BFI pool cart

database/migrations/create_blax_shop_tables.php.stub

@@ -284,10 +284,10 @@ return new class extends Migration
                 $table->foreignUuid('purchase_id')->nullable()->constrained(config('shop.tables.product_purchases', 'product_purchases'))->nullOnDelete();
                 $table->foreignUuid('price_id')->nullable()->constrained(config('shop.tables.product_prices', 'product_prices'))->nullOnDelete();
                 $table->integer('quantity')->default(1);
-                $table->integer('price')->default(0); // Stored in cents
+                $table->integer('price')->nullable(); // Stored in cents, null = unavailable
                 $table->integer('regular_price')->nullable(); // Stored in cents
                 $table->integer('unit_amount')->nullable(); // Base unit price for 1 quantity, 1 day (in cents)
-                $table->integer('subtotal'); // Stored in cents
+                $table->integer('subtotal')->nullable(); // Stored in cents, null = unavailable
                 $table->json('parameters')->nullable();
                 $table->json('meta')->nullable();
                 $table->timestamp('from')->nullable();

src/Exceptions/CartNotReadyException.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Blax\Shop\Exceptions;
+
+use Exception;
+
+class CartNotReadyException extends Exception
+{
+    public function __construct(string $message = "Cart is not ready for checkout. Some items may be unavailable.")
+    {
+        parent::__construct($message);
+    }
+}

src/Models/Cart.php

@@ -408,8 +408,22 @@ class Cart extends Model
                 if ($validateAvailability) {
                     $product = $item->purchasable;
 
-                    // For pool products, track allocation for total validation
+                    // For pool products, check if allocated by reallocatePoolItems
                     if ($product instanceof Product && $product->isPool()) {
+                        $meta = $item->getMeta();
+                        $allocatedSingleItemId = $meta->allocated_single_item_id ?? null;
+
+                        // If this item was NOT allocated (no single assigned), skip updateDates
+                        // to preserve the null price set by reallocatePoolItems
+                        if (empty($allocatedSingleItemId)) {
+                            // Just update the dates without recalculating price
+                            $item->update([
+                                'from' => $itemFrom,
+                                'until' => $itemUntil,
+                            ]);
+                            continue;
+                        }
+
                         $poolKey = $product->id . '|' . $itemFrom->format('Y-m-d H:i:s') . '|' . $itemUntil->format('Y-m-d H:i:s');
 
                         if (!isset($poolValidation[$poolKey])) {
@@ -423,19 +437,19 @@ class Cart extends Model
                         }
 
                         $poolValidation[$poolKey]['requested'] += $item->quantity;
-
-                        $meta = $item->getMeta();
-                        if (isset($meta->allocated_single_item_id)) {
                         $poolValidation[$poolKey]['allocated'] += $item->quantity;
-                        }
                     } elseif ($product && !$product->isAvailableForBooking($itemFrom, $itemUntil, $item->quantity)) {
-                        throw new NotEnoughAvailableInTimespanException(
-                            productName: $product->name ?? 'Product',
-                            requested: $item->quantity,
-                            available: 0,
-                            from: $itemFrom,
-                            until: $itemUntil
-                        );
+                        // Non-pool booking item is not available - mark as unavailable
+                        // Don't throw exception - let user adjust dates freely
+                        $item->update([
+                            'from' => $itemFrom,
+                            'until' => $itemUntil,
+                            'price' => null,
+                            'subtotal' => null,
+                            'unit_amount' => null,
+                        ]);
+                        // Skip updateDates() since we already set the dates with null price
+                        continue;
                     }
                 }
 
@@ -443,21 +457,10 @@ class Cart extends Model
             }
         }
 
-        // Validate pool allocations - all requested items must be allocated
-        if ($validateAvailability) {
-            foreach ($poolValidation as $poolData) {
-                if ($poolData['requested'] > $poolData['allocated']) {
-                    $product = $poolData['product'];
-                    throw new NotEnoughAvailableInTimespanException(
-                        productName: $product->name ?? 'Product',
-                        requested: $poolData['requested'],
-                        available: $poolData['allocated'],
-                        from: $poolData['from'],
-                        until: $poolData['until']
-                    );
-                }
-            }
-        }
+        // Pool validation is now handled by reallocatePoolItems() which marks
+        // unallocated items with null price instead of throwing exceptions.
+        // This allows users to freely adjust dates without exceptions.
+        // Validation happens at checkout time via isReadyForCheckout().
 
         return $this->fresh();
     }
@@ -547,6 +550,22 @@ class Cart extends Model
             }
 
             if (empty($availableWithPrices)) {
+                // No singles available for this period - mark ALL pool items as unavailable
+                foreach ($items as $cartItem) {
+                    // Only update if we should overwrite or item has no dates yet
+                    if (!$overwrite && $cartItem->from && $cartItem->until) {
+                        continue;
+                    }
+
+                    // Clear allocation and set price to null to indicate unavailable
+                    $cartItem->updateMetaKey('allocated_single_item_id', null);
+                    $cartItem->updateMetaKey('allocated_single_item_name', null);
+                    $cartItem->update([
+                        'price' => null,
+                        'subtotal' => null,
+                        'unit_amount' => null,
+                    ]);
+                }
                 continue;
             }
 
@@ -589,9 +608,16 @@ class Cart extends Model
                     }
                 }
 
