feat: calculate NDA from config instead of ATIS

CPDLC.json

@@ -6,6 +6,23 @@
   "MaxArchivedMessages": 50,
   "MaxDisplayMessageLength": 40,
   "MaxExtendedMessageLength": 80,
+  "AtsuCodes": [
+    { "AtsuCode": "YBBB", "Sectors": ["INL", "DOS", "SDY", "BUR", "GOL", "NSA", "ARL", "MDE", "MLD", "OCN", "MNN", "CNK", "KPL", "CVN", "SWY", "KEN", "BAR", "TBP", "WIL", "ISA", "WEG", "ARA", "STR", "TRT", "KIY", "ASH", "TRS", "TSN", "HWE", "FLD", "COL"] },
+    { "AtsuCode": "YMMM", "Sectors": ["GUN", "KAT", "BIK", "WOL", "SNO", "BLA", "ELW", "HUO", "WON", "MUN", "YWE", "OXL", "GTH", "TBD", "AUG", "ASP", "FOR", "WAR", "ASW", "WRA", "BKE", "ESP", "HYD", "JAR", "PIY", "SCR", "GVE", "GEL", "LEA", "OLW", "POT", "PAR", "MEK", "MTK", "NEW", "MZI", "IND", "INE", "INS"] },
+    { "AtsuCode": "NZZO", "Sectors": ["NZZO", "NZZOT"] },
+    { "AtsuCode": "NZCM", "Sectors": ["NZCM"] },
+    { "AtsuCode": "FAJO", "Sectors": ["FAJO"] },
+    { "AtsuCode": "FIMM", "Sectors": ["FIMM", "FIMMU"] },
+    { "AtsuCode": "VRMF", "Sectors": ["VRMF"] },
+    { "AtsuCode": "VCCF", "Sectors": ["VCCF"] },
+    { "AtsuCode": "WIIF", "Sectors": ["WIIF", "WIIFSG", "WIIFBD", "WIIFMN", "WIIFIS"] },
+    { "AtsuCode": "WAAF", "Sectors": ["WAAF", "UBLI", "WAAFNA", "WAAFAN", "WAAFPA"] },
+    { "AtsuCode": "AYPM", "Sectors": ["AYPM"] },
+    { "AtsuCode": "KZAK", "Sectors": ["KZAK", "KZAKE", "KZAKW", "KZAK3", "KZAK5", "KZAK6", "KZAK9"] },
+    { "AtsuCode": "ASIW", "Sectors": ["ASIAW"] },
+    { "AtsuCode": "ASEA", "Sectors": ["ASEA"] },
+    { "AtsuCode": "AFRS", "Sectors": ["AFRS"] }
+  ],
   "UplinkMessages": {
     "MasterMessages": [
       {

TODO.md

@@ -1,9 +1,9 @@
 TODO:
 
-- [ ] Clean up label item creation.
-- [ ] Add strip item cration.
-- [ ] Write documentation.
+- [X] Clean up label item creation.
+- [X] Add strip item cration.
+- [X] Write documentation.
+- [X] Write SOPs.
 - [ ] Dialogue timeouts
-- [ ] Write SOPs.
 - [ ] Write unit tests for plugin code.
 - [ ] Write test cases for same flight across multiple units within the same server.

