cmd/sgblog/gopher.go

   1 /*
   2 SGBlog -- Git-backed CGI/inetd blogging/phlogging engine
   3 Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU Affero General Public License as
   7 published by the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU Affero General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 package main
  19
  20 import (
  21         "bufio"
  22         "errors"
  23         "fmt"
  24         "io"
  25         "log"
  26         "net/url"
  27         "os"
  28         "strconv"
  29         "strings"
  30         "text/template"
  31
  32         "github.com/go-git/go-git/v5"
  33         "github.com/go-git/go-git/v5/plumbing"
  34         "github.com/go-git/go-git/v5/plumbing/object"
  35         "go.stargrave.org/sgblog"
  36 )
  37
  38 const (
  39         TmplGopherMenu = `{{$CR := printf "\r"}}{{$CRLF := printf "\r\n" -}}
  40 {{- define "domainPort" }}      {{.GopherDomain}}       70{{end}}{{$Cfg := .Cfg -}}
  41 i{{.Cfg.Title}} {{if .Topic}}(topic: {{.Topic}}) {{end}}({{.Offset}}-{{.OffsetNext}})   err{{template "domainPort" .Cfg}}{{$CRLF -}}
  42 {{- if .Cfg.AboutURL}}hAbout    URL:{{.Cfg.AboutURL}}{{template "domainPort" .Cfg}}{{$CRLF}}{{end -}}
  43 {{- if .Offset}}1Prev   {{if .Topic}}{{.Topic}}/{{end}}offset/{{.OffsetPrev}}{{template "domainPort" .Cfg}}{{$CRLF}}{{end -}}
  44 {{- if not .LogEnded}}1Next     {{if .Topic}}{{.Topic}}/{{end}}offset/{{.OffsetNext}}{{template "domainPort" .Cfg}}{{$CRLF}}{{end -}}
  45 {{- $datePrev := "0001-01-01" -}}
  46 {{- range .Entries -}}
  47 {{- $dateCur := .Commit.Author.When.Format "2006-01-02" -}}
  48 {{- if ne $dateCur $datePrev}}{{$datePrev = $dateCur}}
  49 i{{$dateCur}}   err{{template "domainPort" $Cfg}}{{$CR}}{{end}}
  50 0[{{.Commit.Author.When.Format "15:04"}}] {{.Title}} ({{.LinesNum}}L){{with .CommentsNum}} ({{.}}C){{end}}{{if .Topics}}{{range .Topics}} {{.}}{{end}}{{end}}   /{{.Commit.Hash.String}}{{template "domainPort" $Cfg}}{{$CR}}{{end}}
  51 {{range .Topics}}
  52 1Topic: {{.}}   {{.}}/offset/0{{template "domainPort" $Cfg}}{{$CR}}{{end}}
  53 iGenerated by: SGBlog {{.Version}}      err{{template "domainPort" .Cfg}}{{$CR}}
  54 .{{$CRLF}}`
  55         TmplGopherEntry = `What: {{.Commit.Hash.String}}
  56 When: {{.When}}
  57 ------------------------------------------------------------------------
  58 {{if .Topics}}Topics:{{range .Topics}} {{.}}{{end}}{{end}}
  59 ------------------------------------------------------------------------
  60 {{.Commit.Message -}}
  61 {{- if .Note}}
  62 ------------------------------------------------------------------------
  63 Note:
  64 {{.Note}}{{end -}}
  65 {{- if .Cfg.CommentsEmail}}
  66 ------------------------------------------------------------------------
  67 leave comment: mailto:{{.Cfg.CommentsEmail}}?subject={{.TitleEscaped}}
  68 {{end}}{{range $idx, $comment := .Comments}}
  69 ------------------------------------------------------------------------
  70 comment {{$idx}}:
  71 {{$comment}}
  72 {{end}}
  73 ------------------------------------------------------------------------
  74 Generated by: SGBlog {{.Version}}
  75 `
  76 )
  77
  78 type TableMenuEntry struct {
  79         Commit      *object.Commit
  80         Title       string
  81         LinesNum    int
  82         CommentsNum int
  83         Topics      []string
  84 }
  85
  86 func serveGopher(cfgPath string) {
  87         cfg, err := readCfg(cfgPath)
  88         if err != nil {
  89                 log.Fatalln(err)
  90         }
  91         if cfg.GopherDomain == "" {
  92                 log.Fatalln("GopherDomain is not configured")
  93         }
  94
  95         headHash, err := initRepo(cfg)
  96         if err != nil {
  97                 log.Fatalln(err)
  98         }
  99
 100         scanner := bufio.NewScanner(io.LimitReader(os.Stdin, 1<<8))
 101         if !scanner.Scan() {
 102                 log.Fatalln(errors.New("no CRLF found"))
 103         }
 104         selector := scanner.Text()
 105         if selector == "" {
 106                 selector = "offset/0"
 107         }
 108         selectorParts := strings.Split(selector, "/")
 109         if strings.HasPrefix(selector, "URL:") {
 110                 selector = selector[len("URL:"):]
