Add Calendar integration (read-only)

main.go

@@ -17,6 +17,7 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	_ "time/tzdata" // calendar TZIDs must resolve even without system zoneinfo
 )
 
 //go:embed assets
@@ -38,10 +39,13 @@ func hashAsset(name string) string {
 }
 
 // tmplFuncs is shared by every layout-based template: the edit template appends
-// editorBundleVersion to its CodeMirror <script> src to cache-bust the bundle.
+// editorBundleVersion to its CodeMirror <script> src to cache-bust the bundle;
+// the layout header renders the maintenance widget.
 var tmplFuncs = template.FuncMap{
 	"editorBundleVersion": func() string { return editorBundleVersion },
 	"fileIcon":            fileIcon,
+	"icon":                readIcon,
+	"maintenanceWidget":   maintenanceWidget,
 }
 
 var (
@@ -88,8 +92,18 @@ func main() {
 	user := flag.String("user", "", "basic auth username (empty = no auth)")
 	pass := flag.String("pass", "", "basic auth password")
 	reindexInterval := flag.Duration("reindex-interval", 30*time.Minute, "periodic search index rebuild interval (0 disables)")
+	calendars := flag.String("calendars", "Calendars", "calendars folder, relative to -dir (empty disables)")
+	tz := flag.String("tz", "", "time zone for calendars and the diary, e.g. Europe/Berlin (default: system)")
 	flag.Parse()
 
+	if *tz != "" {
+		loc, err := time.LoadLocation(*tz)
+		if err != nil {
+			log.Fatalf("-tz: %v", err)
+		}
+		time.Local = loc
+	}
+
 	root, err := filepath.Abs(*wikiDir)
 	if err != nil {
 		log.Fatal(err)
@@ -108,6 +122,15 @@ func main() {
 
 	initMarkdown()
 
+	if *calendars != "" {
+		calendarsDir = filepath.Join(root, filepath.FromSlash(*calendars))
+		rel, err := filepath.Rel(root, calendarsDir)
+		if err != nil || rel == "." || strings.HasPrefix(rel, "..") {
+			log.Fatalf("-calendars must be a folder inside -dir")
+		}
+		calendarsURL = "/" + filepath.ToSlash(rel) + "/"
+	}
+
 	authKey, err := loadOrCreateAuthKey(root)
 	if err != nil {
 		log.Fatal(err)
@@ -158,6 +181,10 @@ func main() {
 		}(*reindexInterval)
 	}
 
+	if calendarsDir != "" {
+		startCalendarSync()
+	}
+
 	log.Printf("datascape listening on %s, wiki at %s", *addr, root)
 	log.Fatal(http.ListenAndServe(*addr, nil))
 }
@@ -188,6 +215,14 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Dotfiles are never served: .page-settings can hold the CalDAV
+	// password and .auth-key signs sessions. Nothing links to them (listing,
+	// tree and search hide them already).
+	if hasDotSegment(r.URL.Path) {
+		http.NotFound(w, r)
+		return
+	}
+
 	if strings.HasPrefix(r.URL.Path, thumbURLPrefix+"/") {
 		h.handleThumb(w, r)
 		return
@@ -255,6 +290,17 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// hasDotSegment reports whether any segment of the cleaned URL path starts
+// with a dot.
+func hasDotSegment(p string) bool {
+	for _, seg := range strings.Split(path.Clean("/"+p), "/") {
+		if strings.HasPrefix(seg, ".") {
+			return true
+		}
+	}
+	return false
+}
+
 // slashedURL returns u's path with a trailing slash appended and the query
 // string intact — the canonical page form that relative destinations resolve
 // against.
@@ -414,6 +460,10 @@ func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fs
 		h.handleSettings(w, r, urlPath, fsPath)
 		return
 	}
+	if query.Has("calsync") {
+		h.handleCalendarSync(w, r, urlPath, fsPath)
+		return
+	}
 
 	if err := r.ParseForm(); err != nil {
 		http.Error(w, "bad request", http.StatusBadRequest)
@@ -525,12 +575,28 @@ func (h *handler) handlePost(w http.ResponseWriter, r *http.Request, urlPath, fs
 // Returns nil if the file does not exist.
 // Format: one "key = value" pair per line; lines starting with # are comments.
 func readPageSettings(dir string) *pageSettings {
+	kv := readSettingsFile(dir)
+	if kv == nil {
+		return nil
+	}
+	// Unknown or missing values fall back to the defaults.
+	return &pageSettings{
+		Type:  kv["type"],
+		View:  validateView(kv["view"]),
+		Sort:  validateSort(kv["sort"]),
+		Order: validateOrder(kv["order"]),
+	}
+}
+
+// readSettingsFile returns every key of dir's .page-settings (last one wins),
+// or nil if the file does not exist. Other features (e.g. the calendars
+// folder) keep their own keys in the same file.
+func readSettingsFile(dir string) map[string]string {
 	data, err := os.ReadFile(filepath.Join(dir, ".page-settings"))
 	if err != nil {
 		return nil
 	}
-	// Defaults; overridden only by valid values present in the file.
-	s := &pageSettings{View: viewList, Sort: sortName, Order: orderAsc}
+	kv := map[string]string{}
 	for _, line := range strings.Split(string(data), "\n") {
 		line = strings.TrimSpace(line)
 		if line == "" || strings.HasPrefix(line, "#") {
@@ -540,17 +606,7 @@ func readPageSettings(dir string) *pageSettings {
 		if len(parts) != 2 {
 			continue
 		}
-		value := strings.TrimSpace(parts[1])
-		switch strings.TrimSpace(parts[0]) {
-		case "type":
-			s.Type = value
-		case "view":
-			s.View = validateView(value)
-		case "sort":
-			s.Sort = validateSort(value)
-		case "order":
-			s.Order = validateOrder(value)
-		}
+		kv[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
 	}
-	return s
+	return kv
 }