Add window() function to Query Builder

Signed-off-by: davidarendsen <davidarendsen@hey.com>

README.md

@@ -39,6 +39,8 @@ composer test
 
 ## Coding style
 
+Run the following commands to check the coding style. We're using the PSR12 standard.
+
 ```
 composer check
 composer format

src/Functions/Window.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace Arendsen\FluxQueryBuilder\Functions;
+
+use Arendsen\FluxQueryBuilder\Type;
+use Arendsen\FluxQueryBuilder\Type\ArrayType;
+use Arendsen\FluxQueryBuilder\Type\DurationType;
+
+class Window extends Base
+{
+    /**
+     * @var string $every
+     */
+    private $every;
+
+    /**
+     * @var string|null $period
+     */
+    private $period;
+
+    /**
+     * @var string|null $offset
+     */
+    private $offset;
+
+    /**
+     * @var string|null $location
+     */
+    private $location;
+
+    /**
+     * @var string|null $timeColumn
+     */
+    private $timeColumn;
+
+    /**
+     * @var string|null $startColumn
+     */
+    private $startColumn;
+
+    /**
+     * @var string|null $stopColumn
+     */
+    private $stopColumn;
+
+    /**
+     * @var bool $createEmpty
+     */
+    private $createEmpty;
+
+    public function __construct(
+        $every,
+        ?string $period = null,
+        ?string $offset = null,
+        ?string $location = null,
+        ?string $timeColumn = null,
+        ?string $startColumn = null,
+        ?string $stopColumn = null,
+        bool $createEmpty = false
+    ) {
+        $this->every = $every;
+        $this->period = $period;
+        $this->offset = $offset;
+        $this->location = $location;
+        $this->timeColumn = $timeColumn;
+        $this->startColumn = $startColumn;
+        $this->stopColumn = $stopColumn;
+        $this->createEmpty = $createEmpty;
+    }
+
+    public function __toString()
+    {
+        $input = new ArrayType(array_filter([
+            'every' => new DurationType($this->every),
+            'period' => $this->period ? new DurationType($this->period) : null,
+            'offset' => $this->offset ? new DurationType($this->offset) : null,
+            'location' => $this->location ? new Type($this->location) : null,
+            'timeColumn' => $this->timeColumn ? new Type($this->timeColumn) : null,
+            'startColumn' => $this->startColumn ? new Type($this->startColumn) : null,
+            'stopColumn' => $this->stopColumn ? new Type($this->stopColumn) : null,
+            'createEmpty' => $this->createEmpty ? new Type($this->createEmpty) : null,
+        ]));
+        return '|> window(' . $input . ') ';
+    }
+}

src/QueryBuilder.php

@@ -13,6 +13,7 @@ use Arendsen\FluxQueryBuilder\Functions\Sort;
 use Arendsen\FluxQueryBuilder\Functions\Map;
 use Arendsen\FluxQueryBuilder\Functions\Group;
 use Arendsen\FluxQueryBuilder\Functions\Limit;
+use Arendsen\FluxQueryBuilder\Functions\Window;
 
 class QueryBuilder
 {
@@ -24,6 +25,7 @@ class QueryBuilder
     public const FLUX_PART_SORT = 'sort';
     public const FLUX_PART_GROUP = 'group';
     public const FLUX_PART_LIMIT = 'limit';
+    public const FLUX_PART_WINDOW = 'window';
 
     public const PARTS = [
         self::FLUX_PART_FROM,
@@ -32,6 +34,7 @@ class QueryBuilder
         self::FLUX_PART_FILTERS,
         self::FLUX_PART_MAP,
         self::FLUX_PART_SORT,
+        self::FLUX_PART_WINDOW,
         self::FLUX_PART_GROUP,
         self::FLUX_PART_LIMIT,
     ];
@@ -167,6 +170,23 @@ class QueryBuilder
         return $this;
     }
 
+    public function addWindow(
+        $every,
+        ?string $period = null,
+        ?string $offset = null,
+        ?string $location = null,
+        ?string $timeColumn = null,
+        ?string $startColumn = null,
+        ?string $stopColumn = null,
+        bool $createEmpty = false
+    ): QueryBuilder {
+        $this->addToQueryArray(
+            self::FLUX_PART_WINDOW,
+            new Window($every, $period, $offset, $location, $timeColumn, $startColumn, $stopColumn, $createEmpty)
+        );
+        return $this;
+    }
+
     protected function addToQuery($key, $query)
     {
         $this->fluxQueryParts[$key] = $query;

src/Type.php

@@ -39,6 +39,8 @@ class Type
                 return new BooleanType($this->value);
             case 'array':
                 return new ArrayType($this->value, $this->settings);
+            case 'NULL':
+                return 'null';
             default:
                 return (string)$this->value;
         }

tests/Functions/WindowFunctionTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Functions;
+
+use Arendsen\FluxQueryBuilder\Functions\Window;
+use PHPUnit\Framework\TestCase;
+
+final class WindowFunctionTest extends TestCase
+{
+    public function testSimpleWindow()
+    {
+        $expression = new Window('20s');
+
+        $query = '|> window(every: 20s) ';
+
+        $this->assertEquals($query, $expression->__toString());
+    }
+
+    public function testAllParameters()
+    {
+        $expression = new Window('20s', 'every', '0s', 'location', '_time', '_start', '_stop', true);
+
+        $query = '|> window(every: 20s, period: every, offset: 0s, location: "location", ' .
+            'timeColumn: "_time", startColumn: "_start", stopColumn: "_stop", createEmpty: true) ';
+
+        $this->assertEquals($query, $expression->__toString());
+    }
+}

tests/Generic/QueryBuilderTest.php

@@ -103,6 +103,7 @@ final class QueryBuilderTest extends TestCase
             ->addFieldFilter(['username', 'ip'])
             ->addMap('r with name: r.user')
             ->addGroup(['_field', 'ip'])
+            ->addWindow('20s')
             ->addReduce(['count' => new MathType('accumulator.count + 1')], ['count' => 0])
             ->addFilter(KeyValue::setGreaterOrEqualTo('count', 1)->andGreaterOrEqualTo('count2', 2));
 
@@ -110,7 +111,7 @@ final class QueryBuilderTest extends TestCase
             '|> reduce(fn: (r, accumulator) => ({count: accumulator.count + 1}), identity: {count: 0}) ' .
             '|> filter(fn: (r) => r._measurement == "test_measurement") |> filter(fn: (r) => ' .
             'r._field == "username" or r._field == "ip") |> filter(fn: (r) => r.count >= 1 and r.count2 >= 2) ' .
-            '|> map(fn: (r) => ({ r with name: r.user })) |> group(columns: ["_field", "ip"], mode: "by") ';
+            '|> map(fn: (r) => ({ r with name: r.user })) |> window(every: 20s) |> group(columns: ["_field", "ip"], mode: "by") ';
 
         $this->assertEquals($expectedQuery, $queryBuilder->build());
     }