Add logfile support

calypso_anemometer/cli.py

@@ -74,6 +74,20 @@ def cli(ctx, quiet: t.Optional[bool], verbose: t.Optional[bool], debug: t.Option
 )
 subscribe_option = click.option("--subscribe", is_flag=True, required=False, help="Continuously receive readings")
 target_option = click.option("--target", type=str, required=False, help="Submit telemetry data to target")
+log_to_option = click.option(
+    "--log-to",
+    type=click.Path(writable=True, dir_okay=False),
+    required=False,
+    help="Path to a file to log telemetry data (e.g., data.csv).",
+)
+log_file_lines_option = click.option(
+    "--log-file-lines",
+    type=int,
+    required=False,
+    default=1000,
+    help="Maximum number of lines to keep in the log file. Default: 1000.",
+)
+
 
 
 @click.command()
@@ -177,6 +191,8 @@ async def handler(calypso: CalypsoDeviceApi):
 @target_option
 @rate_option
 @compass_option
+@log_to_option
+@log_file_lines_option
 @click.pass_context
 @make_sync
 async def read(
@@ -189,6 +205,8 @@ async def read(
     target: t.Optional[str] = None,
     rate: t.Optional[CalypsoDeviceDataRate] = None,
     compass: t.Optional[CalypsoDeviceCompassStatus] = None,
+    log_to: t.Optional[str] = None,
+    log_file_lines: t.Optional[int] = None,
 ):
     quiet = ctx.parent.params.get("quiet")
     settings = Settings(
@@ -197,7 +215,7 @@ async def read(
         ble_discovery_timeout=ble_discovery_timeout,
         ble_connect_timeout=ble_connect_timeout,
     )
-    handler = await handler_factory(subscribe=subscribe, target=target, rate=rate, compass=compass, quiet=quiet)
+    handler = await handler_factory(subscribe=subscribe, target=target, rate=rate, compass=compass, quiet=quiet, log_to=log_to, log_file_lines=log_file_lines)
     await run_engine(workhorse=CalypsoDeviceApi, settings=settings, handler=handler)
 
 
@@ -206,6 +224,8 @@ async def read(
 @target_option
 @rate_option
 @compass_option
+@log_to_option
+@log_file_lines_option
 @click.pass_context
 @make_sync
 async def fake(
@@ -214,11 +234,13 @@ async def fake(
     target: t.Optional[str] = None,
     rate: t.Optional[CalypsoDeviceDataRate] = None,
     compass: t.Optional[CalypsoDeviceCompassStatus] = None,
+    log_to: t.Optional[str] = None,
+    log_file_lines: t.Optional[int] = None,
 ):
     from calypso_anemometer.fake import CalypsoDeviceApiFake
 
     quiet = ctx.parent.params.get("quiet")
-    handler = await handler_factory(subscribe=subscribe, target=target, rate=rate, compass=compass, quiet=quiet)
+    handler = await handler_factory(subscribe=subscribe, target=target, rate=rate, compass=compass, quiet=quiet, log_to=log_to, log_file_lines=log_file_lines)
     await run_engine(workhorse=CalypsoDeviceApiFake, handler=handler)
 
 

calypso_anemometer/engine.py

@@ -11,6 +11,9 @@
 from calypso_anemometer.telemetry.adapter import TelemetryAdapter
 from calypso_anemometer.util import wait_forever
 
+from datetime import datetime, timezone
+import os
+
 logger = logging.getLogger(__name__)
 
 
@@ -34,6 +37,8 @@ async def handler_factory(
     rate: t.Optional[CalypsoDeviceDataRate] = None,
     compass: t.Optional[CalypsoDeviceCompassStatus] = None,
     quiet: bool = False,
+    log_to: t.Optional[str] = None,
+    log_file_lines: t.Optional[int] = None,
 ) -> t.Callable:
     """
     Create an asynchronous handler function for processing readings.
@@ -54,15 +59,49 @@ async def handler_factory(
     telemetry = None
     if target is not None:
         telemetry = TelemetryAdapter(uri=target)
+
+    # Optionally log to a file
+    log_file = None
+    if log_to is not None:
+        log_file = open(log_to, mode="a", encoding="utf-8")
+        # Write header if file is empty
+        if log_file.tell() == 0:
+            log_file.write("wind_speed,wind_direction,temperature\n")
+
+    # Function to write a row to a CSV file, truncating if necessary.
+    def write_row_to_csv(filepath: str, row: str, log_file_lines: int):
+        lines = []
+        if os.path.exists(filepath):
+            with open(filepath, "r") as f:
+                lines = f.readlines()
+
+        lines.append(row + "\n")
+
+        # Truncate if too many lines
+        if log_file_lines is not None and len(lines) > log_file_lines:
+            lines = lines[-log_file_lines:]
+
+        with open(filepath, "w") as f:
+            f.writelines(lines)
 
     # When a reading is received, optionally display on STDOUT or hand over to telemetry adapter.
     def process_reading(reading: CalypsoReading):
         nonlocal message_counter
         message_counter += 1
+        timestamp = datetime.now(timezone.utc).isoformat()
+
+
         if not quiet:
+            print(f"[{timestamp}] ", end="")
             reading.dump()
         if telemetry is not None:
             telemetry.submit(reading)
+
+        # Optionally log to a file.
+        if log_file is not None:
+            row = f"{timestamp},{reading.wind_speed},{reading.wind_direction},{reading.temperature}\n"
+            write_row_to_csv(log_to, row, log_file_lines)
+
         if message_counter % message_counter_log_each == 0:
             logger.info(f"Processed readings: {message_counter}")