RC database server

main.go

package main

import (
	"encoding/json"
	"log"
	"net/http"
)

var m = make(map[string]string)

type errorMessage struct {
	Message    string
	StatusCode int
	Key        string
}

func defaultHandler(w http.ResponseWriter, r *http.Request) {
	b, _ := json.Marshal(m)
	w.Write(b)
}

func setHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	if len(r.Form) != 1 {
		status := 400
		w.WriteHeader(status)
		e := errorMessage{"Must set exactly one key per request", status, ""}
		b, _ := json.Marshal(e)
		w.Write(b)
	} else {
		for key, value := range r.Form {
			if len(value) > 1 {
				status := 400
				w.WriteHeader(status)
				e := errorMessage{"Can’t assign more than one value to a key", status, key}
				b, _ := json.Marshal(e)
				w.Write(b)
			} else {
				m[key] = value[0]
			}
		}
	}
}

func getHandler(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	key := r.Form.Get("key")
	_, ok := m[key]
	if ok == false {
		status := 404
		w.WriteHeader(status)
		e := errorMessage{"Can’t find key", status, key}
		b, _ := json.Marshal(e)
		w.Write(b)
	} else {
		b, _ := json.Marshal(map[string]string{key: m[key]})
		w.Write(b)
	}
}

func main() {
	http.HandleFunc("/get", getHandler)
	http.HandleFunc("/set", setHandler)
	http.HandleFunc("/", defaultHandler)
	log.Fatal(http.ListenAndServe(":4000", nil))
}