import RealmSwift

func masterRealm() throws -> Realm {
    return try MasterRealm.realm()
}

enum MasterRealm {
    static func realm() throws -> Realm {
        return try Realm(configuration: configuration)
    }

    static var configuration: Realm.Configuration {
        let objectTypes: [RealmSwift.Object.Type] = [
            Category.self,
        ]

        let migrationBlock: MigrationBlock = { migration, oldSchemaVersion in
            print("master migration block ")
            // 初期データファイルコピーのためのダミーマイグレーション
            if oldSchemaVersion < 1 {}
            print("master migration complete.")
        }

        return Realm.Configuration(
            fileURL: fileURL,
            schemaVersion: UInt64(schemaVersion),
            migrationBlock: migrationBlock,
            objectTypes: objectTypes
        )
    }

    private static var fileURL: URL {
        let path = NSSearchPathForDirectoriesInDomains(.documentDirectory,
                                                       .userDomainMask, true).first!
        return URL(fileURLWithPath: path).appendingPathComponent(filename)
    }

    private static var filename: String { return "master.realm" }

    private static var schemaVersion: Int {
        return Bundle.main.infoDictionary!["Master Realm Schema Version"] as! Int
    }
}