feat(17-02): implement scheduler package with gocron wrapper and job lifecycle

- Scheduler wraps gocron with Start/Stop lifecycle
- Start loads enabled jobs from DB and registers cron schedules
- AddJob/RemoveJob persist to DB and sync with gocron
- RunJob for manual trigger with OnComplete callback
- JobResult struct for notification bridge
- Promote gocron/v2 v2.19.1 to direct dependency

pkg/scheduler/jobs.go

@@ -1 +1,21 @@
 package scheduler
+
+import "time"
+
+// Job represents a scheduled scan job with its runtime function.
+type Job struct {
+	Name           string
+	CronExpr       string
+	ScanCommand    string
+	NotifyTelegram bool
+	Enabled        bool
+	RunFunc        func(ctx interface{}) (int, error)
+}
+
+// JobResult contains the outcome of a scheduled or manually triggered scan job.
+type JobResult struct {
+	JobName      string
+	FindingCount int
+	Duration     time.Duration
+	Error        error
+}

pkg/scheduler/scheduler.go

@@ -1 +1,179 @@
 package scheduler
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/go-co-op/gocron/v2"
+	"github.com/salvacybersec/keyhunter/pkg/storage"
+)
+
+// Config holds the dependencies for a Scheduler.
+type Config struct {
+	// DB is the storage backend for persisting jobs and subscribers.
+	DB *storage.DB
+	// ScanFunc executes a scan command and returns the finding count.
+	ScanFunc func(ctx context.Context, scanCommand string) (int, error)
+	// OnComplete is called after a job finishes. May be nil.
+	OnComplete func(result JobResult)
+}
+
+// Scheduler wraps gocron with SQLite persistence for scheduled scan jobs.
+type Scheduler struct {
+	cfg   Config
+	sched gocron.Scheduler
+	jobs  map[string]gocron.Job
+	mu    sync.Mutex
+}
+
+// New creates a new Scheduler with the given configuration.
+func New(cfg Config) (*Scheduler, error) {
+	s, err := gocron.NewScheduler()
+	if err != nil {
+		return nil, fmt.Errorf("creating gocron scheduler: %w", err)
+	}
+	return &Scheduler{
+		cfg:   cfg,
+		sched: s,
+		jobs:  make(map[string]gocron.Job),
+	}, nil
+}
+
+// Start loads all enabled jobs from the database and begins scheduling.
+func (s *Scheduler) Start(ctx context.Context) error {
+	jobs, err := s.cfg.DB.ListScheduledJobs()
+	if err != nil {
+		return fmt.Errorf("loading scheduled jobs: %w", err)
+	}
+	for _, sj := range jobs {
+		if !sj.Enabled {
+			continue
+		}
+		if err := s.registerJob(ctx, sj); err != nil {
+			return fmt.Errorf("registering job %q: %w", sj.Name, err)
+		}
+	}
+	s.sched.Start()
+	return nil
+}
+
+// Stop shuts down the gocron scheduler.
+func (s *Scheduler) Stop() error {
+	return s.sched.Shutdown()
+}
+
+// AddJob creates a new scheduled job, persists it, and registers it with gocron.
+func (s *Scheduler) AddJob(name, cronExpr, scanCommand string, notifyTelegram bool) error {
+	sj := storage.ScheduledJob{
+		Name:           name,
+		CronExpr:       cronExpr,
+		ScanCommand:    scanCommand,
+		NotifyTelegram: notifyTelegram,
+		Enabled:        true,
+	}
+	if _, err := s.cfg.DB.SaveScheduledJob(sj); err != nil {
+		return fmt.Errorf("saving job %q: %w", name, err)
+	}
+	return s.registerJob(context.Background(), sj)
+}
+
+// RemoveJob removes a job from gocron and deletes it from the database.
+func (s *Scheduler) RemoveJob(name string) error {
+	s.mu.Lock()
+	j, ok := s.jobs[name]
+	if ok {
+		delete(s.jobs, name)
+	}
+	s.mu.Unlock()
+
+	if ok {
+		if err := s.sched.RemoveJob(j.ID()); err != nil {
+			return fmt.Errorf("removing gocron job %q: %w", name, err)
+		}
+	}
+
+	if _, err := s.cfg.DB.DeleteScheduledJob(name); err != nil {
+		return fmt.Errorf("deleting job %q from DB: %w", name, err)
+	}
+	return nil
+}
+
+// ListJobs returns all scheduled jobs from the database.
+func (s *Scheduler) ListJobs() ([]storage.ScheduledJob, error) {
+	return s.cfg.DB.ListScheduledJobs()
+}
+
+// RunJob manually triggers a job by name. Looks up the job in the DB,
+// runs ScanFunc, updates last_run, and calls OnComplete.
+func (s *Scheduler) RunJob(ctx context.Context, name string) (JobResult, error) {
+	sj, err := s.cfg.DB.GetScheduledJob(name)
+	if err != nil {
+		return JobResult{}, fmt.Errorf("getting job %q: %w", name, err)
+	}
+
+	start := time.Now()
+	findings, scanErr := s.cfg.ScanFunc(ctx, sj.ScanCommand)
+	dur := time.Since(start)
+
+	result := JobResult{
+		JobName:      name,
+		FindingCount: findings,
+		Duration:     dur,
+		Error:        scanErr,
+	}
+
+	// Update last_run regardless of error
+	now := time.Now().UTC()
+	_ = s.cfg.DB.UpdateJobLastRun(name, now, nil)
+
+	if s.cfg.OnComplete != nil {
+		s.cfg.OnComplete(result)
+	}
+
+	return result, nil
+}
+
+// JobCount returns the number of registered gocron jobs.
+func (s *Scheduler) JobCount() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return len(s.jobs)
+}
+
+// registerJob creates a gocron cron job and stores the handle.
+func (s *Scheduler) registerJob(ctx context.Context, sj storage.ScheduledJob) error {
+	jobName := sj.Name
+	scanCmd := sj.ScanCommand
+	notify := sj.NotifyTelegram
+
+	j, err := s.sched.NewJob(
+		gocron.CronJob(sj.CronExpr, false),
+		gocron.NewTask(func() {
+			start := time.Now()
+			findings, scanErr := s.cfg.ScanFunc(ctx, scanCmd)
+			dur := time.Since(start)
+
+			now := time.Now().UTC()
+			_ = s.cfg.DB.UpdateJobLastRun(jobName, now, nil)
+
+			if notify && s.cfg.OnComplete != nil {
+				s.cfg.OnComplete(JobResult{
+					JobName:      jobName,
+					FindingCount: findings,
+					Duration:     dur,
+					Error:        scanErr,
+				})
+			}
+		}),
+	)
+	if err != nil {
+		return fmt.Errorf("creating gocron job: %w", err)
+	}
+
+	s.mu.Lock()
+	s.jobs[sj.Name] = j
+	s.mu.Unlock()
+	return nil
+}