first commit

src/andrewkydev/Database/Migration/Migration.php

@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace andrewkydev\Database\Migration;
+
+use andrewkydev\Database\Query\QueryRunner;
+use andrewkydev\Database\Schema\SchemaManager;
+
+interface Migration {
+    public function version(): int;
+
+    public function up(SchemaManager $schema, QueryRunner $query): void;
+}

src/andrewkydev/Database/Migration/MigrationManager.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace andrewkydev\Database\Migration;
+
+use andrewkydev\Database\Config\DatabaseConfig;
+use andrewkydev\Database\Query\QueryRunner;
+use andrewkydev\Database\Schema\SchemaManager;
+
+final class MigrationManager {
+    /** @var array<int, Migration> */
+    private array $migrations = [];
+
+    public function __construct(
+        private SchemaManager $schema,
+        private QueryRunner $query,
+        private DatabaseConfig $config
+    ) {
+    }
+
+    public function register(Migration $migration): void {
+        $this->migrations[$migration->version()] = $migration;
+    }
+
+    public function runPending(): void {
+        if (!$this->config->migrationsEnabled) {
+            return;
+        }
+        $this->ensureTable();
+        $applied = $this->appliedVersions();
+        ksort($this->migrations);
+        foreach ($this->migrations as $version => $migration) {
+            if (in_array($version, $applied, true)) {
+                continue;
+            }
+            $migration->up($this->schema, $this->query);
+            $this->query->execute(
+                'INSERT INTO ' . $this->config->migrationsTable . ' (version, applied_at) VALUES (?, ?)',
+                [$version, date('Y-m-d H:i:s')]
+            );
+        }
+    }
+
+    private function ensureTable(): void {
+        $sql = 'CREATE TABLE IF NOT EXISTS ' . $this->config->migrationsTable . ' ('
+            . 'version INT PRIMARY KEY, '
+            . 'applied_at VARCHAR(32) NOT NULL'
+            . ')';
+        $this->query->execute($sql);
+    }
+
+    /**
+     * @return int[]
+     */
+    private function appliedVersions(): array {
+        $rows = $this->query->query('SELECT version FROM ' . $this->config->migrationsTable);
+        $versions = [];
+        foreach ($rows as $row) {
+            $versions[] = (int) $row['version'];
+        }
+        return $versions;
+    }
+}