feat(metrics): subscription MRR API on Shop facade

Add Shop::mrr(), activeSubscribers(), mrrByProduct(), subscriptionMetrics()
and subscriberStatuses() to ShopService. Counts active/past_due/trialing
subscribers (not `ends_at IS NULL`, which silently drops still-billing
cancel-at-period-end subs and under-reports MRR), normalizes every interval
to a monthly run-rate (year/12, quarter/3, week & day by the average
days-per-month constant so they match Stripe), and returns `unpriced_items`
so a stale or incomplete price mirror is surfaced, never a silent undercount.

Additive only: no existing method changed. Covered by MrrMetricsTest.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Facades/Shop.php

@@ -53,7 +53,14 @@ use Illuminate\Support\Facades\Facade;
  * @method static array stats()
  * @method static \Illuminate\Support\Collection revenueByDay(\DateTimeInterface $from, \DateTimeInterface $until)
  * @method static \Illuminate\Support\Collection revenueByMonth(\DateTimeInterface $from, \DateTimeInterface $until)
- * 
+ *
+ * Subscription Revenue (MRR):
+ * @method static array subscriberStatuses()
+ * @method static int activeSubscribers()
+ * @method static int mrr()
+ * @method static \Illuminate\Support\Collection mrrByProduct()
+ * @method static array subscriptionMetrics()
+ *
  * Cart Queries:
  * @method static \Illuminate\Database\Eloquent\Builder carts()
  * @method static \Illuminate\Database\Eloquent\Builder activeCarts()

src/Services/ShopService.php

@@ -5,12 +5,15 @@ declare(strict_types=1);
 namespace Blax\Shop\Services;
 
 use Blax\Shop\Enums\OrderStatus;
+use Blax\Shop\Enums\RecurringInterval;
 use Blax\Shop\Models\Cart;
 use Blax\Shop\Models\CartItem;
 use Blax\Shop\Models\Order;
 use Blax\Shop\Models\Product;
 use Blax\Shop\Models\ProductCategory;
+use Blax\Shop\Models\ProductPrice;
 use Blax\Shop\Models\ProductPurchase;
+use Blax\Shop\Models\Subscription;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Collection;
 use Carbon\Carbon;
@@ -509,6 +512,202 @@ class ShopService
             ->get();
     }
 
