/// Parses `--audio-route "<kind>:<source>=<device>:<channel>"` launch arguments (scripted tests until scenes exist).
///
/// `kind` is `ndi` (NDI source name) or `input` (input device name, substring match).
/// `device` is an output device name (substring match), `channel` is 1-based.
/// Example: `--audio-route "ndi:ZOWIEBOX (PGM)=MOTU:2"`
public enum AudioRouteArgument {
    public enum Kind: String, Sendable { case ndi, input }

    public struct Parsed: Equatable, Sendable {
        public var kind: Kind
        public var source: String
        public var device: String
        public var channel: Int // 1-based
    }

    public static func parse(_ arguments: [String]) -> [Parsed] {
        zip(arguments, arguments.dropFirst()).compactMap { flag, value in
            guard flag == "--audio-route",
                  let colon = value.firstIndex(of: ":"),
                  let kind = Kind(rawValue: String(value[..<colon])),
                  let equals = value.lastIndex(of: "="),
                  equals > colon
            else { return nil }
            let source = String(value[value.index(after: colon)..<equals])
            let target = value[value.index(after: equals)...]
            guard let lastColon = target.lastIndex(of: ":"),
                  let channel = Int(target[target.index(after: lastColon)...]), channel >= 1
            else { return nil }
            let device = String(target[..<lastColon])
            guard !source.isEmpty, !device.isEmpty else { return nil }
            return Parsed(kind: kind, source: source, device: device, channel: channel)
        }
    }
}