feat: Begins using swift argument parser and creating cli client dependency

Sources/CliClient/CliClient.swift

@@ -0,0 +1,188 @@
+import Dependencies
+import DependenciesMacros
+import DotEnv
+import Foundation
+import Logging
+import Models
+import MQTTNIO
+import NIO
+
+public extension DependencyValues {
+  var cliClient: CliClient {
+    get { self[CliClient.self] }
+    set { self[CliClient.self] = newValue }
+  }
+}
+
+@DependencyClient
+public struct CliClient {
+
+  public var logLevel: @Sendable (EnvVars) -> Logger.Level = { _ in .debug }
+  public var makeEnvVars: @Sendable (EnvVarsRequest) async throws -> EnvVars
+  public var makeClient: @Sendable (ClientRequest) throws -> MQTTClient
+  public var parseMqttClientVersion: @Sendable (String) -> MQTTClient.Version?
+
+  public struct ClientRequest: Sendable {
+    public let envVars: EnvVars
+    public let eventLoopGroup: MultiThreadedEventLoopGroup
+    public let logger: Logger?
+
+    public init(
+      envVars: EnvVars,
+      eventLoopGroup: MultiThreadedEventLoopGroup,
+      logger: Logger?
+    ) {
+      self.envVars = envVars
+      self.eventLoopGroup = eventLoopGroup
+      self.logger = logger
+    }
+
+  }
+
+  public struct EnvVarsRequest: Sendable {
+
+    public let envFilePath: String?
+    public let logger: Logger?
+    public let mqttClientVersion: String?
+
+    public init(
+      envFilePath: String? = nil,
+      logger: Logger? = nil,
+      version mqttClientVersion: String? = nil
+    ) {
+      self.envFilePath = envFilePath
+      self.logger = logger
+      self.mqttClientVersion = mqttClientVersion
+    }
+  }
+}
+
+extension CliClient: DependencyKey {
+  public static let testValue: CliClient = Self()
+  public static var liveValue: CliClient {
+    Self(
+      logLevel: { Logger.Level.from(environment: $0) },
+      makeEnvVars: {
+        try EnvVars.load(
+          dotEnvFile: $0.envFilePath,
+          logger: $0.logger,
+          version: $0.mqttClientVersion
+        )
+      },
+      makeClient: {
+        MQTTClient(
+          envVars: $0.envVars,
+          eventLoopGroup: $0.eventLoopGroup,
+          logger: $0.logger
+        )
+      },
+      parseMqttClientVersion: { .init(string: $0) }
+    )
+  }
+}
+
+extension EnvVars {
+
+  /// Load the `EnvVars` from the environment.
+  ///
+  /// - Paramaters:
+  ///   - logger: An optional logger to use for debugging.
+  ///   - version: A version that is specified from command line, ignoring any environment variable.
+  static func load(
+    dotEnvFile: String?,
+    logger: Logger?,
+    version: String?
+  ) throws -> EnvVars {
+    let defaultEnvVars = EnvVars()
+    let encoder = JSONEncoder()
+    let decoder = JSONDecoder()
+
+    if let dotEnvFile {
+      try DotEnv.load(path: dotEnvFile)
+    }
+
+    let defaultEnvDict = (try? encoder.encode(defaultEnvVars))
+      .flatMap { try? decoder.decode([String: String].self, from: $0) }
+      ?? [:]
+
+    let envVarsDict = defaultEnvDict
+      .merging(ProcessInfo.processInfo.environment, uniquingKeysWith: { $1 })
+
+    var envVars = (try? JSONSerialization.data(withJSONObject: envVarsDict))
+      .flatMap { try? decoder.decode(EnvVars.self, from: $0) }
+      ?? defaultEnvVars
+
+    if let version {
+      envVars.version = version
+    }
+
+    logger?.debug("Done loading EnvVars...")
+
+    return envVars
+  }
+}
+
+@_spi(Internal)
+public extension MQTTClient {
+  convenience init(
+    envVars: EnvVars,
+    eventLoopGroup: EventLoopGroup,
+    logger: Logger?
+  ) {
+    self.init(
+      host: envVars.host,
+      port: envVars.port != nil ? Int(envVars.port!) : nil,
+      identifier: envVars.identifier,
+      eventLoopGroupProvider: .shared(eventLoopGroup),
+      logger: logger,
+      configuration: .init(
+        version: .parseOrDefualt(string: envVars.version),
+        disablePing: false,
+        userName: envVars.userName,
+        password: envVars.password
+      )
+    )
+  }
+}
+
+extension MQTTClient.Version {
+  static let `default` = Self.v3_1_1
+
+  static func parseOrDefualt(string: String?) -> Self {
+    guard let string, let value = Self(string: string) else {
+      return .default
+    }
+    return value
+  }
+
+  init?(string: String) {
+    if string.contains("5") {
+      self = .v5_0
+    } else if string.contains("3") {
+      self = .v3_1_1
+    } else {
+      return nil
+    }
+  }
+}
+
+@_spi(Internal)
+public extension Logger.Level {
+
+  /// Parse a `Logger.Level` from the loaded `EnvVars`.
+  static func from(environment envVars: EnvVars) -> Self {
+    // If the log level was set via an environment variable.
+    if let logLevel = envVars.logLevel {
+      return logLevel
+    }
+    // Parse the appEnv to derive an log level.
+    switch envVars.appEnv {
+    case .staging, .development:
+      return .debug
+    case .production:
+      return .info
+    case .testing:
+      return .trace
+    }
+  }
+}