modified purchase function

vendorInfo.c

@@ -1,8 +1,11 @@
 /* 
- * Win (Thanawin Pattanaphol) 
  * vendorInfo.c
- * 8th August 2024
-*/
+ *
+ * Program that 
+ *
+ *
+ *    Created by Win (Thanawin Pattanaphol), 28th August 2024
+ */
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,8 +23,22 @@ struct vendor_item
 	int item_price_baht;	
 } vendors[MAX_VENDORS];
 
+struct purchase_res
+{
+	int status;
+	char vendor_name[20];
+	int price_owe_baht; 
+}; 
+
 int read_input(char str[], int n);
-int search(char query[], struct vendor_item vendors[MAX_VENDORS], int total_vendors);
+
+int search(char query[], 
+		   struct vendor_item vendors[MAX_VENDORS], 
+		   int total_vendors);
+		   
+struct purchase_res purchase(int item_id, 
+			 int amount, 
+			 struct vendor_item vendors[MAX_VENDORS]);
 
 int main() 
 {
@@ -52,7 +69,7 @@ int main()
 		strncpy(vendors[index].vendor_name, token, strlen(token) + 1); 
 		
 		token = strtok(NULL, " ");
-		/* TO-DO: VALIDATE MERCHANDISE BY PUTTING EVERYTHING AS LOWERCASE*/
+		/* TO-DO: VALIDATE MERCHANDISE BY PUTTING EVERYTHING AS LOWERCASE */
 		strncpy(vendors[index].merchandise, token, strlen(token) + 1); 
 				
 		token = strtok(NULL, " ");
@@ -84,19 +101,18 @@ int main()
 	
 		printf("%-50s %s\n", vendor_info, vendor_stock);		
 	}
-
-	char user_query[100];
 	
 	while (1) 
 	{
+		char user_query[100];
+		printf("What do you want to buy? (DONE to end) ");
+		read_input(user_query, 100);
+
 		if ((strcmp(user_query, "DONE") == 0)) 
 		{
 			break;
 		}
 
-		printf("What do you want to buy? (DONE to end) ");
-		read_input(user_query, 100);
-
 		// convert string to lowercase - each character one by one
 		int user_query_length = strlen(user_query);	
 		for (int i = 0; i < user_query_length; i++)
@@ -104,18 +120,26 @@ int main()
 			user_query[i] = tolower(user_query[i]);
 		};
 
-		int result = search(user_query, vendors, total_vendors);
-		if(result > 0)
+		int item_id = search(user_query, vendors, total_vendors);
+		printf("THING: %d\n", item_id);
+		if(item_id > 0)
 		{
-			int item_amount; 
-
 			char input[10];
 			read_input(input, 10);
 
 			if(atoi(input) < 0) 
 			{
-				item_amount = atoi(input);
-			} 
+				int item_amount = atoi(input);
+				struct purchase_res response = purchase(item_id, item_amount, vendors);
+
+				if (response.status == 0)
+				{
+					printf("You owe %s a total of %d baht.\n",
+						response.vendor_name,
+						response.price_owe_baht
+					);
+				}
+			}
 			else 
 			{
 				printf("You must enter a positive whole number for the number of items");		
@@ -134,7 +158,7 @@ int main()
 };
 
 /*
-	custom read input function
+	read_input: Custom read input function
 	str = string itself
 	n = max amount of characters that the function is able to read into buffer
 
@@ -168,25 +192,29 @@ int read_input(char str[], int n)
 		- i: Item Number
 		- 0: No results found
 */
+
+/* TO-DO IMPLEMENT RESPONSE STRUCT */
 int search(char query[], struct vendor_item vendors[MAX_VENDORS], int total_vendors)
 {
 	int i; 
 	for (i = 0; i < total_vendors; i++)
 	{
+		printf("Step: %d\n", i);
 		if (strcmp(query, vendors[i].merchandise) == 0)
 		{
-			printf("Query: %s | Result: %s %s\n", 
+			printf("\nQuery: %s | Result: %s %s\n", 
 				query, 
 				vendors[i].vendor_name, 
 				vendors[i].merchandise
 			);
 			return i;
-			break;	
+			break;
 		};
 	};
 
 	if (i == total_vendors)
 	{
+		printf("THING: %d %d", i, total_vendors);
 		return 0;
 	}
 };
@@ -202,16 +230,26 @@ int search(char query[], struct vendor_item vendors[MAX_VENDORS], int total_vend
 	Return values:
 		- 
 */
-int purchase(int item_id, int amount, struct vendor_item vendors[MAX_VENDORS])
+struct purchase_res purchase(int item_id, int amount, struct vendor_item vendors[MAX_VENDORS])
 {
 	if(amount <= vendors[item_id].inventory_count)
 	{
+		// Decrease vendor inventory
 		vendors[item_id].inventory_count = vendors[item_id].inventory_count - amount;
+
+		struct purchase_res response;
+
+		response.status = 0;
+		strcpy(response.vendor_name, vendors[item_id].vendor_name);
+		response.price_owe_baht = vendors[item_id].item_price_baht * amount;
 		
-		return vendors[item_id].inventory_count;
+		return (response);
 	}
 	else
 	{
-		return 0;
+		struct purchase_res response; 
+		response.status = 1;
+		
+		return response;
 	} 
 };