add nio connection layer: tls bootstrap, response handler, command runner

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-13 21:05:44 +01:00
parent 300b583695
commit ec820b2785
3 changed files with 160 additions and 0 deletions
@@ -0,0 +1,82 @@
+import NIO
+import NIOIMAPCore
+import NIOIMAP
+
+// NIO handlers are confined to their event loop; @unchecked Sendable is the
+// standard pattern for crossing the actor/event-loop boundary.
+final class IMAPResponseHandler: ChannelInboundHandler, @unchecked Sendable {
+	typealias InboundIn = Response
+
+	private var buffer: [Response] = []
+	private var expectedTag: String?
+	private var continuation: CheckedContinuation<[Response], Error>?
+	private var greetingContinuation: CheckedContinuation<Void, Error>?
+
+	func channelRead(context: ChannelHandlerContext, data: NIOAny) {
+		let response = unwrapInboundIn(data)
+		buffer.append(response)
+
+		switch response {
+		case .untagged(let payload):
+			if case .conditionalState(let status) = payload, greetingContinuation != nil {
+				switch status {
+				case .ok:
+					greetingContinuation?.resume()
+					greetingContinuation = nil
+				case .preauth:
+					greetingContinuation?.resume()
+					greetingContinuation = nil
+				case .bye(let text):
+					let error = IMAPError.serverError("BYE: \(text)")
+					greetingContinuation?.resume(throwing: error)
+					greetingContinuation = nil
+				default:
+					break
+				}
+			}
+		case .tagged(let tagged):
+			if tagged.tag == expectedTag {
+				let collected = buffer
+				buffer = []
+				expectedTag = nil
+				continuation?.resume(returning: collected)
+				continuation = nil
+			}
+		case .fatal(let text):
+			let error = IMAPError.serverError("FATAL: \(text)")
+			continuation?.resume(throwing: error)
+			continuation = nil
+			greetingContinuation?.resume(throwing: error)
+			greetingContinuation = nil
+		case .fetch, .authenticationChallenge, .idleStarted:
+			break
+		}
+	}
+
+	func errorCaught(context: ChannelHandlerContext, error: Error) {
+		continuation?.resume(throwing: error)
+		continuation = nil
+		greetingContinuation?.resume(throwing: error)
+		greetingContinuation = nil
+		context.close(promise: nil)
+	}
+
+	func waitForGreeting() async throws {
+		try await withCheckedThrowingContinuation { cont in
+			greetingContinuation = cont
+		}
+	}
+
+	func sendCommand(tag: String, continuation cont: CheckedContinuation<[Response], Error>) {
+		expectedTag = tag
+		continuation = cont
+		buffer = []
+	}
+}
+
+public enum IMAPError: Error, Sendable {
+	case notConnected
+	case serverError(String)
+	case authenticationFailed
+	case unexpectedResponse(String)
+}