+    // =========================================================================
+    // SUBSCRIPTION REVENUE (MRR)
+    // =========================================================================
+
+    /**
+     * Subscription statuses that count as a live, revenue-bearing subscriber.
+     *
+     * Mirrors Stripe's "active subscribers" metric: a subscription still
+     * billing counts even when it is set to cancel at period end (status stays
+     * `active` with a future `ends_at`) or is retrying payment (`past_due`).
+     * Filtering on `ends_at IS NULL` — a common mistake — silently drops
+     * paying, cancel-at-period-end subscribers and under-reports MRR.
+     * Override via `config('shop.metrics.subscription_statuses')`.
+     *
+     * @return array<int, string>
+     */
+    public function subscriberStatuses(): array
+    {
+        return config('shop.metrics.subscription_statuses', ['active', 'past_due', 'trialing']);
+    }
+
+    /**
+     * Base query for the subscriptions counted in subscriber/MRR metrics.
+     *
+     * @return Builder<Subscription>
+     */
+    protected function metricSubscriptions(): Builder
+    {
+        $model = config('shop.models.subscription', Subscription::class);
+
+        return $model::query()->whereIn('stripe_status', $this->subscriberStatuses());
+    }
+
+    /**
+     * Number of live subscribers (see {@see subscriberStatuses()}).
+     */
+    public function activeSubscribers(): int
+    {
+        return $this->metricSubscriptions()->count();
+    }
+
+    /**
+     * Monthly Recurring Revenue in cents.
+     *
+     * Every live subscription's line items, each normalized to a monthly
+     * run-rate from its price interval (year ÷ 12, quarter ÷ 3, week/day by the
+     * average-days-per-month constant so weekly/daily match Stripe's own MRR
+     * normalization). Computed from the mirrored {@see ProductPrice} rows — no
+     * Stripe API call — so the total is only as accurate as the mirror:
+     * a `product_prices.unit_amount` that has drifted from the live Stripe
+     * price will skew it, and a line item whose price is not mirrored at all is
+     * excluded. Use {@see subscriptionMetrics()} to see that excluded count
+     * (`unpriced_items`) rather than trusting a silent number, and keep the
+     * mirror synced from Stripe for an exact figure.
+     */
+    public function mrr(): int
+    {
+        return $this->subscriptionMetrics()['mrr'];
+    }
+
+    /**
+     * MRR split by product slug, in cents, highest first.
+     *
+     * @return \Illuminate\Support\Collection<string, int>
+     */
+    public function mrrByProduct(): \Illuminate\Support\Collection
+    {
+        return collect($this->subscriptionMetrics()['by_product']);
+    }
+
+    /**
+     * Every subscription metric in a single pass over the live subscriptions:
+     * subscriber count, MRR (cents), MRR by product slug, and the number of
+     * line items whose price could not be resolved from the mirror — so an
+     * under-count is surfaced, never silent.
+     *
+     * @return array{subscribers: int, mrr: int, by_product: array<string, int>, unpriced_items: int}
+     */
+    public function subscriptionMetrics(): array
+    {
+        $subscriptions = $this->metricSubscriptions()->with(['items', 'product'])->get();
+
+        // Resolve every referenced price in one query, keyed by Stripe price id.
+        $priceModel = config('shop.models.product_price', ProductPrice::class);
+        $priceIds = $subscriptions
+            ->flatMap(fn ($sub) => $sub->items->pluck('stripe_price'))
+            ->filter()
+            ->unique()
+            ->values();
+        $prices = $priceModel::query()
+            ->whereIn('stripe_price_id', $priceIds->all())
