1 files changed, 172 insertions, 0 deletions
diff --git a/services/wiki/wiki_path.go b/services/wiki/wiki_path.go
new file mode 100644
index 0000000..74c7064
--- /dev/null
+++ b/services/wiki/wiki_path.go
@@ -0,0 +1,172 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package wiki
+
+import (
+	"net/url"
+	"path"
+	"strings"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/git"
+	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/services/convert"
+)
+
+// To define the wiki related concepts:
+// * Display Segment: the text what user see for a wiki page (aka, the title):
+//   - "Home Page"
+//   - "100% Free"
+//   - "2000-01-02 meeting"
+// * Web Path:
+//   - "/wiki/Home-Page"
+//   - "/wiki/100%25+Free"
+//   - "/wiki/2000-01-02+meeting.-"
+//   - If a segment has a suffix "DashMarker(.-)", it means that there is no dash-space conversion for this segment.
+//   - If a WebPath is a "*.md" pattern, then use the unescaped value directly as GitPath, to make users can access the raw file.
+// * Git Path (only space doesn't need to be escaped):
+//   - "/.wiki.git/Home-Page.md"
+//   - "/.wiki.git/100%25 Free.md"
+//   - "/.wiki.git/2000-01-02 meeting.-.md"
+// TODO: support subdirectory in the future
+//
+// Although this package now has the ability to support subdirectory, but the route package doesn't:
+// * Double-escaping problem: the URL "/wiki/abc%2Fdef" becomes "/wiki/abc/def" by ctx.Params, which is incorrect
+//   * This problem should have been 99% fixed, but it needs more tests.
+// * The old wiki code's behavior is always using %2F, instead of subdirectory, so there are a lot of legacy "%2F" files in user wikis.
+
+type WebPath string
+
+var reservedWikiNames = []string{"_pages", "_new", "_edit", "raw"}
+
+func validateWebPath(name WebPath) error {
+	for _, s := range WebPathSegments(name) {
+		if util.SliceContainsString(reservedWikiNames, s) {
+			return repo_model.ErrWikiReservedName{Title: s}
+		}
+	}
+	return nil
+}
+
+func hasDashMarker(s string) bool {
+	return strings.HasSuffix(s, ".-")
+}
+
+func removeDashMarker(s string) string {
+	return strings.TrimSuffix(s, ".-")
+}
+
+func addDashMarker(s string) string {
+	return s + ".-"
+}
+
+func unescapeSegment(s string) (string, error) {
+	if hasDashMarker(s) {
+		s = removeDashMarker(s)
+	} else {
+		s = strings.ReplaceAll(s, "-", " ")
+	}
+	unescaped, err := url.QueryUnescape(s)
+	if err != nil {
+		return s, err // un-escaping failed, but it's still safe to return the original string, because it is only a title for end users
+	}
+	return unescaped, nil
+}
+
+func escapeSegToWeb(s string, hadDashMarker bool) string {
+	if hadDashMarker || strings.Contains(s, "-") || strings.HasSuffix(s, ".md") {
+		s = addDashMarker(s)
+	} else {
+		s = strings.ReplaceAll(s, " ", "-")
+	}
+	s = url.QueryEscape(s)
+	return s
+}
+
+func WebPathSegments(s WebPath) []string {
+	a := strings.Split(string(s), "/")
+	for i := range a {
+		a[i], _ = unescapeSegment(a[i])
+	}
+	return a
+}
+
+func WebPathToGitPath(s WebPath) string {
+	if strings.HasSuffix(string(s), ".md") {
+		ret, _ := url.PathUnescape(string(s))
+		return util.PathJoinRelX(ret)
+	}
+
+	a := strings.Split(string(s), "/")
+	for i := range a {
+		shouldAddDashMarker := hasDashMarker(a[i])
+		a[i], _ = unescapeSegment(a[i])
+		a[i] = escapeSegToWeb(a[i], shouldAddDashMarker)
+		a[i] = strings.ReplaceAll(a[i], "%20", " ") // space is safe to be kept in git path
+		a[i] = strings.ReplaceAll(a[i], "+", " ")
+	}
+	return strings.Join(a, "/") + ".md"
+}
+
+func GitPathToWebPath(s string) (wp WebPath, err error) {
+	if !strings.HasSuffix(s, ".md") {
+		return "", repo_model.ErrWikiInvalidFileName{FileName: s}
+	}
+	s = strings.TrimSuffix(s, ".md")
+	a := strings.Split(s, "/")
+	for i := range a {
+		shouldAddDashMarker := hasDashMarker(a[i])
+		if a[i], err = unescapeSegment(a[i]); err != nil {
+			return "", err
+		}
+		a[i] = escapeSegToWeb(a[i], shouldAddDashMarker)
+	}
+	return WebPath(strings.Join(a, "/")), nil
+}
+
+func WebPathToUserTitle(s WebPath) (dir, display string) {
+	dir = path.Dir(string(s))
+	display = path.Base(string(s))
+	if strings.HasSuffix(display, ".md") {
+		display = strings.TrimSuffix(display, ".md")
+		display, _ = url.PathUnescape(display)
+	}
+	display, _ = unescapeSegment(display)
+	return dir, display
+}
+
+func WebPathToURLPath(s WebPath) string {
+	return string(s)
+}
+
+func WebPathFromRequest(s string) WebPath {
+	s = util.PathJoinRelX(s)
+	// The old wiki code's behavior is always using %2F, instead of subdirectory.
+	s = strings.ReplaceAll(s, "/", "%2F")
+	return WebPath(s)
+}
+
+func UserTitleToWebPath(base, title string) WebPath {
+	// TODO: no support for subdirectory, because the old wiki code's behavior is always using %2F, instead of subdirectory.
+	// So we do not add the support for writing slashes in title at the moment.
+	title = strings.TrimSpace(title)
+	title = util.PathJoinRelX(base, escapeSegToWeb(title, false))
+	if title == "" || title == "." {
+		title = "unnamed"
+	}
+	return WebPath(title)
+}
+
+// ToWikiPageMetaData converts meta information to a WikiPageMetaData
+func ToWikiPageMetaData(wikiName WebPath, lastCommit *git.Commit, repo *repo_model.Repository) *api.WikiPageMetaData {
+	subURL := string(wikiName)
+	_, title := WebPathToUserTitle(wikiName)
+	return &api.WikiPageMetaData{
+		Title:      title,
+		HTMLURL:    util.URLJoin(repo.HTMLURL(), "wiki", subURL),
+		SubURL:     subURL,
+		LastCommit: convert.ToWikiCommit(lastCommit),
+	}
+}