input StringFilterInput {
    eq: String
    in: [String]
    notEq: String
    notIn: [String]
}

input TimeFilterInput {
    departureAfter: DateTime
    departureBefore: DateTime
    departureDuring: DateTime
}

input AirportFilterInput {
    id: StringFilterInput
    city: StringFilterInput
    country: StringFilterInput
    weather: StringFilterInput
}

input FlightFilterInput {
    destination: AirportFilterInput
    origin: AirportFilterInput
    time: TimeFilterInput
}

type Query {
    flight(id: ID!): Flight
    flights(filter: FlightFilterInput): [Flight]!
}