cmd/sgblog/http.go

   1 /*
   2 SGBlog -- Git-backed CGI/UCSPI blogging/phlogging/gemlogging engine
   3 Copyright (C) 2020-2023 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         "bytes"
  22         "compress/gzip"
  23         "crypto/sha1"
  24         _ "embed"
  25         "encoding/hex"
  26         "encoding/xml"
  27         "errors"
  28         "fmt"
  29         "hash"
  30         "html"
  31         "io"
  32         "log"
  33         "net/http"
  34         "net/url"
  35         "os"
  36         "strconv"
  37         "strings"
  38         "text/template"
  39         "time"
  40
  41         "github.com/go-git/go-git/v5"
  42         "github.com/go-git/go-git/v5/plumbing"
  43         "github.com/go-git/go-git/v5/plumbing/object"
  44         "github.com/vorlif/spreak"
  45         "go.stargrave.org/sgblog"
  46         "go.stargrave.org/sgblog/cmd/sgblog/atom"
  47         "golang.org/x/crypto/blake2b"
  48 )
  49
  50 const (
  51         AtomPostsFeed    = "feed.atom"
  52         AtomCommentsFeed = "comments.atom"
  53 )
  54
  55 var (
  56         renderableSchemes = map[string]struct{}{
  57                 "finger": {},
  58                 "ftp":    {},
  59                 "gemini": {},
  60                 "gopher": {},
  61                 "http":   {},
  62                 "https":  {},
  63                 "irc":    {},
  64                 "ircs":   {},
  65                 "news":   {},
  66                 "telnet": {},
  67         }
  68
  69         //go:embed http-index.tmpl
  70         TmplHTMLIndexRaw string
  71         TmplHTMLIndex    = template.Must(template.New("http-index").Parse(TmplHTMLIndexRaw))
  72
  73         //go:embed http-entry.tmpl
  74         TmplHTMLEntryRaw string
  75         TmplHTMLEntry    = template.Must(template.New("http-entry").Funcs(
  76                 template.FuncMap{"lineURLize": lineURLizeInTemplate},
  77         ).Parse(TmplHTMLEntryRaw))
  78 )
  79
  80 type TableEntry struct {
  81         Commit      *object.Commit
  82         CommentsRaw []byte
  83         TopicsRaw   []byte
  84         Num         int
  85         Title       string
  86         LinesNum    int
  87         CommentsNum int
  88         DomainURLs  []string
  89         Topics      []string
  90 }
  91
  92 type CommentEntry struct {
  93         HeaderLines []string
  94         BodyLines   []string
  95 }
  96
  97 func makeA(href, text string) string {
  98         return `<a href="` + href + `">` + text + `</a>`
  99 }
 100
 101 func etagString(etag hash.Hash) string {
 102         return `"` + hex.EncodeToString(etag.Sum(nil)) + `"`
 103 }
 104
 105 func urlParse(what string) *url.URL {
 106         if u, err := url.ParseRequestURI(what); err == nil {
 107                 if _, exists := renderableSchemes[u.Scheme]; exists {
 108                         return u
 109                 }
 110         }
 111         return nil
 112 }
 113
 114 func lineURLize(urlPrefix, line string) string {
 115         cols := strings.Split(html.EscapeString(line), " ")
 116         for i, col := range cols {
 117                 if u := urlParse(col); u != nil {
 118                         cols[i] = makeA(col, col)
 119                         continue
 120                 }
 121                 cols[i] = sha1DigestRe.ReplaceAllString(col, makeA(urlPrefix+"/$1", "$1"))
 122         }
 123         return strings.Join(cols, " ")
 124 }
 125
 126 func lineURLizeInTemplate(urlPrefix, line interface{}) string {
 127         return lineURLize(urlPrefix.(string), line.(string))
 128 }
 129
 130 func startHeader(etag hash.Hash, gziped bool) string {
 131         lines := []string{
 132                 "Content-Type: text/html; charset=utf-8",
 133                 "ETag: " + etagString(etag),
 134         }
 135         if gziped {
 136                 lines = append(lines, "Content-Encoding: gzip")
 137         }
 138         lines = append(lines, "")
 139         lines = append(lines, "")
 140         return strings.Join(lines, "\n")
 141 }
 142
 143 func makeErr(err error, status int) {
 144         fmt.Println("Status:", status)
 145         fmt.Print("Content-Type: text/plain; charset=utf-8\n\n")
 146         fmt.Println(err)
 147         log.Fatalln(err)
 148 }
 149
 150 func checkETag(etag hash.Hash) {
 151         ifNoneMatch := os.Getenv("HTTP_IF_NONE_MATCH")
 152         if ifNoneMatch != "" && ifNoneMatch == etagString(etag) {
 153                 fmt.Printf("Status: 304\nETag: %s\n\n", ifNoneMatch)
 154                 os.Exit(0)
 155         }
 156 }
 157
 158 func bytes2uuid(b []byte) string {
 159         raw := new([16]byte)
 160         copy(raw[:], b)
 161         raw[6] = (raw[6] & 0x0F) | uint8(4<<4) // version 4
