updates on the sweeper and eligibility things in the order

internal/assignment/crm_assignment.go

@@ -3,6 +3,7 @@ package assignment
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"os"
 	"strconv"
@@ -18,6 +19,7 @@ import (
 	"doormile/utils"
 
 	"github.com/redis/go-redis/v9"
+	"gorm.io/gorm"
 )
 
 const (
@@ -33,6 +35,24 @@ const (
 	defaultMaxActive = 3
 )
 
+// defaultMaxGPSAgeMinutes: a rider whose app has not reported a position for
+// longer than this is not offered orders. Override with
+// ASSIGNMENT_MAX_GPS_AGE_MINUTES; 0 turns the check off.
+const defaultMaxGPSAgeMinutes = 15
+
+// maxGPSAgeMinutes is read per call, like maxActiveBookings. A typo falls back
+// to the default rather than switching the check off.
+func maxGPSAgeMinutes() int {
+	if v := strings.TrimSpace(os.Getenv("ASSIGNMENT_MAX_GPS_AGE_MINUTES")); v != "" {
+		if n, err := strconv.Atoi(v); err == nil && n >= 0 {
+			return n
+		}
+		utils.Warn("ASSIGNMENT_MAX_GPS_AGE_MINUTES is not a non-negative integer, using the default",
+			"value", v, "default", defaultMaxGPSAgeMinutes)
+	}
+	return defaultMaxGPSAgeMinutes
+}
+
 // maxActiveBookings reads the per-miler concurrent-stop cap, read per call so
 // it can be changed without a redeploy. A non-numeric or non-positive value
 // falls back to the default rather than uncapping the fleet by typo.
@@ -70,6 +90,28 @@ func AssignCRMMiler(bookingID int) {
 	enqueue(bookingID, kindExpress)
 }
 
+// errBookingTaken: the booking got a rider (or was cancelled) between this
+// attempt reading it and committing. Not a failure — the work is done.
+var errBookingTaken = errors.New("booking already assigned or cancelled")
+
+// claimBooking sets the booking's rider only if it still has none and is not
+// cancelled, in the caller's transaction. Two attempts can run for one booking
+// at once — the retry queue, the pending-order sweeper, a hub "auto-assign"
+// tap — and without this both would commit and the booking would end up with
+// two riders.
+func claimBooking(tx *gorm.DB, bookingID int, updates map[string]interface{}) error {
+	res := tx.Model(&models.PickupBooking{}).
+		Where("bookingid = ? AND assignedmileruserid IS NULL AND status <> ?", bookingID, constants.BookingCancelled).
+		Updates(updates)
+	if res.Error != nil {
+		return fmt.Errorf("update PickupBooking: %w", res.Error)
+	}
+	if res.RowsAffected == 0 {
+		return errBookingTaken
+	}
+	return nil
+}
+
 // tryAssign performs a single attempt: queries Redis GEO, scores candidates, commits.
 // Returns (true, nil) on success or when the booking no longer needs assignment.
 // Returns (false, nil) when no eligible miler was found (retry warranted).
@@ -108,6 +150,9 @@ func tryAssign(bookingID int) (bool, error) {
 	}
 
 	if err := commitAssignment(&booking, candidate, agentDecisionID); err != nil {
+		if errors.Is(err, errBookingTaken) {
+			return true, nil
+		}
 		return false, fmt.Errorf("commit: %w", err)
 	}
 
@@ -166,6 +211,9 @@ func TryAssignOnce(bookingID int) (AutoAssignResult, error) {
 	}
 
 	if err := commitAssignment(&booking, candidate, agentDecisionID); err != nil {
+		if errors.Is(err, errBookingTaken) {
+			return AutoAssignResult{Assigned: true}, nil
+		}
 		return AutoAssignResult{}, fmt.Errorf("commit: %w", err)
 	}
 
@@ -209,6 +257,17 @@ func commitAssignment(booking *models.PickupBooking, candidate *milerCandidate,
 
 	tx := db.DB.Begin()
 
+	// Claim the booking first, and only if it is still unassigned and not
+	// cancelled — see claimBooking.
+	if err := claimBooking(tx, booking.Bookingid, map[string]interface{}{
+		"assignedmileruserid": milerUserID,
+		"status":              constants.BookingMilerAssigned,
+		"updatedat":           time.Now(),
+	}); err != nil {
+		tx.Rollback()
+		return err
+	}
+
 	assignment := models.BookingAssignment{
 		Bookingid:        booking.Bookingid,
 		Mileruserid:      milerUserID,
@@ -221,16 +280,6 @@ func commitAssignment(booking *models.PickupBooking, candidate *milerCandidate,
 		return fmt.Errorf("create BookingAssignment: %w", err)
 	}
 
-	now := time.Now()
-	if err := tx.Model(booking).Updates(map[string]interface{}{
-		"assignedmileruserid": milerUserID,
-		"status":              constants.BookingMilerAssigned,
-		"updatedat":           now,
-	}).Error; err != nil {
-		tx.Rollback()
-		return fmt.Errorf("update PickupBooking: %w", err)
-	}
-
 	if err := tx.Model(&models.MilerProfile{}).
 		Where("userid = ?", milerUserID).
 		Update("availabilitystatus", constants.MilerAssigned).Error; err != nil {