package se.bilhalsning;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;
import org.junit.jupiter.api.Test;

class FlywayMigrationFilesTest {

    private static final Pattern VERSION_PATTERN = Pattern.compile("^V(\\d+)__.+\\.sql$");
    private static final Path MIGRATION_DIR = Path.of("src/main/resources/db/migration");

    @Test
    void shouldUseUniqueVersionNumbersAndValidNames() throws IOException {
        assertTrue(
                Files.isDirectory(MIGRATION_DIR),
                () -> "Expected migration directory at " + MIGRATION_DIR.toAbsolutePath());

        Set<Integer> versions = new HashSet<>();

        try (Stream<Path> files = Files.list(MIGRATION_DIR)) {
            for (Path file : files.filter(path -> path.getFileName().toString().endsWith(".sql")).toList()) {
                String name = file.getFileName().toString();
                Matcher matcher = VERSION_PATTERN.matcher(name);
                assertTrue(matcher.matches(), () -> "Invalid migration filename: " + name);

                int version = Integer.parseInt(matcher.group(1));
                assertFalse(
                        versions.contains(version),
                        () -> "Duplicate Flyway version V" + version + " in " + MIGRATION_DIR);
                versions.add(version);
            }
        }

        assertFalse(versions.isEmpty(), "Expected at least one schema migration");
    }
}