From d68966bd6b4187cf4493f13c3c11fb8fbc8bdd8a Mon Sep 17 00:00:00 2001
From: Teemu Rytilahti <tpr@iki.fi>
Date: Fri, 29 Nov 2024 18:24:01 +0100
Subject: [PATCH] Add fixtured-powered device simulator

---
 devtools/simulator.py | 114 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 devtools/simulator.py

diff --git a/devtools/simulator.py b/devtools/simulator.py
new file mode 100644
index 00000000..cc35fb31
--- /dev/null
+++ b/devtools/simulator.py
@@ -0,0 +1,114 @@
+"""Minimalistic, fixture-powered device simulator."""
+
+import asyncio
+import json
+import logging
+import ssl
+
+import asyncclick as click
+
+from kasa.json import dumps as json_dumps
+from kasa.json import loads as json_loads
+
+_LOGGER = logging.getLogger(__name__)
+
+HDR = b"\x02\x00\x00\x01\x01\xe5\x11\x00"
+RESP_HDR = bytearray(16)
+
+
+class DiscoveryProtocol(asyncio.DatagramProtocol):
+    """Simplified discovery protocol implementation."""
+
+    def __init__(self, fixture):
+        self.disco_data = fixture
+
+    def connection_made(self, transport):
+        """Set transport and log incoming connections."""
+        peer = transport.get_extra_info("peername")
+        _LOGGER.info("[UDP] Connection from %s", peer)
+        self.transport = transport
+
+    def datagram_received(self, data: bytes, addr):
+        """Respond to discovery requests."""
+        _LOGGER.info("[UDP] %s << %s", addr, data)
+        if not data.startswith(HDR):
+            _LOGGER.debug("[UDP] Unexpected datagram from %s: %r", addr, data)
+
+        resp_data = {"error_code": 0, "result": self.disco_data}
+        resp = json_dumps(resp_data).encode()
+        _LOGGER.info("[UDP] %s >> %s", addr, resp)
+        self.transport.sendto(RESP_HDR + resp, addr)
+
+
+class AppProtocol(asyncio.Protocol):
+    """App protocol implementation."""
+
+    def connection_made(self, transport):
+        """Set the transport on incoming connections."""
+        peer = transport.get_extra_info("peername")
+        _LOGGER.info("[APP] Connection from %s", peer)
+        self.transport = transport
+
+    def data_received(self, data: bytes):
+        """Handle received requests."""
+        message = data
+        _LOGGER.info("[APP] << %r", message)
+
+        resp = {"error_code": 0}
+
+        _LOGGER.info("[APP] >> %r", resp)
+        self.transport.write(json.dumps(resp).encode())
+
+        # TODO: don't close after response?
+        self.transport.close()
+
+
+async def serve_udp(port, discovery_data):
+    """Serve discovery protocol."""
+    loop = asyncio.get_event_loop()
+    _LOGGER.info("Serving discovery on port %s", port)
+    await loop.create_datagram_endpoint(
+        lambda: DiscoveryProtocol(discovery_data),
+        local_addr=("0.0.0.0", port),  # noqa: S104
+    )
+    while True:
+        await asyncio.sleep(5)
+
+
+async def serve_tcp(port):
+    """Serve app communications protocol."""
+    _LOGGER.info("Serving app on port %s", port)
+    loop = asyncio.get_event_loop()
+
+    # TODO: These settings are not enough to let openssl nor kasa cli to connect
+    #       ssl.SSLError: [SSL: NO_SHARED_CIPHER] no shared cipher (_ssl.c:1000)
+
+    ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    ctx.check_hostname = False
+    ctx.verify_mode = ssl.CERT_NONE
+    ctx.set_ciphers("ALL:@SECLEVEL=0")
+    ctx.minimum_version = ssl.TLSVersion.TLSv1
+
+    server = await loop.create_server(AppProtocol, host="0.0.0.0", port=port, ssl=ctx)  # noqa: S104
+    async with server:
+        await server.serve_forever()
+
+
+@click.command()
+@click.argument("fixture", type=click.File())
+async def main(fixture):
+    """Minimalistic, fixture-powered device simulator."""
+    fixture_data = json_loads(fixture.read())
+    disco_data = fixture_data["discovery_result"]
+    _LOGGER.info(
+        "Starting for %s (%s)", disco_data["device_model"], disco_data["device_type"]
+    )
+
+    async with asyncio.TaskGroup() as tg:
+        tg.create_task(serve_udp(discovery_data=disco_data, port=20002))
+        tg.create_task(serve_tcp(port=4433))
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.DEBUG)
+    main()