<?php

declare(strict_types=1);

namespace MeshVault\Tests\Integration;

use DomainException;
use MeshVault\Repository\PdoCatalogRepository;
use PDO;
use PDOException;
use PHPUnit\Framework\Attributes\DataProvider;
use PHPUnit\Framework\TestCase;

final class PostgresCatalogTest extends TestCase
{
    private string $database;
    private PDO $pdo;
    private PDO $other;
    private PdoCatalogRepository $catalog;
    private PdoCatalogRepository $contender;
    private \ArrayObject $locks;

    protected function setUp(): void
    {
        if (!RepositoryDatabase::postgresConfigured()) {
            self::markTestSkipped('Set MESHVAULT_TEST_PG_DSN to run PostgreSQL catalog contention tests.');
        }
        $this->database = tempnam(sys_get_temp_dir(), 'meshvault-pg-catalog-');
        $this->pdo = RepositoryDatabase::migrate($this->database);
        $this->other = RepositoryDatabase::connect($this->database);
        foreach ([$this->pdo, $this->other] as $pdo) {
            $pdo->exec("SET lock_timeout = '250ms'");
            $pdo->exec("SET statement_timeout = '5s'");
        }
        $this->locks = new \ArrayObject();
        $this->other->setAttribute(PDO::ATTR_STATEMENT_CLASS, [CatalogLockStatement::class, [$this->locks]]);
        $this->catalog = new PdoCatalogRepository($this->pdo);
        $this->contender = new PdoCatalogRepository($this->other);
        self::assertNotSame(
            $this->pdo->query('SELECT pg_backend_pid()')->fetchColumn(),
            $this->other->query('SELECT pg_backend_pid()')->fetchColumn(),
        );
        self::assertSame(
            $this->pdo->query('SELECT current_schema()')->fetchColumn(),
            $this->other->query('SELECT current_schema()')->fetchColumn(),
        );
    }

    protected function tearDown(): void
    {
        foreach (['pdo', 'other'] as $property) {
            if (isset($this->$property) && $this->$property->inTransaction()) {
                $this->$property->rollBack();
            }
        }
        unset($this->catalog, $this->contender, $this->pdo, $this->other);
        if (isset($this->database)) {
            RepositoryDatabase::cleanup($this->database);
        }
    }

    private function fixture(): array
    {
        $source = $this->catalog->createModel('/parts', 'Source');
        $target = $this->catalog->createModel('/parts', 'Target');
        $low = $this->catalog->recordFile($source, 'parts/low.stl', 'low', 3);
        $high = $this->catalog->recordFile($source, 'parts/high.stl', 'high', 4);
        return [$source, $target, $low, $high];
    }

    private function timeout(callable $operation): void
    {
        try {
            $operation();
            self::fail('Expected a PostgreSQL lock timeout, not a successful write or no-op.');
        } catch (PDOException $error) {
            self::assertSame('55P03', $error->getCode());
        }
    }

    private function files(): array
    {
        return $this->other->query('SELECT * FROM files ORDER BY id')->fetchAll(PDO::FETCH_ASSOC);
    }

    #[DataProvider('transactionOutcomes')]
    public function testUncommittedOwnerBlocksThenCommitRejectsStaleOrRollbackAllowsRetry(bool $commit): void
    {
        [$source, $target, $low, $high] = $this->fixture();
        $before = $this->files();
        $this->pdo->beginTransaction();
        $this->catalog->changeFileOwner([$low, $high], $source, $target);
        $this->timeout(fn () => $this->contender->changeFileOwner([$high, $low], $source, null));
        self::assertFalse($this->other->inTransaction());
        self::assertSame($before, $this->files());
        if ($commit) {
            $this->pdo->commit();
            $committed = $this->files();
            try {
                $this->contender->changeFileOwner([$high, $low], $source, null);
                self::fail('Stale expected ownership must not overwrite the winner.');
            } catch (DomainException $error) {
                self::assertSame('File ownership has changed.', $error->getMessage());
            }
            self::assertSame($committed, $this->files());
            self::assertSame([$target, $target], array_column($committed, 'model_id'));
        } else {
            $this->pdo->rollBack();
            $this->contender->changeFileOwner([$high, $low], $source, null);
            self::assertSame([null, null], array_column($this->files(), 'model_id'));
        }
        self::assertFalse($this->other->inTransaction());
    }

