Sources/ApacheBeam/Coders/BeamValue.swift

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 *  License); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an  AS IS BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import Foundation

/// An enum representing values coming over the FnApi Data Plane.
public indirect enum BeamValue {
    /// A value not representable in the Swift SDK
    case invalid(String)

    // Scalar values

    /// Bytes coded
    case bytes(Data?)
    /// UTF8 Strings
    case string(String?)
    /// Integers (Signed 64-bit)
    case integer(Int?)
    /// Doubles
    case double(Double?)
    /// Booleans
    case boolean(Bool?)
    /// A window
    case window(Window)
    /// Schema-valued thing. Doesn't technically need to be a row, but that's the only coder support.
    case row(FieldValue)

    // Composite Values

    /// An iterable
    case array([BeamValue])
    /// A key-value pair
    case kv(BeamValue, BeamValue)
    /// A windowed value
    case windowed(BeamValue, Date, UInt8, BeamValue)

    /// Convenience method for extacting the base value from one
    /// of the scalar representations.
    var baseValue: Any? {
        switch self {
        case let .bytes(d):
            d
        case let .string(s):
            s
        case let .integer(i):
            i
        case let .double(d):
            d
        case let .boolean(b):
            b
        case let .window(w):
            w
        case let .row(r):
            r.baseValue
        default:
            nil as Any?
        }
    }
}