Добавить общий API старого CAN terminal

python/protocan/balsam.py

@@ -0,0 +1,98 @@
+"""Balsam 167 legacy CAN register decoder backed by the shared C99 core."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from .native import NativeProtocolUnavailable, get_native_protocol
+
+
+BASE_ID = 0x00BA0000
+DATA_OFFSET = 0x10
+NODE_COUNT = 13
+
+
+@dataclass(frozen=True)
+class BalsamRegister:
+    address: int
+    value: int
+    name: str
+
+    @property
+    def signed_value(self) -> int:
+        return self.value if self.value < 0x8000 else self.value - 0x10000
+
+
+@dataclass(frozen=True)
+class BalsamFrame:
+    can_id: int
+    device: int
+    device_name: str
+    from_device: bool
+    start_address: int
+    present_mask: int
+    registers: tuple[BalsamRegister, ...]
+
+    @property
+    def summary(self) -> str:
+        direction = "данные" if self.from_device else "команда"
+        values = ", ".join(
+            "%s=0x%04X (%d)" % (item.name or "R%04X" % item.address,
+                                  item.value, item.signed_value)
+            for item in self.registers
+        ) or "нет отмеченных регистров"
+        return "BALZAM · %s · %s · %s" % (self.device_name, direction, values)
+
+
+def is_balsam_id(can_id: int) -> bool:
+    relative = (can_id & 0x1FFFFFFF) - BASE_ID
+    return (0 <= relative < NODE_COUNT
+            or DATA_OFFSET <= relative < DATA_OFFSET + NODE_COUNT)
+
+
+def decode(can_id: int, data: bytes, native=None) -> BalsamFrame | None:
+    """Decode one abstract Balsam frame: BE mask/address plus three BE words."""
+    if native is None:
+        try:
+            native = get_native_protocol()
+        except NativeProtocolUnavailable:
+            return _decode_fallback(can_id, data)
+    status, decoded = native.balsam_decode(can_id, bytes(data))
+    if status == 0:
+        return None
+    if status == -2:
+        raise ValueError("BALZAM CAN frame must contain exactly 8 data bytes")
+    if status != 1 or decoded is None:
+        raise ValueError("invalid BALZAM CAN frame")
+    device, direction, mask, start, values = decoded
+    registers = tuple(
+        BalsamRegister(start + index, values[index],
+                       native.balsam_register_name(device, start + index))
+        for index in range(3) if mask & (4 >> index)
+    )
+    return BalsamFrame(can_id & 0x1FFFFFFF, device,
+                       native.balsam_device_name(device), direction == 1,
+                       start, mask, registers)
+
+
+def _decode_fallback(can_id: int, data: bytes) -> BalsamFrame | None:
+    if not is_balsam_id(can_id):
+        return None
+    if len(data) != 8:
+        raise ValueError("BALZAM CAN frame must contain exactly 8 data bytes")
+    relative = (can_id & 0x1FFFFFFF) - BASE_ID
+    device = (relative & 0x0F) + 1
+    header = int.from_bytes(data[:2], "big")
+    values = tuple(int.from_bytes(data[offset:offset + 2], "big")
+                   for offset in (2, 4, 6))
+    names = {
+        1: "Трансформатор 1", 2: "Трансформатор 2",
+        3: "Силовой блок 1", 4: "Силовой блок 2", 5: "УМП 1", 6: "УМП 2",
+        7: "Двигатель", 8: "ВЭП", 9: "Задатчик", 13: "Терминал",
+    }
+    start, mask = header & 0x1FFF, (header >> 13) & 7
+    registers = tuple(BalsamRegister(start + i, values[i], "")
+                      for i in range(3) if mask & (4 >> i))
+    return BalsamFrame(can_id & 0x1FFFFFFF, device,
+                       names.get(device, "Узел %d" % device),
+                       relative >= DATA_OFFSET, start, mask, registers)