handlers.go

package main

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

	"github.com/google/uuid"
	"github.com/gorilla/mux"
)

func respondWithJSON(w http.ResponseWriter, code int, payload interface{}) {
	response, _ := json.Marshal(payload)

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(code)
	w.Write(response)
}

func getCustomers(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")

	json.NewEncoder(w).Encode(customers)
}

func getCustomer(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	id := mux.Vars(r)["id"]
	if _, ok := customers[id]; ok {
		w.WriteHeader(http.StatusOK)
		json.NewEncoder(w).Encode(customers[id])
	} else {
		w.WriteHeader(http.StatusNotFound)
		json.NewEncoder(w).Encode("not found")
	}
}

func deleteCustomer(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	id := mux.Vars(r)["id"]

	if _, ok := customers[id]; ok {
		delete(customers, id)
		w.WriteHeader(http.StatusOK)
		json.NewEncoder(w).Encode(customers)
	} else {
		w.WriteHeader(http.StatusNotFound)
		json.NewEncoder(w).Encode("not found")
	}
}

func addCustomer(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	id := uuid.New().String()

	if _, ok := customers[id]; ok {
		w.WriteHeader(http.StatusBadRequest)
		json.NewEncoder(w).Encode("id already exits, please use the update route")
	} else {
		var customer Customer
		json.NewDecoder(r.Body).Decode(&customer)
		customers[id] = customer
		respondWithJSON(w, http.StatusCreated, customer)
	}
}

func updateCustomer(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	id := mux.Vars(r)["id"]
	if _, ok := customers[id]; ok {
		var customer Customer
		json.NewDecoder(r.Body).Decode(&customer)
		customers[id] = customer
		respondWithJSON(w, http.StatusOK, customer)
	} else {
		w.WriteHeader(http.StatusNotFound)
		json.NewEncoder(w).Encode("not found")
	}
}