traces

ccu_emulator/policy.py

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+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from .frames import HEARTBEAT_FRAME, NEUTRAL_ACK_FRAME, frame_checksum_ok
+
+
+REPORT_COMMAND_BYTES = frozenset({0x00, 0x01, 0x02})
+
+
+@dataclass(frozen=True)
+class AckDecision:
+    should_ack: bool
+    frame: bytes = NEUTRAL_ACK_FRAME
+    reason: str = ""
+
+
+@dataclass(frozen=True)
+class AckPolicy:
+    """Decides whether an RCP-origin frame should get a continuation ACK."""
+
+    ack_frame: bytes = NEUTRAL_ACK_FRAME
+    ack_reports: bool = True
+    ack_heartbeats: bool = True
+    ack_unlabeled_checksum_frames: bool = True
+
+    def decide(self, frame: bytes, label: str = "") -> AckDecision:
+        if not frame_checksum_ok(frame):
+            return AckDecision(False, self.ack_frame, "checksum_bad")
+
+        if frame == HEARTBEAT_FRAME:
+            if self.ack_heartbeats:
+                return AckDecision(True, self.ack_frame, "heartbeat_report")
+            return AckDecision(False, self.ack_frame, "heartbeat_ignored")
+
+        if frame[0] in REPORT_COMMAND_BYTES:
+            if self.ack_reports:
+                return AckDecision(True, self.ack_frame, f"report_cmd_{frame[0]:02X}")
+            return AckDecision(False, self.ack_frame, "reports_disabled")
+
+        if label == "checksum_ok_unlabeled" and self.ack_unlabeled_checksum_frames:
+            return AckDecision(True, self.ack_frame, "unlabeled_checksum_ok")
+
+        return AckDecision(False, self.ack_frame, f"non_report_cmd_{frame[0]:02X}")