//********************************************************************************************
//
// Name:		meter.c
// Created by:	Razvan Stefan Gornea
//
// Contents:	Device driver for a portable multimeter
//
// Log:			2004-01-15 14:22
//				Writing down initial code.
//
//********************************************************************************************

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include "midas.h"

// globals variables

#define DEFAULT_TIMEOUT 10000 // 10 secondes

typedef struct {
  int  address;
} METERDEV_SETTINGS;

#define METERDEV_SETTINGS_STR "\
Address = INT : 1\n\
"
typedef struct {
  METERDEV_SETTINGS meterdev_settings; // device settings
  float         *array; // data array
  INT           num_channels; // number of channels associated with this device
  INT (*bd)(INT cmd, ...); // bus driver entry function
  void *bd_info; // private settings and data related to the bus driver
  HNDLE hkey; // ODB key for bd_info structure
} METERDEV_INFO;

// routines

// initialization function: access the ODB to creates the settings, initializes the variables
// and calls the initialization function of the bus driver
INT meterdev_init(HNDLE hkey, void **pinfo, INT channels, INT (*bd)(INT cmd, ...))
{
	int status, size;
	HNDLE hDB, hkeydd;
	METERDEV_INFO *info;

	// allocate info structure
	info = calloc(1, sizeof(METERDEV_INFO));
	*pinfo = info;
	// get handle on current experiment ODB
	cm_get_experiment_database(&hDB, NULL);
	// create METERDEV settings record
	status = db_create_record(hDB, hkey, "DD", METERDEV_SETTINGS_STR); // force the ODB structure to match the METERDEV_SETTINGS C structure
	if (status != DB_SUCCESS) {
		return FE_ERR_ODB;
	}
	db_find_key(hDB, hkey, "DD", &hkeydd); // get handle on the DD key in the ODB associated with a certain equipment and device as pointed by the "hkey" handle
	size = sizeof(info->meterdev_settings); // get the size of the device settings structure
	db_get_record(hDB, hkeydd, &info->meterdev_settings, &size, 0); // load the device settings for the ODB, i.e. ontent of DD key
	// initialize the driver
	info->num_channels = channels; // define the nmber of channels
	info->array = calloc(channels, sizeof(float)); // allocate space for data
	info->bd = bd; // set handle on bus driver
	info->hkey = hkey; // set handle on the ODB key for the evice driver
	if (!bd) { // if handle invalid return error
		return FE_ERR_ODB;
	}
	// call the bus driver initialization routine
	status = info->bd(CMD_INIT, info->hkey, &info->bd_info);
	if (status != SUCCESS) {
		return status;
	}
	// initialization of device, something like ... 
	//BD_PUTS("init");
	// for this device no initialization string is needed ...

  return FE_SUCCESS;
}

// decomission function: free memory allocation(s) and close device(s)
INT meterdev_exit(METERDEV_INFO *info)
{
	// call EXIT function of bus driver, usually closes device
	info->bd(CMD_EXIT, info->bd_info);
	// free local variables
	if (info->array) {
		free(info->array);
	}
	free(info);
	
	return FE_SUCCESS;
}

// set channel value
INT meterdev_set(METERDEV_INFO *info, INT channel, float value)
{
	char str[80];
	
	// set channel to a specific value, something like ...
	sprintf(str, "SET %d %lf", channel, value);
	BD_PUTS(str);
	BD_GETS(str, sizeof(str), ">", DEFAULT_TIMEOUT);
	// simulate writing by storing value in local array, has to be removed in a real driver
	if (channel < info->num_channels) {
		info->array[channel] = value;
	}
	
	return FE_SUCCESS;
}

// set all channels values
INT meterdev_set_all(METERDEV_INFO *info, INT channels, float *value)
{
	int  i;
	char str[1000];

