1// Copied from https://git.sr.ht/~sircmpwn/kineto/tree/master/item/main.go
  2package main
  3
  4import (
  5	"fmt"
  6	"html/template"
  7	"io"
  8	"mime"
  9	"net/http"
 10	"net/url"
 11	"strings"
 12	"time"
 13
 14	"git.sr.ht/~adnano/go-gemini"
 15)
 16
 17func proxyGemini(w http.ResponseWriter, r *http.Request) {
 18	if r.Method != "GET" {
 19		w.WriteHeader(http.StatusMethodNotAllowed)
 20		w.Write([]byte("404 Not found"))
 21		return
 22	}
 23	path := strings.SplitN(r.URL.Path, "/", 3)
 24	req := gemini.Request{}
 25	var err error
 26	req.Host = path[1]
 27	if len(path) > 2 {
 28		req.URL, err = url.Parse(fmt.Sprintf("gemini://%s/%s", path[1], path[2]))
 29	} else {
 30		req.URL, err = url.Parse(fmt.Sprintf("gemini://%s/", path[1]))
 31	}
 32	client := gemini.Client{
 33		Timeout:           60 * time.Second,
 34		InsecureSkipTrust: true,
 35	}
 36
 37	if h := (url.URL{Host: req.Host}); h.Port() == "" {
 38		req.Host += ":1965"
 39	}
 40
 41	resp, err := client.Do(&req)
 42	if err != nil {
 43		w.WriteHeader(http.StatusBadGateway)
 44		fmt.Fprintf(w, "Gateway error: %v", err)
 45		return
 46	}
 47	defer resp.Body.Close()
 48
 49	switch resp.Status {
 50	case 10, 11:
 51		// TODO accept input
 52		w.WriteHeader(http.StatusInternalServerError)
 53		return
 54	case 20:
 55		break // OK
 56	case 30, 31:
 57		to, err := url.Parse(resp.Meta)
 58		if err != nil {
 59			w.WriteHeader(http.StatusBadGateway)
 60			w.Write([]byte(fmt.Sprintf("Gateway error: bad redirect %v", err)))
 61		}
 62		next := req.URL.ResolveReference(to)
 63		if next.Scheme != "gemini" {
 64			w.WriteHeader(http.StatusOK)
 65			w.Write([]byte(fmt.Sprintf("This page is redirecting you to %s", next.String())))
 66			return
 67		}
 68		next.Host = r.URL.Host
 69		next.Scheme = r.URL.Scheme
 70		w.Header().Add("Location", next.String())
 71		w.WriteHeader(http.StatusFound)
 72		w.Write([]byte("Redirecting to " + next.String()))
 73		return
 74	case 40, 41, 42, 43, 44:
 75		w.WriteHeader(http.StatusServiceUnavailable)
 76		fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
 77		return
 78	case 50, 51:
 79		w.WriteHeader(http.StatusNotFound)
 80		fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
 81		return
 82	case 52, 53, 59:
 83		w.WriteHeader(http.StatusServiceUnavailable)
 84		fmt.Fprintf(w, "The remote server returned %d: %s", resp.Status, resp.Meta)
 85		return
 86	default:
 87		w.WriteHeader(http.StatusNotImplemented)
 88		fmt.Fprintf(w, "Proxy does not understand Gemini response status %d", resp.Status)
 89		return
 90	}
 91
 92	m, _, err := mime.ParseMediaType(resp.Meta)
 93	if err != nil {
 94		w.WriteHeader(http.StatusBadGateway)
 95		w.Write([]byte(fmt.Sprintf("Gateway error: %d %s: %v",
 96			resp.Status, resp.Meta, err)))
 97		return
 98	}
 99
100	if m != "text/gemini" {
101		w.Header().Add("Content-Type", resp.Meta)
102		io.Copy(w, resp.Body)
103		return
104	}
105
106	w.Header().Add("Content-Type", "text/html")
107
108	htmlString := textToHTML(req.URL, gemini.ParseText(resp.Body))
109	data := struct {
110		SiteBody  template.HTML
111		Favicon   string
112		PageTitle string
113		URI       string
114	}{template.HTML(htmlString), "", req.URL.String(), req.URL.String()}
115
116	err = t.ExecuteTemplate(w, "user_page.html", data)
117	if err != nil {
118		w.WriteHeader(http.StatusInternalServerError)
119		fmt.Fprintf(w, "%v", err)
120		return
121	}
122}