Moved http related functions to their own file; added 'sum.go' for a second endpoint.

functions/http.go

@@ -0,0 +1,74 @@
+package functions
+
+// HTTP helper functions doing the input checking and calling the actual math functions
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+)
+
+func HttpAbort(w http.ResponseWriter, code int, message string) {
+	w.WriteHeader(code)
+	fmt.Fprint(w, message)
+}
+
+func HttpGetPostInt(request *http.Request, key string) (value int, error error) {
+	switch request.Method {
+	case "POST":
+		error = request.ParseForm()
+		if error != nil {
+			error = fmt.Errorf("Unable to parse HTTP POST input: %s",
+				error.Error())
+			return
+		}
+		value, error = strconv.Atoi(request.Form.Get(key))
+		if error != nil {
+			fmt.Printf("Error parsing parameter '%s'\n", key)
+			error = fmt.Errorf("Unable to parse parameter '%s' as an integer: %s",
+				key, error.Error())
+		}
+		return
+	default:
+		error = fmt.Errorf("This endpoint does not support %s operations.\n", request.Method)
+		return
+	}
+}
+
+func HttFibonacci(w http.ResponseWriter, request *http.Request) {
+	seq, error := HttpGetPostInt(request, "seq")
+	if error != nil {
+		HttpAbort(w, http.StatusBadRequest,
+			fmt.Sprintf("Could not get parameter: %s", error.Error()))
+	} else if seq < 1 {
+		HttpAbort(w, http.StatusBadRequest,
+			"Please provide a positive integer as the sequence number.\n")
+	} else {
+		fmt.Printf("Received request for Fibonacci Sequence Number %d\n",
+			seq)
+		fmt.Fprintf(w, "Fibonacci sequence index [%d]: %d\n",
+			seq, MyFibonacci(seq))
+	}
+	return
+}
+
+func HttSum(w http.ResponseWriter, request *http.Request) {
+	var errorstr string
+	first, error := HttpGetPostInt(request, "first")
+	if error != nil {
+		errorstr = error.Error()
+	}
+	second, error := HttpGetPostInt(request, "second")
+	if error != nil {
+		errorstr = error.Error()
+	}
+
+	if errorstr != "" {
+		HttpAbort(w, http.StatusBadRequest,
+			fmt.Sprintf("Invalid input: %s\n", errorstr))
+		return
+	}
+	fmt.Printf("Received a request to add %d and %d.\n", first, second)
+	fmt.Fprintf(w, "The sum of %d and %d is %d.\n", first, second, sum(first, second))
+
+}