 162         return fmt.Sprintf("%x-%x-%x-%x-%x", raw[0:4], raw[4:6], raw[6:8], raw[8:10], raw[10:])
 163 }
 164
 165 type CommitIterNext interface {
 166         Next() (*object.Commit, error)
 167 }
 168
 169 func serveHTTP() {
 170         cfgPath := os.Getenv("SGBLOG_CFG")
 171         if cfgPath == "" {
 172                 log.Fatalln("SGBLOG_CFG is not set")
 173         }
 174         cfg, err := readCfg(cfgPath)
 175         if err != nil {
 176                 log.Fatalln(err)
 177         }
 178         initLocalizer(cfg.Lang)
 179
 180         pathInfo := os.Getenv("PATH_INFO")
 181         if len(pathInfo) == 0 {
 182                 pathInfo = "/"
 183         }
 184         queryValues, err := url.ParseQuery(os.Getenv("QUERY_STRING"))
 185         if err != nil {
 186                 makeErr(err, http.StatusBadRequest)
 187         }
 188
 189         etagHash, err := blake2b.New256(nil)
 190         if err != nil {
 191                 panic(err)
 192         }
 193         for _, s := range []string{
 194                 "SGBLOG",
 195                 sgblog.Version,
 196                 cfg.GitPath,
 197                 cfg.Branch,
 198                 cfg.Title,
 199                 cfg.URLPrefix,
 200                 cfg.AtomBaseURL,
 201                 cfg.AtomId,
 202                 cfg.AtomAuthor,
 203         } {
 204                 if _, err = etagHash.Write([]byte(s)); err != nil {
 205                         panic(err)
 206                 }
 207         }
 208         etagHashForWeb := []string{
 209                 cfg.CSS,
 210                 cfg.Webmaster,
 211                 cfg.AboutURL,
 212                 cfg.CommentsNotesRef,
 213                 cfg.CommentsEmail,
 214         }
 215         for _, gitURL := range cfg.GitURLs {
 216                 etagHashForWeb = append(etagHashForWeb, gitURL)
 217         }
 218
 219         headHash, err := initRepo(cfg)
 220         if err != nil {
 221                 makeErr(err, http.StatusInternalServerError)
 222         }
 223
 224         if notes, err := repo.Notes(); err == nil {
 225                 var notesRef *plumbing.Reference
 226                 var commentsRef *plumbing.Reference
 227                 notes.ForEach(func(ref *plumbing.Reference) error {
 228                         switch string(ref.Name()) {
 229                         case "refs/notes/commits":
 230                                 notesRef = ref
 231                         case cfg.CommentsNotesRef:
 232                                 commentsRef = ref
 233                         }
 234                         return nil
 235                 })
 236                 if notesRef != nil {
 237                         if commentsCommit, err := repo.CommitObject(notesRef.Hash()); err == nil {
 238                                 notesTree, _ = commentsCommit.Tree()
 239                         }
 240                 }
 241                 if commentsRef != nil {
 242                         if commentsCommit, err := repo.CommitObject(commentsRef.Hash()); err == nil {
 243                                 commentsTree, _ = commentsCommit.Tree()
 244                         }
 245                 }
 246         }
 247
 248         var outBuf bytes.Buffer
 249         var out io.Writer
 250         out = &outBuf
 251         var gzipWriter *gzip.Writer
 252         acceptEncoding := os.Getenv("HTTP_ACCEPT_ENCODING")
 253         for _, encoding := range strings.Split(acceptEncoding, ", ") {
 254                 if encoding == "gzip" {
 255                         gzipWriter = gzip.NewWriter(&outBuf)
 256                         out = gzipWriter
 257                 }
 258         }
 259
 260         if pathInfo == "/" {
 261                 offset := 0
 262                 if offsetRaw, exists := queryValues["offset"]; exists {
 263                         offset, err = strconv.Atoi(offsetRaw[0])
 264                         if err != nil {
 265                                 makeErr(err, http.StatusBadRequest)
 266                         }
 267                 }
 268                 repoLog, err := repo.Log(&git.LogOptions{From: *headHash})
 269                 if err != nil {
 270                         makeErr(err, http.StatusInternalServerError)
 271                 }
 272                 topicsCache, err := getTopicsCache(cfg, repoLog)
 273                 if err != nil {
 274                         makeErr(err, http.StatusInternalServerError)
 275                 }
 276                 repoLog, err = repo.Log(&git.LogOptions{From: *headHash})
 277                 if err != nil {
 278                         makeErr(err, http.StatusInternalServerError)
 279                 }