    #[DataProvider('associationTargets')]
    public function testReversedLocksAndNestedFailureReleaseLowerLockWithoutPartialWrites(bool $noop): void
    {
        [$source, $target, $low, $high] = $this->fixture();
        $before = $this->files();
        $this->pdo->beginTransaction();
        $held = $this->pdo->prepare('SELECT id FROM files WHERE id = ? FOR SHARE');
        $held->execute([$high]);
        $held->closeCursor();
        $this->other->beginTransaction();
        $this->other->exec("INSERT INTO tags (name) VALUES ('outer survives')");
        $this->timeout(fn () => $this->contender->changeFileOwner(
            [$high, $low],
            $source,
            $noop ? $source : $target,
        ));
        // A timeout alone cannot establish order, especially when no UPDATE would occur.
        self::assertSame([[$low], [$high]], $this->locks->getArrayCopy());
        self::assertTrue($this->other->inTransaction());
        self::assertSame($before, $this->files());
        self::assertSame('outer survives', $this->other->query('SELECT name FROM tags')->fetchColumn());
        // NOWAIT proves the lower lock was released by B's savepoint rollback, not B's transaction end.
        $released = $this->pdo->prepare('SELECT id FROM files WHERE id = ? FOR UPDATE NOWAIT');
        $released->execute([$low]);
        self::assertSame($low, (int) $released->fetchColumn());
        $released->closeCursor();
        $this->pdo->rollBack();
        $this->contender->changeFileOwner([$high, $low], $source, $noop ? $source : $target);
        self::assertTrue($this->other->inTransaction());
        self::assertSame(
            [$noop ? $source : $target, $noop ? $source : $target],
            array_column($this->files(), 'model_id'),
        );
        $this->other->rollBack();
        self::assertSame($before, $this->files());
        self::assertSame(0, (int) $this->pdo->query('SELECT COUNT(*) FROM tags')->fetchColumn());
    }

    public static function associationTargets(): array
    {
        return ['reassignment' => [false], 'same-owner no-op' => [true]];
    }

    #[DataProvider('creationMethods')]
    public function testRootSerializesCreationAndLegacyLookupAfterRelease(string $method): void
    {
        $this->catalog->createModel('/', 'Root fixture');
        $this->pdo->beginTransaction();
        $winner = $this->catalog->$method('/contested', 'Shared title');
        foreach (['createModel', 'ensureModel'] as $contenderMethod) {
            $this->timeout(fn () => $this->contender->$contenderMethod('/contested', 'Shared title'));
            // A disjoint folder/title cannot contend on the winner's new folder or model rows.
            $this->timeout(fn () => $this->contender->$contenderMethod('/unrelated', 'Other title'));
            self::assertFalse($this->other->inTransaction());
            self::assertSame(1, (int) $this->other->query('SELECT COUNT(*) FROM models')->fetchColumn());
            self::assertSame(1, (int) $this->other->query('SELECT COUNT(*) FROM folders')->fetchColumn());
        }
        $this->pdo->commit();
        self::assertSame($winner, $this->contender->ensureModel('/contested', 'Shared title'));
        $duplicate = $this->contender->createModel('/contested', 'Shared title');
        self::assertNotSame($winner, $duplicate);
        try {
            $this->contender->ensureModel('/contested', 'Shared title');
            self::fail('Legacy lookup must reject two explicit identities.');
        } catch (DomainException $error) {
            self::assertSame('Ambiguous model title in home folder.', $error->getMessage());
        }
        self::assertFalse($this->other->inTransaction());
        self::assertSame(3, (int) $this->other->query('SELECT COUNT(*) FROM models')->fetchColumn());
    }

    public static function creationMethods(): array
    {
        return ['explicit winner' => ['createModel'], 'legacy winner' => ['ensureModel']];
    }

    public static function transactionOutcomes(): array
    {
        return ['commit' => [true], 'rollback' => [false]];
    }
}