Add Gopher support

This adds gopher support to WriteFreely -- both single- and multi-user
instances. It is off by default, but can be enabled with the new
`gopher_port` config value in the `[server]` section.

When enabled, multi-user instances will show all public blogs at
gopher://[host]:[gopher_port]/ -- otherwise, blogs are accessible at
gopher://[host]:[gopher_port]/[blog]/

This is just a proof of concept for now. We still need to handle some
edge cases and different configurations, like private instances.

Ref T559

app.go

@@ -409,6 +409,11 @@ func Serve(app *App, r *mux.Router) {
 		os.Exit(0)
 	}()
 
+	// Start gopher server
+	if app.cfg.Server.GopherPort > 0 {
+		go initGopher(app)
+	}
+
 	// Start web application server
 	var bindAddress = app.cfg.Server.Bind
 	if bindAddress == "" {

config/config.go

@@ -45,6 +45,8 @@ type (
 
 		HashSeed string `ini:"hash_seed"`
 
+		GopherPort int `ini:"gopher_port"`
+
 		Dev bool `ini:"-"`
 	}
 

database.go

@@ -1633,6 +1633,40 @@ func (db *datastore) GetPublishableCollections(u *User, hostName string) (*[]Col
 	return c, nil
 }
 
+func (db *datastore) GetPublicCollections(hostName string) (*[]Collection, error) {
+	rows, err := db.Query(`SELECT c.id, alias, title, description, privacy, view_count
+	FROM collections c
+	LEFT JOIN users u ON u.id = c.owner_id
+	WHERE c.privacy = 1 AND u.status = 0
+	ORDER BY id ASC`)
+	if err != nil {
+		log.Error("Failed selecting public collections: %v", err)
+		return nil, impart.HTTPError{http.StatusInternalServerError, "Couldn't retrieve public collections."}
+	}
+	defer rows.Close()
+
+	colls := []Collection{}
+	for rows.Next() {
+		c := Collection{}
+		err = rows.Scan(&c.ID, &c.Alias, &c.Title, &c.Description, &c.Visibility, &c.Views)
+		if err != nil {
+			log.Error("Failed scanning row: %v", err)
+			break
+		}
+		c.hostName = hostName
+		c.URL = c.CanonicalURL()
+		c.Public = c.IsPublic()
+
+		colls = append(colls, c)
+	}
+	err = rows.Err()
+	if err != nil {
+		log.Error("Error after Next() on rows: %v", err)
+	}
+
+	return &colls, nil
+}
+
 func (db *datastore) GetMeStats(u *User) userMeStats {
 	s := userMeStats{}
 

go.mod

@@ -34,6 +34,7 @@ require (
 	github.com/nu7hatch/gouuid v0.0.0-20131221200532-179d4d0c4d8d
 	github.com/pelletier/go-toml v1.2.0 // indirect
 	github.com/pkg/errors v0.8.1 // indirect
+	github.com/prologic/go-gopher v0.0.0-20191226035442-664dbdb49f44
 	github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be // indirect
 	github.com/smartystreets/assertions v0.0.0-20190116191733-b6c0e53d7304 // indirect
 	github.com/smartystreets/goconvey v0.0.0-20181108003508-044398e4856c // indirect

go.sum

@@ -110,6 +110,8 @@ github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prologic/go-gopher v0.0.0-20191226035442-664dbdb49f44 h1:q5sit1FpzEt59aM2Fd2lSBKF+nxcY1o0StRCiJa/pWo=
+github.com/prologic/go-gopher v0.0.0-20191226035442-664dbdb49f44/go.mod h1:a97DSBRiRljeRVd5CRZL5bYCIeeGjSEngGf+QMR2evA=
 github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be h1:ta7tUOvsPHVHGom5hKW5VXNc2xZIkfCKP8iaqOyYtUQ=
 github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be/go.mod h1:MIDFMn7db1kT65GmV94GzpX9Qdi7N/pQlwb+AN8wh+Q=
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=

