add SMTPClient module: connection layer, message formatter, public API, tests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-14 05:25:03 +01:00
parent 427f197bb3
commit 54ce92e280
9 changed files with 695 additions and 1 deletions
@@ -0,0 +1,90 @@
+import Foundation
+import NIO
+@preconcurrency import NIOSSL
+import Models
+
+actor SMTPConnection {
+	private let host: String
+	private let port: Int
+	private let security: SMTPSecurity
+	private let group: EventLoopGroup
+	private var channel: Channel?
+	private let responseHandler: SMTPResponseHandler
+
+	init(host: String, port: Int, security: SMTPSecurity) {
+		self.host = host
+		self.port = port
+		self.security = security
+		self.group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
+		self.responseHandler = SMTPResponseHandler()
+	}
+
+	func connect() async throws -> SMTPResponse {
+		let handler = responseHandler
+		let hostname = host
+
+		let bootstrap: ClientBootstrap
+		if security == .ssl {
+			let sslContext = try NIOSSLContext(configuration: TLSConfiguration.makeClientConfiguration())
+			bootstrap = ClientBootstrap(group: group)
+				.channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+				.channelInitializer { channel in
+					let sslHandler = try! NIOSSLClientHandler(context: sslContext, serverHostname: hostname)
+					return channel.pipeline.addHandlers([sslHandler, handler])
+				}
+		} else {
+			// STARTTLS: start plain, upgrade later
+			bootstrap = ClientBootstrap(group: group)
+				.channelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
+				.channelInitializer { channel in
+					channel.pipeline.addHandler(handler)
+				}
+		}
+
+		do {
+			channel = try await bootstrap.connect(host: host, port: port).get()
+		} catch {
+			throw SMTPError.connectionFailed(error.localizedDescription)
+		}
+
+		return try await handler.waitForGreeting()
+	}
+
+	func sendCommand(_ command: String) async throws -> SMTPResponse {
+		guard let channel else { throw SMTPError.notConnected }
+		let handler = responseHandler
+
+		var buffer = channel.allocator.buffer(capacity: command.utf8.count + 2)
+		buffer.writeString(command + "\r\n")
+		channel.writeAndFlush(buffer, promise: nil)
+
+		return try await handler.waitForResponse()
+	}
+
+	func upgradeToTLS() async throws {
+		guard let channel else { throw SMTPError.notConnected }
+		let sslContext = try NIOSSLContext(configuration: TLSConfiguration.makeClientConfiguration())
+		let sslHandler = try NIOSSLClientHandler(context: sslContext, serverHostname: host)
+		do {
+			try await channel.pipeline.addHandler(sslHandler, position: .first).get()
+		} catch {
+			throw SMTPError.tlsUpgradeFailed
+		}
+	}
+
+	func sendRawBytes(_ data: Data) async throws {
+		guard let channel else { throw SMTPError.notConnected }
+		var buffer = channel.allocator.buffer(capacity: data.count)
+		buffer.writeBytes(data)
+		channel.writeAndFlush(buffer, promise: nil)
+	}
+
+	func disconnect() async throws {
+		try await channel?.close()
+		channel = nil
+	}
+
+	func shutdown() async throws {
+		try await group.shutdownGracefully()
+	}
+}