package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
	"time"

	"crypto/subtle"
)

func authMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

		expectedKey := os.Getenv("FRONTEND_API_KEY")
		if expectedKey == "" {
			http.Error(w, "server misconfigured", 500)
			return
		}

		authHeader := r.Header.Get("Authorization")

		expectedHeader := "Bearer " + expectedKey

		if subtle.ConstantTimeCompare([]byte(authHeader), []byte(expectedHeader)) != 1 {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}

		next.ServeHTTP(w, r)
	})
}

func logMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		reqMethod := r.Method
		reqUrl := r.URL.String()
		reqIp := r.RemoteAddr
		reqHeaderContentType := r.Header.Get("Content-Type")
		defer r.Body.Close()
		bodyBytes, err := io.ReadAll(r.Body)
		if err != nil {
			http.Error(w, "[log] Failed to read body", http.StatusBadRequest)
			return
		}

		fmt.Printf("\n[%s] %s request on %s\n", reqIp, reqMethod, reqUrl)
		fmt.Println("Timestamp (UTC):      " + time.Now().UTC().String())
		fmt.Println("Header Content-Type:  " + reqHeaderContentType)
		if len(bodyBytes) == 0 {
			fmt.Println("Body:                 <empty>")
		} else {
			fmt.Println("Body:                 " + string(bodyBytes))
		}

		// restore the request body for later
		r.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))

		next.ServeHTTP(w, r)
	})
}