feat: search functionality

backend/src/utils/search/models.py

@@ -0,0 +1,30 @@
+from datetime import datetime
+from typing import Literal
+
+from pydantic import BaseModel
+
+DEFAULT_LIMIT = 50
+MAX_LIMIT = 500
+
+
+class SearchFilters(BaseModel):
+    account_id: int
+    query: str | None = None
+    chat_id: int | None = None
+    sender_id: int | None = None
+    has_media: bool | None = None
+    date_from: datetime | None = None
+    date_to: datetime | None = None
+    regex: str | None = None
+    limit: int = DEFAULT_LIMIT
+    offset: int = 0
+
+
+class SearchHit(BaseModel):
+    chat_id: int
+    message_id: int
+    date: datetime
+    sender_id: int | None
+    text: str | None
+    source: Literal["text", "stt"]
+    extracted_text: str | None