/* calculator.c - Script 1.1 - Version 0.1 */

/* This program takes values from the user
 * assigns these valus to variables
 *And performes a certain operation 
 */
 #include <stdio.h>
 
 int multiply(int fst,int snd);
 int divide(int ist,int ond);
 int add(int st,int nd);
 int subtract(int rst,int ond);
 
 int main(void)
 {
 
	/*Define Variables */
	int input1;  	//Number input by user
	int input2;		//Number2 input by user
	int output; 	// Value returned
	int answer;		// Return value from function
	char function; // Function to be carried out 
	char conf1; // Confirmation 1
	char conf2; // Confirmation 2
	
	 // Assign values to variables
	 input1 = input2 = output = answer = 0;
	 
	 /* Prompt user to enter first number */
	 printf(" Please enter the first number you'd like to be calculated: ");
	 scanf("%d", &input1);
	 getchar();
	 
	 //Confirm if the first number is correct from user
	 printf("You entered %d as your fist value, is that the right number?(Y / N) ", input1);
	 scanf("%c", &conf1);
	 
	 //Switch to check
	switch (conf1) {
		case 'y':
		case 'Y':
			printf(" Alright, let's continue\n");
		break;
		case'n':
		case'N':
			printf("Unfortunately you are incapable of changing the value.");
			printf(" Please exit the program and re-run it, entering the correct value\n");
			printf(" This function will be imrpoved upon in the next update\n");
			printf(" You may exit by pressing CTRL + D\n");
		break;
		default:
			 printf("Error 1 - You were supposed to enter Y or N\n");
		break;
	} // End of checking switch
	
	//Prompt user for calculation type
	printf(" Please enter the function to take place. (I know the commannds +, -, x and /) ");
	scanf("%c", &function);
getchar();
getchar();
	
	//Prompt user for second value
	printf(" Please enter the second value you'd like to be calculated: ");
	scanf("%d", &input2);
	getchar();
	getchar();
	
	 //Confirm if the Second number is correct from user
	 printf("You entered %d as your second value, is that the right number?(Y / N) ", input2);
	 scanf("%c", &conf2);
	
		 //Switch to check
	switch (conf2) {
		case 'y':
		case 'Y':
			printf(" Alright, let's continue\n");
		break;
		case'n':
		case'N':
			printf("Unfortunately you are incapable of changing the value.");
			printf(" Please exit the program and re-run it, entering the correct value\n");
			printf(" This function will be imrpoved upon in the next update\n");
			printf(" You may exit by pressing CTRL + D\n");
		break;
		default:
			 printf("Error 1 - You were supposed to enter Y or N\n");
		break;
	} // End of second switch
	
	// Calculate the values
	printf(" Please hold while I calculate your values\n");
	
	switch (function) {
		case '+':
			answer = add(input1, input2);
			printf("Adding...\n");
		break;
		case '/':
			answer = divide(input1, input2);
			printf("Dividing...\n");
		break;
		case '-':
		answer = subtract(input1, input2);
		printf("Subtracting...\n");
		break;
		case 'x':
			answer = multiply(input1, input2);
			printf("Multiplying...\n");
		break;
		default:
		printf("Error 2 - You were supposed to enter a correct function.");
		printf(" Either +, -, x or / \n");
		printf("Please exit the program, this function will be improved upon in");
		printf(" the next update.\n");
		printf("You can exit by pressing CTRL + D\n");
		break;
	} // End switch for function check
	
	printf(" The answer is %d\n", answer);
	
} // End main function

/* Multiply function */
int multiply(int first, int second)
{ // Begin multiply function
	
	
	return first * second;
	
} // End multiply function

/* add function */
int add(int first, int second)
{ // Begin add function

	
	return first + second;
} // End add function

/* Divide Function */
int divide(int first, int second)
{ // Begin divide function
	
	
	return first / second;
	
} // End divide function 

/* Subtract function */
subtract(int first, int second)
{ // Begin subtract function
	
	
	return first - second;
	
} // End subtract function