 280
 281                 commitN := 0
 282                 var commits CommitIterNext
 283                 var topic string
 284                 if t, exists := queryValues["topic"]; exists {
 285                         topic = t[0]
 286                         hashes := topicsCache[topic]
 287                         if hashes == nil {
 288                                 makeErr(errors.New("no posts with that topic"), http.StatusBadRequest)
 289                         }
 290                         if len(hashes) > offset {
 291                                 hashes = hashes[offset:]
 292                                 commitN += offset
 293                         }
 294                         commits = &HashesIter{hashes}
 295                 } else {
 296                         for i := 0; i < offset; i++ {
 297                                 if _, err = repoLog.Next(); err != nil {
 298                                         break
 299                                 }
 300                                 commitN++
 301                         }
 302                         commits = repoLog
 303                 }
 304
 305                 entries := make([]TableEntry, 0, PageEntries)
 306                 logEnded := false
 307                 for _, data := range etagHashForWeb {
 308                         etagHash.Write([]byte(data))
 309                 }
 310                 etagHash.Write([]byte("INDEX"))
 311                 etagHash.Write([]byte(topic))
 312                 for i := 0; i < PageEntries; i++ {
 313                         commit, err := commits.Next()
 314                         if err != nil {
 315                                 logEnded = true
 316                                 break
 317                         }
 318                         etagHash.Write(commit.Hash[:])
 319                         commentsRaw := sgblog.GetNote(repo, commentsTree, commit.Hash)
 320                         etagHash.Write(commentsRaw)
 321                         topicsRaw := sgblog.GetNote(repo, topicsTree, commit.Hash)
 322                         etagHash.Write(topicsRaw)
 323                         entries = append(entries, TableEntry{
 324                                 Commit:      commit,
 325                                 CommentsRaw: commentsRaw,
 326                                 TopicsRaw:   topicsRaw,
 327                         })
 328                 }
 329                 checkETag(etagHash)
 330
 331                 for i, entry := range entries {
 332                         commitN++
 333                         entry.Num = commitN
 334                         lines := msgSplit(entry.Commit.Message)
 335                         entry.Title = lines[0]
 336                         entry.LinesNum = len(lines) - 2
 337                         for _, line := range lines[2:] {
 338                                 u := urlParse(line)
 339                                 if u == nil {
 340                                         break
 341                                 }
 342                                 entry.DomainURLs = append(entry.DomainURLs, makeA(line, u.Host))
 343                         }
 344                         entry.CommentsNum = len(sgblog.ParseComments(entry.CommentsRaw))
 345                         entry.Topics = sgblog.ParseTopics(entry.TopicsRaw)
 346                         entries[i] = entry
 347                 }
 348                 offsetPrev := offset - PageEntries
 349                 if offsetPrev < 0 {
 350                         offsetPrev = 0
 351                 }
 352                 os.Stdout.Write([]byte(startHeader(etagHash, gzipWriter != nil)))
 353                 err = TmplHTMLIndex.Execute(out, struct {
 354                         T                *spreak.Localizer
 355                         Version          string
 356                         Cfg              *Cfg
 357                         Topic            string
 358                         TopicsEnabled    bool
 359                         Topics           []string
 360                         CommentsEnabled  bool
 361                         AtomPostsFeed    string
 362                         AtomCommentsFeed string
 363                         Offset           int
 364                         OffsetPrev       int
 365                         OffsetNext       int
 366                         LogEnded         bool
 367                         Entries          []TableEntry
 368                 }{
 369                         T:                localizer,
 370                         Version:          sgblog.Version,
 371                         Cfg:              cfg,
 372                         Topic:            topic,