+            ->with('purchasable')
+            ->get()
+            ->keyBy('stripe_price_id');
+
+        $mrr = 0.0;
+        $byProduct = [];
+        $unpricedItems = 0;
+
+        foreach ($subscriptions as $subscription) {
+            foreach ($subscription->items as $item) {
+                $price = $prices->get($item->stripe_price);
+
+                if ($price === null) {
+                    $unpricedItems++;
+
+                    continue;
+                }
+
+                $monthly = $this->priceMonthlyAmount($price, (int) ($item->quantity ?? 1));
+
+                if ($monthly === null) {
+                    // Price resolved but is not recurring (a one-time price on a
+                    // subscription line) — carries no MRR, and is not a data gap.
+                    continue;
+                }
+
+                $mrr += $monthly;
+                $slug = $this->priceProductSlug($price)
+                    ?? $this->subscriptionProductSlug($subscription)
+                    ?? 'unknown';
+                $byProduct[$slug] = ($byProduct[$slug] ?? 0) + $monthly;
+            }
+        }
+
+        arsort($byProduct);
+
+        return [
+            'subscribers' => $subscriptions->count(),
+            'mrr' => (int) round($mrr),
+            'by_product' => array_map(static fn ($cents) => (int) round($cents), $byProduct),
+            'unpriced_items' => $unpricedItems,
+        ];
+    }
+
+    /**
+     * Normalize a recurring price to a monthly amount in cents for `$quantity`
+     * units. Returns null for a non-recurring (one-time) price, which carries
+     * no MRR. Weekly and daily use the Gregorian average-days-per-month
+     * constant so they line up with Cashier/Stripe's MRR normalization.
+     */
+    protected function priceMonthlyAmount(ProductPrice $price, int $quantity = 1): ?int
+    {
+        $interval = $price->interval instanceof RecurringInterval
+            ? $price->interval->value
+            : (is_string($price->interval) ? $price->interval : null);
+
+        if ($interval === null) {
+            return null; // one-time price — not recurring revenue
+        }
+
+        $amount = (float) $price->unit_amount * max(1, $quantity);
+        $count = max(1, (int) ($price->interval_count ?: 1));
+        $daysPerMonth = 30.436875; // Gregorian average month length
+
+        $monthly = match ($interval) {
+            'year' => $amount / (12 * $count),
+            'quarter' => $amount / (3 * $count),
+            'month' => $amount / $count,
+            'week' => $amount / ($count * 7 / $daysPerMonth),
+            'day' => $amount / ($count / $daysPerMonth),
+            default => null,
+        };
+
+        return $monthly === null ? null : (int) round($monthly);
+    }
+
+    /**
+     * Product slug carried by a price's purchasable (usually a Product), or
+     * null when the purchasable is absent or has no slug/name.
+     */
+    protected function priceProductSlug(ProductPrice $price): ?string
+    {
+        $purchasable = $price->purchasable;
+
+        if (! is_object($purchasable)) {
+            return null;
+        }
+
+        return $purchasable->slug ?? $purchasable->name ?? null;
+    }
+
+    /**
+     * Product slug for the subscription's linked product, or null.
+     */
+    protected function subscriptionProductSlug(Subscription $subscription): ?string
+    {
+        $product = $subscription->product;
+
+        if (! is_object($product)) {
+            return null;
+        }
+
+        return $product->slug ?? $product->name ?? null;
+    }
+
     // =========================================================================
     // CART QUERIES
     // =========================================================================

