func show()

in json-rpc/Sources/LightsdDemo/main.swift [108:195]
78 lines of code
23 McCabe index (conditional complexity)

func show(_ client: TCPClient) {
    let colors: [Color] = [.red, .orange, .yellow, .green, .blue, .purple]

    // read lights state
    var bulbs: [Lifx]
    switch try! client.call(method: "get_light_state", params: RPCObject(["target": "*"])).wait() {
    case .failure(let error):
        fatalError("get_light_state failed with \(error)")
    case .success(let response):
        switch response {
        case .list(let value):
            bulbs = value.map { Lifx($0) }.compactMap { $0 }
        default:
            fatalError("unexpected reponse with \(response)")
        }
    }
    if 0 == bulbs.count {
        fatalError("no bulbs found")
    }

    off(client, id: "*")
    sleep(1)

    var bulbIndex = 0
    for _ in 0 ..< bulbs.count * 10 {
        for (index, bulb) in bulbs.enumerated() {
            if index == bulbIndex {
                on(client, id: bulb.id, color: .white, transition: 100)
            } else {
                off(client, id: bulb.id)
            }
        }
        bulbIndex = bulbIndex < bulbs.count - 1 ? bulbIndex + 1 : 0
        usleep(300_000)
    }

    off(client, id: "*")
    sleep(1)

    bulbIndex = 0
    for colorIndex in 0 ..< colors.count {
        for _ in 0 ..< bulbs.count {
            for (index, bulb) in bulbs.enumerated() {
                if index == bulbIndex {
                    on(client, id: bulb.id, color: colors[colorIndex], transition: 100)
                } else {
                    off(client, id: bulb.id)
                }
            }
            bulbIndex = bulbIndex < bulbs.count - 1 ? bulbIndex + 1 : 0
            usleep(300_000)
        }
    }

    off(client, id: "*")
    sleep(1)

    bulbIndex = 0
    var colorIndex = 0
    for _ in 0 ..< bulbs.count * colors.count {
        for (index, bulb) in bulbs.enumerated() {
            if index == bulbIndex {
                on(client, id: bulb.id, color: colors[colorIndex], transition: 100)
                colorIndex = colorIndex < colors.count - 1 ? colorIndex + 1 : 0
            } else {
                off(client, id: bulb.id)
            }
        }
        bulbIndex = bulbIndex < bulbs.count - 1 ? bulbIndex + 1 : 0
        usleep(300_000)
    }

    off(client, id: "*")
    sleep(1)

    var colorsMap: [String: Color] = bulbs.enumerated().reduce(into: [String: Color]()) {
        $0[$1.element.id] = $1.offset < colors.count ? colors[$1.offset] : colors.first!
    }
    while true {
        for bulb in bulbs {
            let clr = colorsMap[bulb.id] ?? colors.first!
            on(client, id: bulb.id, color: clr, transition: 100)
            let newIndex = colors.firstIndex(of: clr)! + 1
            colorsMap[bulb.id] = newIndex < colors.count ? colors[newIndex] : colors.first!
        }
        usleep(300_000)
    }
}