Add PagesInterface::getNbPages()

src/Exception/InvalidPerPageException.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ray\MediaQuery\Exception;
+
+/**
+ * PerPage must be a positive integer
+ */
+final class InvalidPerPageException extends LogicException
+{
+}

src/MappedPages.php

@@ -61,4 +61,10 @@ public function count(): int
     {
         return $this->pages->count();
     }
+
+    #[Override]
+    public function getNbPages(): int
+    {
+        return $this->pages->getNbPages();
+    }
 }

src/Pages.php

@@ -9,16 +9,26 @@
 use Ray\AuraSqlModule\Pagerfanta\AuraSqlPagerInterface;
 use Ray\AuraSqlModule\Pagerfanta\ExtendedPdoAdapter;
 use Ray\AuraSqlModule\Pagerfanta\Page;
+use Ray\MediaQuery\Exception\InvalidPerPageException;
 use Ray\MediaQuery\Exception\LogicException;
 
+use function ceil;
 use function is_array;
+use function max;
 
 /** @template T of class-string|mixed */
 final class Pages implements PagesInterface
 {
     /** @var (callable(array<array-key, mixed>): mixed)|null */
     private $rowMapper;
 
+    /**
+     * Memoized result count, shared by count() and getNbPages() as in Pagerfanta
+     *
+     * @var int<0, max>|null
+     */
+    private int|null $nbResults = null;
+
     /**
      * @param array<string, mixed>                            $params
      * @param (callable(array<array-key, mixed>): mixed)|null $rowMapper
@@ -28,8 +38,13 @@ public function __construct(
         private ExtendedPdoInterface $pdo,
         private string $sql,
         private array $params,
+        private int $perPage,
         callable|null $rowMapper = null,
     ) {
+        if ($this->perPage < 1) {
+            throw new InvalidPerPageException((string) $this->perPage);
+        }
+
         $this->rowMapper = $rowMapper;
     }
 
@@ -93,6 +108,12 @@ public function offsetUnset(mixed $offset): void
     #[Override]
     public function count(): int
     {
-        return (new ExtendedPdoAdapter($this->pdo, $this->sql, $this->params))->getNbResults();
+        return $this->nbResults ??= (new ExtendedPdoAdapter($this->pdo, $this->sql, $this->params))->getNbResults();
+    }
+
+    #[Override]
+    public function getNbPages(): int
+    {
+        return max(1, (int) ceil($this->count() / $this->perPage));
     }
 }

src/PagesInterface.php

@@ -10,4 +10,8 @@
 /** @extends ArrayAccess<int, mixed> */
 interface PagesInterface extends ArrayAccess, Countable
 {
+    /**
+     * Returns the total number of pages (ceil of result count / perPage, minimum 1 as in Pagerfanta).
+     */
+    public function getNbPages(): int;
 }

src/SqlQuery.php

@@ -236,7 +236,7 @@ public function getPages(string $sqlId, array $values, int $perPage, string $que
         $pager = $this->pagerFactory->newInstance($this->pdo, $this->getSql($sqlId), $values, $perPage, $queryTemplate, $entity);
 
         /** @var array<string, mixed> $values */
-        return new Pages($pager, $this->pdo, $this->getSql($sqlId), $values);
+        return new Pages($pager, $this->pdo, $this->getSql($sqlId), $values, $perPage);
     }
 
     private function getSql(string $sqlId): string

tests/Fake/FakeEmptyPages.php

@@ -40,4 +40,10 @@ public function count(): int
     {
         return $this->iter->count();
     }
+
+    public function getNbPages(): int
+    {
+        // Empty result set is still one (empty) page, as in Pagerfanta
+        return 1;
+    }
 }

tests/Fake/FakePages.php

@@ -30,4 +30,10 @@ public function count(): int
     {
         // TODO: Implement count() method.
     }
+
+    public function getNbPages(): int
+    {
+        // TODO: Implement getNbPages() method.
+        return 0;
+    }
 }

tests/Fake/MappedPagesFakePages.php

@@ -46,4 +46,9 @@ public function count(): int
     {
         return 1;
     }
+
+    public function getNbPages(): int
+    {
+        return 1;
+    }
 }

tests/MappedPagesTest.php

@@ -62,6 +62,17 @@ public function testDelegatesMutationAndCount(): void
         $this->assertSame(1, $pages->count());
     }
 
