package main

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

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

func main() {

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

	// Parse the API URL

	r.Handle("/cats/*", reverseProxy("https://catfact.ninja", "/cats"))

	r.Handle("/coins/*", reverseProxy("https://api.coindesk.com/v1/bpi", "/coins"))

	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 string, prefixToStrip string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Parse the target URL
		parsedURL, err := url.Parse(target)
		if err != nil {
			log.Fatalf("Failed to parse target URL: %v", err)
		}

		// Create a reverse proxy
		proxy := httputil.NewSingleHostReverseProxy(parsedURL)

		// Rewrite the request path by stripping the prefix
		originalPath := r.URL.Path
		strippedPath := strings.TrimPrefix(originalPath, prefixToStrip)
		log.Printf("stripped path %s", strippedPath)
		// Update the proxied request URL
		r.URL.Path = strippedPath // Use the stripped path in the proxy
		r.URL.Scheme = parsedURL.Scheme
		r.URL.Host = parsedURL.Host
		r.Host = parsedURL.Host

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

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