package main

import (
	"fmt"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"time"
)

type pageRoute struct {
	Path string
	File string
}

func main() {

	port := os.Getenv("PORT")

	if port == "" {
		port = "8080"
	}

	root, err := filepath.Abs(".")
	if err != nil {
		log.Fatalf("resolve website directory: %v", err)
	}

	mux := http.NewServeMux()
	registerPages(mux, root)
	registerAssets(mux, root)

	server := &http.Server{
		Addr:              ":" + port,
		Handler:           mux,
		ReadHeaderTimeout: 5 * time.Second,
	}

	fmt.Printf("Venus Photo Studio And Lab running on port %s\n", port)

	if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
		log.Fatalf("start server: %v", err)
	}
}

func registerPages(mux *http.ServeMux, root string) {
	pages := []pageRoute{
		{Path: "/", File: "index.html"},
		{Path: "/about", File: "about.html"},
		{Path: "/gallery", File: "gallery.html"},
		{Path: "/services", File: "services.html"},
		{Path: "/contact", File: "contact.html"},
	}

	for _, page := range pages {
		route := page

		mux.HandleFunc(route.Path, func(w http.ResponseWriter, r *http.Request) {

			if r.URL.Path != route.Path {
				http.NotFound(w, r)
				return
			}

			servePage(w, r, filepath.Join(root, route.File))
		})
	}

	redirects := map[string]string{
		"/index.html":    "/",
		"/about.html":    "/about",
		"/gallery.html":  "/gallery",
		"/services.html": "/services",
		"/contact.html":  "/contact",
	}

	for from, to := range redirects {

		target := to

		mux.HandleFunc(from, func(w http.ResponseWriter, r *http.Request) {
			http.Redirect(w, r, target, http.StatusMovedPermanently)
		})
	}
}

func registerAssets(mux *http.ServeMux, root string) {

	fileServer := http.FileServer(http.Dir(root))

	mux.Handle("/assets/", fileServer)

	mux.HandleFunc("/tailwind.config.js", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, filepath.Join(root, "tailwind.config.js"))
	})
}

func servePage(w http.ResponseWriter, r *http.Request, file string) {

	if r.Method != http.MethodGet && r.Method != http.MethodHead {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	w.Header().Set("Cache-Control", "no-cache")

	http.ServeFile(w, r, file)
}