-                // If we couldn't allocate (ran out of available singles), stop
+                // If we couldn't allocate (ran out of available singles), mark as unavailable
                 if (!$allocated) {
-                    break;
+                    // Clear allocation and set price to null to indicate unavailable
+                    $cartItem->updateMetaKey('allocated_single_item_id', null);
+                    $cartItem->updateMetaKey('allocated_single_item_name', null);
+                    $cartItem->update([
+                        'price' => null,
+                        'subtotal' => null,
+                        'unit_amount' => null,
+                    ]);
                 }
             }
         }
@@ -605,6 +631,15 @@ class Cart extends Model
      * @return void
      * @throws NotEnoughAvailableInTimespanException
      */
+    /**
+     * Mark booking items as unavailable if they cannot be booked for the given dates.
+     * Instead of throwing exceptions, this marks items with null price.
+     *
+     * @param \DateTimeInterface $from Start date
+     * @param \DateTimeInterface $until End date
+     * @param bool $useProvidedDates Whether to use provided dates or item's own dates
+     * @return void
+     */
     protected function validateDateAvailability(\DateTimeInterface $from, \DateTimeInterface $until, bool $useProvidedDates = false): void
     {
         foreach ($this->items as $item) {
@@ -617,18 +652,23 @@ class Cart extends Model
                 continue;
             }
 
+            // Skip pool products - they are handled by reallocatePoolItems()
+            if ($product->type === ProductType::POOL) {
+                continue;
+            }
+
             // Use provided dates when validating date overwrites, otherwise use item's specific dates
             $checkFrom = $useProvidedDates ? $from : ($item->from ?? $from);
             $checkUntil = $useProvidedDates ? $until : ($item->until ?? $until);
 
             if (!$product->isAvailableForBooking($checkFrom, $checkUntil, $item->quantity)) {
-                throw new NotEnoughAvailableInTimespanException(
-                    productName: $product->name ?? 'Product',
-                    requested: $item->quantity,
-                    available: 0, // Could calculate actual available amount
-                    from: $checkFrom,
-                    until: $checkUntil
-                );
+                // Mark item as unavailable instead of throwing exception
+                // This allows users to freely adjust dates
+                $item->update([
+                    'price' => null,
+                    'subtotal' => null,
+                    'unit_amount' => null,
+                ]);
             }
         }
     }
@@ -768,9 +808,25 @@ class Cart extends Model
                         "Pool product '{$cartable->name}' has only {$availableForThisRequest} items available for the requested period. Requested: {$quantity}"
                     );
                 }
+            } else {
+                // When dates are not provided, validate against total pool capacity (not current availability)
+                // This allows adding items even if currently claimed - dates will be validated later
+                $totalCapacity = $cartable->getPoolTotalCapacity(); // Total capacity ignoring claims
+
+                // Subtract items already in cart
+                $itemsInCart = $this->items()
+                    ->where('purchasable_id', $cartable->getKey())
+                    ->where('purchasable_type', get_class($cartable))
+                    ->sum('quantity');
+
+                $availableForThisRequest = $totalCapacity === PHP_INT_MAX ? PHP_INT_MAX : max(0, $totalCapacity - $itemsInCart);
+
+                if ($availableForThisRequest !== PHP_INT_MAX && $quantity > $availableForThisRequest) {
+                    throw new NotEnoughStockException(
+                        "Pool product '{$cartable->name}' has only {$availableForThisRequest} items available. Requested: {$quantity}"
+                    );
+                }
             }
-            // When dates are not provided, skip availability validation - allow flexible cart behavior
-            // The cart will validate when dates are set via setDates()
 
             // Add items one at a time for progressive pricing
             $lastCartItem = null;
@@ -831,13 +887,27 @@ class Cart extends Model
                 // If only one date is provided, it's an error
                 throw new CartDatesRequiredException();
             } else {
-                // When adding pool items without dates, allow adding even if currently unavailable
-                // Items may be claimed now but available in the future
-                // Validation will happen when dates are set or at checkout
-                // This enables flexible booking workflows where users add items first, then select dates
+                // When adding pool items without dates, validate against total pool capacity
+                // This allows adding items even if currently claimed - date-based validation happens later
+                if ($cartable->isPool()) {
+                    $totalCapacity = $cartable->getPoolTotalCapacity(); // Total capacity ignoring claims
 
-                // Note: We skip availability validation here for pool products without dates
-                // The cart will not be ready for checkout without dates anyway
+                    // Subtract items already in cart (without dates or with any dates)
+                    $itemsInCart = $this->items()
+                        ->where('purchasable_id', $cartable->getKey())
+                        ->where('purchasable_type', get_class($cartable))
+                        ->sum('quantity');
+
+                    $availableForThisRequest = $totalCapacity === PHP_INT_MAX ? PHP_INT_MAX : max(0, $totalCapacity - $itemsInCart);
+
+                    if ($availableForThisRequest !== PHP_INT_MAX && $quantity > $availableForThisRequest) {
+                        throw new NotEnoughStockException(
+                            "Pool product '{$cartable->name}' has only {$availableForThisRequest} items available. Requested: {$quantity}"
+                        );
+                    }
+                }
+                // Items may be claimed now but available in the future
+                // Full date-based validation will happen when dates are set via setDates() or at checkout
             }
         }
 
@@ -1518,9 +1588,9 @@ class Cart extends Model
      */
     public function checkoutSessionLink(array $option = [], ?string $url = null): string|null|false
     {
-        if (! @$this->validateForCheckout(false)) {
-            return null;
-        }
+        // Validate cart - throw exceptions if validation fails
+        // This ensures users know what's wrong instead of silently returning null
+        $this->validateForCheckout();
 
         $checkoutSession = $this->checkoutSession($option, $url);
 

src/Models/CartItem.php

@@ -180,6 +180,15 @@ class CartItem extends Model
             return false;
         }
 
