Feature: Toggle interaction limitations on coupons and discounts

This feature allows customization of the interaction between coupons and discounts that are applied to the cart of the user. Discounts can disallow usage of coupons and vice versa.

Also added in this feature is a fix for the validation exception response in the cart, this would show the error message related to "code" to both coupons add input field and the gift card add input field.

Closes: feature/coupon-and-discount-interaction-limitations

database/migrations/2024_02_25_000000_add_shop_coupons_can_be_redeemed_with_discounts.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('shop_coupons', function (Blueprint $table) {
+            $table->boolean('discount_allowed')->default(true)->after('can_cumulate');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('shop_coupons', function (Blueprint $table) {
+            $table->dropColumn('discount_allowed');
+        });
+    }
+};

database/migrations/2024_02_25_000001_add_shop_discounts_allows_coupons.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('shop_discounts', function (Blueprint $table) {
+            $table->boolean('coupons_allowed')->default(true)->after('discount');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('shop_discounts', function (Blueprint $table) {
+            $table->dropColumn('coupons_allowed');
+        });
+    }
+};

resources/lang/en/admin.php

@@ -52,6 +52,7 @@
         'active' => 'Active',
         'usage' => 'Under usage limit',
         'enable' => 'Enable the coupon',
+        'discount' => 'Allow usage of discounts with coupon',
     ],
 
     'giftcards' => [
@@ -72,6 +73,7 @@
         'global' => 'Should the discount be active on all the shop ?',
         'active' => 'Active',
         'enable' => 'Enable the discount',
+        'coupons' => 'Allow usage of coupons with discount',
     ],
 
     'packages' => [

resources/lang/en/messages.php

@@ -84,6 +84,7 @@
         'add' => 'Add a coupon',
         'error' => 'This coupon does not exist, has expired or can no longer be used.',
         'cumulate' => 'You cannot use this coupon with an other coupon.',
+        'discount' => 'You cannot use this coupon with one or more of the existing discounts applied.',
     ],
 
     'payment' => [

resources/views/admin/coupons/_form.blade.php

@@ -116,3 +116,8 @@
     <input type="checkbox" class="form-check-input" id="enableSwitch" name="is_enabled" @checked($coupon->is_enabled ?? true)>
     <label class="form-check-label" for="enableSwitch">{{ trans('shop::admin.coupons.enable') }}</label>
 </div>
+
+<div class="mb-3 form-check form-switch">
+    <input type="checkbox" class="form-check-input" id="discountSwitch" name="discount_allowed" @checked($coupon->discount_allowed ?? true)>
+    <label class="form-check-label" for="discountSwitch">{{ trans('shop::admin.coupons.discount') }}</label>
+</div>

resources/views/admin/discounts/_form.blade.php

@@ -77,3 +77,8 @@
     <input type="checkbox" class="form-check-input" id="enableSwitch" name="is_enabled" @checked($discount->is_enabled ?? true)>
     <label class="form-check-label" for="enableSwitch">{{ trans('shop::admin.discounts.enable') }}</label>
 </div>
+
+<div class="mb-3 form-check form-switch">
+    <input type="checkbox" class="form-check-input" id="allowCouponsSwitch" name="coupons_allowed" @checked($discount->coupons_allowed ?? true)>
+    <label class="form-check-label" for="allowCouponsSwitch">{{ trans('shop::admin.discounts.coupons') }}</label>
+</div>

resources/views/cart/index.blade.php

@@ -76,14 +76,14 @@
                         <form action="{{ route('shop.cart.coupons.add') }}" method="POST" >
                             @csrf
 
-                            <div class="input-group mb-3 @error('code') has-validation @enderror">
-                                <input type="text" class="form-control @error('code') is-invalid @enderror" placeholder="{{ trans('shop::messages.fields.code') }}" id="code" name="code" value="{{ old('code') }}">
+                            <div class="input-group mb-3 @error('coupon_code') has-validation @enderror">
+                                <input type="text" class="form-control @error('coupon_code') is-invalid @enderror" placeholder="{{ trans('shop::messages.fields.code') }}" id="coupon_code" name="coupon_code" value="{{ old('coupon_code') }}">
 
                                 <button type="submit" class="btn btn-primary">
                                     <i class="bi bi-plus-lg"></i> {{ trans('messages.actions.add') }}
                                 </button>
 
-                                @error('code')
+                                @error('coupon_code')
                                 <span class="invalid-feedback" role="alert"><strong>{{ $message }}</strong></span>
                                 @enderror
                             </div>

src/Cart/Cart.php

@@ -2,8 +2,10 @@
 
 namespace Azuriom\Plugin\Shop\Cart;
 
