feat(k1): add local connection matrix

plugins/xgrids-k1/macos/associate_wifi.swift

@@ -0,0 +1,79 @@
+import CoreWLAN
+import Foundation
+
+private struct AssociationRequest: Decodable {
+    let ssid: String
+    let password: String
+}
+
+private struct AssociationResponse: Encodable {
+    let ok: Bool
+    let alreadyAssociated: Bool?
+    let reasonCode: String?
+
+    enum CodingKeys: String, CodingKey {
+        case ok
+        case alreadyAssociated = "already_associated"
+        case reasonCode = "reason_code"
+    }
+}
+
+private func emit(_ response: AssociationResponse, exitCode: Int32) -> Never {
+    let encoder = JSONEncoder()
+    if let data = try? encoder.encode(response) {
+        FileHandle.standardOutput.write(data)
+    }
+    exit(exitCode)
+}
+
+private let input = FileHandle.standardInput.readDataToEndOfFile()
+guard input.count <= 1024 else {
+    emit(
+        AssociationResponse(ok: false, alreadyAssociated: nil, reasonCode: "request-too-large"),
+        exitCode: 1
+    )
+}
+
+do {
+    let request = try JSONDecoder().decode(AssociationRequest.self, from: input)
+    guard let ssidData = request.ssid.data(using: .utf8),
+          (1 ... 32).contains(ssidData.count),
+          let passwordData = request.password.data(using: .utf8),
+          (1 ... 64).contains(passwordData.count)
+    else {
+        emit(
+            AssociationResponse(ok: false, alreadyAssociated: nil, reasonCode: "credential-bounds"),
+            exitCode: 1
+        )
+    }
+
+    guard let interface = CWWiFiClient.shared().interface() else {
+        emit(
+            AssociationResponse(ok: false, alreadyAssociated: nil, reasonCode: "wifi-interface-unavailable"),
+            exitCode: 1
+        )
+    }
+
+    if interface.ssid() == request.ssid {
+        emit(AssociationResponse(ok: true, alreadyAssociated: true, reasonCode: nil), exitCode: 0)
+    }
+
+    let networks = try interface.scanForNetworks(withSSID: ssidData)
+    guard let network = networks.first(where: { $0.ssid == request.ssid }) else {
+        emit(
+            AssociationResponse(ok: false, alreadyAssociated: nil, reasonCode: "network-not-found"),
+            exitCode: 1
+        )
+    }
+
+    try interface.associate(to: network, password: request.password)
+    // CoreWLAN's synchronous association call throws on failure. Reading the
+    // current SSID again would require Location authorization on recent macOS
+    // versions and could turn a successful association into a false negative.
+    emit(AssociationResponse(ok: true, alreadyAssociated: false, reasonCode: nil), exitCode: 0)
+} catch {
+    emit(
+        AssociationResponse(ok: false, alreadyAssociated: nil, reasonCode: "corewlan-error"),
+        exitCode: 1
+    )
+}