+        // Check if item has a valid price (null or <= 0 means unavailable)
+        if ($this->price === null || $this->price <= 0) {
+            return false;
+        }
+
+        // Note: Pool items don't require pre-allocation to be ready for checkout.
+        // The checkout process can allocate singles on-the-fly via claimPoolStock().
+        // The price check above is sufficient - if price is null, item is unavailable.
+
         // Check if dates are required (for booking products or pools with booking items)
         $requiresDates = $product->isBooking() ||
             ($product->isPool() && $product->hasBookingSingleItems());
@@ -323,6 +332,15 @@ class CartItem extends Model
             return $adjustments;
         }
 
+        // Check if price is invalid (null, zero or negative means unavailable)
+        if ($this->price === null || $this->price <= 0) {
+            $adjustments['price'] = 'unavailable';
+        }
+
+        // Note: Pool items don't require pre-allocation to be ready for checkout.
+        // The checkout process can allocate singles on-the-fly via claimPoolStock().
+        // The price check above is sufficient - if price is null, item is unavailable.
+
         // Check if dates are required (for booking products or pools with booking items)
         $requiresDates = $product->isBooking() ||
             ($product->isPool() && $product->hasBookingSingleItems());

src/Traits/MayBePoolProduct.php

@@ -112,6 +112,55 @@ trait MayBePoolProduct
         return $availableCount;
     }
 
+    /**
+     * Get the total capacity of the pool (sum of all single item stock quantities)
+     * 
+     * Unlike getPoolMaxQuantity(), this method returns the TOTAL capacity regardless
+     * of current claims or availability. This is useful for validating cart additions
+     * without dates - you can't add more items than the pool has single items, even
+     * if you haven't chosen dates yet.
+     * 
+     * @return int Total capacity (sum of single item stock quantities)
+     */
+    public function getPoolTotalCapacity(): int
+    {
+        if (!$this->isPool()) {
+            return $this->manage_stock ? ($this->stock_quantity ?? 0) : PHP_INT_MAX;
+        }
+
+        $singleItems = $this->singleProducts;
+
+        if ($singleItems->isEmpty()) {
+            return 0;
+        }
+
+        $hasUnlimitedItem = false;
+        $total = 0;
+
+        foreach ($singleItems as $item) {
+            if (!$item->manage_stock) {
+                $hasUnlimitedItem = true;
+                continue;
+            }
+
+            // Get total stock quantity (not available stock)
+            // Sum all INCREASE entries to get the total capacity
+            $itemCapacity = $item->stocks()
+                ->where('type', \Blax\Shop\Enums\StockType::INCREASE->value)
+                ->where('status', \Blax\Shop\Enums\StockStatus::COMPLETED->value)
+                ->sum('quantity');
+
+            $total += $itemCapacity;
+        }
+
+        // If ALL items are unlimited, pool is unlimited
+        if ($hasUnlimitedItem && $total === 0) {
+            return PHP_INT_MAX;
+        }
+
+        return $total;
+    }
+
     /**
      * Claim stock for a pool product
      * This will claim stock from the available single items, respecting the pricing strategy

tests/Feature/CartDateManagementTest.php

@@ -468,7 +468,7 @@ class CartDateManagementTest extends TestCase
     }
 
     /** @test */
-    public function validate_date_availability_throws_exception_when_product_not_available()
+    public function validate_date_availability_marks_items_unavailable_when_product_not_available()
     {
         $product = Product::factory()->create([
             'type' => ProductType::BOOKING,
@@ -490,13 +490,17 @@ class CartDateManagementTest extends TestCase
         // Set item dates that consume the stock
         $item->updateDates(Carbon::now()->addDays(1), Carbon::now()->addDays(3));
 
-        // Try to set cart dates that overlap - should throw exception
-        $this->expectException(NotEnoughAvailableInTimespanException::class);
+        // Try to set cart dates that overlap - should NOT throw, instead mark items unavailable
         $cart->setDates(Carbon::now()->addDays(2), Carbon::now()->addDays(4), validateAvailability: true);
+
+        // Item should now be marked as unavailable (null price)
+        $item->refresh();
+        $this->assertNull($item->price, 'Unavailable item should have null price');
+        $this->assertFalse($item->is_ready_to_checkout, 'Unavailable item should not be ready for checkout');
     }
 
     /** @test */
-    public function apply_dates_to_items_throws_exception_when_product_not_available()
+    public function apply_dates_to_items_marks_items_unavailable_when_product_not_available()
     {
         $product = Product::factory()->create([
             'type' => ProductType::BOOKING,
@@ -520,9 +524,13 @@ class CartDateManagementTest extends TestCase
         // Add item that would exceed available stock
         $item = $cart->addToCart($product, 2);
 
-        // Should throw exception because only 1 available but requesting 2
-        $this->expectException(NotEnoughAvailableInTimespanException::class);
+        // Should NOT throw exception, instead mark items as unavailable
         $cart->applyDatesToItems(validateAvailability: true);
+
+        // Item should be marked as unavailable (null price)
+        $item->refresh();
+        $this->assertNull($item->price, 'Unavailable item should have null price');
+        $this->assertFalse($item->is_ready_to_checkout, 'Unavailable item should not be ready for checkout');
     }
 
