// This is honestly terrible. It only exists to replace the AWS S3 website hosting feature missing in minio
package main

import (
	"log"
	"net"
	"net/http"
	"net/http/httputil"
	"os"
	"strings"
	"time"

	internal_s3utils "git.makerforce.io/photos/photos/internal/s3utils"
	"github.com/miekg/dns"
)

var endpoint string
var endpointSecure bool
var domain string
var behindProxy bool

func main() {
	// Read configuration
	endpoint = os.Getenv("MINIO_ENDPOINT")
	endpointSecure = os.Getenv("MINIO_ENDPOINT_SECURE") == "true"
	domain = os.Getenv("MINIO_DOMAIN")
	behindProxy = os.Getenv("BEHIND_PROXY") == "true"

	server := &http.Server{
		Addr:         ":80",
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
		Handler:      &httputil.ReverseProxy{Director: director},
	}
	err := server.ListenAndServe()
	if err != nil {
		panic(err)
	}
}

func director(req *http.Request) {
	// Validate host
	host, port, err := net.SplitHostPort(req.Host)
	if err != nil {
		// Assumption: IsDomainName will handle other cases
		host = req.Host
	}
	if _, ok := dns.IsDomainName(host); !ok {
		req.URL.Scheme = ""
		return
	}

	// Rewrite URL
	req.URL.Scheme = "http"
	if endpointSecure {
		req.URL.Scheme = "https"
	}
	req.URL.Host = endpoint
	if len(domain) < 1 {
		// If we are using domains, rewrite the host into path
		req.URL.Path = internal_s3utils.PathFromHost(mapPath(*req), host)
	} else {
		// If we are using subdomains, set the host header
		req.URL.Path = mapPath(*req)
		//req.Header.Set("Host", host)
	}

	// Prevent MINIO from issuing redirects
	userAgent := req.Header.Get("User-Agent")
	userAgent = strings.ReplaceAll(userAgent, "Mozilla", "M-o-z-i-l-l-a")
	req.Header.Set("User-Agent", userAgent)

	if !behindProxy {
		// Clear existing unsafe headers
		req.Header.Del("Forwarded")
		req.Header.Del("X-Forwarded-For")

		// Unnecessary, but might as well
		req.Header.Set("X-Forwarded-Proto", req.URL.Scheme)
		req.Header.Set("X-Forwarded-Host", host)
		req.Header.Set("X-Forwarded-Port", port)
	}

	log.Println(req.Header.Get("Host"), req.URL)
}

func mapPath(req http.Request) string {
	path := req.URL.Path
	if req.FormValue("list-type") == "2" {
		return path
	}
	if strings.HasSuffix(path, "/") {
		path += "index.html"
	}
	return path
}