From ef937530af4946c8ef1a5ee97ca05d24def69346 Mon Sep 17 00:00:00 2001
From: Ondrej Vlach <ondrej@vlach.xyz>
Date: Wed, 7 Aug 2024 12:53:46 +0200
Subject: [PATCH] feast(services): add duration solver

---
 app/Services/WorkingDays/DurationSolver.php   | 55 ++++++++++++++++
 .../WorkingDays/DurationSolverFactory.php     | 29 +++++++++
 .../WorkingDays/DurationSolverTest.php        | 64 +++++++++++++++++++
 3 files changed, 148 insertions(+)
 create mode 100644 app/Services/WorkingDays/DurationSolver.php
 create mode 100644 app/Services/WorkingDays/DurationSolverFactory.php
 create mode 100644 tests/Unit/Services/WorkingDays/DurationSolverTest.php

diff --git a/app/Services/WorkingDays/DurationSolver.php b/app/Services/WorkingDays/DurationSolver.php
new file mode 100644
index 0000000..1a6a61f
--- /dev/null
+++ b/app/Services/WorkingDays/DurationSolver.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\WorkingDays;
+
+use App\Services\Utils\DurationConvertor;
+
+/**
+ * Solves the duration of a given period based on working days and return new end date.
+ */
+class DurationSolver
+{
+    protected const int MAX_ITERATIONS = 100;
+
+    public function __construct(
+        protected readonly WorkingDayDeterminerInterface $workingDayDeterminer,
+        protected readonly DurationConvertor $durationConvertor,
+    ) {
+    }
+
+    /**
+     * Calculate the duration of a given period based on working days.
+     * @param \DateTimeImmutable $startDate
+     * @param \DateTimeImmutable $endDate
+     * @return \DateTimeImmutable
+     * @throws \Exception
+     */
+    public function calculateDuration(
+        \DateTimeImmutable $startDate,
+        \DateTimeImmutable $endDate,
+    ): \DateTimeImmutable {
+        $loopId = 0;
+        $requiredWorkingDaysCount = (int) ($startDate->setTime(0, 0)->diff($endDate->setTime(0, 0))->format('%a')) + 1;
+
+        do {
+            $workingDaysCount = (int) ($startDate->setTime(0, 0)->diff($endDate->setTime(0, 0))->format('%a')) + 1;
+            $workingDaysCountInInterval = $this->workingDayDeterminer->getWorkingDaysCount($startDate, $workingDaysCount);
+
+            if ($workingDaysCountInInterval >= $requiredWorkingDaysCount) {
+                // there is no weekends or holidays in the given interval
+                break;
+            } else {
+                $endDate = $endDate->add(new \DateInterval(sprintf('P%dD', $requiredWorkingDaysCount - $workingDaysCountInInterval)));
+                if ($loopId > static::MAX_ITERATIONS) {
+                    throw new \InvalidArgumentException('No working days found in the given interval');
+                }
+            }
+
+            $loopId++;
+        } while ($workingDaysCount != $workingDaysCountInInterval);
+
+        return $endDate;
+    }
+}
diff --git a/app/Services/WorkingDays/DurationSolverFactory.php b/app/Services/WorkingDays/DurationSolverFactory.php
new file mode 100644
index 0000000..9c35330
--- /dev/null
+++ b/app/Services/WorkingDays/DurationSolverFactory.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\WorkingDays;
+
+use App\Services\Utils\DurationConvertor;
+
+class DurationSolverFactory
+{
+    public function __construct(
+        private readonly WorkingDayDeterminerFactory $workingDayDeterminerFactory,
+        private readonly DurationConvertor $durationConvertor,
+    ) {
+    }
+
+    /**
+     * Create DurationSolver instance for a specific country
+     * @param string $countryCode
+     * @return DurationSolver
+     */
+    public function createDurationSolverForCountry(string $countryCode): DurationSolver
+    {
+        return new DurationSolver(
+            $this->workingDayDeterminerFactory->createForCountry($countryCode),
+            $this->durationConvertor,
+        );
+    }
+}
diff --git a/tests/Unit/Services/WorkingDays/DurationSolverTest.php b/tests/Unit/Services/WorkingDays/DurationSolverTest.php
new file mode 100644
index 0000000..478a37a
--- /dev/null
+++ b/tests/Unit/Services/WorkingDays/DurationSolverTest.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Unit\Services\WorkingDays;
+
+use App\Services\Utils\DurationConvertor;
+use App\Services\WorkingDays\DurationSolver;
+use App\Services\WorkingDays\WorkingDayDeterminerInterface;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Tests\TestCase;
+
+class DurationSolverTest extends TestCase
+{
+    /**
+     * @return array<array<int|array<int>>>
+     */
+    public static function solverDurationProvider(): array
+    {
+        // 4 days is required state
+        return [
+            [3, [4]], /* without holidays */
+            [4, [3, 4]], /* 1 day */
+            [6, [2, 3, 4]], /* 1 weekend, monday holiday */
+            [5, [2, 4]], /* 1 weekend */
+        ];
+    }
+
+    /**
+     * @param int $expectedResult
+     * @param array<int> $solverResults
+     * @return void
+     * @throws \PHPUnit\Framework\MockObject\Exception
+     */
+    #[DataProvider('solverDurationProvider')]
+    public function testSolverWillSolveDuration(int $expectedResult, array $solverResults): void
+    {
+        $workingDayDeterminer = $this->createMock(WorkingDayDeterminerInterface::class);
+        $workingDayDeterminer->method('getWorkingDaysCount')->willReturnCallback(function () use ($solverResults) {
+            static $calledCount = 0;
+            return $solverResults[$calledCount++] ?? throw new \Exception("Not enough solver results for try $calledCount" . print_r($solverResults, true));
+        });
+        $durationSolver = new DurationSolver(
+            $workingDayDeterminer,
+            new DurationConvertor()
+        );
+        $this->assertEquals(
+            (new \DateTimeImmutable('2022-01-01 23:59:59'))->add(new \DateInterval(sprintf('P%dD', $expectedResult))),
+            $durationSolver->calculateDuration(new \DateTimeImmutable('2022-01-01 00:00:00'), new \DateTimeImmutable('2022-01-04 23:59:59'))
+        );
+    }
+
+    public function testDurationSolverWillThrowExceptionWhenCantSolveDuration(): void
+    {
+        $workingDayDeterminer = $this->createMock(WorkingDayDeterminerInterface::class);
+        $workingDayDeterminer->method('getWorkingDaysCount')->willReturn(0);
+        $durationSolver = new DurationSolver(
+            $workingDayDeterminer,
+            new DurationConvertor()
+        );
+        $this->expectException(\InvalidArgumentException::class);
+        $durationSolver->calculateDuration(new \DateTimeImmutable('2022-01-01 00:00:00'), new \DateTimeImmutable('2022-01-04 23:59:59'));
+    }
+}