     /** @test */

tests/Feature/CartItemAvailabilityValidationTest.php

@@ -0,0 +1,390 @@
+<?php
+
+namespace Blax\Shop\Tests\Feature;
+
+use Blax\Shop\Enums\ProductType;
+use Blax\Shop\Models\Cart;
+use Blax\Shop\Models\Product;
+use Blax\Shop\Models\ProductPrice;
+use Blax\Shop\Tests\TestCase;
+use Carbon\Carbon;
+use Workbench\App\Models\User;
+
+/**
+ * Tests for cart item validation when dates change and items become unavailable.
+ * 
+ * Bug: When adjusting dates in cart, some cart items show null/0 price because they
+ * are not available for the new dates. But IsReadyToCheckout incorrectly returns true.
+ * 
+ * Expected behavior:
+ * - setDates() should NOT throw - it should allow users to fiddle with dates
+ * - Items that become unavailable should have price = null
+ * - Items with null price should NOT be ready for checkout  
+ * - Cart.isReadyForCheckout() should return false if any items are unavailable
+ * - Exception should only be thrown at checkout time, not when changing dates
+ */
+class CartItemAvailabilityValidationTest extends TestCase
+{
+    protected User $user;
+    protected Cart $cart;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->user = User::factory()->create();
+        auth()->login($this->user);
+        $this->cart = Cart::factory()->create([
+            'customer_id' => $this->user->id,
+            'customer_type' => get_class($this->user),
+        ]);
+    }
+
+    /**
+     * Create a pool with limited singles for testing
+     */
+    protected function createPoolWithLimitedSingles(int $numSingles = 3): Product
+    {
+        $pool = Product::factory()->create([
+            'name' => 'Limited Pool',
+            'type' => ProductType::POOL,
+            'manage_stock' => false,
+        ]);
+
+        ProductPrice::factory()->create([
+            'purchasable_id' => $pool->id,
+            'purchasable_type' => Product::class,
+            'unit_amount' => 5000,
+            'currency' => 'USD',
+            'is_default' => true,
+        ]);
+
+        $pool->setPoolPricingStrategy('lowest');
+
+        // Create singles with 1 stock each
+        for ($i = 1; $i <= $numSingles; $i++) {
+            $single = Product::factory()->create([
+                'name' => "Single {$i}",
+                'type' => ProductType::BOOKING,
+                'manage_stock' => true,
+            ]);
+            $single->increaseStock(1);
+
+            ProductPrice::factory()->create([
+                'purchasable_id' => $single->id,
+                'purchasable_type' => Product::class,
+                'unit_amount' => 5000,
+                'currency' => 'USD',
+                'is_default' => true,
+            ]);
+
+            $pool->attachSingleItems([$single->id]);
+        }
+
+        return $pool;
+    }
+
+    /** @test */
+    public function cart_item_with_null_price_is_not_ready_for_checkout()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // Add 3 items without dates
+        $this->cart->addToCart($pool, 3);
+
+        // Manually set one item's price to null to simulate unavailable item
+        $item = $this->cart->items()->first();
+        $item->update(['price' => null, 'subtotal' => null]);
+        $item->refresh();
+
+        // Item with null price should NOT be ready for checkout
+        $this->assertNull($item->price);
+        $this->assertFalse($item->is_ready_to_checkout, 'Item with null price should not be ready for checkout');
+
+        // Cart should NOT be ready for checkout
+        $this->assertFalse($this->cart->fresh()->is_ready_to_checkout, 'Cart with null-price item should not be ready');
+    }
+
+    /** @test */
+    public function cart_item_with_zero_price_is_not_ready_for_checkout()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // Add 3 items without dates
+        $this->cart->addToCart($pool, 3);
+
+        // Manually set one item's price to 0 to simulate unavailable item
+        $item = $this->cart->items()->first();
+        $item->update(['price' => 0, 'subtotal' => 0]);
+        $item->refresh();
+
+        // Item with 0 price should NOT be ready for checkout
+        $this->assertEquals(0, $item->price);
+        $this->assertFalse($item->is_ready_to_checkout, 'Item with price 0 should not be ready for checkout');
+
+        // Cart should NOT be ready for checkout
+        $this->assertFalse($this->cart->fresh()->is_ready_to_checkout, 'Cart with 0-price item should not be ready');
+    }
+
+    /** @test */
+    public function unallocated_pool_item_with_null_price_is_not_ready_for_checkout()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Add 3 items with dates - all should be allocated
+        $this->cart->addToCart($pool, 3, [], $from, $until);
+
+        // Manually simulate an item becoming unavailable:
+        // - Remove allocation
+        // - Set price to null (the real indicator of unavailability)
+        $item = $this->cart->items()->first();
+        $meta = $item->getMeta();
+        unset($meta->allocated_single_item_id);
+        unset($meta->allocated_single_item_name);
+        $item->update([
+            'meta' => json_encode($meta),
+            'price' => null,
+            'subtotal' => null,
+        ]);
+        $item->refresh();
+
+        // Item with null price should NOT be ready for checkout
+        $this->assertFalse($item->is_ready_to_checkout, 'Item with null price should not be ready for checkout');
+
+        // Cart should NOT be ready for checkout
+        $this->assertFalse($this->cart->fresh()->is_ready_to_checkout, 'Cart with unavailable item should not be ready');
+    }
+
+    /** @test */
+    public function setDates_does_not_throw_when_items_become_unavailable()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // First user books all 3 singles for specific dates
+        $user1 = User::factory()->create();
+        $user1Cart = $user1->currentCart();
+
+        $bookedFrom = now()->addDays(5);
+        $bookedUntil = now()->addDays(6);
+
+        $user1Cart->addToCart($pool, 3, [], $bookedFrom, $bookedUntil);
+        $user1Cart->checkout(); // Claims the stock
+
+        // Our user adds items without dates (should work - we have 3 total capacity)
+        $this->cart->addToCart($pool, 3);
+
+        // All items should have prices > 0 initially
+        foreach ($this->cart->items as $item) {
+            $this->assertGreaterThan(0, $item->price, 'Item should have positive price initially');
+        }
+
+        // Now set dates that conflict with the booked period
+        // This should NOT throw - it should just mark items as unavailable
+        $this->cart->setDates($bookedFrom, $bookedUntil);
+
+        $this->cart->refresh();
+        $this->cart->load('items');
+
+        // Cart should NOT be ready for checkout (items are unavailable)
+        $this->assertFalse(
+            $this->cart->is_ready_to_checkout,
+            'Cart should not be ready when items are unavailable for selected dates'
+        );
+    }
+