tests/Feature/Subscriptions/MrrMetricsTest.php

@@ -0,0 +1,162 @@
+<?php
+
+namespace Blax\Shop\Tests\Feature\Subscriptions;
+
+use Blax\Shop\Enums\PriceType;
+use Blax\Shop\Enums\ProductStatus;
+use Blax\Shop\Enums\ProductType;
+use Blax\Shop\Enums\RecurringInterval;
+use Blax\Shop\Facades\Shop;
+use Blax\Shop\Models\Product;
+use Blax\Shop\Models\ProductPrice;
+use Blax\Shop\Models\Subscription;
+use Blax\Shop\Models\SubscriptionItem;
+use Blax\Shop\Tests\TestCase;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use PHPUnit\Framework\Attributes\Test;
+use Workbench\App\Models\User;
+
+/**
+ * Covers Shop::mrr()/activeSubscribers()/mrrByProduct()/subscriptionMetrics().
+ *
+ * Regression anchors for the two ways an app's hand-rolled MRR goes wrong:
+ * excluding still-billing subscribers (past_due, cancel-at-period-end), and
+ * silently dropping line items whose price is not mirrored locally.
+ */
+class MrrMetricsTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private string $userId;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->userId = (string) User::factory()->create()->getKey();
+    }
+
+    private function product(string $name): Product
+    {
+        return Product::create([
+            'name' => $name,
+            'sku' => 'SKU-'.uniqid(),
+            'type' => ProductType::SIMPLE,
+            'status' => ProductStatus::PUBLISHED,
+            'manage_stock' => false,
+        ]);
+    }
+
+    private function price(Product $product, string $stripePrice, int $unitAmount, RecurringInterval|string|null $interval, int $intervalCount = 1): ProductPrice
+    {
+        return ProductPrice::create([
+            'purchasable_type' => Product::class,
+            'purchasable_id' => $product->id,
+            'stripe_price_id' => $stripePrice,
+            'type' => $interval === null ? PriceType::ONE_TIME : PriceType::RECURRING,
+            'currency' => 'EUR',
+            'unit_amount' => $unitAmount,
+            'is_default' => true,
+            'active' => true,
+            'interval' => $interval,
+            'interval_count' => $intervalCount,
+        ]);
+    }
+
+    private function subscription(Product $product, string $status, string $stripePrice, ?\DateTimeInterface $endsAt = null): Subscription
+    {
+        $sub = Subscription::create([
+            'user_id' => $this->userId,
+            'product_id' => $product->id,
+            'type' => 'default',
+            'stripe_id' => 'sub_'.uniqid(),
+            'stripe_status' => $status,
+            'stripe_price' => $stripePrice,
+            'quantity' => 1,
+            'ends_at' => $endsAt,
+        ]);
+
+        SubscriptionItem::create([
+            'subscription_id' => $sub->id,
+            'stripe_id' => 'si_'.uniqid(),
+            'stripe_product' => 'prod_x',
+            'stripe_price' => $stripePrice,
+            'quantity' => 1,
+        ]);
+
+        return $sub;
+    }
+
+    #[Test]
+    public function it_counts_live_subscribers_including_past_due_and_cancel_at_period_end(): void
+    {
+        $seat = $this->product('Full Seat');
+        $this->price($seat, 'price_seat', 2550, RecurringInterval::MONTH);
+
+        $this->subscription($seat, 'active', 'price_seat');
+        $this->subscription($seat, 'past_due', 'price_seat');                    // still billing -> counts
+        $this->subscription($seat, 'active', 'price_seat', now()->addMonth());   // cancel-at-period-end -> counts
+        $this->subscription($seat, 'trialing', 'price_seat');                    // counts
+        $this->subscription($seat, 'canceled', 'price_seat');                    // gone -> excluded
+
+        $this->assertSame(4, Shop::activeSubscribers());
+        $this->assertSame(4 * 2550, Shop::mrr());
+    }
+
+    #[Test]
+    public function it_normalizes_every_interval_to_a_monthly_run_rate(): void
+    {
+        $p = $this->product('Simulator');
+        $this->price($p, 'price_month', 1410, RecurringInterval::MONTH);
+        $this->price($p, 'price_year', 13500, RecurringInterval::YEAR);        // ÷12
+        $this->price($p, 'price_week', 610, RecurringInterval::WEEK);          // ×30.436875/7
+        $this->price($p, 'price_quarter', 4900, RecurringInterval::MONTH, 3);  // ÷3
+
+        $this->subscription($p, 'active', 'price_month');
+        $this->subscription($p, 'active', 'price_year');
+        $this->subscription($p, 'active', 'price_week');
+        $this->subscription($p, 'active', 'price_quarter');
+
+        $expected = 1410
+            + (int) round(13500 / 12)
+            + (int) round(610 * 30.436875 / 7)
+            + (int) round(4900 / 3);
+
+        $this->assertSame($expected, Shop::mrr());
+    }
+
+    #[Test]
+    public function it_surfaces_line_items_whose_price_is_not_mirrored_rather_than_guessing(): void
+    {
+        $p = $this->product('Full Seat');
+        $this->price($p, 'price_seat', 2550, RecurringInterval::MONTH);
+
+        $this->subscription($p, 'active', 'price_seat');
+        $this->subscription($p, 'active', 'price_missing'); // no ProductPrice mirrored
+
+        $metrics = Shop::subscriptionMetrics();
+
+        $this->assertSame(2550, $metrics['mrr']);         // unmirrored item excluded, never guessed
+        $this->assertSame(1, $metrics['unpriced_items']); // but surfaced, not silent
+        $this->assertSame(2, $metrics['subscribers']);
+    }
+
+    #[Test]
+    public function it_splits_mrr_by_product(): void
+    {
+        $seat = $this->product('Full Seat');
+        $sim = $this->product('Simulator');
+        $this->price($seat, 'price_seat', 2550, RecurringInterval::MONTH);
+        $this->price($sim, 'price_sim', 890, RecurringInterval::MONTH);
+
+        $this->subscription($seat, 'active', 'price_seat');
+        $this->subscription($seat, 'active', 'price_seat');
+        $this->subscription($sim, 'active', 'price_sim');
+
+        $byProduct = Shop::mrrByProduct();
+
+        $this->assertSame(Shop::mrr(), $byProduct->sum());
+        $this->assertCount(2, $byProduct);
+        // arsort() puts the biggest product first; values are label-independent.
+        $this->assertSame([5100, 890], array_values($byProduct->all()));
+    }
+}