create an mqtt_dummy that sends string every second

src/config.gleam

@@ -4,7 +4,13 @@ import gleam/result
 import simplifile
 
 pub type Config {
-  Config(mqtt_host: String, mqtt_user: String, mqtt_pw: String, jwt_key: String)
+  Config(
+    mqtt_host: String,
+    mqtt_user: String,
+    mqtt_pw: String,
+    mqtt_client_id: String,
+    jwt_key: String,
+  )
 }
 
 fn load_file() -> Result(String, String) {
@@ -36,19 +42,33 @@ fn compile_config(doc: glaml.Document) -> Result(Config, String) {
     glaml.select_sugar(root, "mqtt.user")
     |> result.map_error(fn(_) { "mqtt.user not found in config.yml" }),
   )
+  use mqtt_client_id_result <- result.try(
+    glaml.select_sugar(root, "mqtt.client_id")
+    |> result.map_error(fn(_) { "mqtt.client_id not found in config.yml" }),
+  )
   use jwt_key_result <- result.try(
     glaml.select_sugar(root, "jwt_key")
     |> result.map_error(fn(_) { "jwt_key not found in config.yml" }),
   )
 
   // Extract strings from nodes
-  case mqtt_host_result, mqtt_user_result, jwt_key_result {
-    glaml.NodeStr(host), glaml.NodeStr(user), glaml.NodeStr(key) -> {
+  case
+    mqtt_host_result,
+    mqtt_user_result,
+    jwt_key_result,
+    mqtt_client_id_result
+  {
+    glaml.NodeStr(host),
+      glaml.NodeStr(user),
+      glaml.NodeStr(key),
+      glaml.NodeStr(client_id)
+    -> {
       let yaml_config =
         Config(
           mqtt_host: host,
           mqtt_user: user,
           mqtt_pw: "placeholder",
+          mqtt_client_id: client_id,
           jwt_key: key,
         )
 
@@ -61,13 +81,15 @@ fn compile_config(doc: glaml.Document) -> Result(Config, String) {
             |> result.unwrap(yaml_config.mqtt_user),
           mqtt_pw: envoy.get("MQTT_PW")
             |> result.unwrap(yaml_config.mqtt_pw),
+          mqtt_client_id: envoy.get("MQTT_CLIENT_ID")
+            |> result.unwrap(yaml_config.mqtt_client_id),
           jwt_key: envoy.get("JWT_KEY")
             |> result.unwrap(yaml_config.jwt_key),
         )
 
       Ok(final_config)
     }
-    _, _, _ -> Error("Config values must be strings in config.yml")
+    _, _, _, _ -> Error("Config values must be strings in config.yml")
   }
 }
 

src/mqtt_dummy.gleam

@@ -0,0 +1,48 @@
+import gleam/erlang/process
+import gleam/list
+import gleam/otp/actor
+
+pub type Subscriber =
+  process.Subject(String)
+
+pub type Message {
+  Subscribe(subscriber: Subscriber)
+  Proc
+}
+
+pub type Subscribers =
+  List(Subscriber)
+
+fn handle_message(
+  subscribers: Subscribers,
+  message: Message,
+) -> actor.Next(Subscribers, Message) {
+  case message {
+    Subscribe(subscriber) -> {
+      let new_subscribers = [subscriber, ..subscribers]
+      actor.continue(new_subscribers)
+    }
+    Proc -> {
+      list.each(subscribers, fn(subscriber) {
+        process.send(subscriber, "Hello from dummy mqtt action")
+      })
+      actor.continue(subscribers)
+    }
+  }
+}
+
+// Subscribe to receive ticks from the dummy actor
+pub fn subscribe(actor_ref: process.Subject(Message)) -> Subscriber {
+  let mailbox = process.new_subject()
+  process.send(actor_ref, Subscribe(mailbox))
+  mailbox
+}
+
+// Start the actor
+pub fn start() -> Result(process.Subject(Message), actor.StartError) {
+  let assert Ok(started) =
+    actor.new([])
+    |> actor.on_message(handle_message)
+    |> actor.start
+  Ok(started.data)
+}

src/weather_portal.gleam

@@ -1,5 +1,7 @@
 import config
+import gleam/erlang/process
 import gleam/io
+import mqtt_dummy
 
 pub fn main() -> Nil {
   case config.load_config() {
@@ -14,4 +16,40 @@ pub fn main() -> Nil {
       io.println("Failed to load config: " <> err)
     }
   }
+
+  let assert Ok(subject) = mqtt_dummy.start()
+  let mailbox = mqtt_dummy.subscribe(subject)
+
+  // Kick off the first message
+  process.send_after(subject, 1000, mqtt_dummy.Proc)
+
+  receive_and_reschedule(mailbox, subject)
+  // case process.receive(mailbox, 5000) {
+  //   Ok(msg) -> {
+  //     io.println("Got message:" <> msg)
+  //     // process_messages(mailbox, n - 1)
+  //   }
+  //   Error(Nil) -> {
+  //     io.println("Timeout waiting for message")
+  //   }
+  // }
+  Nil
+}
+
+fn receive_and_reschedule(
+  mailbox: process.Subject(String),
+  subject: process.Subject(mqtt_dummy.Message),
+) -> Nil {
+  case process.receive(mailbox, 2000) {
+    Ok(msg) -> {
+      io.println("Got message: " <> msg)
+      // Reschedule the next Proc message
+      process.send_after(subject, 1000, mqtt_dummy.Proc)
+      receive_and_reschedule(mailbox, subject)
+    }
+    Error(Nil) -> {
+      io.println("Timeout - waiting again...")
+      receive_and_reschedule(mailbox, subject)
+    }
+  }
 }