+    public function testDelegatesGetNbPages(): void
+    {
+        $delegate = $this->pages($this->page([]));
+        $pages = new MappedPages(
+            $delegate,
+            static fn (array $row): array => $row,
+        );
+
+        $this->assertSame(1, $pages->getNbPages());
+    }
+
     private function page(mixed $data): Page
     {
         $reflection = new ReflectionClass(Page::class);

tests/PagesTest.php

@@ -7,6 +7,7 @@
 use Aura\Sql\ExtendedPdoInterface;
 use PHPUnit\Framework\TestCase;
 use Ray\AuraSqlModule\Pagerfanta\AuraSqlPagerInterface;
+use Ray\MediaQuery\Exception\InvalidPerPageException;
 
 final class PagesTest extends TestCase
 {
@@ -20,9 +21,71 @@ public function testOffsetGetReturnsNullWhenDelegateHasNoPage(): void
             $this->createStub(ExtendedPdoInterface::class),
             'SELECT 1',
             [],
+            10,
         );
 
         $this->assertFalse(isset($pages[3]));
         $this->assertNull($pages[3]);
     }
+
+    public function testConstructorRejectsZeroPerPage(): void
+    {
+        $this->expectException(InvalidPerPageException::class);
+
+        new Pages(
+            $this->createStub(AuraSqlPagerInterface::class),
+            $this->createStub(ExtendedPdoInterface::class),
+            'SELECT 1',
+            [],
+            0,
+        );
+    }
+
+    public function testConstructorRejectsNegativePerPage(): void
+    {
+        $this->expectException(InvalidPerPageException::class);
+
+        new Pages(
+            $this->createStub(AuraSqlPagerInterface::class),
+            $this->createStub(ExtendedPdoInterface::class),
+            'SELECT 1',
+            [],
+            -1,
+        );
+    }
+
+    public function testGetNbPagesReturnsOneWhenEmpty(): void
+    {
+        $pdo = $this->createStub(ExtendedPdoInterface::class);
+        $pdo->method('fetchValue')->willReturn('0');
+
+        $pages = new Pages(
+            $this->createStub(AuraSqlPagerInterface::class),
+            $pdo,
+            'SELECT * FROM todo',
+            [],
+            10,
+        );
+
+        $this->assertSame(0, $pages->count());
+        $this->assertSame(1, $pages->getNbPages());
+    }
+
+    public function testCountQueryRunsOnlyOnce(): void
+    {
+        $pdo = $this->createMock(ExtendedPdoInterface::class);
+        $pdo->expects($this->once())->method('fetchValue')->willReturn('3');
+
+        $pages = new Pages(
+            $this->createStub(AuraSqlPagerInterface::class),
+            $pdo,
+            'SELECT * FROM todo',
+            [],
+            2,
+        );
+
+        $this->assertSame(3, $pages->count());
+        $this->assertSame(2, $pages->getNbPages());
+        $this->assertSame(2, $pages->getNbPages());
+    }
 }

tests/SqlQueryTest.php

@@ -108,6 +108,38 @@ public function testPagerCount(Pages $pages): void
         $this->assertSame(2, count($pages));
     }
 
+    /** @param Pages<mixed> $pages */
+    #[Depends('testPager')]
+    public function testPagerNbPages(Pages $pages): void
+    {
+        $this->assertSame(2, $pages->getNbPages());
+    }
+
+    public function testPagerNbPagesWithPerPage2(): void
+    {
+        $this->sqlQuery->exec('todo_add', ['id' => '2', 'title' => 'walk']);
+        $pages = $this->sqlQuery->getPages('todo_list', [], 2);
+
+        $this->assertSame(1, $pages->getNbPages());
+    }
+
+    public function testPagerNbPagesRoundsUp(): void
+    {
+        $this->sqlQuery->exec('todo_add', ['id' => '2', 'title' => 'walk']);
+        $this->sqlQuery->exec('todo_add', ['id' => '3', 'title' => 'sleep']);
+        $pages = $this->sqlQuery->getPages('todo_list', [], 2);
+
+        $this->assertSame(2, $pages->getNbPages());
+    }
+
+    public function testPagerNbPagesMinimumOneWhenEmpty(): void
+    {
+        $pages = $this->sqlQuery->getPages('todo_item', ['id' => '__none__'], 10);
+
+        $this->assertSame(0, count($pages));
+        $this->assertSame(1, $pages->getNbPages());
+    }
+
     public function testCount(): void
     {
         $this->sqlQuery->exec('todo_add', ['id' => '2', 'title' => 'walk']);