feat: RainCalculator with timezone-aware day mapping and month total

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tests/RainCalculatorTest.php

@@ -0,0 +1,106 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Weerscherm\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Weerscherm\RainCalculator;
+
+final class RainCalculatorTest extends TestCase
+{
+    private \DateTimeZone $tz;
+
+    protected function setUp(): void
+    {
+        $this->tz = new \DateTimeZone('Europe/Berlin');
+    }
+
+    /** @return array<string, mixed> */
+    private function fixture(string $name): array
+    {
+        return json_decode((string) file_get_contents(__DIR__ . "/fixtures/$name.json"), true)['body'];
+    }
+
+    private function now(string $s): \DateTimeImmutable
+    {
+        return new \DateTimeImmutable($s, $this->tz);
+    }
+
+    public function testNormalWeek(): void
+    {
+        $r = RainCalculator::compute($this->fixture('getmeasure'), $this->now('2026-09-11 14:32'), 9.9);
+
+        self::assertSame(2.4, $r['today']);
+        self::assertSame([
+            ['date' => '2026-09-08', 'mm' => 1.2],
+            ['date' => '2026-09-09', 'mm' => 6.8],
+            ['date' => '2026-09-10', 'mm' => 0.0],
+        ], $r['previous_days']);
+        self::assertEqualsWithDelta(38.5, $r['month_total'], 0.0001);
+    }
+
+    public function testMissingPreviousDayIsNullAndExcludedFromTotal(): void
+    {
+        $body = $this->fixture('getmeasure');
+        $sep9 = (string) $this->now('2026-09-09 03:17')->getTimestamp();
+        unset($body[$sep9]);
+
+        $r = RainCalculator::compute($body, $this->now('2026-09-11 14:32'), null);
+
+        self::assertNull($r['previous_days'][1]['mm']);
+        self::assertSame('2026-09-09', $r['previous_days'][1]['date']);
+        self::assertEqualsWithDelta(31.7, $r['month_total'], 0.0001);
+    }
+
+    public function testMissingTodayFallsBackToSumRain24(): void
+    {
+        $body = $this->fixture('getmeasure');
+        unset($body[(string) $this->now('2026-09-11 03:17')->getTimestamp()]);
+
+        self::assertSame(2.4, RainCalculator::compute($body, $this->now('2026-09-11 14:32'), 2.4)['today']);
+        self::assertNull(RainCalculator::compute($body, $this->now('2026-09-11 14:32'), null)['today']);
+    }
+
+    public function testMonthBoundaryKeepsPreviousDaysButNotInMonthTotal(): void
+    {
+        $r = RainCalculator::compute($this->fixture('getmeasure-month'), $this->now('2026-10-02 09:00'), null);
+
+        self::assertSame(5.0, $r['today']);
+        self::assertSame([
+            ['date' => '2026-09-29', 'mm' => 2.0],
+            ['date' => '2026-09-30', 'mm' => 3.0],
+            ['date' => '2026-10-01', 'mm' => 4.0],
+        ], $r['previous_days']);
+        self::assertEqualsWithDelta(9.0, $r['month_total'], 0.0001);
+    }
+
+    public function testDaylightSavingTransitionMapsTimestampsToLocalDates(): void
+    {
+        $r = RainCalculator::compute($this->fixture('getmeasure-dst'), $this->now('2026-10-25 12:00'), null);
+
+        self::assertSame(4.0, $r['today'], 'meting om 01:30 lokaal (nog zomertijd) hoort bij 25 oktober');
+        self::assertSame([
+            ['date' => '2026-10-22', 'mm' => 1.0],
+            ['date' => '2026-10-23', 'mm' => 2.0],
+            ['date' => '2026-10-24', 'mm' => 3.0],
+        ], $r['previous_days']);
+        self::assertEqualsWithDelta(10.0, $r['month_total'], 0.0001, '26 oktober telt niet mee, ook al ligt de timestamp op 25 oktober in UTC');
+    }
+
+    public function testEmptyBodyGivesNulls(): void
+    {
+        $r = RainCalculator::compute([], $this->now('2026-09-11 14:32'), null);
+
+        self::assertNull($r['today']);
+        self::assertSame([null, null, null], array_column($r['previous_days'], 'mm'));
+        self::assertNull($r['month_total']);
+    }
+
+    public function testDateBeginIsMinOfFirstOfMonthAndThreeDaysAgo(): void
+    {
+        self::assertSame('2026-09-01 00:00:00', RainCalculator::dateBegin($this->now('2026-09-15 14:32'))->format('Y-m-d H:i:s'));
+        self::assertSame('2026-09-29 00:00:00', RainCalculator::dateBegin($this->now('2026-10-02 09:00'))->format('Y-m-d H:i:s'));
+        self::assertSame('Europe/Berlin', RainCalculator::dateBegin($this->now('2026-10-02 09:00'))->getTimezone()->getName());
+    }
+}

tests/fixtures/getmeasure-dst.json

@@ -0,0 +1,20 @@
+{
+    "body": {
+        "1792621800": [
+            1
+        ],
+        "1792708200": [
+            2
+        ],
+        "1792794600": [
+            3
+        ],
+        "1792884600": [
+            4
+        ],
+        "1792971000": [
+            9
+        ]
+    },
+    "status": "ok"
+}

tests/fixtures/getmeasure-month.json

@@ -0,0 +1,20 @@
+{
+    "body": {
+        "1790558220": [
+            1
+        ],
+        "1790644620": [
+            2
+        ],
+        "1790731020": [
+            3
+        ],
+        "1790817420": [
+            4
+        ],
+        "1790903820": [
+            5
+        ]
+    },
+    "status": "ok"
+}

tests/fixtures/getmeasure.json

@@ -0,0 +1,40 @@
+{
+    "body": {
+        "1788225420": [
+            4.3
+        ],
+        "1788311820": [
+            0
+        ],
+        "1788398220": [
+            3.2
+        ],
+        "1788484620": [
+            5.1
+        ],
+        "1788571020": [
+            0
+        ],
+        "1788657420": [
+            0
+        ],
+        "1788743820": [
+            15.5
+        ],
+        "1788830220": [
+            1.2
+        ],
+        "1788916620": [
+            6.8
+        ],
+        "1789003020": [
+            0
+        ],
+        "1789089420": [
+            2.4
+        ]
+    },
+    "status": "ok",
+    "time_exec": 0.02,
+    "time_server": 1789129925
+}