feat: implement core daemon (config, fire client, scheduler)

self-hosted/scheduler.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+
+	"github.com/robfig/cron/v3"
+)
+
+// Scheduler wires cron schedules to FireClient invocations.
+type Scheduler struct {
+	cron *cron.Cron
+	fire *FireClient
+	log  *slog.Logger
+}
+
+// NewScheduler builds a Scheduler with all schedules registered. Returns an
+// error if any registration fails (defensive — config.go already validates
+// expressions, but the cron library may have stricter rules at AddFunc time).
+func NewScheduler(cfg *Config, fire *FireClient, log *slog.Logger) (*Scheduler, error) {
+	c := cron.New(cron.WithLocation(cfg.Location))
+	s := &Scheduler{cron: c, fire: fire, log: log}
+
+	for _, expr := range cfg.Schedules {
+		expr := expr
+		_, err := c.AddFunc(expr, func() {
+			ctx, cancel := context.WithTimeout(context.Background(), httpFireTimeout)
+			defer cancel()
+			if err := fire.Fire(ctx, expr); err != nil {
+				log.Error("fire returned error", "cron", expr, "err", err.Error())
+			}
+		})
+		if err != nil {
+			return nil, fmt.Errorf("register cron %q: %w", expr, err)
+		}
+	}
+	return s, nil
+}
+
+// Start the underlying cron scheduler. Non-blocking.
+func (s *Scheduler) Start() {
+	s.cron.Start()
+}
+
+// Stop the scheduler and wait for in-flight tasks to finish or for the
+// supplied context to be cancelled, whichever comes first.
+func (s *Scheduler) Stop(ctx context.Context) {
+	stopped := s.cron.Stop().Done()
+	select {
+	case <-stopped:
+	case <-ctx.Done():
+		s.log.Warn("shutdown deadline reached before all fires completed")
+	}
+}
+
+// EntryCount exposes the number of registered schedules for tests/diagnostics.
+func (s *Scheduler) EntryCount() int {
+	return len(s.cron.Entries())
+}