package main

import (
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
)

func main() {
	apiURL := "https://catfact.ninja"

	r := chi.NewRouter()
	r.Use(middleware.Logger)
	r.Use(middleware.Recoverer)

	// Parse the API URL
	parsedURL, err := url.Parse(apiURL)
	if err != nil {
		log.Fatalf("Failed to parse API URL: %v", err)
	}

	r.Handle("/cats", reverseProxy(parsedURL, "/fact"))

	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("root."))
	})

	log.Println("Proxy running on http://localhost:3333")
	http.ListenAndServe(":3333", r)
}

// reverseProxy forwards requests to the target URL with path rewriting
func reverseProxy(target *url.URL, targetPath string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Create a reverse proxy
		proxy := httputil.NewSingleHostReverseProxy(target)

		// Update the request path to the target API path
		r.URL.Path = targetPath
		r.URL.Host = target.Host
		r.URL.Scheme = target.Scheme

		// Set the Host header explicitly to match the target
		r.Host = target.Host

		// Debug: Log the final URL being proxied
		log.Printf("Proxying request to: %s%s", target, targetPath)

		// Serve the proxied request
		proxy.ServeHTTP(w, r)
	})
}