From 4bf44b16562335b3d09b6df0150521bb5b5f776f Mon Sep 17 00:00:00 2001
From: Feuerfuchs <git@feuerfuchs.dev>
Date: Mon, 18 May 2020 12:12:43 +0200
Subject: WIP: Refactoring

---
 internal/port/gopher.go | 217 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 217 insertions(+)
 create mode 100644 internal/port/gopher.go

(limited to 'internal/port/gopher.go')

diff --git a/internal/port/gopher.go b/internal/port/gopher.go
new file mode 100644
index 0000000..ebeb213
--- /dev/null
+++ b/internal/port/gopher.go
@@ -0,0 +1,217 @@
+package port
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"git.vulpes.one/Feuerfuchs/port/port/libgopher"
+
+	"github.com/davidbyttow/govips/pkg/vips"
+	"github.com/temoto/robotstxt"
+)
+
+type Item struct {
+	Link template.URL
+	Type string
+	Text string
+}
+
+func renderGopherDirectory(w http.ResponseWriter, tpl *template.Template, assetList AssetList, uri string, hostport string, d libgopher.Directory) error {
+	var title string
+
+	out := make([]Item, len(d.Items))
+
+	for i, x := range d.Items {
+		if x.Type == libgopher.INFO && x.Selector == "TITLE" {
+			title = x.Description
+			continue
+		}
+
+		tr := Item{
+			Text: x.Description,
+			Type: x.Type.String(),
+		}
+
+		if x.Type == libgopher.INFO {
+			out[i] = tr
+			continue
+		}
+
+		if strings.HasPrefix(x.Selector, "URL:") || strings.HasPrefix(x.Selector, "/URL:") {
+			link := strings.TrimPrefix(strings.TrimPrefix(x.Selector, "/"), "URL:")
+			if strings.HasPrefix(link, "gemini://") {
+				link = fmt.Sprintf(
+					"/gemini/%s",
+					strings.TrimPrefix(link, "gemini://"),
+				)
+			} else if strings.HasPrefix(link, "gopher://") {
+				link = fmt.Sprintf(
+					"/gopher/%s",
+					strings.TrimPrefix(link, "gopher://"),
+				)
+			}
+			tr.Link = template.URL(link)
+		} else {
+			var linkHostport string
+			if x.Port != "70" {
+				linkHostport = net.JoinHostPort(x.Host, x.Port)
+			} else {
+				linkHostport = x.Host
+			}
+
+			path := url.PathEscape(x.Selector)
+			path = strings.Replace(path, "%2F", "/", -1)
+			tr.Link = template.URL(
+				fmt.Sprintf(
+					"/gopher/%s/%s%s",
+					linkHostport,
+					string(byte(x.Type)),
+					path,
+				),
+			)
+		}
+
+		out[i] = tr
+	}
+
+	if title == "" {
+		if uri != "" {
+			title = fmt.Sprintf("%s/%s", hostport, uri)
+		} else {
+			title = hostport
+		}
+	}
+
+	return tpl.Execute(w, TemplateVariables{
+		Title:    title,
+		URI:      fmt.Sprintf("%s/%s", hostport, uri),
+		Assets:   assetList,
+		Lines:    out,
+		Protocol: "gopher",
+	})
+}
+
+// GopherHandler returns a Handler that proxies requests
+// to the specified Gopher server as denoated by the first argument
+// to the request path and renders the content using the provided template.
+// The optional robots parameters points to a robotstxt.RobotsData struct
+// to test user agents against a configurable robotst.txt file.
+func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, assetList AssetList, robotsdebug bool) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		agent := req.UserAgent()
+		path := strings.TrimPrefix(req.URL.Path, "/gopher/")
+
+		if robotsdata != nil && robotsdebug && !robotsdata.TestAgent(path, agent) {
+			log.Printf("UserAgent %s ignored robots.txt", agent)
+		}
+
+		parts := strings.Split(path, "/")
+		hostport := parts[0]
+
+		if len(hostport) == 0 {
+			http.Redirect(w, req, "/", http.StatusFound)
+			return
+		}
+
+		title := hostport
+
+		var qs string
+
+		if req.URL.RawQuery != "" {
+			qs = fmt.Sprintf("?%s", url.QueryEscape(req.URL.RawQuery))
+		}
+
+		uri, err := url.QueryUnescape(strings.Join(parts[1:], "/"))
+		if err != nil {
+			if e := tpl.Execute(w, TemplateVariables{
+				Title:    title,
+				URI:      hostport,
+				Assets:   assetList,
+				RawText:  fmt.Sprintf("Error: %s", err),
+				Error:    true,
+				Protocol: "gopher",
+			}); e != nil {
+				log.Println("Template error: " + e.Error())
+				log.Println(err.Error())
+			}
+			return
+		}
+
+		if uri != "" {
+			title = fmt.Sprintf("%s/%s", hostport, uri)
+		}
+
+		res, err := libgopher.Get(
+			fmt.Sprintf(
+				"gopher://%s/%s%s",
+				hostport,
+				uri,
+				qs,
+			),
+		)
+
+		if err != nil {
+			if e := tpl.Execute(w, TemplateVariables{
+				Title:    title,
+				URI:      fmt.Sprintf("%s/%s", hostport, uri),
+				Assets:   assetList,
+				RawText:  fmt.Sprintf("Error: %s", err),
+				Error:    true,
+				Protocol: "gopher",
+			}); e != nil {
+				log.Println("Template error: " + e.Error())
+			}
+			return
+		}
+
+		if res.Body != nil {
+			if len(parts) < 2 {
+				io.Copy(w, res.Body)
+			} else if strings.HasPrefix(parts[1], "0") && !strings.HasSuffix(uri, ".xml") && !strings.HasSuffix(uri, ".asc") {
+				buf := new(bytes.Buffer)
+				buf.ReadFrom(res.Body)
+
+				if err := tpl.Execute(w, TemplateVariables{
+					Title:    title,
+					URI:      fmt.Sprintf("%s/%s", hostport, uri),
+					Assets:   assetList,
+					RawText:  buf.String(),
+					Protocol: "gopher",
+				}); err != nil {
+					log.Println("Template error: " + err.Error())
+				}
+			} else if strings.HasPrefix(parts[1], "T") {
+				_, _, err = vips.NewTransform().
+					Load(res.Body).
+					ResizeStrategy(vips.ResizeStrategyAuto).
+					ResizeWidth(160).
+					Quality(75).
+					Output(w).
+					Apply()
+			} else {
+				io.Copy(w, res.Body)
+			}
+		} else {
+			if err := renderGopherDirectory(w, tpl, assetList, uri, hostport, res.Dir); err != nil {
+				if e := tpl.Execute(w, TemplateVariables{
+					Title:    title,
+					URI:      fmt.Sprintf("%s/%s", hostport, uri),
+					Assets:   assetList,
+					RawText:  fmt.Sprintf("Error: %s", err),
+					Error:    true,
+					Protocol: "gopher",
+				}); e != nil {
+					log.Println("Template error: " + e.Error())
+					log.Println(e.Error())
+				}
+			}
+		}
+	}
+}
-- 
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