Fake JSON API server

main.go

package main

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
)

const (
	apiKey = "test-api-key"
	port   = 9876
)

func main() {
	fmt.Printf("Server running on port %d...\n", port)

	http.HandleFunc("/poll", func(w http.ResponseWriter, r *http.Request) {
		authHeader := r.Header.Get("Authorization")
		if authHeader != "" {
			fmt.Printf("Authorization Header: %s\n", authHeader)
		} else {
			fmt.Println("No Authorization Header received")
		}

		if !validateAuth(authHeader) {
			w.Header().Set("WWW-Authenticate", `Basic realm="API Access"`)
			http.Error(w, "Unauthorized", http.StatusUnauthorized)
			return
		}

		responseData := map[string]interface{}{
			"y_axis": map[string]string{
				"format": "currency",
				"unit":   "USD",
			},
			"series": []map[string]interface{}{
				{
					"name": "GBP -> USD",
					"data": []float64{
						1.62529, 1.56991, 1.50420, 1.52265, 1.55356,
						1.51930, 1.52148, 1.51173, 1.55170, 1.61966,
						1.59255, 1.63762,
					},
				},
			},
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(responseData)
	})

	if err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil); err != nil {
		fmt.Println("Error starting server:", err)
	}
}

func validateAuth(authHeader string) bool {
	if !strings.HasPrefix(authHeader, "Basic ") {
		return false
	}

	encodedCredentials := strings.TrimPrefix(authHeader, "Basic ")
	decodedBytes, err := base64.StdEncoding.DecodeString(encodedCredentials)
	if err != nil {
		fmt.Printf("Error decoding Authorization header: %v\n", err)
		return false
	}

	credentials := string(decodedBytes)
	username := strings.SplitN(credentials, ":", 2)[0]
	fmt.Println("Received API Key:", username)
	return username == apiKey
}