FlurSchnaps-Server/Sources/App/configure.swift

import Vapor
import SwiftyGPIO

var apns: APNSInterface?
var tokenStorage: TokenStorage!

// configures your application
public func configure(_ app: Application) throws {
    
    let resourcesFolderUrl = URL(fileURLWithPath: app.directory.resourcesDirectory)
    let configUrl = resourcesFolderUrl.appendingPathComponent("config.json")
    
    tokenStorage = .init(in: resourcesFolderUrl)
    
    let config: ServerConfiguration
    do {
        let data = try Data(contentsOf: configUrl)
        config = try JSONDecoder().decode(from: data)
    } catch {
        print("Failed to load config from \(configUrl.path): \(error)")
        return
    }
    
    app.http.server.configuration.port = config.port
    
    apns = .init(config)
    guard apns != nil else {
        serverStatus = .failedToStart
        return
    }
    
    configureGPIO(config)
    
    // register routes
    try routes(app)
    
    serverStatus = .running
}

private extension JSONDecoder {
    
    func decode<T>(from data: Data) throws -> T where T: Decodable {
        try self.decode(T.self, from: data)
    }
}

private func configureGPIO(_ config: ServerConfiguration) {
    let gpio = RaspberryGPIO(
        name: "GPIO\(config.buttonPin)",
        id: config.buttonPin,
        baseAddr: 0x7E000000)

    gpio.direction = .IN
    gpio.pull = .down
    gpio.bounceTime = config.bounceTime
    gpio.onChange { _ in
        log(info: "Push detected")
        sendPush()
    }
    log(info: "GPIO \(config.buttonPin) configured")
}

private func sendPush() {
    guard !tokenStorage.tokens.isEmpty else {
        log(info: "No tokens registered to send push")
        return
    }
    Task(priority: .userInitiated) {
        await apns?.sendPush(to: tokenStorage.tokens)
    }
}