<?php

namespace DoctrineMigrations;

use Doctrine\DBAL\Connection;
use Doctrine\DBAL\Schema\Index;
use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;

final class Version20260912000400 extends AbstractMigration
{
    public function getDescription(): string
    {
        return 'Page hierarchy, public paths and content types without changing any stored document.';
    }

    public function isTransactional(): bool
    {
        return false;
    }

    /**
     * Columns only. Changing an index here would make Doctrine rebuild the whole page table on
     * SQLite, which the foreign key from revision.page_id rejects. The indexes are swapped in
     * applyIndexes() instead, after the backfill has given every row a unique path.
     */
    public function up(Schema $schema): void
    {
        $page = $schema->getTable('page');
        // Nullable on purpose: the unique path index is created while existing rows are still
        // empty, and repeated NULLs do not collide in either SQLite or MySQL. The repository
        // never writes a page without a path.
        $page->addColumn('path', 'string', ['length' => 400, 'notnull' => false]);
        // No foreign key: adding one would force the same table rebuild described above.
        // PageRepository resolves and checks the parent inside the same transaction as every write.
        $page->addColumn('parent_id', 'string', ['length' => 64, 'notnull' => false]);
        $page->addColumn('type', 'string', ['length' => 16, 'notnull' => true, 'default' => 'page']);
        $page->addColumn('created_at', 'datetime_immutable', ['notnull' => false]);
    }

    public function postUp(Schema $schema): void
    {
        // Every existing page is a root page, so its public path already equals its slug.
        $this->connection->executeStatement('UPDATE page SET path = slug WHERE path IS NULL');
        $this->connection->executeStatement('UPDATE page SET created_at = ? WHERE created_at IS NULL', [gmdate('Y-m-d H:i:s')]);
        $open = (int) $this->connection->fetchOne('SELECT COUNT(*) FROM page WHERE path IS NULL');
        $this->abortIf(0 !== $open, 'Backfill left pages without a public path. Restore the backup taken before this migration.');
        self::applyIndexes($this->connection);
    }

    /**
     * A slug only has to be unique among its siblings, so the site-wide unique index moves from
     * the slug to the full path. Shared with the test bootstraps so they exercise the same
     * constraints as a migrated database.
     */
    public static function applyIndexes(Connection $connection): void
    {
        $platform = $connection->getDatabasePlatform();
        $manager = $connection->createSchemaManager();
        $existing = $manager->listTableIndexes('page');
        foreach ($existing as $name => $index) {
            if ($index->isUnique() && ['website_id', 'locale', 'slug'] === $index->getUnquotedColumns()) {
                $connection->executeStatement($platform->getDropIndexSQL($name, 'page'));
            }
        }
        foreach ([
            new Index('uniq_page_path', ['website_id', 'locale', 'path'], true),
            new Index('idx_page_parent', ['parent_id']),
        ] as $index) {
            if (!isset($existing[$index->getName()])) {
                $connection->executeStatement($platform->getCreateIndexSQL($index, 'page'));
            }
        }
    }

    public function down(Schema $schema): void
    {
        $this->throwIrreversibleMigrationException('Removing the hierarchy would drop parent references of customer pages. Restore a verified database backup with matching code.');
    }
}