refactor: split service into ServiceBase and LiveService

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

tests/php/Unit/LiveServiceTest.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace KTXT\ProviderImap\Tests\Unit;
+
+use KTXM\ProviderImap\Providers\ServiceBase;
+use KTXM\ProviderImap\Providers\LiveService;
+use KTXM\ProviderImap\Service\Live\LiveMailService;
+use PHPUnit\Framework\TestCase;
+use ReflectionProperty;
+
+final class LiveServiceTest extends TestCase
+{
+    public function testEntityExtantReportsExistenceOfEachIdentifier(): void
+    {
+        $service = new LiveService();
+        $live = new LiveServiceTestLiveStub($this->createStub(ServiceBase::class));
+        $live->existing = [5];
+        (new ReflectionProperty(LiveService::class, 'mailService'))->setValue($service, $live);
+
+        $result = $service->entityExtant('INBOX', 5, '6', 'abc', 0);
+
+        $this->assertSame([5 => true, 6 => false, 'abc' => false, 0 => false], $result);
+        $this->assertSame([['INBOX', [5, 6]]], $live->extantCalls);
+    }
+}
+
+final class LiveServiceTestLiveStub extends LiveMailService
+{
+    /** @var int[] */
+    public array $existing = [];
+    public array $extantCalls = [];
+
+    public function entityExtant(string $collection, int ...$uids): array
+    {
+        $this->extantCalls[] = [$collection, $uids];
+        return array_values(array_intersect($uids, $this->existing));
+    }
+}