2. Vaporを動かす- iPhoneとラズパイ間をVaporで通信 1

$ brew install vapor
$ vapor --help
$ vapor new SwiftHomeServer
# ① Select using Fluent or not. (ORM framework for Swift.)
> Would you like to use Fluent? (--fluent/--no-fluent)　#→ y
# ②Select database(If using in Heroku, ‘Postgres’ is required.)
> Which database would you like to use? (--fluent.db)　#→ y
# ③Select using Leaf or not.(a powerful templating language with Swift-inspired syntax.)
> Would you like to use Leaf? (--leaf/--no-leaf) #→ y or n(this time, n)

$ cd SwiftHomeServer
$ swift run

// (Omit)
func routes(_ app: Application) throws {
    app.get { req async in // ①Called if no endpoint specified
        "It works!"
    }
    // ②can use async/await
    app.get("hello") { req async -> String in // ③Specify the endpoint and method type here
        "Hello, world!"
    }
// (Omit)

import Vapor
import SwiftHomeCredentials

// Ref: https://docs.vapor.codes/security/authentication/
public struct User: Authenticatable {
    public let name: String
}

public struct UserAuthenticator: {
    public init() {}

    public func authenticate(
        basic: BasicAuthorization,
        for request: Request
    ) async throws {
        let userCredential = SwiftHomeCredentials.basicAuthentication // defined in SwiftHomeCredentials
        if basic.username == userCredential.id && basic.password == userCredential.password {
            request.auth.login(User(name: \(username_defined)))
        }
   }
}

// protected is an implementation that applies Basic authentication
let protected = app.grouped(UserAuthenticator())
// ①Post API can be implemented by setting post
protected.post(.constant(EndPointKind.deviceInfo.endPoint)) { req async throws -> HTTPResponseStatus in
    let response = try req.content.decode(DeviceInfoModel.self).asDBModel // ②Convert to model for DB
// (Omit: Process of storing data in Postgres)
    let jsonString = try response.asJsonString() // ③asJsonString converts Encodable to json
    try await deviceInfoWebSocket?.send(jsonString) // ④Send data to Raspberry Pi (details will be described later)
    return .ok // ⑤Returns ok if no Error is thrown
}

import Fluent
import Vapor

public enum DeviceInfoModelFields: FieldKey {
    case deviceId
    case deviceLatitude
    case deviceLongitude
    case absoluteAltimeter
}

public final class DeviceInfoDBModel: Model, Content {

    public static let schema = "DeviceInfo"

    @ID(key: .id)
    public var id: UUID?

    @Field(key: DeviceInfoModelFields.deviceId.rawValue)
    public var deviceId: String
    @Field(key: DeviceInfoModelFields.deviceLatitude.rawValue)
    public var deviceLatitude: Double
    @Field(key: DeviceInfoModelFields.deviceLongitude.rawValue)
    public var deviceLongitude: Double
    @Field(key: DeviceInfoModelFields.absoluteAltimeter.rawValue)
    public var absoluteAltimeter: Double

    public init() {}

    public init(deviceId: String, deviceLatitude: Double, deviceLongitude: Double, absoluteAltimeter: Double) {
        self.id = UUID()
        self.deviceId = deviceId
        self.deviceLatitude = deviceLatitude
        self.deviceLongitude = deviceLongitude
        self.absoluteAltimeter = absoluteAltimeter
    }

    public func update(model: DeviceInfoDBModel) {
        deviceId = model.deviceId
        deviceLatitude = model.deviceLatitude
        deviceLongitude = model.deviceLongitude
        absoluteAltimeter = model.absoluteAltimeter
    }
}

app.migrations.add(CreateDeviceInfo())

try app.register(collection: DeviceInfoController())

// ①If saved, update the data; if not saved, create new
if let deviceInfoModel = try await DeviceInfoDBModel.query(on: req.db) // ②Extract data from DB
    .filter(\.$deviceId == response.deviceId).all().first { // ③Extract all data matching deviceId
    deviceInfoModel.update(model: response)
    try await deviceInfoModel.save(on: req.db) // ④Save updated data
} else {
    try await response.create(on: req.db) // ⑤Save new data
}

// ①Server-side in routes.swift
app.webSocket("echo") { req, ws in // ②Get, Post同様にWebSocketのメソッドを設定する 
    // Connected WebSocket.
    echoWebSocket = ws // ③Keep webSocket instance
}
// ④Client-side
WebSocket.connect(to: "ws://echo.websocket.org", on: eventLoop) { ws in
    // Connected WebSocket.
    echoWebSocket = ws // ⑤Keep webSocket instance
}

var echoWebSocket : WebSocket?
// (Omit)

// ①when sending text
echoWebSocket?.send("Hello, world")

// ②when sending integer([UInt8])
echoWebSocket?.send([1, 2, 3])

// ①when receiving text
echoWebSocket?.onText { ws, text in
    print(text)
}
// ②when receiving integer([UInt8])
echoWebSocket?.onBinary { ws, binary in
    print(binary)
}

echoWebSocket?.close()

var deviceInfoWebSocket: WebSocket?
// (Omit)
protected.webSocket(.constant(EndPointKind.deviceInfo.webSocketEndPoint)) { _, ws in
    deviceInfoWebSocket = ws // ①Keep webSocket instance
    ws.onText { ws, text in
        print(text)
    }
}
// (Omit)
try await deviceInfoWebSocket?.send(jsonString) // ②Send post data using WebSocket

private var deviceInfoWebSocket: WebSocket?
// ①ID/Password is defined in SwiftHomeCredentials
let basicAuthentication = SwiftHomeCredentials.basicAuthentication
// ②Convert ID/Password data to data type with utf8
let plainString = "\(basicAuthentication.id):\(basicAuthentication.password)".data(using: .utf8)
// ③convert to base64
let credential = plainString?.base64EncodedString(options: [])
// ④set base64 in header
let headers: Vapor.HTTPHeaders = [
    "Authorization": "Basic \(credential!)"
]
// (Omit) // ⑤serverConfigはLocalhostとHerokuの接続を切り替えやすくする処理
_ = WebSocket.connect(to: "\(serverConfig.URLString(type: .webSocket))/\(EndPointKind.deviceInfo.webSocketEndPoint)", headers: headers, on: eventLoopGroup) { [weak self] ws in
    guard let self = self else { return }
    // ⑥Retain the WebSocket instance after connecting
    self.deviceInfoWebSocket = ws
    // (Omit: DB update process)
}