Initial commit

Assisted-by: GLM 5.3

internal/admin/posts_history.go

@@ -0,0 +1,160 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0
+
+package admin
+
+import (
+	"fmt"
+	"net/http"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"sourcedock.dev/petrbalvin/volumen/internal/diff"
+)
+
+// unsafeSlugRe strips anything that is not safe in a header value.
+var unsafeSlugRe = regexp.MustCompile(`[^a-z0-9._-]`)
+
+// attachmentName reduces a path segment to a safe Content-Disposition
+// filename.
+func attachmentName(value string) string { return unsafeSlugRe.ReplaceAllString(value, "") }
+
+func (a *Admin) handleDownload(w http.ResponseWriter, r *http.Request) {
+	slug := r.PathValue("slug")
+	p := a.deps.Store.Find(slug, "")
+	if p == nil {
+		http.NotFound(w, r)
+		return
+	}
+	content, err := p.ToFile()
+	if err != nil {
+		http.Error(w, "export failed", http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "text/markdown; charset=utf-8")
+	w.Header().Set("Content-Disposition",
+		fmt.Sprintf(`attachment; filename="%s.md"`, attachmentName(slug)))
+	fmt.Fprint(w, content)
+}
+
+func (a *Admin) handleHistory(w http.ResponseWriter, r *http.Request) {
+	slug := r.PathValue("slug")
+	p := a.deps.Store.Find(slug, "")
+	if p == nil {
+		http.NotFound(w, r)
+		return
+	}
+	revisions := a.deps.Store.Revisions(slug)
+	rows := make([]revisionRow, 0, len(revisions))
+	for _, rev := range revisions {
+		rows = append(rows, newRevisionRow(rev))
+	}
+	heading := p.Title()
+	if heading == "" {
+		heading = slug
+	}
+	data := a.pageData(r)
+	data.Slug = slug
+	data.Heading = heading
+	data.Revisions = rows
+	data.Post = newEditorPost(p)
+	data.Crumbs = []Crumb{
+		{Label: "Posts", Href: "/admin/", UI: true},
+		{Label: heading, Href: "/admin/posts/" + slug + "/edit"},
+		{Label: "History", IsLast: true, UI: true},
+	}
+	a.renderPage(w, r, "history.html", data, http.StatusOK)
+}
+
+func (a *Admin) handleHistoryDownload(w http.ResponseWriter, r *http.Request) {
+	slug := r.PathValue("slug")
+	name := r.PathValue("name")
+	content := a.deps.Store.RevisionContent(slug, name)
+	if content == "" {
+		http.NotFound(w, r)
+		return
+	}
+	// The revision name is a server-generated stamp, but it arrives from
+	// the URL: the value is reduced to what cannot end the quoted string
+	// (a quote, a backslash, a control byte). Unlike attachmentName this
+	// keeps the stamp's uppercase T and Z.
+	safeName := strings.Map(func(r rune) rune {
+		if r == '"' || r == '\\' || r < 0x20 || r == 0x7f {
+			return -1
+		}
+		return r
+	}, filepath.Base(name))
+	w.Header().Set("Content-Type", "text/markdown; charset=utf-8")
+	w.Header().Set("Content-Disposition",
+		fmt.Sprintf(`attachment; filename="%s-%s"`, attachmentName(slug), safeName))
+	fmt.Fprint(w, content)
+}
+
+// handleHistoryDiff compares one archived revision with the current
+// content, so the editor can judge what a restore would change before
+// committing to it.
+func (a *Admin) handleHistoryDiff(w http.ResponseWriter, r *http.Request) {
+	slug := r.PathValue("slug")
+	name := r.PathValue("name")
+	p := a.deps.Store.Find(slug, "")
+	if p == nil {
+		http.NotFound(w, r)
+		return
+	}
+	revision := a.deps.Store.RevisionContent(slug, name)
+	if revision == "" {
+		http.NotFound(w, r)
+		return
+	}
+	current, err := p.ToFile()
+	if err != nil {
+		http.Error(w, "export failed", http.StatusInternalServerError)
+		return
+	}
+	var when string
+	for _, rev := range a.deps.Store.Revisions(slug) {
+		if rev.Name == name {
+			when = rev.When
+			break
+		}
+	}
+	heading := p.Title()
+	if heading == "" {
+		heading = slug
+	}
+	data := a.pageData(r)
+	data.Slug = slug
+	data.Heading = heading
+	data.DiffName = name
+	data.DiffWhen = when
+	data.DiffChunks = diff.Chunks(revision, current, 3)
+	data.Post = newEditorPost(p)
+	data.Crumbs = []Crumb{
+		{Label: "Posts", Href: "/admin/", UI: true},
+		{Label: heading, Href: "/admin/posts/" + slug + "/edit"},
+		{Label: "History", Href: "/admin/posts/" + slug + "/history", UI: true},
+		{Label: "Changes", IsLast: true, UI: true},
+	}
+	a.renderPage(w, r, "diff.html", data, http.StatusOK)
+}
+
+func (a *Admin) handleHistoryRestore(w http.ResponseWriter, r *http.Request) {
+	if !a.requireCSRF(w, r) {
+		return
+	}
+	slug := r.PathValue("slug")
+	name := r.PathValue("name")
+	p := a.deps.Store.Find(slug, "")
+	if p == nil {
+		http.NotFound(w, r)
+		return
+	}
+	if a.deps.Store.RestoreRevision(p, name) == nil {
+		http.NotFound(w, r)
+		return
+	}
+	http.Redirect(w, r, "/admin/posts/"+slug+"/edit?restored=1", http.StatusSeeOther)
+}
+
+// --- uploads and static SVGs ------------------------------------------------