feat: split nights off an accommodation booking as separate periods

addresses #869f6z36v

tests/Service/GroupsPriceCalculatorTest.php

@@ -48,6 +48,97 @@ class GroupsPriceCalculatorTest extends TestCase
         self::assertSame(50, $result['undersubscriptionThreshold']);
     }
 
+    public function testTheShortTermSurchargeIsJudgedOnTheWholeStay(): void
+    {
+        // Three nights priced for the group, but one night split off a four-night stay: the
+        // stay is not short-term, so the three nights must not pick up the 10 % surcharge.
+        $price = $this->price('2026-06-01', '2026-08-31', 20);
+
+        $split = $this->calculateMain('2026-07-02', '2026-07-05', '2026-07-01', 4, [$price]);
+        $unsplit = $this->calculateMain('2026-07-02', '2026-07-05', '2026-07-02', 3, [$price]);
+
+        self::assertSame(0, $split['shortTermSurcharge']);
+        self::assertSame(3, $split['nights']);
+        self::assertSame((int) round(($unsplit['basePrice'] + $unsplit['additionalPersonsPrice']) * 10 / 100), $unsplit['shortTermSurcharge']);
+    }
+
+    public function testTheShortTermSurchargeOfAShortStayIsChargedOnThePricedNightsOnly(): void
+    {
+        // A three-night stay with one night split off: 10 % on the two nights the group pays
+        // for, not 20 % for a two-night stay and not on the split-off night's lines.
+        $price = $this->price('2026-06-01', '2026-08-31', 20);
+
+        $result = $this->calculateMain('2026-07-02', '2026-07-04', '2026-07-01', 3, [$price]);
+
+        self::assertSame(2 * 100_00, $result['basePrice']);
+        self::assertSame((int) round(($result['basePrice'] + $result['additionalPersonsPrice']) * 10 / 100), $result['shortTermSurcharge']);
+    }
+
+    public function testTheIncludedPaxFloorComesFromTheStaysFirstNight(): void
+    {
+        // The stay starts in a price period with a floor of 30; the main group arrives a day
+        // later, in one with a floor of 50. Splitting the first night off must not raise the
+        // floor the 20 people are billed at.
+        $prices = [
+            $this->price('2026-06-01', '2026-07-01', 30),
+            $this->price('2026-07-02', '2026-08-31', 50),
+        ];
+
+        $result = $this->calculateMain('2026-07-02', '2026-07-08', '2026-07-01', 7, $prices, paxCount: 20, boardServicePrice: 1500);
+
+        self::assertSame(30, $result['includedPax']);
+        self::assertSame(30, $result['effectivePax']);
+        self::assertSame(1500 * 30 * 6, $result['boardPrice']);
+    }
+
+    /**
+     * @param list<AccommodationPrice> $prices
+     *
+     * @return array<string, mixed>
+     */
+    private function calculateMain(string $from, string $to, string $stayFrom, int $stayNights, array $prices, int $paxCount = 20, ?int $boardServicePrice = null): array
+    {
+        $dateFrom = new \DateTimeImmutable($from);
+        $dateTo = new \DateTimeImmutable($to);
+
+        return $this->calculator()->calculateFromSnapshots(
+            $paxCount,
+            0,
+            $dateFrom->diff($dateTo)->days,
+            $dateFrom,
+            $dateTo,
+            new \DateTimeImmutable($stayFrom),
+            $stayNights,
+            $prices,
+            $boardServicePrice,
+            [],
+            'EUR',
+        );
+    }
+
+    private function price(string $from, string $to, int $includedPax): AccommodationPrice
+    {
+        return (new AccommodationPrice())
+            ->setDateFrom(new \DateTimeImmutable($from))
+            ->setDateTo(new \DateTimeImmutable($to))
+            ->setIncludedPax($includedPax)
+            ->setPricePerNight(100_00)
+            ->setPriceAdditionalPerson(10_00)
+            ->setMinNights(1);
+    }
+
+    private function calculator(): GroupsPriceCalculator
+    {
+        return new GroupsPriceCalculator(new PriceTimelineBuilder(), [
+            'runningCostsEur' => 0,
+            'runningCostsChf' => 0,
+            'undersubscription30Eur' => 5.0,
+            'undersubscription30Chf' => 6.0,
+            'undersubscription40Eur' => 2.5,
+            'undersubscription40Chf' => 3.0,
+        ]);
+    }
+
     /**
      * @return array<string, mixed>
      */
@@ -64,21 +155,14 @@ class GroupsPriceCalculatorTest extends TestCase
             ->setPriceAdditionalPerson(10_00)
             ->setMinNights(1);
 
-        $calculator = new GroupsPriceCalculator(new PriceTimelineBuilder(), [
-            'runningCostsEur' => 0,
-            'runningCostsChf' => 0,
-            'undersubscription30Eur' => 5.0,
-            'undersubscription30Chf' => 6.0,
-            'undersubscription40Eur' => 2.5,
-            'undersubscription40Chf' => 3.0,
-        ]);
-
-        return $calculator->calculateFromSnapshots(
+        return $this->calculator()->calculateFromSnapshots(
             $paxCount,
             0,
             self::NIGHTS,
             $dateFrom,
             $dateTo,
+            $dateFrom,
+            self::NIGHTS,
             [$price],
             $boardServicePrice,
             [],