first commit

app/state.py

@@ -0,0 +1,31 @@
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+
+class SentOffersStore:
+    def __init__(self, file_path: Path) -> None:
+        self._file_path = file_path
+        self._file_path.parent.mkdir(parents=True, exist_ok=True)
+        self._sent_keys = self._load()
+
+    def has(self, key: str) -> bool:
+        return key in self._sent_keys
+
+    def add(self, key: str) -> None:
+        self._sent_keys.add(key)
+        self._persist()
+
+    def _load(self) -> set[str]:
+        if not self._file_path.exists():
+            return set()
+
+        with self._file_path.open("r", encoding="utf-8") as file:
+            data = json.load(file)
+
+        return set(data)
+
+    def _persist(self) -> None:
+        with self._file_path.open("w", encoding="utf-8") as file:
+            json.dump(sorted(self._sent_keys), file, ensure_ascii=False, indent=2)