package main

import (
	"encoding/json"
	"fmt"
	"log"
	"math/rand"
	"net/http"
)

type prob struct {
	Operation string
	First     int
	Second      int
}

type JsonHandler func(http.ResponseWriter, *http.Request)

func (h JsonHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Content-Type", "application/json")
    h(w, req)
}

func problem(w http.ResponseWriter, req *http.Request) {
	operation := "+"
	if r := rand.Intn(2); r == 0 {
		operation = "-"
	}

	first := rand.Intn(MAX)
	var second int
	if operation == "-" {
		if first == 0 {
			second = 0
		} else {
			second = rand.Intn(first)
		}
	} else {
		second = rand.Intn(MAX)
	}

	r := prob{operation, first, second}

	b, err := json.Marshal(r)
	if err != nil {
		log.Fatal("issue with json marshalling")
	}
	j := string(b)
	fmt.Println(j)
	fmt.Fprintf(w, j)
}

func attempt(w http.ResponseWriter, req *http.Request) {
	fmt.Fprintf(w, "hello world")
}