+    /** @test */
+    public function partial_availability_marks_some_items_unavailable()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // First user books 2 of 3 singles for specific dates
+        $user1 = User::factory()->create();
+        $user1Cart = $user1->currentCart();
+
+        $bookedFrom = now()->addDays(5);
+        $bookedUntil = now()->addDays(6);
+
+        $user1Cart->addToCart($pool, 2, [], $bookedFrom, $bookedUntil);
+        $user1Cart->checkout(); // Claims 2 singles
+
+        // Verify that only 1 single is available for the booked period
+        $available = $pool->getPoolMaxQuantity($bookedFrom, $bookedUntil);
+        $this->assertEquals(1, $available, 'Only 1 single should be available after booking 2');
+
+        // Our user adds 3 items without dates
+        $this->cart->addToCart($pool, 3);
+
+        $this->assertEquals(3, $this->cart->items()->sum('quantity'));
+
+        // Set dates where only 1 single is available
+        // Should NOT throw - just mark some items as unavailable
+        $this->cart->setDates($bookedFrom, $bookedUntil);
+
+        $this->cart->refresh();
+        $this->cart->load('items');
+
+        // Check how many items are available vs unavailable
+        $availableItems = $this->cart->items->filter(
+            fn($item) =>
+            $item->price !== null && $item->price > 0
+        );
+        $unavailableItems = $this->cart->items->filter(
+            fn($item) =>
+            $item->price === null || $item->price <= 0
+        );
+
+        // Should have 1 available and 2 unavailable
+        $this->assertEquals(1, $availableItems->count(), 'Should have 1 available item');
+        $this->assertEquals(2, $unavailableItems->count(), 'Should have 2 unavailable items');
+
+        // Cart should NOT be ready for checkout
+        $this->assertFalse($this->cart->is_ready_to_checkout, 'Cart with unavailable items should not be ready');
+    }
+
+    /** @test */
+    public function cart_item_without_allocated_single_for_pool_is_not_ready()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Add 3 items with dates
+        $this->cart->addToCart($pool, 3, [], $from, $until);
+
+        // Verify all items are allocated and ready
+        foreach ($this->cart->items as $item) {
+            $meta = $item->getMeta();
+            $this->assertNotNull($meta->allocated_single_item_id ?? null, 'Item should be allocated');
+            $this->assertTrue($item->is_ready_to_checkout, 'Allocated item should be ready');
+        }
+
+        // All items ready - cart is ready
+        $this->assertTrue($this->cart->fresh()->is_ready_to_checkout);
+    }
+
+    /** @test */
+    public function removing_unavailable_items_makes_cart_ready()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // Add 3 items without dates
+        $this->cart->addToCart($pool, 3);
+
+        // Manually make one item unavailable (price = null)
+        $unavailableItem = $this->cart->items()->first();
+        $unavailableItem->update(['price' => null, 'subtotal' => null]);
+
+        // Cart should NOT be ready
+        $this->assertFalse($this->cart->fresh()->is_ready_to_checkout);
+
+        // Remove the unavailable item
+        $unavailableItem->delete();
+
+        // Set dates for remaining items
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+        $this->cart->setDates($from, $until);
+
+        // Now cart should be ready
+        $this->assertTrue($this->cart->fresh()->is_ready_to_checkout);
+    }
+
+    /** @test */
+    public function getItemsRequiringAdjustments_includes_null_price_items()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Add 3 items with dates
+        $this->cart->addToCart($pool, 3, [], $from, $until);
+
+        // Make one item have null price
+        $item = $this->cart->items()->first();
+        $item->update(['price' => null, 'subtotal' => null]);
+
+        $this->cart->refresh();
+        $this->cart->load('items');
+
+        // Get items requiring adjustments
+        $itemsNeedingAdjustment = $this->cart->getItemsRequiringAdjustments();
+
+        // The null-price item should be in the list
+        $this->assertGreaterThanOrEqual(
+            1,
+            $itemsNeedingAdjustment->count(),
+            'Null price item should require adjustment'
+        );
+
+        // Check that it has 'unavailable' as the price adjustment reason
+        $nullPriceItem = $itemsNeedingAdjustment->first(fn($i) => $i->price === null);
+        $this->assertNotNull($nullPriceItem, 'Should find the null-price item');
+
+        $adjustments = $nullPriceItem->requiredAdjustments();
+        $this->assertArrayHasKey('price', $adjustments);
+        $this->assertEquals('unavailable', $adjustments['price']);
+    }
+
+    /** @test */
+    public function changing_dates_to_available_period_makes_items_available_again()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // First user books all 3 singles for specific dates
+        $user1 = User::factory()->create();
+        $user1Cart = $user1->currentCart();
+
+        $bookedFrom = now()->addDays(5);
+        $bookedUntil = now()->addDays(6);
+
+        $user1Cart->addToCart($pool, 3, [], $bookedFrom, $bookedUntil);
+        $user1Cart->checkout();
+
+        // Our user adds 3 items without dates
+        $this->cart->addToCart($pool, 3);
+
+        // Set dates that conflict - items become unavailable
+        $this->cart->setDates($bookedFrom, $bookedUntil);
+        $this->assertFalse($this->cart->fresh()->is_ready_to_checkout);
+
+        // Change to different dates where all singles are available
+        $availableFrom = now()->addDays(10);
+        $availableUntil = now()->addDays(11);
+
+        $this->cart->setDates($availableFrom, $availableUntil);
+
+        $this->cart->refresh();
+        $this->cart->load('items');
+
+        // All items should now have valid prices
+        foreach ($this->cart->items as $item) {
+            $this->assertNotNull($item->price, 'Item should have price after changing to available dates');
+            $this->assertGreaterThan(0, $item->price, 'Item should have positive price');
+        }
+
+        // Cart should be ready for checkout
+        $this->assertTrue($this->cart->is_ready_to_checkout, 'Cart should be ready after changing to available dates');
+    }
+
+    /** @test */
+    public function checkout_throws_when_items_are_unavailable()
+    {
+        $pool = $this->createPoolWithLimitedSingles(3);
+
+        // Add items and make one unavailable
+        $this->cart->addToCart($pool, 3);
+
+        $item = $this->cart->items()->first();
+        $item->update(['price' => null, 'subtotal' => null]);
+
+        // Trying to checkout should throw CartItemMissingInformationException
+        // because the item has 'price' => 'unavailable' in requiredAdjustments()
+        $this->expectException(\Blax\Shop\Exceptions\CartItemMissingInformationException::class);
+        $this->cart->checkout();
+    }
+}

