Fix: Move carrier live-pricing choice onto ShippingMethod.charge_by

Reverts the earlier per-rate pricing_mode column in favor of extending Lunar's existing charge_by field (cart_total/weight) with a third "live" option, gated by a SupportsLivePricing capability check on the driver. Adds a shared ResolvesFixedPricing trait so any carrier driver can fall back to Lunar's normal price-break resolution, matching the vendor ShipBy driver's own charge_by handling instead of introducing a separate mechanism. Also fixes an incorrect Get() path in the admin form that silently hid the new "live" option.

src/Shipping/Extensions/ShippingMethodResourceExtension.php

@@ -6,20 +6,88 @@ use Filament\Forms\Components\Component;
 use Filament\Forms\Components\Concerns\HasChildComponents;
 use Filament\Forms\Components\Select;
 use Filament\Forms\Form;
+use Filament\Forms\Get;
 use Filament\Tables\Columns\TextColumn;
 use Filament\Tables\Table;
 use Lunar\Admin\Support\Extending\ResourceExtension;
 use Lunar\Shipping\Facades\Shipping;
+use Modules\Core\Shipping\Contracts\SupportsLivePricing;
 
 class ShippingMethodResourceExtension extends ResourceExtension
 {
     public function extendForm(Form $form): Form
     {
         return $form->schema(
-            $this->replaceDriverField($form->getComponents())
+            $this->replaceChargeByField(
+                $this->replaceDriverField($form->getComponents())
+            )
         );
     }
 
+    /**
+     * Extend the vendor's cart_total/weight charge_by Select with a third
+     * "live" option — only offered when the currently selected driver
+     * supports live pricing (see SupportsLivePricing). Picking it is what
+     * tells the driver to call its carrier API instead of resolving a
+     * price break.
+     */
+    private function replaceChargeByField(array $components): array
+    {
+        return array_map(function (Component $component) {
+            if (method_exists($component, 'getName') && $component->getName() === 'charge_by') {
+                return $this->chargeBySelect();
+            }
+
+            if (in_array(HasChildComponents::class, class_uses_recursive($component), true)) {
+                $component->schema(
+                    $this->replaceChargeByField($component->getChildComponents())
+                );
+            }
+
+            return $component;
+        }, $components);
+    }
+
+    private function chargeBySelect(): Select
+    {
+        return Select::make('charge_by')
+            ->label('Charge by')
+            ->options(function (Get $get) {
+                $options = [
+                    'cart_total' => 'Cart Total',
+                    'weight' => 'Weight',
+                ];
+
+                // "charge_by" is nested inside a Group with
+                // ->statePath('data'), while "driver" sits one level up, at
+                // the form root. Note: an *absolute* path here would need to
+                // additionally account for the page's own form wrapper
+                // (EditRecord::getFormStatePath() === 'data'), which relative
+                // paths never cross — so "../driver" (relative) is the
+                // correct, page-independent way to reach it, not an
+                // absolute 'driver' string.
+                if ($this->driverSupportsLivePricing($get('../driver'))) {
+                    $options['live'] = 'Live API pricing';
+                }
+
+                return $options;
+            })
+            ->live();
+    }
+
+    private function driverSupportsLivePricing(?string $driver): bool
+    {
+        if (! $driver) {
+            return false;
+        }
+
+        try {
+            return Shipping::driver($driver) instanceof SupportsLivePricing;
+        } catch (\InvalidArgumentException) {
+            return false;
+        }
+    }
+
     public function extendTable(Table $table): Table
     {
         return $table->columns(
@@ -78,6 +146,7 @@ class ShippingMethodResourceExtension extends ResourceExtension
             ->label('Type')
             ->options(fn () => collect(Shipping::getSupportedDrivers())
                 ->mapWithKeys(fn ($driver, $key) => [$key => $driver->name()]))
-            ->default('flat-rate');
+            ->default('flat-rate')
+            ->live();
     }
 }