Add worker class

src/worker.py

@@ -0,0 +1,111 @@
+# This is the main printing thread
+# As explained in the task file, this is where we command
+# printing to happen.
+
+import threading
+import time
+from task import TaskType
+
+class PrintWorker(threading.Thread):
+    def __init__(self, app, print_queue, printer, socketio=None):
+        super().__init__(daemon=True)
+        self.app = app
+        self.print_queue = print_queue
+        self.printer = printer
+        self.socketio = socketio  # Optional
+        self.running = True
+        self.state = "idle" # idle, printing, dead, drinking-a-beer
+
+        self.app.logger.debug("Ho great, I'm alive... I'm ready to work another day...")
+
+    def run(self):
+        """Background thread that processes queue items"""
+        self.app.logger.info("Worker started working.")
+        while True:
+            if not self.running:
+                time.sleep(0.2)
+                continue
+
+            # TODO: This could be improved to simply no start
+            # the while loop as long as the printer is not ready.
+            # and maybe get out of it when the printer is not ready anymore ?
+            if not self.printer.ready:
+                self.app.logger.debug("Waiting for the printer to be ready...")
+                time.sleep(1)
+                continue
+
+            try:
+                task = self.print_queue.dequeue()
+            except Exception as e:
+                self.app.logger.error("Could not get a new task ! %s ", str(e))
+                raise RuntimeError("We could not get a new task because " + str(e)) from e
+
+            if task:
+                try:
+                    self.app.logger.info("Got a new task")
+                    self.app.logger.debug("Got task %s", task.task_id)
+                    self.state = "printing"
+                    task.status = "processing"
+                    self._emit_status(task.task_id, "processing")
+
+                    print_data = task.get_print_data()
+                    try:
+                        self.printer.print_task(task.task_type, print_data)
+                    except Exception as e:
+                        self.app.logger.error("Could not print : %s", str(e))
+                        raise e
+
+                    task.status = "completed"
+                    self.print_queue.mark_completed(task.task_id, "completed")
+                    self._emit_status(task.task_id, "completed")
+
+                except Exception as e:
+                    task.status = "failed"
+                    self.print_queue.mark_completed(task.task_id, "failed")
+                    self._emit_status(task.task_id, "failed", error=str(e))
+                    print(f"Print task {task.task_id} failed: {e}")
+            else:
+                # When they are no new tasks to handle, we put the thread to sleep.
+                self.state = "idle"
+                time.sleep(0.1)
+
+    def _emit_status(self, task_id, status, error=None):
+        """Emit status update via Socket.IO if available"""
+        if not self.socketio:
+            return
+
+        room = f"task_{task_id}"
+        data = {
+            "task_id": task_id,
+            "status": status,
+            "position": None  # Task no longer in queue
+        }
+
+        if error:
+            data["error"] = error
+
+        self.socketio.emit('task_status', data, room=room)
+
+    def stop_worker(self):
+        """
+        Give the worker a break
+        """
+        self.state = "drinking-a-beer"
+        self.running = False
+
+    def start_worker(self):
+        """
+        Get the worker back to it
+        """
+        self.state = "idle"
+        self.running = True
+
+    def current_state(self):
+        """
+        Return the worker state
+        """
+        return {
+            "is_running": self.running,
+            "queue_size": len(self.print_queue),
+            "state" : self.state
+        }