add function for getting info about installed tape

labeler/infra/e550w_printer/printer.py

@@ -0,0 +1,74 @@
+from math import inf
+
+from pysnmp.entity.engine import SnmpEngine
+from pysnmp.hlapi import getCmd, CommunityData, UdpTransportTarget, ContextData
+from pysnmp.smi.rfc1902 import ObjectType, ObjectIdentity
+
+from labeler.domain.objects import MediaDefinition, Dimension
+from labeler.infra.e550w_printer.media_definitions import (
+    media_width,
+    tape_color,
+    text_color,
+    media_type,
+    WIDTH_BYTE,
+    COLOR_BYTE,
+    TEXT_COLOR_BYTE,
+    TYPE_BYTE,
+)
+from labeler.interfaces import Printer
+
+
+class E550W(Printer):
+    def __init__(self, ip_address: str):
+        self.ip_address = ip_address
+        self.snmp_port = 161
+
+    def get_installed_media(self) -> MediaDefinition:
+        pass
+
+    def __get_printer_status(self):
+        raw_snmp_data = self.__get_snmp_status().asNumbers()
+        width = media_width(raw_snmp_data[WIDTH_BYTE])
+        media_tape_color = tape_color(raw_snmp_data[COLOR_BYTE])
+        media_text_color = text_color(raw_snmp_data[TEXT_COLOR_BYTE])
+        tape_type = media_type(raw_snmp_data[TYPE_BYTE])
+
+        return MediaDefinition(
+            width=Dimension(mm=width),
+            length=Dimension(mm=inf),
+            minimal_margin_vertical=Dimension(mm=1),
+            minimal_margin_horizontal=Dimension(mm=2),
+            dpi=600,
+            description=f"{tape_type} - {width}mm, {media_text_color} on {media_tape_color} background",
+        )
+
+    def __get_snmp_status(self):
+        """
+        This oid was found by using wireshark, however it's also documented here:
+        https://support.brother.com/g/s/es/dev/en/command/faq/index.html?c=eu_ot&lang=en&navi=offall&comple=on&redirect=on
+        just not for the E550W model.
+        """
+        oid = "1.3.6.1.4.1.2435.3.3.9.1.6.1.0"
+
+        error_indication, error_status, error_index, var_binds = next(
+            getCmd(
+                SnmpEngine(),
+                CommunityData("public", mpModel=0),
+                UdpTransportTarget((self.ip_address, self.snmp_port)),
+                ContextData(),
+                ObjectType(ObjectIdentity(oid)),
+            )
+        )
+
+        if error_indication:
+            raise Exception(error_indication)
+        elif error_status:
+            raise Exception(
+                "%s at %s"
+                % (
+                    error_status.prettyPrint(),
+                    error_index and var_binds[int(error_index) - 1][0] or "?",
+                )
+            )
+        else:
+            return var_binds[0][1]