 373                         TopicsEnabled:    topicsTree != nil,
 374                         Topics:           topicsCache.Topics(),
 375                         CommentsEnabled:  commentsTree != nil,
 376                         AtomPostsFeed:    AtomPostsFeed,
 377                         AtomCommentsFeed: AtomCommentsFeed,
 378                         Offset:           offset,
 379                         OffsetPrev:       offsetPrev,
 380                         OffsetNext:       offset + PageEntries,
 381                         LogEnded:         logEnded,
 382                         Entries:          entries,
 383                 })
 384                 if err != nil {
 385                         makeErr(err, http.StatusInternalServerError)
 386                 }
 387         } else if pathInfo == "/twtxt.txt" {
 388                 commit, err := repo.CommitObject(*headHash)
 389                 if err != nil {
 390                         makeErr(err, http.StatusInternalServerError)
 391                 }
 392                 etagHash.Write([]byte("TWTXT POSTS"))
 393                 etagHash.Write(commit.Hash[:])
 394                 checkETag(etagHash)
 395                 repoLog, err := repo.Log(&git.LogOptions{From: *headHash})
 396                 if err != nil {
 397                         makeErr(err, http.StatusInternalServerError)
 398                 }
 399                 for i := 0; i < PageEntries; i++ {
 400                         commit, err = repoLog.Next()
 401                         if err != nil {
 402                                 break
 403                         }
 404                         fmt.Fprintf(
 405                                 out, "%s\t%s\n",
 406                                 commit.Author.When.Format(time.RFC3339),
 407                                 msgSplit(commit.Message)[0],
 408                         )
 409                 }
 410                 os.Stdout.WriteString("Content-Type: text/plain; charset=utf-8\n")
 411                 os.Stdout.WriteString("ETag: " + etagString(etagHash) + "\n")
 412                 if gzipWriter != nil {
 413                         os.Stdout.WriteString("Content-Encoding: gzip\n")
 414                         gzipWriter.Close()
 415                 }
 416                 os.Stdout.WriteString("\n")
 417                 os.Stdout.Write(outBuf.Bytes())
 418                 return
 419         } else if pathInfo == "/"+AtomPostsFeed {
 420                 commit, err := repo.CommitObject(*headHash)
 421                 if err != nil {
 422                         makeErr(err, http.StatusInternalServerError)
 423                 }
 424
 425                 var topic string
 426                 if t, exists := queryValues["topic"]; exists {
 427                         topic = t[0]
 428                 }
 429
 430                 etagHash.Write([]byte("ATOM POSTS"))
 431                 etagHash.Write([]byte(topic))
 432                 etagHash.Write(commit.Hash[:])
 433                 checkETag(etagHash)
 434                 var title string
 435                 if topic == "" {
 436                         title = cfg.Title
 437                 } else {
 438                         title = fmt.Sprintf("%s (topic: %s)", cfg.Title, topic)
 439                 }
 440                 idHasher, err := blake2b.New256(nil)
 441                 if err != nil {
 442                         panic(err)
 443                 }
 444                 idHasher.Write([]byte("ATOM POSTS"))
 445                 idHasher.Write([]byte(cfg.AtomId))
 446                 idHasher.Write([]byte(topic))
 447                 feed := atom.Feed{
 448                         Title:   title,
 449                         ID:      "urn:uuid:" + bytes2uuid(idHasher.Sum(nil)),
 450                         Updated: atom.Time(commit.Author.When),
 451                         Link: []atom.Link{{
 452                                 Rel:  "self",
 453                                 Href: cfg.AtomBaseURL + cfg.URLPrefix + "/" + AtomPostsFeed,
 454                         }},
 455                         Author: &atom.Person{Name: cfg.AtomAuthor},
 456                 }
 457
 458                 repoLog, err := repo.Log(&git.LogOptions{From: *headHash})
 459                 if err != nil {
 460                         makeErr(err, http.StatusInternalServerError)
 461                 }
 462                 var commits CommitIterNext
 463                 if topic == "" {
 464                         commits = repoLog
 465                 } else {
 466                         topicsCache, err := getTopicsCache(cfg, repoLog)
 467                         if err != nil {
