Add Calendar integration (read-only)

calendarpage.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"bytes"
+	"html/template"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func init() {
+	pageTypeHandlers = append(pageTypeHandlers, &calendarsHandler{})
+}
+
+// calendarsHandler renders folders whose .page-settings declares
+// type = calendars: the maintenance table and the sync status. Markdown
+// content and the listing stay visible, as in the fitness folder.
+type calendarsHandler struct{}
+
+func (c *calendarsHandler) redirect(root, fsPath, urlPath string, r *http.Request) (string, bool) {
+	return "", false
+}
+
+func (c *calendarsHandler) handle(root, fsPath, urlPath string, r *http.Request) *specialPage {
+	s := readPageSettings(fsPath)
+	if s == nil || s.Type != "calendars" {
+		return nil
+	}
+	return &specialPage{Content: renderCalendarsPage(fsPath), SuppressTOC: true}
+}
+
+type calFileRow struct {
+	Name    string
+	Roles   string
+	Events  string
+	Updated string // file modification time
+	Error   string // last sync or parse error
+}
+
+type calPageData struct {
+	HasMaintenance bool
+	Maintenance    []maintSeriesRow
+	Calendars      []calFileRow
+	// Sync is only shown for the configured calendars folder.
+	IsSyncDir   bool
+	SyncEnabled bool
+	LastRun     string
+	LastError   string
+}
+
+var calPageTmpl = template.Must(template.ParseFS(assets, "assets/calendar/page.html"))
+
+func renderCalendarsPage(dir string) template.HTML {
+	s := readCalendarSettings(dir)
+	data := calPageData{
+		HasMaintenance: len(s.Maintenance) > 0,
+		Maintenance:    maintenanceSeries(dir, s.Maintenance, time.Now()),
+		IsSyncDir:      calendarsDir != "" && dir == calendarsDir,
+		SyncEnabled:    s.CaldavURL != "",
+	}
+
+	var results map[string]calSyncResult
+	if data.IsSyncDir {
+		var lastRun time.Time
+		lastRun, data.LastError, results = calSyncSnapshot()
+		if !lastRun.IsZero() {
+			data.LastRun = lastRun.Format("2006-01-02 15:04")
+		}
+	}
+
+	roles := map[string][]string{}
+	for role, names := range map[string][]string{"diary": s.Diary, "weight": s.Weight, "maintenance": s.Maintenance} {
+		for _, n := range names {
+			roles[n] = append(roles[n], role)
+		}
+	}
+	entries, _ := os.ReadDir(dir)
+	for _, e := range entries {
+		name := e.Name()
+		if e.IsDir() || strings.HasPrefix(name, ".") || !strings.EqualFold(filepath.Ext(name), ".ics") {
+			continue
+		}
+		name = strings.TrimSuffix(name, filepath.Ext(name))
+		sort.Strings(roles[name])
+		row := calFileRow{Name: name, Roles: strings.Join(roles[name], ", "), Error: results[name].Error}
+		if info, err := e.Info(); err == nil {
+			row.Updated = info.ModTime().Format("2006-01-02 15:04")
+		}
+		if f := loadCalendar(filepath.Join(dir, e.Name())); f != nil {
+			row.Events = strconv.Itoa(f.events)
+		} else if row.Error == "" {
+			row.Error = "cannot parse file"
+		}
+		data.Calendars = append(data.Calendars, row)
+		delete(results, name)
+	}
+	// Calendars whose download failed before a file ever existed.
+	for name, r := range results {
+		if r.Error != "" {
+			data.Calendars = append(data.Calendars, calFileRow{Name: name, Error: r.Error})
+		}
+	}
+	sort.SliceStable(data.Calendars, func(i, j int) bool { return data.Calendars[i].Name < data.Calendars[j].Name })
+
+	var buf bytes.Buffer
+	if err := calPageTmpl.Execute(&buf, data); err != nil {
+		log.Printf("calendars page template: %v", err)
+		return ""
+	}
+	return template.HTML(buf.String())
+}