tests/Feature/PoolMaxQuantityValidationTest.php

@@ -0,0 +1,250 @@
+<?php
+
+namespace Blax\Shop\Tests\Feature;
+
+use Blax\Shop\Enums\ProductType;
+use Blax\Shop\Models\Cart;
+use Blax\Shop\Models\Product;
+use Blax\Shop\Models\ProductPrice;
+use Blax\Shop\Tests\TestCase;
+use Carbon\Carbon;
+use Workbench\App\Models\User;
+
+/**
+ * Tests to ensure pool products cannot exceed available single items
+ * even when adding without dates (flexible cart behavior)
+ */
+class PoolMaxQuantityValidationTest extends TestCase
+{
+    protected User $user;
+    protected Cart $cart;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->user = User::factory()->create();
+        auth()->login($this->user);
+        $this->cart = Cart::factory()->create([
+            'customer_id' => $this->user->id,
+            'customer_type' => get_class($this->user),
+        ]);
+    }
+
+    /**
+     * Create a pool with 7 single items (production scenario)
+     */
+    protected function createPoolWith7Singles(): Product
+    {
+        $pool = Product::factory()->create([
+            'name' => 'Production Pool',
+            'type' => ProductType::POOL,
+            'manage_stock' => false,
+        ]);
+
+        ProductPrice::factory()->create([
+            'purchasable_id' => $pool->id,
+            'purchasable_type' => Product::class,
+            'unit_amount' => 5000,
+            'currency' => 'USD',
+            'is_default' => true,
+        ]);
+
+        $pool->setPoolPricingStrategy('lowest');
+
+        // Create 7 single items, each with 1 stock
+        for ($i = 1; $i <= 7; $i++) {
+            $single = Product::factory()->create([
+                'name' => "Single {$i}",
+                'type' => ProductType::BOOKING,
+                'manage_stock' => true,
+            ]);
+            $single->increaseStock(1);
+
+            ProductPrice::factory()->create([
+                'purchasable_id' => $single->id,
+                'purchasable_type' => Product::class,
+                'unit_amount' => 5000,
+                'currency' => 'USD',
+                'is_default' => true,
+            ]);
+
+            $pool->attachSingleItems([$single->id]);
+        }
+
+        return $pool;
+    }
+
+    /** @test */
+    public function cannot_add_more_items_than_available_singles_without_dates()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        // Pool has 7 single items, each with 1 stock
+        $this->assertEquals(7, $pool->getPoolMaxQuantity());
+
+        // Should be able to add 7 items
+        $this->cart->addToCart($pool, 7);
+        $this->assertEquals(7, $this->cart->fresh()->items->sum('quantity'));
+
+        // Should NOT be able to add 8th item - should throw exception
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 0 items available');
+
+        $this->cart->addToCart($pool, 1);
+    }
+
+    /** @test */
+    public function cannot_add_more_items_than_available_singles_with_dates()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Pool has 7 single items, each with 1 stock
+        $this->assertEquals(7, $pool->getPoolMaxQuantity($from, $until));
+
+        // Should be able to add 7 items with dates
+        $this->cart->addToCart($pool, 7, [], $from, $until);
+        $this->assertEquals(7, $this->cart->fresh()->items->sum('quantity'));
+
+        // Should NOT be able to add 8th item - should throw exception
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 0 items available');
+
+        $this->cart->addToCart($pool, 1, [], $from, $until);
+    }
+
+    /** @test */
+    public function cannot_add_batch_exceeding_available_singles_without_dates()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        // Trying to add 8 items at once should fail
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 7 items available');
+
+        $this->cart->addToCart($pool, 8);
+    }
+
+    /** @test */
+    public function cannot_add_batch_exceeding_available_singles_with_dates()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Trying to add 8 items at once should fail
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 7 items available');
+
+        $this->cart->addToCart($pool, 8, [], $from, $until);
+    }
+
+    /** @test */
+    public function adding_items_without_dates_then_adding_more_validates_correctly()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        // Add 5 items without dates
+        $this->cart->addToCart($pool, 5);
+        $this->assertEquals(5, $this->cart->fresh()->items->sum('quantity'));
+
+        // Should be able to add 2 more (total 7)
+        $this->cart->addToCart($pool, 2);
+        $this->assertEquals(7, $this->cart->fresh()->items->sum('quantity'));
+
+        // Should NOT be able to add 1 more
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->cart->addToCart($pool, 1);
+    }
+
+    /** @test */
+    public function checkoutSessionLink_throws_exception_when_cart_invalid()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        // Add items without dates - cart is not ready for checkout
+        $this->cart->addToCart($pool, 3);
+
+        // checkoutSessionLink should throw exception, not return null
+        // When items don't have dates, validation throws CartItemMissingInformationException
+        $this->expectException(\Blax\Shop\Exceptions\CartItemMissingInformationException::class);
+        $this->expectExceptionMessage('is missing required information: from, until');
+
+        $this->cart->checkoutSessionLink();
+    }
+
+    /** @test */
+    public function checkoutSessionLink_throws_exception_when_not_enough_stock()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Add 7 items with dates
+        $this->cart->addToCart($pool, 7, [], $from, $until);
+
+        // Simulate another cart claiming all stock for the same period
+        $otherCart = Cart::factory()->create([
+            'customer_id' => User::factory()->create()->id,
+            'customer_type' => User::class,
+        ]);
+        $otherCart->addToCart($pool, 7, [], $from, $until);
+        $otherCart->checkout(); // This claims the stock
+
+        // Our cart should now fail validation when trying to create checkout session
+        // The validation throws NotEnoughStockException when checking availability
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 0 items available');
+
+        $this->cart->fresh()->checkoutSessionLink();
+    }
+
+    /** @test */
+    public function cart_aware_validation_accounts_for_items_already_in_cart()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        $from = now()->addDays(1);
+        $until = now()->addDays(2);
+
+        // Add 5 items to cart
+        $this->cart->addToCart($pool, 5, [], $from, $until);
+
+        // Pool has 7 total, 5 in cart, so 2 available for this request
+        $this->assertEquals(7, $pool->getPoolMaxQuantity($from, $until));
+
+        // Should be able to add 2 more
+        $this->cart->addToCart($pool, 2, [], $from, $until);
+        $this->assertEquals(7, $this->cart->fresh()->items->sum('quantity'));
+
+        // Should NOT be able to add 1 more
+        $this->expectException(\Blax\Shop\Exceptions\NotEnoughStockException::class);
+        $this->expectExceptionMessage('has only 0 items available');
+
+        $this->cart->addToCart($pool, 1, [], $from, $until);
+    }
+
+    /** @test */
+    public function validation_message_shows_correct_remaining_availability()
+    {
+        $pool = $this->createPoolWith7Singles();
+
+        // Add 5 items without dates
+        $this->cart->addToCart($pool, 5);
+
+        try {
+            // Try to add 5 more (total would be 10, but max is 7)
+            // Should fail saying only 2 available
+            $this->cart->addToCart($pool, 5);
+            $this->fail('Should have thrown NotEnoughStockException');
+        } catch (\Blax\Shop\Exceptions\NotEnoughStockException $e) {
+            $this->assertStringContainsString('has only 2 items available', $e->getMessage());
+            $this->assertStringContainsString('Requested: 5', $e->getMessage());
+        }
+    }
+}

