from typing import List, Optional
from sqlalchemy.orm import Session
from sqlalchemy import desc
from datetime import datetime
from app.models.circuit import Circuit
from app.schemas.circuit import CircuitCreate, CircuitUpdate
from app.models.journal import EntityType
from app.crud.crud_journal import journal


class CRUDCircuit:
    def get(self, db: Session, circuit_id: int) -> Optional[Circuit]:
        return db.query(Circuit).filter(Circuit.id == circuit_id).first()

    def get_by_local_flight(self, db: Session, local_flight_id: int) -> List[Circuit]:
        """Get all circuits for a specific local flight"""
        return db.query(Circuit).filter(
            Circuit.local_flight_id == local_flight_id
        ).order_by(Circuit.circuit_timestamp).all()

    def get_by_arrival(self, db: Session, arrival_id: int) -> List[Circuit]:
        """Get all circuits for a specific arrival"""
        return db.query(Circuit).filter(
            Circuit.arrival_id == arrival_id
        ).order_by(Circuit.circuit_timestamp).all()

    def get_multi(
        self, 
        db: Session, 
        skip: int = 0, 
        limit: int = 100
    ) -> List[Circuit]:
        return db.query(Circuit).order_by(desc(Circuit.created_at)).offset(skip).limit(limit).all()

    def create(self, db: Session, obj_in: CircuitCreate, user: str = "system", user_ip: Optional[str] = None) -> Circuit:
        db_obj = Circuit(
            local_flight_id=obj_in.local_flight_id,
            arrival_id=obj_in.arrival_id,
            circuit_timestamp=obj_in.circuit_timestamp
        )
        db.add(db_obj)
        db.commit()
        db.refresh(db_obj)
        
        # Log circuit creation in journal
        # Use LOCAL_FLIGHT entity type if local_flight_id exists, otherwise ARRIVAL
        entity_type = EntityType.LOCAL_FLIGHT if obj_in.local_flight_id else EntityType.ARRIVAL
        entity_id = obj_in.local_flight_id if obj_in.local_flight_id else obj_in.arrival_id
        
        journal.log_change(
            db,
            entity_type,
            entity_id,
            f"Circuit recorded at {obj_in.circuit_timestamp.isoformat()}",
            user,
            user_ip
        )
        
        return db_obj

    def update(self, db: Session, db_obj: Circuit, obj_in: CircuitUpdate, user: str = "system", user_ip: Optional[str] = None) -> Circuit:
        obj_data = obj_in.dict(exclude_unset=True)
        changes = []
        
        for field, value in obj_data.items():
            old_value = getattr(db_obj, field)
            if old_value != value:
                changes.append(f"{field} changed from '{old_value}' to '{value}'")
                setattr(db_obj, field, value)
        
        db.add(db_obj)
        db.commit()
        db.refresh(db_obj)
        
        # Log changes in journal if any were made
        if changes:
            entity_type = EntityType.LOCAL_FLIGHT if db_obj.local_flight_id else EntityType.ARRIVAL
            entity_id = db_obj.local_flight_id if db_obj.local_flight_id else db_obj.arrival_id
            
            for change in changes:
                journal.log_change(
                    db,
                    entity_type,
                    entity_id,
                    f"Circuit: {change}",
                    user,
                    user_ip
                )
        
        return db_obj

    def delete(self, db: Session, circuit_id: int, user: str = "system", user_ip: Optional[str] = None) -> bool:
        circuit = self.get(db, circuit_id)
        if circuit:
            # Determine which entity this circuit belongs to
            entity_type = EntityType.LOCAL_FLIGHT if circuit.local_flight_id else EntityType.ARRIVAL
            entity_id = circuit.local_flight_id if circuit.local_flight_id else circuit.arrival_id
            
            db.delete(circuit)
            db.commit()
            
            # Log deletion in journal
            journal.log_change(
                db,
                entity_type,
                entity_id,
                f"Circuit deleted (recorded at {circuit.circuit_timestamp.isoformat()})",
                user,
                user_ip
            )
            
            return True
        return False


crud_circuit = CRUDCircuit()