Digitigrade/Db/Migrator.php


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<?php
namespace Digitigrade\Db;

use Digitigrade\Db;
use Digitigrade\Singleton;

class Migrator extends Singleton {
    private array $migrations = [];

    public function register(int $newVersion, callable $fn) {
        $this->migrations[$newVersion] = $fn;
    }

    /**
     * Runs all available migrations
     * @return void
     */
    public function migrate() {
        $db = Db::getInstance();
        $currentVersion = null;
        try {
            $currentVersion = $db->getDbVersion();
            error_log('starting on version ' . $currentVersion);
        } catch (\PDOException $e) {
            if ($e->getCode() == '42P01') { // undefined table
                error_log("initialising database because db version table doesn't exist");
                $db->runInitialSchema();
                $currentVersion = $db->getDbVersion();
                error_log('starting on version ' . $currentVersion);
            } else
                throw $e;
        }

        // find migrations that haven't been run yet
        $available = array_filter($this->migrations, function (int $key) use ($currentVersion) {
            return $key > $currentVersion;
        }, ARRAY_FILTER_USE_KEY);

        try {
            // run them in order (at least they should be in order?)
            foreach (array_keys($available) as $version) {
                $fn = $available[$version];
                $filename = basename((new \ReflectionFunction($fn))->getFileName());
                error_log("running migration $filename");
                $available[$version]($db->getPdo());
                $db->setDbVersion($version);
            }
        } finally {
            error_log('now on version ' . $db->getDbVersion());
        }
    }
}