from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session
from .. import models, schemas
from ..database import get_db

router = APIRouter(
    prefix="/operations",
    tags=["Operations"]
)

@router.post("/check-in", response_model=schemas.Item)
def check_in_item(op: schemas.OperationCreate, db: Session = Depends(get_db)):
    if op.quantity <= 0:
         raise HTTPException(status_code=400, detail="Quantity must be greater than zero")
         
    item = db.query(models.Item).filter(models.Item.barcode == op.barcode).first()
    if not item:
        raise HTTPException(status_code=404, detail="Item not found. Register item first.")
        
    # Update quantity
    item.quantity += op.quantity
    
    # Create Mandatory Audit Log
    audit = models.AuditLog(
        user_id=op.user_id,
        action="CHECK_IN",
        target_item_id=item.id,
        quantity_change=op.quantity
    )
    
    db.add(audit)
    db.commit()
    db.refresh(item)
    return item

@router.post("/check-out", response_model=schemas.Item)
def check_out_item(op: schemas.OperationCreate, db: Session = Depends(get_db)):
    if op.quantity <= 0:
         raise HTTPException(status_code=400, detail="Quantity must be greater than zero")
         
    item = db.query(models.Item).filter(models.Item.barcode == op.barcode).first()
    if not item:
        raise HTTPException(status_code=404, detail="Item not found")
        
    if item.quantity < op.quantity:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Insufficient stock")
        
    # Update quantity
    item.quantity -= op.quantity
        
    # Create Mandatory Audit Log
    audit = models.AuditLog(
        user_id=op.user_id,
        action="CHECK_OUT",
        target_item_id=item.id,
        quantity_change=-op.quantity
    )
    
    db.add(audit)
    db.commit()
    db.refresh(item)
    return item

@router.post("/trash", response_model=schemas.Item)
def trash_item(op: schemas.TrashOperationCreate, db: Session = Depends(get_db)):
    if op.quantity <= 0:
         raise HTTPException(status_code=400, detail="Quantity must be greater than zero")
         
    item = db.query(models.Item).filter(models.Item.barcode == op.barcode).first()
    if not item:
        raise HTTPException(status_code=404, detail="Item not found")
        
    if item.quantity < op.quantity:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Insufficient stock to trash")
        
    # Update quantity
    item.quantity -= op.quantity
        
    # Create Mandatory Audit Log with TRASH action and reason
    audit = models.AuditLog(
        user_id=op.user_id,
        action=f"TRASH: {op.reason}",
        target_item_id=item.id,
        quantity_change=-op.quantity
    )
    
    db.add(audit)
    db.commit()
    db.refresh(item)
    return item

@router.post("/bulk-check-out")
def bulk_check_out(bulk_op: schemas.BulkOperationCreate, db: Session = Depends(get_db)):
    results = {"success": [], "errors": []}
    
    for op in bulk_op.items:
        try:
            item = db.query(models.Item).filter(models.Item.barcode == op.barcode).first()
            if not item:
                results["errors"].append({"barcode": op.barcode, "error": "Not found"})
                continue
                
            if item.quantity < op.quantity:
                results["errors"].append({"barcode": op.barcode, "error": f"Insufficient stock (Available: {item.quantity})"})
                continue
            
            # Update quantity
            item.quantity -= op.quantity
            
            # Log individual audit for this item
            audit = models.AuditLog(
                user_id=bulk_op.user_id,
                action="BULK_CHECK_OUT",
                target_item_id=item.id,
                quantity_change=-op.quantity
            )
            db.add(audit)
            results["success"].append({"barcode": op.barcode, "new_quantity": item.quantity})
            
        except Exception as e:
            results["errors"].append({"barcode": op.barcode, "error": str(e)})
            
    db.commit()
    return results