Add exception handling

pyproject.toml

@@ -3,7 +3,7 @@ name = "py-watersmart"
 authors = [
   {name = "J.C. Jones", email = "[email protected]"},
 ]
-version = "0.1.1"
+version = "0.1.2"
 readme = "README.md"
 description = "Obtain water usage data from Watersmart.com"
 classifiers = [
@@ -14,7 +14,8 @@ classifiers = [
 keywords = ["water meter"]
 dependencies = [
   "aiohttp",
-  "aiohttp-client-cache[sqlite]"
+  "aiohttp-client-cache[sqlite]",
+  "async_timeout"
 ]
 requires-python = ">=3.11"
 

src/client/client.py

@@ -3,7 +3,12 @@
 import asyncio
 import argparse
 import logging
-from watersmart import WatersmartClient
+from watersmart import (
+    WatersmartClient,
+    WatersmartClientAuthenticationError,
+    WatersmartClientCommunicationError,
+    WatersmartClientError,
+)
 
 
 PARSER = argparse.ArgumentParser(description=__doc__)
@@ -24,15 +29,22 @@ async def main():
     log_format = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
     logging.basicConfig(level=args.log_level, format=log_format)
     wc = WatersmartClient(args.url, args.email, args.password)
-    data = await wc.usage()
-    for datapoint in sorted(data, key=lambda x: x["read_datetime"]):
-        parts = [
-            f"{datapoint['local_datetime']}",
-            f"usage: {datapoint['gallons']:8}gal",
-            f"leak: {datapoint['leak_gallons']:8}gal",
-            f"flags: {datapoint['flags']}",
-        ]
-        print(" | ".join(parts))
+    try:
+        data = await wc.usage()
+        for datapoint in sorted(data, key=lambda x: x["read_datetime"]):
+            parts = [
+                f"{datapoint['local_datetime']}",
+                f"usage: {datapoint['gallons']:8}gal",
+                f"leak: {datapoint['leak_gallons']:8}gal",
+                f"flags: {datapoint['flags']}",
+            ]
+            print(" | ".join(parts))
+    except WatersmartClientAuthenticationError:
+        logging.exception("Login failure")
+    except WatersmartClientCommunicationError:
+        logging.exception("Communications error")
+    except WatersmartClientError:
+        logging.exception("Unknown error")
 
 
 def start():

src/watersmart/__init__.py

@@ -1,12 +1,28 @@
 """Main WaterSmart module"""
 
+import aiohttp
+import asyncio
+import async_timeout
 import logging
+import socket
 import time
 
 from aiohttp_client_cache import CachedSession, SQLiteBackend
 from importlib.metadata import version
 
 
+class WatersmartClientError(Exception):
+    """Exception to indicate a general API error."""
+
+
+class WatersmartClientCommunicationError(WatersmartClientError):
+    """Exception to indicate a communication error."""
+
+
+class WatersmartClientAuthenticationError(WatersmartClientError):
+    """Exception to indicate an authentication error."""
+
+
 class WatersmartClient:
     def __init__(self, url, email, password):
         self._url = url
@@ -30,11 +46,14 @@ def __init__(self, url, email, password):
     async def _login(self):
         url = f"{self._url}/index.php/welcome/login?forceEmail=1"
         login = {"token": "", "email": self._email, "password": self._password}
-        await self._session.post(url, data=login)
+        result = await self._session.post(url, data=login)
+        logging.debug(result)
 
     async def _populate_data(self):
         url = f"{self._url}/index.php/rest/v1/Chart/RealTimeChart"
         chart_rsp = await self._session.get(url)
+        if chart_rsp.status != 200:
+            raise WatersmartClientAuthenticationError()
         data = await chart_rsp.json()
         self._data_series = data["data"]["series"]
 
@@ -49,16 +68,31 @@ def _amend_with_local_ts(cls, datapoint):
 
     async def usage(self):
         if not self._data_series:
-            logging.debug("Loading watersmart data")
-            await self._login()
-            await self._populate_data()
-            await self._close()
+            try:
+                async with async_timeout.timeout(10):
+                    logging.debug("Loading watersmart data from %s", self._url)
+                    await self._login()
+                    await self._populate_data()
+            except WatersmartClientAuthenticationError as e:
+                raise e
+            except asyncio.TimeoutError as exception:
+                raise WatersmartClientCommunicationError(
+                    "Timeout error fetching information",
+                ) from exception
+            except (aiohttp.ClientError, socket.gaierror) as exception:
+                raise WatersmartClientCommunicationError(
+                    "Error fetching information",
+                ) from exception
+            except Exception as exception:  # pylint: disable=broad-except
+                raise WatersmartClientError(
+                    "Something really wrong happened!"
+                ) from exception
+            finally:
+                await self._close()
 
         result = []
-
         for datapoint in self._data_series:
             result.append(WatersmartClient._amend_with_local_ts(datapoint))
-
         return result
 
     async def _close(self):