyears; i++)
				{
					payment_factor += 
					  1.0f 
			  		  / (float) pow((double)(1.0+
					 			 (input->interest_rate
								 /100.0)),
							(double) i);
				}
				input->payment = input->amount/payment_factor;

			}
			/* ------ }}Your_InitializationCode (#VKOT) END ------ */

			if( Gen_StateInfo->StateInfo == NULL )
			{
					DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG2, 10 );
			}

			/* Register the private state info in Gen_fParam. */
			mi_fp_setfuncstate( Gen_fparam, Gen_StateInfo );

			break;

		case SET_RETONE:		/* Iterate */

			/*
			** Before  using,  insure  that  the  state
			** information  is valid. It might  not  be
			** if the function has not been  called  as
			** an iterator.
			*/
			Gen_StateInfo = (struct _StateInfo *)mi_fp_funcstate( Gen_fparam );
			if( Gen_StateInfo == NULL )
			{
				DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG2, 10 );
			}

			/* Retrieve the connection. */
			Gen_Con = Gen_StateInfo->Conn;



			/* ------ {{Your_SetReturnCode (PreserveSection) BEGIN ------ */
			{
				/*
				** Write to the trace file indicating
				** that LoanAmortization has been called.
				*/
				DBDK_TRACE_ENTER( "LoanAmortization" );
			

				/* recover the amortization state from the MI_FPARAM */
				input = (AMORT_STATE *)Gen_StateInfo->StateInfo;

				/* if the loan's paid off, we're done */
				if(input->iter > input->numyears)
				{
					mi_fp_setisdone( Gen_fparam, MI_TRUE );
					mi_fp_setreturnisnull( Gen_fparam, 0, MI_TRUE );

					return ((MI_ROW *) NULL);
				} 
				else
				{
					mi_fp_setreturnisnull( Gen_fparam, 0, MI_FALSE );

					/* we are not done, so update the private state */
  
					if (input->iter > 1)
					{
						input->amount = input->balance;
					}

					/* calculate values for the ExmLoanAmortResult */
					iter_interest = input->amount * (input->interest_rate / 100.0);
					iter_principal = input->payment - iter_interest;
					iter_balance = input->amount 
							   - (input->payment - iter_interest);

					/* bring the balance forward for the next iteration */
					input->balance = iter_balance;

					/*
					 *  Now we set up the composite ExmLoanAmortResult value with
					 *  the numbers for this iteration.  The 'values' array
					 *  holds the attribute values for the composite, in row
					 *  order, and the 'nulls' array tells MakeCompositeValue
					 *  whether any of the values we're supplying are SQL
					 *  NULL values.  None are, in this case, so we set all the
					 *  nulls[] array entries to MI_FALSE.
					 *
					 *  The ExmLoanAmortResult row type is defined as
					 *
					 *	create type ExmLoanAmortResult (
					 *					Year integer,
					 *					BegAmount real, 
					 *					Payment real,
					 *					Interest real,
					 *					Principal real,
					 *					Balance real
					 *				       );
					 *			
					 */

					/* get typeid.
					 * Here we use a C string containing the type name.
					 * Another way would be to look at the rettype in fparam.
					 */
					typid = mi_typestring_to_id(Gen_Con, "ExmLoanAmortResult");

					/* create a row desc */
					rowdesc = mi_row_desc_create(typid);

					/* create the return value */
					for (i = 0; i < 6; i++)
					{
						nulls[i] = MI_FALSE;
					}
					values[0] = (void *) input->iter; 
					values[1] = (void *) &input->amount;
					values[2] = (void *) &input->payment; 
					values[3] = (void *) &iter_interest; 
					values[4] = (void *) &iter_principal;
					values[5] = (void *) &iter_balance;

					Gen_RetVal = mi_row_create(Gen_Con, 
								   rowdesc, 
								   (MI_DATUM *)values,
								   nulls);

					/* cleanup */
					(void) mi_free((char *)typid);

					/* get set for next iteration */
					input->iter++;

					/*
					** Write to the trace file indicating
					** that LoanAmortization has successfully exited.
					*/
					DBDK_TRACE_EXIT( "LoanAmortization" );
				}