 111                 fmt.Printf(`<html>
 112 <head>
 113         <meta http-equiv="Refresh" content="1; url=%s" />
 114         <title>Redirect to non-gopher URL</title>
 115 </head>
 116 <body>
 117 Redirecting to <a href="%s">%s</a>...
 118 </body>
 119 </html>
 120 `, selector, selector, selector)
 121         } else if sha1DigestRe.MatchString(selector) {
 122                 commit, err := repo.CommitObject(plumbing.NewHash(selector[1:]))
 123                 if err != nil {
 124                         log.Fatalln(err)
 125                 }
 126                 tmpl := template.Must(template.New("entry").Parse(TmplGopherEntry))
 127                 err = tmpl.Execute(os.Stdout, struct {
 128                         Commit       *object.Commit
 129                         When         string
 130                         Cfg          *Cfg
 131                         Note         string
 132                         Comments     []string
 133                         Topics       []string
 134                         Version      string
 135                         TitleEscaped string
 136                 }{
 137                         Commit:   commit,
 138                         When:     commit.Author.When.Format(sgblog.WhenFmt),
 139                         Cfg:      cfg,
 140                         Note:     string(sgblog.GetNote(repo, notesTree, commit.Hash)),
 141                         Comments: sgblog.ParseComments(sgblog.GetNote(repo, commentsTree, commit.Hash)),
 142                         Topics:   sgblog.ParseTopics(sgblog.GetNote(repo, topicsTree, commit.Hash)),
 143                         Version:  sgblog.Version,
 144                         TitleEscaped: url.PathEscape(fmt.Sprintf(
 145                                 "Re: %s (%s)", msgSplit(commit.Message)[0], commit.Hash,
 146                         )),
 147                 })
 148                 if err != nil {
 149                         log.Fatalln(err)
 150                 }
 151         } else if len(selectorParts) > 1 &&
 152                 selectorParts[len(selectorParts)-2] == "offset" {
 153                 offset, err := strconv.Atoi(selectorParts[len(selectorParts)-1])
 154                 if err != nil {
 155                         log.Fatalln(err)
 156                 }
 157                 repoLog, err := repo.Log(&git.LogOptions{From: *headHash})
 158                 if err != nil {
 159                         log.Fatalln(err)
 160                 }
 161                 topicsCache, err := getTopicsCache(cfg, repoLog)
 162                 if err != nil {
 163                         log.Fatalln(err)
 164                 }
 165                 repoLog, err = repo.Log(&git.LogOptions{From: *headHash})
 166                 if err != nil {
 167                         log.Fatalln(err)
 168                 }
 169
 170                 var topic string
 171                 if len(selectorParts) == 3 {
 172                         topic = selectorParts[0]
 173                 }
 174                 var commits CommitIterNext
 175                 if topic == "" {
 176                         for i := 0; i < offset; i++ {
 177                                 if _, err = repoLog.Next(); err != nil {
 178                                         break
 179                                 }
 180                         }
 181                         commits = repoLog
 182                 } else {
 183                         hashes := topicsCache[topic]
 184                         if hashes == nil {
 185                                 log.Fatalln(errors.New("no posts with that topic"))
 186                         }
 187                         if len(hashes) > offset {
 188                                 hashes = hashes[offset:]
 189                         }
 190                         commits = &HashesIter{hashes}
 191                 }
 192
 193                 logEnded := false
 194                 entries := make([]TableMenuEntry, 0, PageEntries)
 195                 for i := 0; i < PageEntries; i++ {
 196                         commit, err := commits.Next()
 197                         if err != nil {
 198                                 logEnded = true
 199                                 break
 200                         }
 201                         lines := msgSplit(commit.Message)
 202                         entries = append(entries, TableMenuEntry{
 203                                 Commit:      commit,
 204                                 Title:       lines[0],
 205                                 LinesNum:    len(lines) - 2,
 206                                 CommentsNum: len(sgblog.ParseComments(sgblog.GetNote(repo, commentsTree, commit.Hash))),
 207                                 Topics:      sgblog.ParseTopics(sgblog.GetNote(repo, topicsTree, commit.Hash)),
 208                         })
 209                 }
 210                 tmpl := template.Must(template.New("menu").Parse(TmplGopherMenu))
 211                 offsetPrev := offset - PageEntries
 212                 if offsetPrev < 0 {
 213                         offsetPrev = 0
 214                 }
 215                 err = tmpl.Execute(os.Stdout, struct {
 216                         Cfg        *Cfg
 217                         Topic      string
 218                         Offset     int
 219                         OffsetPrev int
 220                         OffsetNext int
 221                         LogEnded   bool
 222                         Entries    []TableMenuEntry
 223                         Topics     []string
 224                         Version    string
 225                 }{
 226                         Cfg:        cfg,
 227                         Topic:      topic,
 228                         Offset:     offset,
 229                         OffsetPrev: offsetPrev,
 230                         OffsetNext: offset + PageEntries,
 231                         LogEnded:   logEnded,
 232                         Entries:    entries,
 233                         Topics:     topicsCache.Topics(),
 234                         Version:    sgblog.Version,
 235                 })
 236                 if err != nil {
 237                         log.Fatalln(err)
 238                 }
 239         } else {
 240                 log.Fatalln(errors.New("unknown selector"))
 241         }
 242 }