Implement transaction handling

app/schemas/transaction.py

@@ -1,5 +1,7 @@
 from datetime import datetime
+from decimal import Decimal
 import enum
+from typing import Optional
 from uuid import UUID
 from pydantic import BaseModel
 
@@ -31,15 +33,16 @@ class TransactionEventTriggerReason(enum.Enum):
     RESET_COMMAND = "ResetCommand"
 
 class Transaction(BaseModel):
-    id: UUID
+    id: str
     status: TransactionStatus
     started_at: datetime
-    ended_at: datetime
-    meter_start: float
-    meter_end: float
-    end_reason: TransactionEventTriggerReason
-    connector_id: str
-    id_token_id: str
+    ended_at: Optional[datetime] = None
+    meter_start: Decimal
+    meter_end: Optional[Decimal] = None
+    end_reason: Optional[TransactionEventTriggerReason] = None
+    price: Decimal
+    user_id: Optional[UUID] = None
+    chargepoint_id: UUID
 
     class Config:
         from_attributes = True