Fix braket ahs devices incompatibility

mpqp/execution/connection/aws_connection.py

@@ -356,7 +356,11 @@ def get_aws_braket_account_info() -> str:
     return result
 
 
-def get_braket_device(device: AWSDevice, is_noisy: bool = False) -> "BraketDevice":
+def get_braket_device(
+    device: AWSDevice,
+    is_noisy: bool = False,
+    is_gate_model: bool = True,
+) -> "BraketDevice":
     """Returns the AwsDevice device associate with the AWSDevice in parameter.
 
     Args:
@@ -378,6 +382,11 @@ def get_braket_device(device: AWSDevice, is_noisy: bool = False) -> "BraketDevic
     """
     from braket.devices import LocalSimulator
 
+    from mpqp.tools.errors import (
+        AWSBraketRemoteExecutionError,
+        DeviceJobIncompatibleError,
+    )
+
     if not device.is_remote():
         if is_noisy:
             return LocalSimulator("braket_dm")
@@ -397,7 +406,8 @@ def get_braket_device(device: AWSDevice, is_noisy: bool = False) -> "BraketDevic
         aws_session.add_braket_user_agent(
             user_agent="APN/1.0 ColibriTD/1.0 MPQP/" + mpqp_version
         )
-        return AwsDevice(device.get_arn(), aws_session=aws_session)
+        braket_device = AwsDevice(device.get_arn(), aws_session=aws_session)
+
     except ValueError as ve:
         raise AWSBraketRemoteExecutionError(
             "Failed to retrieve remote AWS device. Please check the arn, or if the "
@@ -410,6 +420,23 @@ def get_braket_device(device: AWSDevice, is_noisy: bool = False) -> "BraketDevic
             "\nTrace: " + str(err)
         )
 
+    if is_gate_model:
+        actions = getattr(getattr(braket_device, "properties", None), "action", None)
+        if actions is not None:
+            supported = [getattr(k, "value", str(k)) for k in actions.keys()]
+            supports_gate_model = any(
+                ("openqasm" in action.lower()) or ("jaqcd" in action.lower())
+                for action in supported
+            )
+            if not supports_gate_model:
+                raise DeviceJobIncompatibleError(
+                    f"{device.name} does not support gate-model workloads. "
+                    f"Supported Braket action types: {supported}. "
+                    "This is an AHS device, which cannot run MPQP QCircuit."
+                )
+
+    return braket_device
+
 
 def get_all_task_ids() -> list[str]:
     """Retrieves all the task ids of this account/group from AWS.

mpqp/execution/providers/aws.py

@@ -16,7 +16,11 @@
 from mpqp.execution.job import Job, JobStatus, JobType
 from mpqp.execution.result import Result, Sample, StateVector
 from mpqp.noise.noise_model import NoiseModel
-from mpqp.tools.errors import AWSBraketRemoteExecutionError, DeviceJobIncompatibleError
+from mpqp.tools.errors import (
+    AWSBraketRemoteExecutionError,
+    DeviceJobIncompatibleError,
+    DeviceJobIncompatibleWarning,
+)
 
 if TYPE_CHECKING:
     from braket.circuits import Circuit
@@ -109,16 +113,31 @@ def run_braket(job: Job) -> Result:
             f"{job.device} instead"
         )
 
+    import warnings
+
     from braket.tasks import GateModelQuantumTaskResult
 
-    if isinstance(job.measure, ExpectationMeasure):
-        return run_braket_observable(job)
-    _, task = submit_job_braket(job)
-    res = task.result()
-    if TYPE_CHECKING:
-        assert isinstance(res, GateModelQuantumTaskResult)
+    try:
+        if isinstance(job.measure, ExpectationMeasure):
+            return run_braket_observable(job)
+
+        _, task = submit_job_braket(job)
+        res = task.result()
+        if TYPE_CHECKING:
+            assert isinstance(res, GateModelQuantumTaskResult)
 
-    return extract_result(res, job, job.device)
+        return extract_result(res, job, job.device)
+
+    except DeviceJobIncompatibleError as e:
+        warnings.warn(str(e), DeviceJobIncompatibleWarning, stacklevel=5)
+
+        job.status = JobStatus.ERROR
+        return Result(
+            job,
+            data=None,
+            errors="Unsupported Braket backend for QCircuit (see warning).",
+            shots=0,
+        )
 
 
 def run_braket_observable(job: Job):
@@ -151,6 +170,7 @@ def run_braket_observable(job: Job):
         job.device,
         is_noisy=bool(job.circuit.noises),
     )
+
     if job.measure is None:
         raise NotImplementedError("job.measure is None")
     assert isinstance(job.measure, ExpectationMeasure)
@@ -270,7 +290,7 @@ def run_braket_observable(job: Job):
                 )
 
         if braket_sum is not None:
-            from braket.program_sets import ProgramSet, CircuitBinding
+            from braket.program_sets import CircuitBinding, ProgramSet
             from braket.tasks.program_set_quantum_task_result import (
                 ProgramSetQuantumTaskResult,
             )

mpqp/execution/result.py

@@ -30,7 +30,7 @@
 import numpy.typing as npt
 
 from mpqp.core.instruction.measurement.basis_measure import BasisMeasure
-from mpqp.execution import Job, JobType
+from mpqp.execution import Job, JobStatus, JobType
 from mpqp.execution.devices import AvailableDevice
 from mpqp.tools.display import clean_1D_array, clean_number_repr
 from mpqp.tools.errors import ResultAttributeError
@@ -288,8 +288,8 @@ class Result:
     def __init__(
         self,
         job: Job,
-        data: float | dict["str", float] | StateVector | list[Sample],
-        errors: Optional[float | dict[Any, Any]] = None,
+        data: float | dict["str", float] | StateVector | list[Sample] | None,
+        errors: Optional[float | dict[Any, Any] | str] = None,
         shots: int = 0,
     ):
         self.job = job
@@ -305,6 +305,11 @@ def __init__(
         """See parameter description."""
         self._data = data
 
+        if data is None:
+            if job.status != JobStatus.ERROR:
+                raise TypeError("Result data cannot be None unless job.status == ERROR")
+            return
+
         # depending on the type of job, fills the result info from the data in parameter
         if job.job_type == JobType.OBSERVABLE:
             if not isinstance(data, float) and not isinstance(data, dict):
@@ -458,6 +463,9 @@ def __str__(self):
         label = "" if self.job.circuit.label is None else self.job.circuit.label + ", "
         header = f"Result: {label}{type(self.device).__name__}, {self.device.name}"
 
+        if self.job.status == JobStatus.ERROR:
+            return f"{header}\n  Error: {self.error}"
+
         if self.job.job_type == JobType.SAMPLE:
             measures = self.job.circuit.measurements
             if not len(measures) == 1:

mpqp/tools/errors.py

@@ -34,6 +34,10 @@ class DeviceJobIncompatibleError(ValueError):
     for the selected device (for example SAMPLE job on a statevector simulator)."""
 
 
+class DeviceJobIncompatibleWarning(UserWarning):
+    """A warning is issued when a job is not compatible with the selected device."""
+
+
 class RemoteExecutionError(ConnectionError):
     """Raised when an error occurred during a remote connection, submission or
     execution."""