feat: add web push and sadhna tracker

internal/repository/push_repo.go

@@ -0,0 +1,64 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/prabhupadasays/spsays-bff/internal/model"
+)
+
+// PushRepo stores Web Push subscriptions (one per browser/device endpoint).
+type PushRepo struct{ pg *Postgres }
+
+func NewPushRepo(pg *Postgres) *PushRepo { return &PushRepo{pg: pg} }
+
+// Upsert records (or refreshes) a subscription. The endpoint is unique, so a
+// browser re-subscribing — possibly under a different user — rebinds cleanly.
+func (r *PushRepo) Upsert(ctx context.Context, userID, endpoint, p256dh, auth, userAgent string) error {
+	_, err := r.pg.Pool.Exec(ctx, `
+		INSERT INTO push_subscriptions (user_id, endpoint, p256dh, auth, user_agent)
+		VALUES ($1, $2, $3, $4, $5)
+		ON CONFLICT (endpoint) DO UPDATE
+		    SET user_id = EXCLUDED.user_id,
+		        p256dh = EXCLUDED.p256dh,
+		        auth = EXCLUDED.auth,
+		        user_agent = EXCLUDED.user_agent,
+		        last_used_at = now()`,
+		userID, endpoint, p256dh, auth, userAgent,
+	)
+	if err != nil {
+		return fmt.Errorf("upsert push subscription: %w", err)
+	}
+	return nil
+}
+
+// ListByUser returns the user's active subscriptions.
+func (r *PushRepo) ListByUser(ctx context.Context, userID string) ([]model.PushSubscription, error) {
+	rows, err := r.pg.Pool.Query(ctx, `
+		SELECT id, user_id, endpoint, p256dh, auth
+		FROM push_subscriptions WHERE user_id = $1`, userID)
+	if err != nil {
+		return nil, fmt.Errorf("list push subscriptions: %w", err)
+	}
+	defer rows.Close()
+	var out []model.PushSubscription
+	for rows.Next() {
+		var s model.PushSubscription
+		if err := rows.Scan(&s.ID, &s.UserID, &s.Endpoint, &s.P256dh, &s.Auth); err != nil {
+			return nil, fmt.Errorf("scan push subscription: %w", err)
+		}
+		out = append(out, s)
+	}
+	return out, rows.Err()
+}
+
+// DeleteByEndpoint removes a subscription (on unsubscribe or when the push
+// service reports it gone).
+func (r *PushRepo) DeleteByEndpoint(ctx context.Context, endpoint string) error {
+	_, err := r.pg.Pool.Exec(ctx,
+		`DELETE FROM push_subscriptions WHERE endpoint = $1`, endpoint)
+	if err != nil {
+		return fmt.Errorf("delete push subscription: %w", err)
+	}
+	return nil
+}