class Multiwoven::Integrations::Source::Databricks::Client

def check_connection(connection_config)
  connection_config = connection_config.with_indifferent_access
  create_connection(connection_config)
  ConnectionStatus.new(status: ConnectionStatusType["succeeded"]).to_multiwoven_message
rescue Sequel::DatabaseConnectionError => e
  ConnectionStatus.new(status: ConnectionStatusType["failed"], message: e.message).to_multiwoven_message
end

def create_connection(connection_config)
  Sequel.odbc(drvconnect: generate_drvconnect(connection_config))
end

def create_streams(records)
  group_by_table(records).map do |r|
    Multiwoven::Integrations::Protocol::Stream.new(name: r[:tablename], action: StreamAction["fetch"], json_schema: convert_to_json_schema(r[:columns]))
  end
end

def discover(connection_config)
  connection_config = connection_config.with_indifferent_access
  query = "SELECT table_name, column_name, data_type, is_nullable
          FROM system.information_schema.columns
          WHERE table_schema = \'#{connection_config[:schema]}\' AND table_catalog = \'#{connection_config[:catalog]}\'
          ORDER BY table_name, ordinal_position;"
  db = create_connection(connection_config)
  records = []
  db.fetch(query.gsub("\n", "")) do |row|
    records << row
  end
  catalog = Catalog.new(streams: create_streams(records))
  catalog.to_multiwoven_message
rescue StandardError => e
  handle_exception(
    "DATABRICKS:DISCOVER:EXCEPTION",
    "error",
    e
  )
end

def generate_drvconnect(connection_config)
  "Driver=#{DATABRICKS_DRIVER_PATH};
  Host=#{connection_config[:host]};
  PORT=#{connection_config[:port]};
  SSL=1;
  HTTPPath=#{connection_config[:http_path]};
  PWD=#{connection_config[:access_token]};
  UID=token;
  ThriftTransport=2;AuthMech=3;
  AllowSelfSignedServerCert=1;
  CAIssuedCertNamesMismatch=1"
end

def group_by_table(records)
  records.group_by { |entry| entry[:table_name] }.map do |table_name, columns|
    {
      tablename: table_name,
      columns: columns.map { |column| { column_name: column[:column_name], type: column[:data_type], optional: column[:is_nullable] == "YES" } }
    }
  end
end

def query(connection, query)
  records = []
  connection.fetch(query) do |row|
    records << RecordMessage.new(data: row, emitted_at: Time.now.to_i).to_multiwoven_message
  end
  records
end

def read(sync_config)
  connection_config = sync_config.source.connection_specification
  connection_config = connection_config.with_indifferent_access
  query = sync_config.model.query
  query = batched_query(query, sync_config.limit, sync_config.offset) unless sync_config.limit.nil? && sync_config.offset.nil?
  db = create_connection(connection_config)
  query(db, query)
rescue StandardError => e
  handle_exception(
    "DATABRICKS:READ:EXCEPTION",
    "error",
    e
  )
end