collection: extract numeric aggregation logic to aggregator

nextras · Jul 12, 2022 · 1131b3f · 1131b3f
1 parent 0642852
commit 1131b3f
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Showing 8 changed files with 112 additions and 101 deletions.
diff --git a/src/Collection/Aggregations/IArrayAggregator.php b/src/Collection/Aggregations/IArrayAggregator.php
@@ -10,7 +10,7 @@ interface IArrayAggregator extends IAggregator
 {
 	/**
 	 * @param array<T> $values
-	 * @return T
+	 * @return T|null
 	 */
 	function aggregateValues(array $values);
 }
diff --git a/src/Collection/Aggregations/NumericAggregator.php b/src/Collection/Aggregations/NumericAggregator.php
@@ -0,0 +1,54 @@
+<?php declare(strict_types = 1);
+
+namespace Nextras\Orm\Collection\Aggregations;
+
+
+use Nextras\Dbal\QueryBuilder\QueryBuilder;
+use Nextras\Orm\Collection\Functions\Result\DbalExpressionResult;
+
+
+/**
+ * @internal
+ * @implements IArrayAggregator<number>
+ */
+class NumericAggregator implements IDbalAggregator, IArrayAggregator
+{
+	/**
+	 * @param callable(array<number>): (number|null) $arrayAggregation
+	 * @param literal-string $dbalAggregationFunction
+	 */
+	public function __construct(
+		private readonly mixed $arrayAggregation,
+		private readonly string $dbalAggregationFunction,
+	)
+	{
+	}
+
+
+	public function getAggregateKey(): string
+	{
+		return '_' . $this->dbalAggregationFunction;
+	}
+
+
+	public function aggregateValues(array $values): mixed
+	{
+		$cb = $this->arrayAggregation;
+		return $cb($values);
+	}
+
+
+	public function aggregateExpression(
+		QueryBuilder $queryBuilder,
+		DbalExpressionResult $expression
+	): DbalExpressionResult
+	{
+		return new DbalExpressionResult(
+			expression: "{$this->dbalAggregationFunction}($expression->expression)",
+			args: $expression->args,
+			joins: $expression->joins,
+			groupBy: $expression->groupBy,
+			isHavingClause: true,
+		);
+	}
+}
diff --git a/src/Collection/Functions/AvgAggregateFunction.php b/src/Collection/Functions/AvgAggregateFunction.php
@@ -3,25 +3,24 @@
 namespace Nextras\Orm\Collection\Functions;
 
 
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 use function array_sum;
 use function count;
 
 
-class AvgAggregateFunction extends BaseAggregateFunction
+class AvgAggregateFunction extends BaseNumericAggregateFunction
 {
 	public function __construct()
 	{
-		parent::__construct('AVG');
-	}
-
-
-	protected function calculateAggregation(array $values)
-	{
-		$count = count($values);
-		if ($count === 0) {
-			return null;
-		}
-
-		return array_sum($values) / $count;
+		parent::__construct(
+			new NumericAggregator(
+				arrayAggregation: static function (array $values) {
+					$count = count($values);
+					if ($count === 0) return null;
+					return array_sum($values) / $count;
+				},
+				dbalAggregationFunction: 'AVG',
+			)
+		);
 	}
 }
diff --git a/...ction/Functions/BaseAggregateFunction.php → ...unctions/BaseNumericAggregateFunction.php b/...ction/Functions/BaseAggregateFunction.php → ...unctions/BaseNumericAggregateFunction.php
@@ -6,6 +6,7 @@
 use Nextras\Dbal\QueryBuilder\QueryBuilder;
 use Nextras\Orm\Collection\Aggregations\IArrayAggregator;
 use Nextras\Orm\Collection\Aggregations\IDbalAggregator;
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 use Nextras\Orm\Collection\Functions\Result\ArrayExpressionResult;
 use Nextras\Orm\Collection\Functions\Result\DbalExpressionResult;
 use Nextras\Orm\Collection\Helpers\ArrayCollectionHelper;
@@ -19,28 +20,15 @@
 use function is_string;
 
 
-abstract class BaseAggregateFunction implements IArrayFunction, IQueryBuilderFunction
+abstract class BaseNumericAggregateFunction implements IArrayFunction, IQueryBuilderFunction
 {
-	/** @var literal-string */
-	private $sqlFunction;
-
-
-	/**
-	 * @param literal-string $sqlFunction
-	 */
-	protected function __construct(string $sqlFunction)
+	protected function __construct(
+		private readonly NumericAggregator $aggregator,
+	)
 	{
-		$this->sqlFunction = $sqlFunction;
 	}
 
