Add rudimentary sniper script

cli_sniper.py

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+import sys
+from sniper import Sniper
+
+class CLISniper(Sniper):
+    UPDATE_MESSAGE = "The detected accommodation page is different to the previous one, indicating a possible change in application status! Please check the accommodation page as soon as possbible!"
+    def on_change(self):
+        print(self.UPDATE_MESSAGE)
+    
+    def on_same(self):
+        print("No change from last check...", file=sys.stderr)
+
+def main():
+    print("Now running Accommodation sniper...", file=sys.stderr)
+    sniper = CLISniper()
+    sniper.loop()
+
+if __name__ == "__main__":
+    main()

requirements.txt

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+requests

sniper.py

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+from abc import ABC, abstractmethod
+import time
+from typing import Optional
+import requests
+import difflib
+
+ACCOMMODATION_URL = "https://warwick.ac.uk/services/accommodation/students/current/"
+def get_accommodation_page() -> Optional[str]:
+    r = requests.get(ACCOMMODATION_URL)
+    if r is None:
+        return None
+    else:
+        return r.text
+
+def get_difference(page_before: str, page_after: str) -> Optional[list[str]]:
+    if page_before == page_after:
+        return None
+    
+    return [*difflib.context_diff(page_before.splitlines(), page_after.splitlines())]
+
+THIRTY_MINUTES = 30 * 60
+TIMEOUT = THIRTY_MINUTES
+class Sniper(ABC):
+    previous_page: str
+
+    def __init__(self):
+        self.previous_page = get_accommodation_page()
+
+    def update(self) -> None:
+        current_page = get_accommodation_page()
+        if get_difference(self.previous_page, current_page):
+            self.on_change()
+        else:
+            self.on_same()
+        self.previous_page = current_page
+
+    @abstractmethod
+    def on_change(self) -> None:
+        pass
+    
+    def on_same(self) -> None:
+        pass
+
+    def loop(self):
+        while True:
+            time.sleep(TIMEOUT)
+            self.update()