Created Turnpike, event attendee and volunteer management

Built after prototype, Traverse, an attendee and volunteer list
maintainer.

handle_sync.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// handleSyncPull returns all records modified since the `since` query parameter.
+// If `since` is empty, returns all records (initial sync).
+func (app *App) handleSyncPull(w http.ResponseWriter, r *http.Request) {
+	since := r.URL.Query().Get("since")
+
+	event, _ := app.getEvent()
+	attendees, _ := app.attendeesSince(since)
+	departments, _ := app.listDepartments(since)
+	volunteers, _ := app.listVolunteers("", nil, since)
+	shifts, _ := app.listShifts(nil, "", since)
+	volunteerShifts, _ := app.listVolunteerShifts(since)
+
+	if attendees == nil {
+		attendees = []Attendee{}
+	}
+	if departments == nil {
+		departments = []Department{}
+	}
+	if volunteers == nil {
+		volunteers = []Volunteer{}
+	}
+	if shifts == nil {
+		shifts = []Shift{}
+	}
+	if volunteerShifts == nil {
+		volunteerShifts = []VolunteerShift{}
+	}
+
+	writeJSON(w, map[string]any{
+		"server_time":      time.Now().UTC().Format("2006-01-02T15:04:05Z"),
+		"event":            event,
+		"attendees":        attendees,
+		"departments":      departments,
+		"volunteers":       volunteers,
+		"shifts":           shifts,
+		"volunteer_shifts": volunteerShifts,
+	})
+}
+
+// handleSyncStream is an SSE endpoint that broadcasts real-time events
+// (check-ins, etc.) to connected clients.
+func (app *App) handleSyncStream(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("X-Accel-Buffering", "no")
+
+	flusher, ok := w.(http.Flusher)
+	if !ok {
+		http.Error(w, "streaming not supported", http.StatusInternalServerError)
+		return
+	}
+
+	ch := app.broker.subscribe()
+	defer app.broker.unsubscribe(ch)
+
+	fmt.Fprintf(w, "data: {\"event\":\"connected\"}\n\n")
+	flusher.Flush()
+
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-r.Context().Done():
+			return
+		case payload, ok := <-ch:
+			if !ok {
+				return
+			}
+			fmt.Fprintf(w, "data: %s\n\n", payload)
+			flusher.Flush()
+		case <-ticker.C:
+			fmt.Fprintf(w, ": ping\n\n")
+			flusher.Flush()
+		}
+	}
+}