 468                                 makeErr(err, http.StatusInternalServerError)
 469                         }
 470                         hashes := topicsCache[topic]
 471                         if hashes == nil {
 472                                 makeErr(errors.New("no posts with that topic"), http.StatusBadRequest)
 473                         }
 474                         commits = &HashesIter{hashes}
 475                 }
 476
 477                 for i := 0; i < PageEntries; i++ {
 478                         commit, err = commits.Next()
 479                         if err != nil {
 480                                 break
 481                         }
 482                         lines := msgSplit(commit.Message)
 483                         var categories []atom.Category
 484                         for _, topic := range sgblog.ParseTopics(sgblog.GetNote(
 485                                 repo, topicsTree, commit.Hash,
 486                         )) {
 487                                 categories = append(categories, atom.Category{Term: topic})
 488                         }
 489                         htmlized := make([]string, 0, len(lines))
 490                         htmlized = append(htmlized, "<pre>")
 491                         for _, l := range lines[2:] {
 492                                 htmlized = append(htmlized, lineURLize(cfg.AtomBaseURL+cfg.URLPrefix, l))
 493                         }
 494                         htmlized = append(htmlized, "</pre>")
 495                         feed.Entry = append(feed.Entry, &atom.Entry{
 496                                 Title: lines[0],
 497                                 ID:    "urn:uuid:" + bytes2uuid(commit.Hash[:]),
 498                                 Link: []atom.Link{{
 499                                         Rel:  "alternate",
 500                                         Href: cfg.AtomBaseURL + cfg.URLPrefix + "/" + commit.Hash.String(),
 501                                 }},
 502                                 Published: atom.Time(commit.Author.When),
 503                                 Updated:   atom.Time(commit.Author.When),
 504                                 Summary:   &atom.Text{Type: "text", Body: lines[0]},
 505                                 Content: &atom.Text{
 506                                         Type: "html",
 507                                         Body: strings.Join(htmlized, "\n"),
 508                                 },
 509                                 Category: categories,
 510                         })
 511                 }
 512                 data, err := xml.MarshalIndent(&feed, "", "  ")
 513                 if err != nil {
 514                         makeErr(err, http.StatusInternalServerError)
 515                 }
 516                 out.Write([]byte(xml.Header))
 517                 out.Write(data)
 518                 goto AtomFinish
 519         } else if pathInfo == "/"+AtomCommentsFeed {
 520                 commit, err := repo.CommitObject(commentsRef.Hash())
 521                 if err != nil {
 522                         makeErr(err, http.StatusInternalServerError)
 523                 }
 524                 etagHash.Write([]byte("ATOM COMMENTS"))
 525                 etagHash.Write(commit.Hash[:])
 526                 checkETag(etagHash)
 527                 idHasher, err := blake2b.New256(nil)
 528                 if err != nil {
 529                         panic(err)
 530                 }
 531                 idHasher.Write([]byte("ATOM COMMENTS"))
 532                 idHasher.Write([]byte(cfg.AtomId))
 533                 feed := atom.Feed{
 534                         Title:   cfg.Title + " comments",
 535                         ID:      "urn:uuid:" + bytes2uuid(idHasher.Sum(nil)),
 536                         Updated: atom.Time(commit.Author.When),
 537                         Link: []atom.Link{{
 538                                 Rel:  "self",
 539                                 Href: cfg.AtomBaseURL + cfg.URLPrefix + "/" + AtomCommentsFeed,
 540                         }},
 541                         Author: &atom.Person{Name: cfg.AtomAuthor},
 542                 }
 543                 repoLog, err := repo.Log(&git.LogOptions{From: commentsRef.Hash()})
 544                 if err != nil {
 545                         makeErr(err, http.StatusInternalServerError)
 546                 }
 547                 for i := 0; i < PageEntries; i++ {
 548                         commit, err = repoLog.Next()
 549                         if err != nil {
 550                                 break
 551                         }
 552                         fileStats, err := commit.Stats()
 553                         if err != nil {