+use Azuriom\Plugin\Shop\Exceptions\CouponNotAllowedException;
 use Azuriom\Plugin\Shop\Models\Concerns\Buyable;
 use Azuriom\Plugin\Shop\Models\Coupon;
+use Azuriom\Plugin\Shop\Models\Discount;
 use Azuriom\Plugin\Shop\Models\Giftcard;
 use Azuriom\Plugin\Shop\Models\Package;
 use Illuminate\Contracts\Session\Session;
@@ -37,12 +39,21 @@ class Cart implements Arrayable
      */
     private Collection $giftcards;
 
+    /**
+     * A collection of discounts applied to the cart.
+     */
+    private Collection $packageDiscounts;
+
     /**
      * Create a new cart instance.
      */
-    private function __construct(Session $session = null)
+    private function __construct(?Session $session = null)
     {
         $this->session = $session;
+        $this->packageDiscounts = collect();
+
+        // Always add active global discounts instantly.
+        $this->addAppliedDiscounts(Discount::global()->active()->get());
 
         if ($session === null) {
             $this->items = collect();
@@ -58,14 +69,20 @@ private function __construct(Session $session = null)
     /**
      * Add an item to the cart.
      */
-    public function add(Buyable $buyable, int $quantity = 1, float $userPrice = null): void
+    public function add(Buyable $buyable, int $quantity = 1, ?float $userPrice = null): void
     {
         if ($quantity <= 0) {
             return;
         }
 
         $cartItem = $this->get($buyable);
 
+        if ($buyable instanceof Package) {
+            /** @var Collection $discounts */
+            $discounts = $buyable->discounts()->active()->get();
+            $this->addAppliedDiscounts($discounts);
+        }
+
         if ($cartItem === null) {
             $this->set($buyable, $quantity, $userPrice);
 
@@ -81,7 +98,7 @@ public function add(Buyable $buyable, int $quantity = 1, float $userPrice = null
     /**
      * Set the quantity of an item in the cart.
      */
-    public function set(Buyable $buyable, int $quantity = 1, float $userPrice = null): void
+    public function set(Buyable $buyable, int $quantity = 1, ?float $userPrice = null): void
     {
         if ($quantity <= 0) {
             $this->remove($buyable);
@@ -116,6 +133,10 @@ public function remove(Buyable $buyable): void
     {
         $this->items->forget($this->getItemId($buyable));
 
+        if ($buyable instanceof Package) {
+            $this->removeAppliedDiscounts($buyable->discounts()->active()->get());
+        }
+
         $this->save();
     }
 
@@ -251,9 +272,15 @@ public function coupons(): Collection
 
     /**
      * Add a coupon to the cart.
+     *
+     * @throws CouponNotAllowedException
      */
     public function addCoupon(Coupon $coupon): void
     {
+        if ($this->couponClashesWithActiveDiscount($coupon)) {
+            throw new CouponNotAllowedException();
+        }
+
         $this->coupons->put($coupon->id, $coupon);
 
         $this->save();
@@ -405,4 +432,59 @@ public function toArray(): array
             'giftcards' => $this->giftcards->pluck('code')->all(),
         ];
     }
+
+    /**
+     * Add discounts applied to cart.
+     */
+    private function addAppliedDiscounts(Collection $discounts): void
+    {
+        if ($discounts->count() > 0) {
+            $discounts->each(function (Discount $discount) {
+                if (! $this->packageDiscounts->contains($discount->id)) {
+                    $this->packageDiscounts->put($discount->id, $discount);
+                }
+            });
+        }
+    }
+
+    /**
+     * Remove given discounts from applied discounts collection.
+     * Skip global discounts as they are always applied regardless of what item
+     * has been placed in or removed from the cart.
+     */
+    private function removeAppliedDiscounts(Collection $discounts): void
+    {
+        if ($discounts->count() > 0) {
+            $discounts->each(function (Discount $discount) {
+                if ($this->packageDiscounts->contains($discount->id) && ! $discount->is_global) {
+                    $this->packageDiscounts->forget($discount->id);
+                }
+            });
+        }
+    }
+
+    /**
+     * Determine if the given coupon will clash with applied discounts.
+     */
+    private function couponClashesWithActiveDiscount(Coupon $coupon): bool
+    {
+        $couponClashes = false;
+
+        if ($this->packageDiscounts->count() === 0) {
+            return false;
+        }
+
+        if (! $coupon->discount_allowed) {
+            return true;
+        }
+
+        /** @var Discount $discount */
+        foreach ($this->packageDiscounts as $discount) {
+            if (! $discount->coupons_allowed) {
+                $couponClashes = true;
+            }
+        }
+
+        return $couponClashes;
+    }
 }

src/Controllers/CouponController.php

@@ -4,6 +4,7 @@
 
 use Azuriom\Http\Controllers\Controller;
 use Azuriom\Plugin\Shop\Cart\Cart;
+use Azuriom\Plugin\Shop\Exceptions\CouponNotAllowedException;
 use Azuriom\Plugin\Shop\Models\Coupon;
 use Illuminate\Http\Request;
 use Illuminate\Validation\ValidationException;
@@ -17,13 +18,14 @@ class CouponController extends Controller
      */
     public function add(Request $request)
     {
-        $validated = $this->validate($request, ['code' => 'required']);
+        $validated = $this->validate($request, ['coupon_code' => 'required']);
 
