Send DTMF events typed

src/main.rs

@@ -14,19 +14,27 @@ static CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
 });
 
 #[derive(Debug, Clone)]
-struct DtmfEvent {
-    number: Option<i32>,
-    volume: Option<i32>,
-    start: bool,
+enum DtmfEvent {
+    Start(DtmfStart),
+    End(i32),
+}
+
+#[derive(Debug, Clone)]
+struct DtmfStart {
+    number: i32,
+    volume: i32,
 }
 
 impl DtmfEvent {
-    fn from_number(number: i32) -> Self {
-        Self { number: Some(number), volume: Some(36), start: true }
+    fn start(number: i32) -> Self {
+        Self::Start(DtmfStart { number, volume: 36 })
     }
 
-    fn end(&self) -> Self {
-        Self { number: None, volume: None, start: false }
+    fn end(self) -> Self {
+        match self {
+            Self::Start(start) => Self::End(start.number),
+            Self::End(_) => self,
+        }
     }
 }
 
@@ -38,26 +46,35 @@ impl TryFrom<&gst::StructureRef> for DtmfEvent {
         if !name.starts_with("dtmf-event") {
             anyhow::bail!("Not a dtmf-event structure: {name}");
         }
-        let number = structure.get_optional::<i32>("number")?;
-        let volume = structure.get_optional::<i32>("volume")?;
-        let start = structure.get::<bool>("start")?;
-        Ok(Self { number, volume, start })
+        let number = structure.get::<i32>("number")?;
+        return if structure.get::<bool>("start")? {
+            let volume = structure.get::<i32>("volume")?;
+            Ok(Self::Start(DtmfStart { number, volume }))
+        } else {
+            Ok(Self::End(number))
+        }
     }
 }
 
 impl From<DtmfEvent> for gst::Structure {
     fn from(event: DtmfEvent) -> Self {
-        let mut st = gst::Structure::builder("dtmf-event")
-            .field("type", 1)
-            .field("start", event.start)
-            .build();
-        if let Some(number) = event.number {
-            st.set("number", number);
+        match event {
+            DtmfEvent::Start(start) => {
+                gst::Structure::builder("dtmf-event")
+                    .field("type", 1)
+                    .field("start", true)
+                    .field("number", start.number)
+                    .field("volume", start.volume)
+                    .build()
+            }
+            DtmfEvent::End(number) => {
+                gst::Structure::builder("dtmf-event")
+                    .field("type", 1)
+                    .field("start", false)
+                    .field("number", number)
+                    .build()
+            }
         }
-        if let Some(volume) = event.volume {
-            st.set("volume", volume);
-        }
-        st
     }
 }
 
@@ -103,7 +120,7 @@ fn main() -> Result<()> {
                     let dtmf_event = match DtmfEvent::try_from(element.structure().unwrap()) {
                         Ok(ev) => ev,
                         Err(err) => {
-                            gst::error!(CAT, "Failed to parse DTMF event {:?} with error: {:?}", element.structure().unwrap(), err);
+                            gst::info!(CAT, "Failed to parse DTMF event {:?} with error: {:?}", element.structure().unwrap(), err);
                             return glib::Continue(true);
                         }
                     };
@@ -112,10 +129,13 @@ fn main() -> Result<()> {
                             gst::info!(CAT, "Detected DTMF event");
                         }
                         "dtmf-event-processed" => {
-                            if dtmf_event.start {
-                                gst::info!(CAT, "DTMF event processed: {:?}", dtmf_event);
-                            } else {
-                                gst::info!(CAT, "Ending DTMF event processed");
+                            match dtmf_event {
+                                DtmfEvent::Start(start) => {
+                                    gst::info!(CAT, "DTMF event {} processed", start.number);
+                                }
+                                DtmfEvent::End(number) => {
+                                    gst::info!(CAT, "Ending DTMF event {number} processed");
+                                }
                             }
                         }
                         _ => {
@@ -142,7 +162,7 @@ fn main() -> Result<()> {
 
             let mut rng = rand::thread_rng();
             loop {
-                let dtmf_event = DtmfEvent::from_number(rng.gen_range(0..15));
+                let dtmf_event = DtmfEvent::start(rng.gen_range(0..15));
 
                 source.send_event(gst::event::CustomUpstream::new(dtmf_event.clone().into()));
                 gst::info!(CAT, "Sent DTMF event {:?}", dtmf_event);