Create Relay Bot MVP

app/attachments/service.py

@@ -0,0 +1,30 @@
+from pathlib import Path
+
+from app.attachments.extractors import SUPPORTED_EXTENSIONS, extract_text
+
+
+def explicitly_requested(
+    *,
+    is_private: bool,
+    caption: str | None,
+    replied_with_request: bool,
+    command: bool,
+    bot_username: str | None,
+) -> bool:
+    mention = bool(caption and bot_username and f"@{bot_username.lower()}" in caption.lower())
+    return is_private or mention or replied_with_request or command
+
+
+class AttachmentService:
+    def __init__(self, max_bytes: int):
+        self.max_bytes = max_bytes
+
+    def validate(self, filename: str, size: int) -> None:
+        if size > self.max_bytes:
+            raise ValueError("Файл слишком большой")
+        if Path(filename).suffix.lower() not in SUPPORTED_EXTENSIONS:
+            raise ValueError("Неподдерживаемый или небезопасный файл")
+
+    def extract(self, filename: str, content: bytes) -> str:
+        self.validate(filename, len(content))
+        return extract_text(filename, content)