-        $coupon = Coupon::active()->firstWhere($validated);
+        /** @var Coupon $coupon */
+        $coupon = Coupon::active()->firstWhere(['code' => $validated['coupon_code']]);
 
         if ($coupon === null || $coupon->hasReachLimit($request->user())) {
             throw ValidationException::withMessages([
-                'code' => trans('shop::messages.coupons.error'),
+                'coupon_code' => trans('shop::messages.coupons.error'),
             ]);
         }
 
@@ -32,11 +34,17 @@ public function add(Request $request)
         if ((! $coupon->can_cumulate && ! $cart->coupons()->isEmpty())
             || $cart->coupons()->contains('can_cumulate', false)) {
             throw ValidationException::withMessages([
-                'code' => trans('shop::messages.coupons.cumulate'),
+                'coupon_code' => trans('shop::messages.coupons.cumulate'),
             ]);
         }
 
-        $cart->addCoupon($coupon);
+        try {
+            $cart->addCoupon($coupon);
+        } catch (CouponNotAllowedException) {
+            throw ValidationException::withMessages([
+                'coupon_code' => trans('shop::messages.coupons.discount'),
+            ]);
+        }
 
         return to_route('shop.cart.index');
     }

src/Exceptions/CouponNotAllowedException.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Azuriom\Plugin\Shop\Exceptions;
+
+use Exception;
+
+final class CouponNotAllowedException extends Exception
+{
+}

src/Models/Coupon.php

@@ -14,6 +14,7 @@
  * @property int $user_limit
  * @property int $global_limit
  * @property bool $can_cumulate
+ * @property bool $discount_allowed
  * @property bool $is_enabled
  * @property bool $is_global
  * @property bool $is_fixed
@@ -42,7 +43,7 @@ class Coupon extends Model
      * @var array<int, string>
      */
     protected $fillable = [
-        'code', 'discount', 'start_at', 'expire_at', 'user_limit', 'global_limit', 'can_cumulate', 'is_enabled', 'is_global', 'is_fixed',
+        'code', 'discount', 'start_at', 'expire_at', 'user_limit', 'global_limit', 'can_cumulate', 'is_enabled', 'is_global', 'is_fixed', 'discount_allowed',
     ];
 
     /**
@@ -57,6 +58,7 @@ class Coupon extends Model
         'is_enabled' => 'boolean',
         'is_global' => 'boolean',
         'is_fixed' => 'boolean',
+        'discount_allowed' => 'boolean',
     ];
 
     /**

src/Models/Discount.php

@@ -10,6 +10,7 @@
  * @property int $id
  * @property string $name
  * @property int $discount
+ * @property bool $coupons_allowed
  * @property bool $is_global
  * @property bool $is_enabled
  * @property \Carbon\Carbon $start_at
@@ -37,7 +38,7 @@ class Discount extends Model
      * @var array<int, string>
      */
     protected $fillable = [
-        'name', 'discount', 'packages', 'is_global', 'is_enabled', 'start_at', 'end_at',
+        'name', 'discount', 'packages', 'is_global', 'is_enabled', 'start_at', 'end_at', 'coupons_allowed',
     ];
 
     /**
@@ -50,6 +51,7 @@ class Discount extends Model
         'end_at' => 'datetime',
         'is_global' => 'boolean',
         'is_enabled' => 'boolean',
+        'coupons_allowed' => 'boolean',
     ];
 
     /**

src/Requests/CouponRequest.php

@@ -18,7 +18,7 @@ class CouponRequest extends FormRequest
      * @var array<int, string>
      */
     protected array $checkboxes = [
-        'can_cumulate', 'is_enabled', 'is_global',
+        'can_cumulate', 'is_enabled', 'is_global', 'discount_allowed',
     ];
 
     /**
@@ -50,6 +50,7 @@ public function rules(): array
             'is_enabled' => ['filled', 'boolean'],
             'is_global' => ['filled', 'boolean'],
             'is_fixed' => ['filled', 'boolean'],
+            'discount_allowed' => ['filled', 'boolean'],
         ];
     }
 }