 
-	/**
-	 * @param array<number> $values
-	 * @return number|null
-	 */
-	abstract protected function calculateAggregation(array $values);
-
-
 	public function processArrayExpression(
 		ArrayCollectionHelper $helper,
 		IEntity $entity,
@@ -57,7 +45,7 @@ public function processArrayExpression(
 		assert(is_array($valueReference->value));
 
 		return new ArrayExpressionResult(
-			value: $this->calculateAggregation($valueReference->value),
+			value: $this->aggregator->aggregateValues($valueReference->value),
 		);
 	}
 
@@ -75,33 +63,6 @@ public function processQueryBuilderExpression(
 			throw new InvalidStateException("Cannot apply two aggregations simultaneously.");
 		}
 
-		$aggregator = new class implements IDbalAggregator {
-			/** @var literal-string */
-			public $sqlFunction;
-
-
-			public function getAggregateKey(): string
-			{
-				return '_' . $this->sqlFunction;
-			}
-
-
-			public function aggregateExpression(
-				QueryBuilder $queryBuilder,
-				DbalExpressionResult $expression
-			): DbalExpressionResult
-			{
-				return new DbalExpressionResult(
-					expression: "{$this->sqlFunction}($expression->expression)",
-					args: $expression->args,
-					joins: $expression->joins,
-					groupBy: $expression->groupBy,
-					isHavingClause: true,
-				);
-			}
-		};
-		$aggregator->sqlFunction = $this->sqlFunction;
-
-		return $helper->processPropertyExpr($builder, $args[0], $aggregator)->applyAggregator($builder);
+		return $helper->processPropertyExpr($builder, $args[0], $this->aggregator)->applyAggregator($builder);
 	}
 }
diff --git a/src/Collection/Functions/CountAggregateFunction.php b/src/Collection/Functions/CountAggregateFunction.php
@@ -3,19 +3,19 @@
 namespace Nextras\Orm\Collection\Functions;
 
 
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 use function count;
 
 
-class CountAggregateFunction extends BaseAggregateFunction
+class CountAggregateFunction extends BaseNumericAggregateFunction
 {
 	public function __construct()
 	{
-		parent::__construct('COUNT');
-	}
-
-
-	protected function calculateAggregation(array $values)
-	{
-		return count($values);
+		parent::__construct(
+			new NumericAggregator(
+				arrayAggregation: static fn (array $values): int => count($values),
+				dbalAggregationFunction: 'COUNT',
+			)
+		);
 	}
 }
diff --git a/src/Collection/Functions/MaxAggregateFunction.php b/src/Collection/Functions/MaxAggregateFunction.php
@@ -3,24 +3,23 @@
 namespace Nextras\Orm\Collection\Functions;
 
 
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 use function count;
 use function max;
 
 
-class MaxAggregateFunction extends BaseAggregateFunction
+class MaxAggregateFunction extends BaseNumericAggregateFunction
 {
 	public function __construct()
 	{
-		parent::__construct('MAX');
-	}
-
-
-	protected function calculateAggregation(array $values)
-	{
-		if (count($values) === 0) {
-			return null;
-		}
-
-		return max($values);
+		parent::__construct(
+			new NumericAggregator(
+				arrayAggregation: static function (array $values) {
+					if (count($values) === 0) return null;
+					return max($values);
+				},
+				dbalAggregationFunction: 'MAX',
+			)
+		);
 	}
 }
diff --git a/src/Collection/Functions/MinAggregateFunction.php b/src/Collection/Functions/MinAggregateFunction.php
@@ -3,24 +3,23 @@
 namespace Nextras\Orm\Collection\Functions;
 
 
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 use function count;
 use function min;
 
 
-class MinAggregateFunction extends BaseAggregateFunction
+class MinAggregateFunction extends BaseNumericAggregateFunction
 {
 	public function __construct()
 	{
-		parent::__construct('MIN');
-	}
-
-
-	protected function calculateAggregation(array $values)
-	{
-		if (count($values) === 0) {
-			return null;
-		}
-
-		return min($values);
+		parent::__construct(
+			new NumericAggregator(
+				arrayAggregation: static function (array $values) {
+					if (count($values) === 0) return null;
+					return min($values);
+				},
+				dbalAggregationFunction: 'MIN',
+			)
+		);
 	}
 }
diff --git a/src/Collection/Functions/SumAggregateFunction.php b/src/Collection/Functions/SumAggregateFunction.php
@@ -3,19 +3,18 @@
 namespace Nextras\Orm\Collection\Functions;
 
 
-use function array_sum;
+use Nextras\Orm\Collection\Aggregations\NumericAggregator;
 
 
-class SumAggregateFunction extends BaseAggregateFunction
+class SumAggregateFunction extends BaseNumericAggregateFunction
 {
 	public function __construct()
 	{
-		parent::__construct('SUM');
-	}
-
-
-	protected function calculateAggregation(array $values)
-	{
-		return array_sum($values);
+		parent::__construct(
+			new NumericAggregator(
+				arrayAggregation: static fn (array $values) => array_sum($values),
+				dbalAggregationFunction: 'SUM',
+			)
+		);
 	}
 }