#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <sys\float.h>

struct scada_point{
	char name[35];
	char tag[20];
	double current_value;
	double next_value;
	unsigned char write_to_driver; //set to 1 to write to driver, set to 0 to write to real time DB
	unsigned int checksum;
};

/*
Internal scada variables and functions
	exit_loop : initialized at 0,on stop of driver its value is 1
	scada_db : scada vector of struct scada_point items
	int numSamplePoints; : number of sample point inside scada database
	int processed_id; : itemID of the processed value

	void scan_rate(void) : scan rate
	void lock(void) : lock access of other threads to scada_db
	void unlock(void) : let other threads to access scada_db
	void post_value() : post the processed value to real time DB or to driver
*/

int calc_output_from_one_input(char* name_output, char* tag_output, char* name_input, int processed_id, char* processed_name, char* processed_tag, double delta, unsigned int bit_position);

int main(int argc, char **argv)
{
	int itemID; //index of item in database
	int r;
	double delta = 0.1;
    
	for(itemID = 0; ;)
	{
		if(exit_loop)
		{
			break;
		}

		lock();

		processed_id = itemID;
		//////////Add your code from here/////////////////////
		
		//Example code
		calc_output_from_one_input("CALCpoint01","VALUE", "MDBPoint23", itemID, scada_db[itemID].name, scada_db[itemID].tag, delta, 4);
		calc_output_from_one_input("CALCpoint02","VALUE", "MDBPoint23", itemID, scada_db[itemID].name, scada_db[itemID].tag, delta, 5);		
		
		//Uncomment this to see relation between itemID and sample point name e tag name
		//printf("itemID = %d\n", itemID);
		//printf("scada_db[%d].name = %s\n", itemID, scada_db[itemID].name);
		//printf("scada_db[%d].tag = %s\n", itemID, scada_db[itemID].tag);
		//printf("scada_db[%d].current_value = %lf\n", itemID, scada_db[itemID].current_value);


		///////////////////to here//////////////////////////////////////////////
		unlock();

		fflush(stdout);

		if(itemID == 0)
		{
			scan_rate();
		}

		itemID++;

		if(itemID == numSamplePoints)
		{
			itemID = 0;
		}
	}
	
    return 0;
}

// Extracting the bit_position bit (0-based index)
int calc_output_from_one_input(char* name_output, char* tag_output, char* name_input, int processed_id, char* processed_name, char* processed_tag, double delta, unsigned int bit_position)
{
	int r;
	int item_id_input;
	double calculated;
	double input_value;
	unsigned int num;
	unsigned int mask;
	unsigned int extracted_bit;

	if((r = strcmp(processed_name, name_output) == 0) && (r = strcmp(processed_tag, tag_output) == 0))
	{
		for(item_id_input = 0; item_id_input < numSamplePoints; item_id_input++)
		{	
			if(r = strcmp(scada_db[item_id_input].name, name_input) == 0)
			{
				printf("scada_db[%d].current_value = %lf\n", processed_id, scada_db[processed_id].current_value);
				printf("scada_db[%d].current_value = %lf\n", item_id_input, scada_db[item_id_input].current_value);
				printf("\n");

				input_value = scada_db[item_id_input].current_value;

				//////////Edit here your calculation////////////////////

				// C Program to Extract a given bit of a binary number

				num = input_value;

				// Create a mask with only the 5th bit set to 1
				mask = 1 << bit_position;

				// Extract the bit using AND and right shift
				extracted_bit = (num & mask) >> bit_position;

				// Print the result
				printf("Extracted Bit: %u\n", extracted_bit);

				calculated = extracted_bit;

				if((abs(scada_db[processed_id].current_value - calculated) > delta))
				{
					scada_db[processed_id].write_to_driver = 0;
					scada_db[processed_id].current_value = calculated;

					post_value();
				}

				return 1;
			}
		}
	}

	return 0;
}