 554                                 makeErr(err, http.StatusInternalServerError)
 555                         }
 556                         t, err := commit.Tree()
 557                         if err != nil {
 558                                 makeErr(err, http.StatusInternalServerError)
 559                         }
 560                         commentedHash := plumbing.NewHash(strings.ReplaceAll(
 561                                 fileStats[0].Name, "/", "",
 562                         ))
 563                         commit, err = repo.CommitObject(commentedHash)
 564                         if err != nil {
 565                                 continue
 566                         }
 567                         comments := sgblog.ParseComments(sgblog.GetNote(repo, t, commentedHash))
 568                         if len(comments) == 0 {
 569                                 continue
 570                         }
 571                         commentN := strconv.Itoa(len(comments) - 1)
 572                         lines := strings.Split(comments[len(comments)-1], "\n")
 573                         from := strings.TrimPrefix(lines[0], "From: ")
 574                         date := strings.TrimPrefix(lines[1], "Date: ")
 575                         htmlized := make([]string, 0, len(lines))
 576                         htmlized = append(htmlized, "<pre>")
 577                         for _, l := range lines[2:] {
 578                                 htmlized = append(htmlized, lineURLize(cfg.AtomBaseURL+cfg.URLPrefix, l))
 579                         }
 580                         htmlized = append(htmlized, "</pre>")
 581                         idHasher.Reset()
 582                         idHasher.Write([]byte("COMMENT"))
 583                         idHasher.Write(commit.Hash[:])
 584                         idHasher.Write([]byte(commentN))
 585                         feed.Entry = append(feed.Entry, &atom.Entry{
 586                                 Title: fmt.Sprintf(
 587                                         "Comment %s for \"%s\" by %s",
 588                                         commentN, msgSplit(commit.Message)[0], from,
 589                                 ),
 590                                 Author: &atom.Person{Name: from},
 591                                 ID:     "urn:uuid:" + bytes2uuid(idHasher.Sum(nil)),
 592                                 Link: []atom.Link{{
 593                                         Rel: "alternate",
 594                                         Href: strings.Join([]string{
 595                                                 cfg.AtomBaseURL, cfg.URLPrefix, "/",
 596                                                 commit.Hash.String(), "#comment", commentN,
 597                                         }, ""),
 598                                 }},
 599                                 Published: atom.TimeStr(strings.Replace(date, " ", "T", -1)),
 600                                 Updated:   atom.TimeStr(strings.Replace(date, " ", "T", -1)),
 601                                 Content: &atom.Text{
 602                                         Type: "html",
 603                                         Body: strings.Join(htmlized, "\n"),
 604                                 },
 605                         })
 606                 }
 607                 data, err := xml.MarshalIndent(&feed, "", "  ")
 608                 if err != nil {
 609                         makeErr(err, http.StatusInternalServerError)
 610                 }
 611                 out.Write([]byte(xml.Header))
 612                 out.Write(data)
 613                 goto AtomFinish
 614         } else if sha1DigestRe.MatchString(pathInfo[1:]) {
 615                 commit, err := repo.CommitObject(plumbing.NewHash(pathInfo[1 : 1+sha1.Size*2]))
 616                 if err != nil {
 617                         makeErr(err, http.StatusBadRequest)
 618                 }
 619                 for _, data := range etagHashForWeb {
 620                         etagHash.Write([]byte(data))
 621                 }
 622                 etagHash.Write([]byte("ENTRY"))
 623                 etagHash.Write(commit.Hash[:])
 624                 atomCommentsURL := strings.Join([]string{
 625                         cfg.AtomBaseURL, cfg.URLPrefix, "/",
 626                         commit.Hash.String(), "/", AtomCommentsFeed,
 627                 }, "")
 628                 commentsRaw := sgblog.GetNote(repo, commentsTree, commit.Hash)
 629                 etagHash.Write(commentsRaw)
 630                 topicsRaw := sgblog.GetNote(repo, topicsTree, commit.Hash)
 631                 etagHash.Write(topicsRaw)
 632                 if strings.HasSuffix(pathInfo, AtomCommentsFeed) {