tests/Feature/PoolParkingCartPricingTest.php

@@ -315,7 +315,7 @@ class PoolParkingCartPricingTest extends TestCase
     }
 
     /** @test */
-    public function config_a_validates_availability_when_setting_dates()
+    public function config_a_marks_items_unavailable_when_setting_dates_to_unavailable_period()
     {
         $this->cart = $this->createCart();
         ['pool' => $pool, 'spots' => $spots] = $this->createParkingPool(hasPoolPrice: true, poolManagesStock: false);
@@ -334,8 +334,13 @@ class PoolParkingCartPricingTest extends TestCase
         $spots[2]->claimStock(2, null, $from, $until);
 
         // Try to set dates for period when no stock is available
-        $this->expectException(\Blax\Shop\Exceptions\NotEnoughAvailableInTimespanException::class);
+        // Should NOT throw, but mark items as unavailable
         $this->cart->setDates($from, $until, validateAvailability: true);
+
+        // Item should be marked as unavailable (null price)
+        $item = $this->cart->items()->first();
+        $this->assertNull($item->price, 'Unavailable item should have null price');
+        $this->assertFalse($item->is_ready_to_checkout, 'Unavailable item should not be ready for checkout');
     }
 
     // ==========================================
@@ -667,7 +672,7 @@ class PoolParkingCartPricingTest extends TestCase
     // ==========================================
 
     /** @test */
-    public function set_dates_validates_availability_for_each_cart_item()
+    public function set_dates_marks_items_unavailable_when_all_claimed()
     {
         $this->cart = $this->createCart();
         ['pool' => $pool, 'spots' => $spots] = $this->createParkingPool(hasPoolPrice: true, poolManagesStock: false);
@@ -686,10 +691,17 @@ class PoolParkingCartPricingTest extends TestCase
         $spots[1]->claimStock(2, null, $from, $until);
         $spots[2]->claimStock(2, null, $from, $until);
 
-        // Setting dates should validate and throw exception
-        // because ALL spots are claimed for this period and we need 5
-        $this->expectException(\Blax\Shop\Exceptions\NotEnoughAvailableInTimespanException::class);
+        // Setting dates should NOT throw, but mark items as unavailable
         $this->cart->setDates($from, $until, validateAvailability: true);
+
+        // All items should be marked as unavailable (null price)
+        $this->cart->refresh();
+        $this->cart->load('items');
+        foreach ($this->cart->items as $item) {
+            $this->assertNull($item->price, 'Unavailable item should have null price');
+            $this->assertFalse($item->is_ready_to_checkout, 'Unavailable item should not be ready');
+        }
+        $this->assertFalse($this->cart->is_ready_to_checkout, 'Cart should not be ready');
     }
 
