<?php

declare(strict_types=1);

namespace MeshVault\Tests\Integration;

use PDO;
use Phinx\Config\Config;
use Phinx\Migration\Manager;
use Symfony\Component\Console\Input\ArrayInput;
use Symfony\Component\Console\Output\NullOutput;

/** Runs production migrations against SQLite, or an explicitly configured PostgreSQL database. */
final class RepositoryDatabase
{
    /** @var array<string, array{schema: string, connection: PDO}> */
    private static array $schemas = [];

    /** @var array<string, Config> */
    private static array $configs = [];

    public static function migrateTo(string $path, int $target): void
    {
        self::runTarget($path, $target, false);
    }

    public static function rollbackTo(string $path, int $target): void
    {
        self::runTarget($path, $target, true);
    }

    private static function runTarget(string $path, int $target, bool $down): void
    {
        $config = self::$configs[$path] ?? throw new \LogicException('Migrate this isolated path first.');
        $manager = new Manager($config, new ArrayInput([]), new NullOutput());
        $pdo = $config->getEnvironment('test')['connection'];
        if ($pdo->inTransaction()) {
            throw new \LogicException('Migration helpers require no active caller transaction.');
        }
        try {
            if ($down) {
                $manager->rollback('test', $target);
            } else {
                $manager->migrate('test', $target);
            }
        } catch (\Throwable $error) {
            if ($pdo->inTransaction()) {
                $pdo->rollBack();
            }
            throw $error;
        } finally {
            if (isset(self::$schemas[$path])) {
                $pdo->exec('SET search_path TO "' . self::$schemas[$path]['schema'] . '"');
            }
        }
    }

    public static function postgresConfigured(): bool
    {
        $dsn = getenv('MESHVAULT_TEST_PG_DSN');
        return $dsn !== false && $dsn !== '';
    }

    /** Never a hand-maintained test schema: drift must fail the suite. */
    public static function migrate(string $path, ?int $target = null): PDO
    {
        if (isset(self::$configs[$path]) || isset(self::$schemas[$path])) {
            throw new \LogicException('Clean up the previous database before migrating this path again.');
        }
        $environment = ['adapter' => 'sqlite'];
        if (self::postgresConfigured()) {
            $pdo = self::postgresConnection();
            $schema = 'meshvault_test_' . bin2hex(random_bytes(16));
            $pdo->exec('CREATE SCHEMA "' . $schema . '"');
            self::$schemas[$path] = ['schema' => $schema, 'connection' => $pdo];
            $pdo->exec('SET search_path TO "' . $schema . '"');
            $environment = ['adapter' => 'pgsql', 'schema' => $schema];
        } else {
            $pdo = self::connect($path);
        }
        try {
            $config = new Config([
                'paths' => ['migrations' => dirname(__DIR__, 2) . '/db/migrations'],
                'environments' => [
                    'default_migration_table' => 'phinxlog',
                    'default_database' => 'test',
                    'test' => $environment + ['connection' => $pdo],
                ],
            ]);
            self::$configs[$path] = $config;
            (new Manager($config, new ArrayInput([]), new NullOutput()))->migrate('test', $target);
            if (isset(self::$schemas[$path])) {
                // Phinx may add public to search_path; repository queries must remain isolated.
                $pdo->exec('SET search_path TO "' . self::$schemas[$path]['schema'] . '"');
            }
            return $pdo;
        } catch (\Throwable $error) {
            self::cleanup($path);
            throw $error;
        }
    }

    public static function connect(string $path): PDO
    {
        if (isset(self::$schemas[$path])) {
            $pdo = self::postgresConnection();
            $pdo->exec('SET search_path TO "' . self::$schemas[$path]['schema'] . '"');
            return $pdo;
        }
        if (self::postgresConfigured()) {
            throw new \LogicException('Migrate this path before connecting to PostgreSQL.');
        }
        $pdo = new PDO('sqlite:' . $path, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
        $pdo->exec('PRAGMA foreign_keys = ON');
        $pdo->exec('PRAGMA busy_timeout = 5000');
        return $pdo;
    }

    public static function cleanup(string $path): void
    {
        unset(self::$configs[$path]);
        if (isset(self::$schemas[$path])) {
            ['schema' => $schema, 'connection' => $pdo] = self::$schemas[$path];
            if ($pdo->inTransaction()) {
                $pdo->rollBack();
            }
            // Only identifiers generated and registered by migrate() can reach this statement.
            $pdo->exec('DROP SCHEMA "' . $schema . '" CASCADE');
            unset(self::$schemas[$path]);
        }
        if (is_file($path)) {
            unlink($path);
        }
    }

    private static function postgresConnection(): PDO
    {
        $dsn = (string) getenv('MESHVAULT_TEST_PG_DSN');
        if (!str_starts_with($dsn, 'pgsql:')) {
            throw new \InvalidArgumentException('MESHVAULT_TEST_PG_DSN must be a pgsql: DSN.');
        }
        return new PDO(
            $dsn,
            ($user = getenv('MESHVAULT_TEST_PG_USER')) === false ? null : $user,
            ($password = getenv('MESHVAULT_TEST_PG_PASSWORD')) === false ? null : $password,
            [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION],
        );
    }

    public static function directory(string $prefix): string
    {
        $path = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'meshvault-' . $prefix . '-' . bin2hex(random_bytes(6));
        mkdir($path, 0777, true);
        return (string) realpath($path);
    }

    public static function remove(string $path): void
    {
        foreach (array_diff(@scandir($path) ?: [], ['.', '..']) as $entry) {
            $child = $path . DIRECTORY_SEPARATOR . $entry;
            is_dir($child) ? self::remove($child) : @unlink($child);
        }
        @rmdir($path);
    }
}