From 640d684e442e06228671919cd2d771b358170da9 Mon Sep 17 00:00:00 2001
From: tpetry <github@tpetry.me>
Date: Mon, 26 Feb 2024 14:22:57 +0100
Subject: [PATCH] wip

---
 src/Language/Cast.php       | 58 +++++++++++++++++++++++++++++++++++++
 tests/Language/CastTest.php | 49 +++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 src/Language/Cast.php
 create mode 100644 tests/Language/CastTest.php

diff --git a/src/Language/Cast.php b/src/Language/Cast.php
new file mode 100644
index 0000000..6388e73
--- /dev/null
+++ b/src/Language/Cast.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tpetry\QueryExpressions\Language;
+
+use Illuminate\Contracts\Database\Query\Expression;
+use Illuminate\Database\Grammar;
+use RuntimeException;
+use Tpetry\QueryExpressions\Concerns\IdentifiesDriver;
+use Tpetry\QueryExpressions\Concerns\StringizeExpression;
+
+class Cast implements Expression
+{
+    use IdentifiesDriver;
+    use StringizeExpression;
+
+    /**
+     * @param  'bigint'|'int'  $type
+     */
+    public function __construct(
+        private readonly string|Expression $expression,
+        private readonly string $type,
+    ) {
+    }
+
+    public function getValue(Grammar $grammar): string
+    {
+        $expression = $this->stringize($grammar, $this->expression);
+        $type = match ($this->type) {
+            'bigint' => $this->typeBigInt($grammar),
+
+            'int' => $this->typeInt($grammar),
+            default => throw new RuntimeException("Unknown casting type '{$this->type}'."),
+        };
+
+        return match ($this->identify($grammar)) {
+            'pgsql' => "({$expression})::{$type}",
+            default => "(cast({$expression} as {$type}))",
+        };
+    }
+
+    private function typeBigInt(Grammar $grammar): string
+    {
+        return match ($this->identify($grammar)) {
+            'mysql' => 'signed',
+            default => 'bigint',
+        };
+    }
+
+    private function typeInt(Grammar $grammar): string
+    {
+        return match ($this->identify($grammar)) {
+            'mysql' => 'signed',
+            default => 'int',
+        };
+    }
+}
diff --git a/tests/Language/CastTest.php b/tests/Language/CastTest.php
new file mode 100644
index 0000000..391185e
--- /dev/null
+++ b/tests/Language/CastTest.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Query\Expression;
+use Illuminate\Database\Schema\Blueprint;
+use Tpetry\QueryExpressions\Language\Cast;
+
+it('can cast a column to an bigint')
+    ->expect(new Cast('val', 'bigint'))
+    ->toBeExecutable(function (Blueprint $table) {
+        $table->string('val');
+    })
+    ->toBeMysql('cast(`val` as signed)')
+    ->toBePgsql('("val")::bigint')
+    ->toBeSqlite('cast("val" as bigint)')
+    ->toBeSqlsrv('cast([val] as bigint)');
+
+it('can cast an expression to an bigint')
+    ->expect(new Cast(new Expression(3.1415), 'bigint'))
+    ->toBeExecutable()
+    ->toBeMysql('cast(3.1415` as signed)')
+    ->toBePgsql('(3.1415)::bigint')
+    ->toBeSqlite('cast(3.1415 as bigint)')
+    ->toBeSqlsrv('cast(3.1415 as bigint)');
+
+it('can cast a column to an int')
+    ->expect(new Cast('val', 'int'))
+    ->toBeExecutable(function (Blueprint $table) {
+        $table->string('val');
+    })
+    ->toBeMysql('cast(`val` as signed)')
+    ->toBePgsql('("val")::int')
+    ->toBeSqlite('cast("val" as int)')
+    ->toBeSqlsrv('cast([val] as int)');
+
+it('can cast an expression to an int')
+    ->expect(new Cast(new Expression(3.1415), 'int'))
+    ->toBeExecutable()
+    ->toBeMysql('cast(3.1415` as signed)')
+    ->toBePgsql('(3.1415)::int')
+    ->toBeSqlite('cast(3.1415 as int)')
+    ->toBeSqlsrv('cast(3.1415 as int)');
+
+it('throws an exception for unknown types', fn (string $type) => new Cast('0', $type))->with([
+    'enum',
+    'varchar',
+    'timestamptz',
+]);