 633                         etagHash.Write([]byte("ATOM COMMENTS"))
 634                         checkETag(etagHash)
 635                         type Comment struct {
 636                                 n    string
 637                                 from string
 638                                 date string
 639                                 body []string
 640                         }
 641                         commentsRaw := sgblog.ParseComments(commentsRaw)
 642                         var toSkip int
 643                         if len(commentsRaw) > PageEntries {
 644                                 toSkip = len(commentsRaw) - PageEntries
 645                         }
 646                         comments := make([]Comment, 0, len(commentsRaw)-toSkip)
 647                         for i := len(commentsRaw) - 1; i >= toSkip; i-- {
 648                                 lines := strings.Split(commentsRaw[i], "\n")
 649                                 from := strings.TrimPrefix(lines[0], "From: ")
 650                                 date := strings.TrimPrefix(lines[1], "Date: ")
 651                                 comments = append(comments, Comment{
 652                                         n:    strconv.Itoa(i),
 653                                         from: from,
 654                                         date: strings.Replace(date, " ", "T", 1),
 655                                         body: lines[3:],
 656                                 })
 657                         }
 658                         idHasher, err := blake2b.New256(nil)
 659                         if err != nil {
 660                                 panic(err)
 661                         }
 662                         idHasher.Write([]byte("ATOM COMMENTS"))
 663                         idHasher.Write(commit.Hash[:])
 664                         feed := atom.Feed{
 665                                 Title:  fmt.Sprintf("\"%s\" comments", msgSplit(commit.Message)[0]),
 666                                 ID:     "urn:uuid:" + bytes2uuid(idHasher.Sum(nil)),
 667                                 Link:   []atom.Link{{Rel: "self", Href: atomCommentsURL}},
 668                                 Author: &atom.Person{Name: cfg.AtomAuthor},
 669                         }
 670                         if len(comments) > 0 {
 671                                 feed.Updated = atom.TimeStr(comments[0].date)
 672                         } else {
 673                                 feed.Updated = atom.Time(commit.Author.When)
 674                         }
 675                         for _, comment := range comments {
 676                                 idHasher.Reset()
 677                                 idHasher.Write([]byte("COMMENT"))
 678                                 idHasher.Write(commit.Hash[:])
 679                                 idHasher.Write([]byte(comment.n))
 680                                 htmlized := make([]string, 0, len(comment.body))
 681                                 htmlized = append(htmlized, "<pre>")
 682                                 for _, l := range comment.body {
 683                                         htmlized = append(
 684                                                 htmlized,
 685                                                 lineURLize(cfg.AtomBaseURL+cfg.URLPrefix, l),
 686                                         )
 687                                 }
 688                                 htmlized = append(htmlized, "</pre>")
 689                                 feed.Entry = append(feed.Entry, &atom.Entry{
 690                                         Title:  fmt.Sprintf("Comment %s by %s", comment.n, comment.from),
 691                                         Author: &atom.Person{Name: comment.from},
 692                                         ID:     "urn:uuid:" + bytes2uuid(idHasher.Sum(nil)),
 693                                         Link: []atom.Link{{
 694                                                 Rel: "alternate",
 695                                                 Href: strings.Join([]string{
 696                                                         cfg.AtomBaseURL,
 697                                                         cfg.URLPrefix, "/",
 698                                                         commit.Hash.String(),
 699                                                         "#comment", comment.n,
 700                                                 }, ""),
 701                                         }},
 702                                         Published: atom.TimeStr(
 703                                                 strings.Replace(comment.date, " ", "T", -1),
