Send alert emails for particular rocket launches

Closes: #156

agenda/thespacedevs.py

@@ -7,13 +7,15 @@ from datetime import datetime
 
 import requests
 
+from .types import StrDict
+
 Launch = dict[str, typing.Any]
 Summary = dict[str, typing.Any]
 
 ttl = 60 * 60 * 2  # two hours
 
 
-def next_launch_api(rocket_dir: str, limit: int = 200) -> list[Launch]:
+def next_launch_api_data(rocket_dir: str, limit: int = 200) -> StrDict:
     """Get the next upcoming launches from the API."""
     now = datetime.now()
     filename = os.path.join(rocket_dir, now.strftime("%Y-%m-%d_%H:%M:%S.json"))
@@ -21,8 +23,14 @@ def next_launch_api(rocket_dir: str, limit: int = 200) -> list[Launch]:
 
     params: dict[str, str | int] = {"limit": limit}
     r = requests.get(url, params=params)
-    data = r.json()
+    data: StrDict = r.json()
     open(filename, "w").write(r.text)
+    return data
+
+
+def next_launch_api(rocket_dir: str, limit: int = 200) -> list[Launch]:
+    """Get the next upcoming launches from the API."""
+    data = next_launch_api_data(rocket_dir, limit)
     return [summarize_launch(launch) for launch in data["results"]]
 
 
@@ -138,7 +146,7 @@ def summarize_launch(launch: Launch) -> Summary:
     }
 
 
-def read_cached_launches(rocket_dir: str) -> list[Summary]:
+def load_cached_launches(rocket_dir: str) -> StrDict:
     """Read the most recent cache of launches."""
     existing = [x for x in (filename_timestamp(f) for f in os.listdir(rocket_dir)) if x]
 
@@ -146,7 +154,12 @@ def read_cached_launches(rocket_dir: str) -> list[Summary]:
     f = existing[0][1]
 
     filename = os.path.join(rocket_dir, f)
-    data = json.load(open(filename))
+    return typing.cast(StrDict, json.load(open(filename)))
+
+
+def read_cached_launches(rocket_dir: str) -> list[Summary]:
+    """Read cached launches."""
+    data = load_cached_launches(rocket_dir)
     return [summarize_launch(launch) for launch in data["results"]]