5 files changed, 98 insertions, 1 deletions
diff --git a/waterspout_radar/__main__.py b/waterspout_radar/__main__.py
new file mode 100644
index 0000000..ec840b5
--- /dev/null
+++ b/waterspout_radar/__main__.py
@@ -0,0 +1,8 @@
+import sys
+
+from . import cli
+
+if __name__ == "__main__":
+	if "__main__" in sys.arg[0]:
+		sys.argv[0] = "waterspout_radar"
+	cli.main()
diff --git a/waterspout_radar/_config.py b/waterspout_radar/_config.py
index 36d9c0b..eaa6c58 100644
--- a/waterspout_radar/_config.py
+++ b/waterspout_radar/_config.py
@@ -39,7 +39,7 @@ class ConfigError(Exception):
 	"Raised when configuration could not be loaded or was malformed."
 
 
-def load(pathname: str="radar.conf") -> Config:
+def load(pathname: str) -> Config:
 	"Loads configuration from a file at *pathname*. May raise ConfigError when content does not meet expectations."
 	config = configparser.ConfigParser(allow_no_value=True)
 	config.read(pathname)
diff --git a/waterspout_radar/_radar.py b/waterspout_radar/_radar.py
new file mode 100644
index 0000000..629ec55
--- /dev/null
+++ b/waterspout_radar/_radar.py
@@ -0,0 +1,52 @@
+import dataclasses
+import datetime
+import typing
+
+import szilagyi
+from geopy import geocoders
+from metpy import calc
+from metpy import units as metunits
+from windy import point_forecast, Windy
+
+_L = point_forecast.Level
+
+
+@dataclasses.dataclass
+class Prediction:
+	time: datetime.datetime
+	swi: float
+
+
+def calculate(config) -> typing.List[Prediction]:
+	units = metunits.units
+	windy = Windy(units)
+
+	def _calculate(latitude, longitude):
+		forecasts = windy.point_forecast(
+			config.key,
+			latitude, longitude,
+			point_forecast.Model.ICONEU,
+			("temp", "dewpoint", "wind", "pressure"),
+			tuple(_L))
+		for cast in forecasts:
+			dt = abs(cast.at("temp", _L.H850) - cast.at("temp", _L.SURFACE))
+			pressure, _ = calc.lcl(
+				cast.at("pressure", _L.SURFACE),
+				cast.at("temp", _L.SURFACE),
+				cast.at("dewpoint", _L.SURFACE))
+			lcl = calc.pressure_to_height_std(pressure)
+			pressure, _ = calc.el(cast["pressure"], cast["temp"], cast["dewpoint"])
+			el = calc.pressure_to_height_std(pressure)
+			ccd = (el - lcl).to(units.ft)
+			try:
+				swi = szilagyi.calculate_swi(dt, ccd)
+			except ValueError:
+				swi = -10
+			yield Prediction(time=cast.timestamp, swi=swi)
+
+	predictions = []
+	locator = geocoders.Nominatim(user_agent="waterspout-radar")
+	for location in config.locations:
+		found = locator.geocode(location)
+		predictions.extend(_calculate(found.latitude, found.longitude))
+	return predictions
diff --git a/waterspout_radar/_storage.py b/waterspout_radar/_storage.py
new file mode 100644
index 0000000..a410259
--- /dev/null
+++ b/waterspout_radar/_storage.py
@@ -0,0 +1,18 @@
+import datetime
+import typing
+
+from . import _radar
+
+Period = typing.Tuple[datetime.datetime, datetime.datetime]
+
+
+class Storage:
+	def __init__(self, pathname):
+		pass
+
+	def show(self, period: Period=None):
+		return []
+
+	def extend(self, predictions: typing.Iterable[_radar.Prediction]):
+		for prediction in predictions:
+			print(prediction)
diff --git a/waterspout_radar/cli.py b/waterspout_radar/cli.py
new file mode 100644
index 0000000..ecf79d8
--- /dev/null
+++ b/waterspout_radar/cli.py
@@ -0,0 +1,19 @@
+import argparse
+
+from . import _config, _radar, _storage
+
+
+def main():
+	parser = argparse.ArgumentParser()
+	parser.add_argument(
+		"-c", "--config", default="radar.conf",
+		help="Pathname of the instance configuration file (default: %(default)s)")
+	args = parser.parse_args()
+	config = _config.load(args.config)
+	storage = _storage.Storage(config.db)
+	predictions = _radar.calculate(config)
+	storage.extend(predictions)
+
+
+if __name__ == "__main__":
+	main()