     /** @test */

tests/Feature/PoolProductionBugTest.php

@@ -428,16 +428,24 @@ class PoolProductionBugTest extends TestCase
         $this->assertFalse($secondCart->isReadyForCheckout());
         $this->assertFalse($secondCart->IsReadyToCheckout);
 
-        $this->assertThrows(
-            fn() => $secondCart->setDates($from1, $until1),
-            \Blax\Shop\Exceptions\NotEnoughAvailableInTimespanException::class
-        );
+        // Setting dates to a fully booked period should NOT throw,
+        // but mark items as unavailable instead
+        $secondCart->setDates($from1, $until1);
+        
+        // All items should be marked as unavailable
+        $secondCart->refresh();
+        $secondCart->load('items');
+        foreach ($secondCart->items as $item) {
+            $this->assertNull($item->price, 'Item should have null price for unavailable period');
+            $this->assertFalse($item->is_ready_to_checkout);
+        }
+        $this->assertFalse($secondCart->isReadyForCheckout());
 
         // Now second user tries different dates - should succeed
         $from2 = Carbon::tomorrow()->addDays(2)->startOfDay();
         $until2 = Carbon::tomorrow()->addDays(3)->startOfDay(); // 1 day later
 
-        // This should work without exception
+        // This should work - items become available again with new dates
         $secondCart->setDates($from2, $until2);
         $this->assertTrue($secondCart->isReadyForCheckout());
         $this->assertTrue($secondCart->isReadyToCheckout);

tests/Feature/PoolSmartAllocationTest.php

@@ -167,7 +167,7 @@ class PoolSmartAllocationTest extends TestCase
     }
 
     /**
-     * Test: User1 purchases items, User2 can add same items for different dates
+     * Test: User1 purchases items, User2 can add same items but only available ones get allocated
      */
     /** @test */
     public function user2_can_book_same_items_for_different_dates_after_user1_purchase()
@@ -179,6 +179,7 @@ class PoolSmartAllocationTest extends TestCase
         $purchaseFrom = Carbon::yesterday()->startOfDay();
         $purchaseUntil = Carbon::tomorrow()->addDay()->startOfDay();
 
+        // User1 books 5 of 6 available singles
         $user1Cart->addToCart($this->pool, 5, [], $purchaseFrom, $purchaseUntil);
         $user1Cart->checkout();
 
@@ -194,9 +195,22 @@ class PoolSmartAllocationTest extends TestCase
         $this->assertEquals(6, $user2Cart->fresh()->items->sum('quantity'));
         $this->assertFalse($user2Cart->fresh()->isReadyForCheckout(), 'Cart should not be ready without dates');
 
-        // User2 tries to set dates that conflict with User1
-        $this->expectException(\Blax\Shop\Exceptions\NotEnoughAvailableInTimespanException::class);
+        // User2 sets dates that conflict with User1's booking
+        // Only 1 single is still available (User1 took 5)
         $user2Cart->setDates($purchaseFrom, $purchaseUntil);
+
+        // 5 items should be unavailable (null price), 1 should be available
+        $user2Cart->refresh();
+        $user2Cart->load('items');
+
+        $availableItems = $user2Cart->items->filter(fn($item) => $item->price !== null && $item->price > 0);
+        $unavailableItems = $user2Cart->items->filter(fn($item) => $item->price === null);
+
+        $this->assertEquals(1, $availableItems->count(), 'Should have 1 available item (6th single not booked by user1)');
+        $this->assertEquals(5, $unavailableItems->count(), 'Should have 5 unavailable items (user1 booked those singles)');
+
+        // Cart should NOT be ready (has unavailable items)
+        $this->assertFalse($user2Cart->isReadyForCheckout(), 'Cart should not be ready with unavailable items');
     }
 
     /**

tests/Unit/CartTest.php

@@ -234,29 +234,31 @@ class CartTest extends TestCase
     }
 
     /** @test */
-    public function checkout_session_link_is_null_when_stripe_disabled()
+    public function checkout_session_link_throws_when_stripe_disabled()
     {
         config(['shop.stripe.enabled' => false]);
 
         $cart = Cart::create();
 
-        $this->assertNull($cart->checkoutSessionLink());
+        // Now throws CartEmptyException (validation happens before stripe check)
+        $this->expectException(\Blax\Shop\Exceptions\CartEmptyException::class);
+        $cart->checkoutSessionLink();
     }
 
     /** @test */
-    public function checkout_session_link_returns_null_when_no_session_exists()
+    public function checkout_session_link_throws_when_cart_empty()
     {
         config(['shop.stripe.enabled' => true]);
 
         $cart = Cart::create();
 
-        $link = $cart->checkoutSessionLink();
-
-        $this->assertNull($link);
+        // Now throws CartEmptyException instead of returning null
+        $this->expectException(\Blax\Shop\Exceptions\CartEmptyException::class);
+        $cart->checkoutSessionLink();
     }
 
     /** @test */
-    public function checkout_session_link_returns_null_when_session_id_empty()
+    public function checkout_session_link_throws_when_cart_empty_even_with_meta()
     {
         config(['shop.stripe.enabled' => true]);
 
@@ -264,9 +266,9 @@ class CartTest extends TestCase
             'meta' => ['other_data' => 'value'],
         ]);
 
-        $link = $cart->checkoutSessionLink();
-
-        $this->assertNull($link);
+        // Now throws CartEmptyException instead of returning null
+        $this->expectException(\Blax\Shop\Exceptions\CartEmptyException::class);
+        $cart->checkoutSessionLink();
     }
 
     /** @test */