Initial radio implementation

Notable changes:
- Add radio gRPC API protobuf definitation and generated files.
- Reworked existing single gRPC APIs library to split it into
  per-API libraries to avoid name collision issues.
- Add radio gRPC client class and associated radio state class
  and RiverPod providers.
- Split media controls and play list table classes into media
  player and radio specific versions to facilitate customization
  and wiring up their appropriate backends in a straightforward
  fashion.  Some potential rationalization of styling widgets
  may be done as a follow up to avoid some duplication.
- Added radio configuration and presets loading.  The presets
  will be populated with the contents of a radio-presets.yaml
  file from the configured location, the default location is
  the /etc/xdg/AGL/ics-homescreen directory.
- Implemented FM radio player against the radio gRPC API.
  For the sake of expediency, no attempt has been made to make
  the player able to handle AM band support.
- Reworked media page navigation state so that active player is
  restored when coming back to the page.  Logic has been added to
  start/stop the radio on navigating to or leaving the FM radio
  sub-page.  This will potentially be reworked before CES to work
  with the pause/stop button present on the other pages.
- Started pruning down global exports.dart a bit to remove files
  only used in a specific page/hierarchy, starting with media.

Bug-AGL: SPEC-5029

Change-Id: I1ae0aca4a7a8218e69e4286c863f01509a1cccb7
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

1 files changed, 161 insertions, 0 deletions

diff --git a/lib/data/data_providers/radio_client.dart b/lib/data/data_providers/radio_client.dart
new file mode 100644
index 0000000..2cde65e
--- /dev/null
+++ b/lib/data/data_providers/radio_client.dart
@@ -0,0 +1,161 @@
+import 'package:flutter_ics_homescreen/export.dart';
+import 'package:protos/radio-api.dart' as api;
+
+class RadioClient {
+  final RadioConfig config;
+  final Ref ref;
+  late api.ClientChannel channel;
+  late api.RadioClient stub;
+
+  RadioClient({required this.config, required this.ref}) {
+    debugPrint(
+        "Connecting to radio service at ${config.hostname}:${config.port}");
+    api.ChannelCredentials creds = const api.ChannelCredentials.insecure();
+    channel = api.ClientChannel(config.hostname,
+        port: config.port, options: api.ChannelOptions(credentials: creds));
+    stub = api.RadioClient(channel);
+  }
+
+  void run() async {
+    getBandParameters();
+
+    try {
+      var responseStream = stub.getStatusEvents(api.StatusRequest());
+      await for (var event in responseStream) {
+        handleStatusEvent(event);
+      }
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void getBandParameters() async {
+    try {
+      var response = await stub.getBandParameters(
+          api.GetBandParametersRequest(band: api.Band.BAND_FM));
+      ref.read(radioStateProvider.notifier).updateBandParameters(
+          freqMin: response.min,
+          freqMax: response.max,
+          freqStep: response.step);
+
+      // Get initial frequency
+      var freqResponse = await stub.getFrequency(api.GetFrequencyRequest());
+      ref
+          .read(radioStateProvider.notifier)
+          .updateFrequency(freqResponse.frequency);
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void handleStatusEvent(api.StatusResponse response) {
+    switch (response.whichStatus()) {
+      case api.StatusResponse_Status.frequency:
+        var status = response.frequency;
+        ref.read(radioStateProvider.notifier).updateFrequency(status.frequency);
+        break;
+      case api.StatusResponse_Status.play:
+        var status = response.play;
+        ref.read(radioStateProvider.notifier).updatePlaying(status.playing);
+        break;
+      case api.StatusResponse_Status.scan:
+        var status = response.scan;
+        if (status.stationFound) {
+          ref.read(radioStateProvider.notifier).updateScanning(false);
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  void start() async {
+    try {
+      var response = await stub.start(api.StartRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void stop() async {
+    try {
+      var response = await stub.stop(api.StopRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void setFrequency(int frequency) async {
+    var radioState = ref.read(radioStateProvider);
+    if ((frequency < radioState.freqMin) ||
+        (frequency > radioState.freqMax) ||
+        ((frequency - radioState.freqMin) % radioState.freqStep) != 0) {
+      debugPrint("setFrequency: invalid frequency $frequency!");
+      return;
+    }
+    try {
+      var response = await stub
+          .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void tuneForward() async {
+    var radioState = ref.read(radioStateProvider);
+    if (radioState.freqCurrent < radioState.freqMax) {
+      int frequency = radioState.freqCurrent + radioState.freqStep;
+      if (frequency > radioState.freqMax) {
+        frequency = radioState.freqMax;
+      }
+      try {
+        var response = await stub
+            .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+      } catch (e) {
+        print(e);
+      }
+    }
+  }
+
+  void tuneBackward() async {
+    var radioState = ref.read(radioStateProvider);
+    if (radioState.freqCurrent > radioState.freqMin) {
+      int frequency = radioState.freqCurrent - radioState.freqStep;
+      if (frequency < radioState.freqMin) {
+        frequency = radioState.freqMin;
+      }
+      try {
+        var response = await stub
+            .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+      } catch (e) {
+        print(e);
+      }
+    }
+  }
+
+  void scanForward() async {
+    try {
+      var response = await stub.scanStart(api.ScanStartRequest(
+          direction: api.ScanDirection.SCAN_DIRECTION_FORWARD));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void scanBackward() async {
+    try {
+      var response = await stub.scanStart(api.ScanStartRequest(
+          direction: api.ScanDirection.SCAN_DIRECTION_BACKWARD));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void scanStop() async {
+    try {
+      var response = await stub.scanStop(api.ScanStopRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+}