	// put here some optimized form of setting all channels simultaneously like ...
	strcpy(str, "SETALL ");
	for (i=0 ; i<min(info->num_channels, channels) ; i++) {
		sprintf(str+strlen(str), "%lf ", value[i]);
	}
	BD_PUTS(str);
	BD_GETS(str, sizeof(str), ">", DEFAULT_TIMEOUT);
	// simulate writing by storing values in local array
	for (i=0 ; i<min(info->num_channels, channels) ; i++) {
		info->array[i] = value[i];
	}
	
	return FE_SUCCESS;
}

// get channel value
INT meterdev_get(METERDEV_INFO *info, INT channel, float *pvalue)
{
	int  status, i;
	char str[80];
	char ascii_number[5];

	// read value from channel, something like ...
	//sprintf(str, "GET %d", channel);
	sprintf(str, "D"); // request data
	BD_PUTS(str);
	status = BD_GETS(str, sizeof(str), "\n", DEFAULT_TIMEOUT); // read until getting a cariage return or exit on timeout
	for (i = 0; i < 4; i++) { // transfer the number
		ascii_number[i] = str[i+4];
	}
	ascii_number[4] = '\0'; // end of string
	*pvalue = (float) atof(ascii_number); // convert from ASCII to float
	// simulate reading by copying set data from local array
	//if (channel < info->num_channels) {
	//	*pvalue = info->array[channel];
	//}
	//else {
	//	*pvalue = 0.f;
	//}
	
	return FE_SUCCESS;
}

// get all channels values
INT meterdev_get_all(METERDEV_INFO *info, INT channels, float *pvalue)
{
	// int  i;
	
	/* put here some optimized form of reading all channels. If the deviced
	does not support such a function, one can call nulldev_get() in a loop 
	strcpy(str, "GETALL");
	BD_PUTS(str);
	BD_GETS(str, sizeof(str), ">", DEFAULT_TIMEOUT);
	for (i=0 ; i<min(info->num_channels, channels) ; i++)
	pvalue[i] = atof(str+i*5); // extract individual values from reply
	*/
	/* simulate reading by copying set data from local array */
	//for (i=0 ; i<min(info->num_channels, channels) ; i++)
	//	pvalue[i] = info->array[i];
	
	return FE_SUCCESS;
}

// device driver entry point
INT meterdev(INT cmd, ...)
{
	va_list argptr;
	HNDLE   hKey;
	INT     channel, status;
	DWORD   flags;
	float   value, *pvalue;
	void    *info, *bd;
	va_start(argptr, cmd);
	status = FE_SUCCESS;
	
	switch (cmd) {
	case CMD_INIT:
		hKey = va_arg(argptr, HNDLE);
		info = va_arg(argptr, void *);
		channel = va_arg(argptr, INT);
		flags = va_arg(argptr, DWORD);
		bd = va_arg(argptr, void *);
		status = meterdev_init(hKey, info, channel, bd);
		break;
	case CMD_EXIT:
		info = va_arg(argptr, void *);
		status = meterdev_exit(info);
		break;
	case CMD_SET:
		info = va_arg(argptr, void *);
		channel = va_arg(argptr, INT);
		value = (float) va_arg(argptr, double); // floats are passed as double
		status = meterdev_set(info, channel, value);
		break;
	case CMD_SET_ALL:
		info = va_arg(argptr, void *);
		channel = va_arg(argptr, INT);
		pvalue   = (float *) va_arg(argptr, float *);
		status = meterdev_set_all(info, channel, pvalue);
		break;
	case CMD_GET:
		info = va_arg(argptr, void *);
		channel = va_arg(argptr, INT);
		pvalue  = va_arg(argptr, float*);
		status = meterdev_get(info, channel, pvalue);
		break;
	case CMD_GET_ALL:
		info = va_arg(argptr, void *);
		channel = va_arg(argptr, INT);
		pvalue  = va_arg(argptr, float*);
		status = meterdev_get_all(info, channel, pvalue);
		break;
	default:
		break;
	}
	va_end(argptr);
	
	return status;
}