docs/docs/vatsys-plugin/configuration.md

@@ -75,6 +75,48 @@ Maximum character length for messages shown in the extended message view. Messag
 "MaxExtendedMessageLength": 80
 ```
 
+## Next Data Authority
+
+### AtsuCodes
+
+Maps ATSU/CPDLC logon codes to the vatSys sector names they cover. The plugin uses this to determine the Next Data Authority (NDA) for each tracked aircraft by walking the FDR route and finding the first sector that belongs to a different ATSU.
+
+Each entry has an `AtsuCode` (the code aircraft logon to) and a `Sectors` array of sector names from the vatSys `Sectors.xml` file.
+
+When calculating the NDA, the plugin walks the sector hierarchy from most-specific to least-specific (subsector to parent to grandparent). For each level it collects ATSU code candidates, then selects the first candidate that is currently connected to the ACARS network. This allows FIRs that use individual Hoppie logon codes per controller position to be mapped at the subsector level.
+
+**Example (FIR using a single logon code):**
+```json
+"AtsuCodes": [
+  { "AtsuCode": "YBBB", "Sectors": ["ARL", "INL", "KPL", "TSN"] },
+  { "AtsuCode": "YMMM", "Sectors": ["GUN", "BLA", "IND"] }
+]
+```
+
+**Example (FIR using per-position logon codes):**
+```json
+"AtsuCodes": [
+  { "AtsuCode": "WIIF",   "Sectors": ["WIIF"] },
+  { "AtsuCode": "WIIFSG", "Sectors": ["WIIFSG", "WIIFBD"] },
+  { "AtsuCode": "WIIFMN", "Sectors": ["WIIFMN", "WIIFIS"] }
+]
+```
+
+In the per-position example, an aircraft entering `WIIFBD` airspace will have `WIIFSG` set as its NDA if that controller is online, falling back to `WIIF` if not.
+
+If a sector appears in more than one entry, the NDA calculation will produce an error for that aircraft. If a sector does not appear in any entry, it is treated as outside CPDLC coverage and skipped.
+
+### NdaRecalculationIntervalMinutes
+
+How often (in minutes) the plugin recalculates the NDA for all tracked aircraft in the background. The NDA is also recalculated on every FDR update, so this is a catch-all interval.
+
+Default: `1`
+
+**Example:**
+```json
+"NdaRecalculationIntervalMinutes": 1
+```
+
 ## Uplink Messages
 
 The `UplinkMessages` object defines the available CPDLC messages for the controller to send.
@@ -166,6 +208,11 @@ Array of message groups for organizing messages in the editor. Each group has:
   "MaxArchivedMessages": 50,
   "MaxDisplayMessageLength": 40,
   "MaxExtendedMessageLength": 80,
+  "AtsuCodes": [
+    { "AtsuCode": "YBBB", "Sectors": ["ARL", "INL", "KPL", "TSN"] },
+    { "AtsuCode": "YMMM", "Sectors": ["GUN", "BLA", "IND"] }
+  ],
+  "NdaRecalculationIntervalMinutes": 1,
   "UplinkMessages": {
     "MasterMessages": [
       {

example.env

@@ -22,8 +22,8 @@ Acars__0__AuthenticationCode=your-authentication-code-here
 # Acars__1__AuthenticationCode=your-other-authentication-code
 
 # Handoff Configuration
-# How many minutes before the expected transfer time to send the NEXT DATA AUTHORITY message (default: 10)
-Handoff__NotificationLeadTime=10
+# How many minutes before the expected transfer time to send the NEXT DATA AUTHORITY message (default: 20)
+Handoff__NotificationLeadTime=20
 
 # ngrok auth token to allow remote connections to your local debug server
 # https://ngrok.com/

source/CPDLCPlugin/AcarsStation.cs

@@ -0,0 +1,3 @@
+namespace CPDLCPlugin;
+
+public record AcarsStation(string StationId);

source/CPDLCPlugin/AcarsStationStore.cs

@@ -0,0 +1,63 @@
+namespace CPDLCPlugin;
+
+public class AcarsStationStore
+{
+    readonly HashSet<string> _stationIds = new(StringComparer.OrdinalIgnoreCase);
+    readonly SemaphoreSlim _semaphore = new(1, 1);
+
+    public async Task Populate(string[] stationIds, CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            _stationIds.Clear();
+            foreach (var stationId in stationIds)
+            {
+                _stationIds.Add(stationId);
+            }
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    public async Task<bool> IsOnline(string stationId, CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            return _stationIds.Contains(stationId);
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    public async Task<AcarsStation[]> All(CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            return _stationIds.Select(id => new AcarsStation(id)).ToArray();
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    public async Task Clear(CancellationToken cancellationToken = default)
+    {
+        await _semaphore.WaitAsync(cancellationToken);
+        try
+        {
+            _stationIds.Clear();
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+}

source/CPDLCPlugin/Configuration/AtsuCodeMapping.cs

@@ -0,0 +1,3 @@
+namespace CPDLCPlugin.Configuration;
+
+public record AtsuCodeMapping(string AtsuCode, string[] Sectors);

source/CPDLCPlugin/Configuration/PluginConfiguration.cs

@@ -13,4 +13,12 @@ public class PluginConfiguration
     public required UplinkMessagesConfiguration UplinkMessages { get; init; }
     public int MaxLogFileAgeDays { get; init; } = 5;
     public LogEventLevel LogLevel { get; init; } = LogEventLevel.Information;
+
+    // Maps ATSU/CPDLC codes to the sector names they cover (as reported by vatSys SectorsVolumes).
+    // Used to determine the Next Data Authority when walking the FDR route.
+    public AtsuCodeMapping[] AtsuCodes { get; init; } = [];
+
+    // How often (in minutes) to recalculate the NDA for all tracked aircraft.
+    // NDA is also recalculated on every FDR update, so this is a catch-all interval.
+    public int NdaRecalculationIntervalMinutes { get; init; } = 1;
 }