gopher.go

@@ -0,0 +1,146 @@
+/*
+ * Copyright © 2020 A Bunch Tell LLC.
+ *
+ * This file is part of WriteFreely.
+ *
+ * WriteFreely is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, included
+ * in the LICENSE file in this source code package.
+ */
+
+package writefreely
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/prologic/go-gopher"
+	"github.com/writeas/web-core/log"
+)
+
+func initGopher(apper Apper) {
+	handler := NewWFHandler(apper)
+
+	gopher.HandleFunc("/", handler.Gopher(handleGopher))
+	log.Info("Serving on gopher://localhost:%d", apper.App().Config().Server.GopherPort)
+	gopher.ListenAndServe(fmt.Sprintf(":%d", apper.App().Config().Server.GopherPort), nil)
+}
+
+func handleGopher(app *App, w gopher.ResponseWriter, r *gopher.Request) error {
+	parts := strings.Split(r.Selector, "/")
+	if app.cfg.App.SingleUser {
+		if parts[1] != "" {
+			return handleGopherCollectionPost(app, w, r)
+		}
+		return handleGopherCollection(app, w, r)
+	}
+
+	// Show all public collections (a gopher Reader view, essentially)
+	if len(parts) == 3 {
+		return handleGopherCollection(app, w, r)
+	}
+
+	w.WriteInfo(fmt.Sprintf("Welcome to %s", app.cfg.App.SiteName))
+
+	colls, err := app.db.GetPublicCollections(app.cfg.App.Host)
+	if err != nil {
+		return err
+	}
+
+	for _, c := range *colls {
+		w.WriteItem(&gopher.Item{
+			Type:        gopher.DIRECTORY,
+			Description: c.DisplayTitle(),
+			Selector:    "/" + c.Alias + "/",
+		})
+	}
+	return w.End()
+}
+
+func handleGopherCollection(app *App, w gopher.ResponseWriter, r *gopher.Request) error {
+	var collAlias, slug string
+	var c *Collection
+	var err error
+	var baseSel = "/"
+
+	parts := strings.Split(r.Selector, "/")
+	if app.cfg.App.SingleUser {
+		// sanity check
+		slug = parts[1]
+		if slug != "" {
+			return handleGopherCollectionPost(app, w, r)
+		}
+
+		c, err = app.db.GetCollectionByID(1)
+		if err != nil {
+			return err
+		}
+	} else {
+		collAlias = parts[1]
+		slug = parts[2]
+		if slug != "" {
+			return handleGopherCollectionPost(app, w, r)
+		}
+
+		c, err = app.db.GetCollection(collAlias)
+		if err != nil {
+			return err
+		}
+		baseSel = "/" + c.Alias + "/"
+	}
+	c.hostName = app.cfg.App.Host
+
+	posts, err := app.db.GetPosts(app.cfg, c, 0, false, false, false)
+	if err != nil {
+		return err
+	}
+
+	for _, p := range *posts {
+		w.WriteItem(&gopher.Item{
+			Type:        gopher.FILE,
+			Description: p.CreatedDate() + " - " + p.DisplayTitle(),
+			Selector:    baseSel + p.Slug.String,
+		})
+	}
+	return w.End()
+}
+
+func handleGopherCollectionPost(app *App, w gopher.ResponseWriter, r *gopher.Request) error {
+	var collAlias, slug string
+	var c *Collection
+	var err error
+
+	parts := strings.Split(r.Selector, "/")
+	if app.cfg.App.SingleUser {
+		slug = parts[1]
+		c, err = app.db.GetCollectionByID(1)
+		if err != nil {
+			return err
+		}
+	} else {
+		collAlias = parts[1]
+		slug = parts[2]
+		c, err = app.db.GetCollection(collAlias)
+		if err != nil {
+			return err
+		}
+	}
+	c.hostName = app.cfg.App.Host
+
+	p, err := app.db.GetPost(slug, c.ID)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.Buffer{}
+	if p.Title.String != "" {
+		b.WriteString(p.Title.String + "\n")
+	}
+	b.WriteString(p.DisplayDate + "\n\n")
+	b.WriteString(p.Content)
+	io.Copy(w, &b)
+
+	return w.End()
+}

handle.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/gorilla/sessions"
+	"github.com/prologic/go-gopher"
 	"github.com/writeas/impart"
 	"github.com/writeas/web-core/log"
 	"github.com/writeas/writefreely/config"
@@ -64,6 +65,7 @@ func UserLevelReader(cfg *config.Config) UserLevel {
 
 type (
 	handlerFunc          func(app *App, w http.ResponseWriter, r *http.Request) error
+	gopherFunc           func(app *App, w gopher.ResponseWriter, r *gopher.Request) error
 	userHandlerFunc      func(app *App, u *User, w http.ResponseWriter, r *http.Request) error
 	userApperHandlerFunc func(apper Apper, u *User, w http.ResponseWriter, r *http.Request) error
 	dataHandlerFunc      func(app *App, w http.ResponseWriter, r *http.Request) ([]byte, string, error)
@@ -891,6 +893,24 @@ func (h *Handler) LogHandlerFunc(f http.HandlerFunc) http.HandlerFunc {
 	}
 }
 
+func (h *Handler) Gopher(f gopherFunc) gopher.HandlerFunc {
+	return func(w gopher.ResponseWriter, r *gopher.Request) {
+		defer func() {
+			if e := recover(); e != nil {
+				log.Error("%s: %s", e, debug.Stack())
+				w.WriteError("An internal error occurred")
+			}
+			log.Info("gopher: %s", r.Selector)
+		}()
+
+		err := f(h.app.App(), w, r)
+		if err != nil {
+			log.Error("failed: %s", err)
+			w.WriteError("the page failed for some reason (see logs)")
+		}
+	}
+}
+
 func sendRedirect(w http.ResponseWriter, code int, location string) int {
 	w.Header().Set("Location", location)
 	w.WriteHeader(code)