			}

			/* ------ }}Your_SetReturnCode (#6MM0) END ------ */


			/* Check for a NULL return value. */
			if( Gen_RetVal == 0 )
			{
				mi_fp_setreturnisnull( Gen_fparam, 0, MI_TRUE );
			}
			else
			{
				mi_fp_setreturnisnull( Gen_fparam, 0, MI_FALSE );
			}


			return ( Gen_RetVal );

		case SET_END:			/* Conclude */

			/* Get the state information. */
			Gen_StateInfo = (struct _StateInfo *)mi_fp_funcstate( Gen_fparam );

			if( Gen_StateInfo != NULL )
			{
				/* Retrieve the connection. */
				Gen_Con = Gen_StateInfo->Conn;


				/* Close the open connection. */
				mi_close( Gen_Con );

				/* ------ {{Your_SetFinalCode (PreserveSection) BEGIN ------ */
				{
					/* TO DO: free any private resources. */
				}
				/* ------ }}Your_SetFinalCode (#000J) END ------ */


				/* Free the private state information. */
				if( Gen_StateInfo->StateInfo != NULL )
				{
					mi_free( Gen_StateInfo->StateInfo );
				}

				/* Free the state information. */
				mi_free( Gen_StateInfo );
			}

			break;

		default:

			/* Get the state information. */
			Gen_StateInfo = (struct _StateInfo *)mi_fp_funcstate( Gen_fparam );

			if( Gen_StateInfo != NULL )
			{
				/* Retrieve the connection. */
				Gen_Con = Gen_StateInfo->Conn;
			}

			/*
			** This is an invalid state so issue
			** the following message and quit.
			**
			** 	"Invalid iterator state used in LoanAmortization."
			*/
			DBDK_TRACE_ERROR( "LoanAmortization", ERRORMESG17, 10 );

			/* not reached */

			break;
	}


	mi_fp_setreturnisnull( Gen_fparam, 0, MI_TRUE );
	return ( 0 );
}
/* }}FUNCTION (#3QRA52N8) */




/* {{FUNCTION(594117f0-5f4c-11d0-93a5-00a0c9202325) (MergeSection) */

/****************************************************************
**
** Function name:
**
**	FutureValue
**
** Description:
**
** Special Comments:
**
**	Entrypoint for the SQL routine ExmFV (real,integer,real) returns real.
**
** Parameters:
**
** Return value:
**
**	mi_real
**
** History:
**
**	06/30/1998 - Generated by BladeSmith Version 3.60.630  .
**
** Identification:
**
** NOTE:
**
**	BladeSmith will add and remove parameters from the function
**	prototype, and will generate tracing calls.  ONLY EDIT code
**	in blocks marked  Your_<section>.  Any other  modifications
**	will require manual merging.
**
*****************************************************************
*/
UDREXPORT mi_real *FutureValue
(

mi_real *               amount,

mi_integer              numyears,

mi_real *               interest_rate,
MI_FPARAM *             Gen_fparam        /* Standard info - see DBDK docs.*/
)
{
	mi_real*        Gen_RetVal;       /* The return value. */
	MI_CONNECTION * Gen_Con;          /* The connection handle. */
	/* ------ {{Your_Declarations (PreserveSection) BEGIN ------ */
	double			fv;

	/* ------ }}Your_Declarations (#0000) END ------ */

	/* Use the NULL connection. */
	Gen_Con = NULL;

	/* ------ {{Your_Code (PreserveSection) BEGIN ------ */
	/*
	** Write to the trace file indicating
	** that FutureValue has been called.
	*/
	DBDK_TRACE_ENTER( "FutureValue" );

	/* simple sanity checks */
	if( (*amount <0.0) || (numyears < 0) || (*interest_rate <0) )
	{
		mi_db_error_raise( Gen_Con, MI_SQL, "UE001",
                        "FUNCT%s", "FutureValue", (mi_integer)NULL);
		/* not reached */
        }

	/* compute the future value of the loan */
	fv  = *amount * pow((double) (1.0 + *interest_rate/100.0),
			    (double) numyears);

	/* allocate return value */
	Gen_RetVal = (mi_real *) mi_alloc(sizeof(mi_real));
	*Gen_RetVal = (mi_real) fv;

	/*
	** Write to the trace file indicating
	** that FutureValue has successfully exited.
	*/
	DBDK_TRACE_EXIT( "FutureValue" );

	/* ------ }}Your_Code (#A0VP) END ------ */


	/* Return the function's return value. */
	return Gen_RetVal;
}
/* }}FUNCTION (#1D1CLFOH) */



#ifdef __cplusplus

}

#endif