 704                                         ),
 705                                         Updated: atom.TimeStr(
 706                                                 strings.Replace(comment.date, " ", "T", -1),
 707                                         ),
 708                                         Content: &atom.Text{
 709                                                 Type: "html",
 710                                                 Body: strings.Join(htmlized, "\n"),
 711                                         },
 712                                 })
 713                         }
 714                         data, err := xml.MarshalIndent(&feed, "", "  ")
 715                         if err != nil {
 716                                 makeErr(err, http.StatusInternalServerError)
 717                         }
 718                         out.Write([]byte(xml.Header))
 719                         out.Write(data)
 720                         goto AtomFinish
 721                 }
 722                 notesRaw := sgblog.GetNote(repo, notesTree, commit.Hash)
 723                 etagHash.Write(notesRaw)
 724                 checkETag(etagHash)
 725
 726                 lines := msgSplit(commit.Message)
 727                 title := lines[0]
 728                 when := commit.Author.When.Format(sgblog.WhenFmt)
 729                 var parent string
 730                 if len(commit.ParentHashes) > 0 {
 731                         parent = commit.ParentHashes[0].String()
 732                 }
 733                 commentsParsed := sgblog.ParseComments(commentsRaw)
 734                 comments := make([]CommentEntry, 0, len(commentsParsed))
 735                 for _, comment := range commentsParsed {
 736                         lines := strings.Split(comment, "\n")
 737                         comments = append(comments, CommentEntry{lines[:3], lines[3:]})
 738                 }
 739                 var notesLines []string
 740                 if len(notesRaw) > 0 {
 741                         notesLines = strings.Split(string(notesRaw), "\n")
 742                 }
 743
 744                 os.Stdout.Write([]byte(startHeader(etagHash, gzipWriter != nil)))
 745                 err = TmplHTMLEntry.Execute(out, struct {
 746                         T               *spreak.Localizer
 747                         Version         string
 748                         Cfg             *Cfg
 749                         Title           string
 750                         TitleEscaped    string
 751                         When            string
 752                         AtomCommentsURL string
 753                         Parent          string
 754                         Commit          *object.Commit
 755                         Lines           []string
 756                         NoteLines       []string
 757                         Comments        []CommentEntry
 758                         Topics          []string
 759                 }{
 760                         T:               localizer,
 761                         Version:         sgblog.Version,
 762                         Cfg:             cfg,
 763                         Title:           title,
 764                         TitleEscaped:    url.PathEscape(fmt.Sprintf("Re: %s (%s)", title, commit.Hash)),
 765                         When:            when,
 766                         AtomCommentsURL: atomCommentsURL,
 767                         Parent:          parent,
 768                         Commit:          commit,
 769                         Lines:           lines[2:],
 770                         NoteLines:       notesLines,
 771                         Comments:        comments,
 772                         Topics:          sgblog.ParseTopics(topicsRaw),
 773                 })
 774                 if err != nil {
 775                         makeErr(err, http.StatusInternalServerError)
 776                 }
 777         } else {
 778                 makeErr(errors.New("unknown URL action"), http.StatusNotFound)
 779         }
 780         out.Write([]byte("</body></html>\n"))
 781         if gzipWriter != nil {
 782                 gzipWriter.Close()
 783         }
 784         os.Stdout.Write(outBuf.Bytes())
 785         return
 786
 787 AtomFinish:
 788         os.Stdout.WriteString("Content-Type: application/atom+xml; charset=utf-8\n")
 789         os.Stdout.WriteString("ETag: " + etagString(etagHash) + "\n")
 790         if gzipWriter != nil {
 791                 os.Stdout.WriteString("Content-Encoding: gzip\n")
 792                 gzipWriter.Close()
 793         }
 794         os.Stdout.WriteString("\n")
 795         os.Stdout.Write(outBuf.Bytes())
 796 }