import 'package:drift/drift.dart';
import 'package:drift/internal/versioned_schema.dart';
import 'package:drift_dev/api/migrations.dart';

import 'tables.dart';
import 'src/versions.dart';

part 'database.g.dart';

/// This isn't a Flutter app, so we have to define the constant. In a real app,
/// just use the constant defined in the Flutter SDK.
const kDebugMode = true;

@DriftDatabase(
  tables: [Users],
  include: {'tables.drift'},
)
class Database extends _$Database {
  static const latestSchemaVersion = 10;

  @override
  int get schemaVersion => latestSchemaVersion;

  Database(DatabaseConnection super.connection);

  @override
  MigrationStrategy get migration {
    return MigrationStrategy(
      onUpgrade: (m, from, to) async {
        // Following the advice from https://drift.simonbinder.eu/docs/advanced-features/migrations/#tips
        await customStatement('PRAGMA foreign_keys = OFF');

        await transaction(
          () => VersionedSchema.runMigrationSteps(
            migrator: m,
            from: from,
            to: to,
            steps: _upgrade,
          ),
        );

        if (kDebugMode) {
          final wrongForeignKeys =
              await customSelect('PRAGMA foreign_key_check').get();
          assert(wrongForeignKeys.isEmpty,
              '${wrongForeignKeys.map((e) => e.data)}');
        }

        await customStatement('PRAGMA foreign_keys = ON');
      },
      beforeOpen: (details) async {
        // For Flutter apps, this should be wrapped in an if (kDebugMode) as
        // suggested here: https://drift.simonbinder.eu/docs/advanced-features/migrations/#verifying-a-database-schema-at-runtime
        await validateDatabaseSchema();
      },
    );
  }

  static final _upgrade = migrationSteps(
    from1To2: (m, schema) async {
      // Migration from 1 to 2: Add name column in users. Use "no name"
      // as a default value.

      await m.alterTable(
        TableMigration(
          schema.users,
          columnTransformer: {
            schema.users.name: const Constant<String>('no name'),
          },
          newColumns: [schema.users.name],
        ),
      );
    },
    from2To3: (m, schema) async => m.createTable(schema.groups),
    from3To4: (m, schema) async {
      // Migration from 3 to 4: users.name now has a default value
      // No need to transform any data, just re-create the table
      final usersAtV4 = schema.users;

      await m.alterTable(TableMigration(usersAtV4));
    },
    from4To5: (m, schema) async {
      // Just add a new column that was added in version 5;
      await m.addColumn(schema.users, schema.users.nextUser);

      // And create the view on users
      await m.createView(schema.groupCount);
    },
    from5To6: (m, schema) async {
      await m.addColumn(schema.users, schema.users.birthday);
    },
    from6To7: (m, schema) async {
      await m.createTable(schema.notes);
    },
    from7To8: (m, schema) async {
      // Added a unique key to the users table
      await m.alterTable(TableMigration(schema.users));
    },
    from8To9: (m, schema) async {
      // Added a check to the users table
      await m.alterTable(TableMigration(schema.users));
    },
    from9To10: (m, schema) async {
      // Added an index to the users table
      await m.create(schema.userName);
    },
  );
}