excel-mcp-server/src/excel_mcp/calculations.py

from typing import Any
import logging

from .workbook import get_or_create_workbook
from .cell_utils import validate_cell_reference
from .exceptions import ValidationError, CalculationError
from .validation import validate_formula

logger = logging.getLogger(__name__)

def apply_formula(
    filepath: str,
    sheet_name: str,
    cell: str,
    formula: str
) -> dict[str, Any]:
    """Apply any Excel formula to a cell."""
    try:
        if not validate_cell_reference(cell):
            raise ValidationError(f"Invalid cell reference: {cell}")
            
        wb = get_or_create_workbook(filepath)
        if sheet_name not in wb.sheetnames:
            raise ValidationError(f"Sheet '{sheet_name}' not found")
            
        sheet = wb[sheet_name]
        
        # Ensure formula starts with =
        if not formula.startswith('='):
            formula = f'={formula}'
            
        # Validate formula syntax
        is_valid, message = validate_formula(formula)
        if not is_valid:
            raise CalculationError(f"Invalid formula syntax: {message}")
            
        try:
            # Apply formula to the cell
            cell_obj = sheet[cell]
            cell_obj.value = formula
        except Exception as e:
            raise CalculationError(f"Failed to apply formula to cell: {str(e)}")
            
        try:
            wb.save(filepath)
        except Exception as e:
            raise CalculationError(f"Failed to save workbook after applying formula: {str(e)}")
        
        return {
            "message": f"Applied formula '{formula}' to cell {cell}",
            "cell": cell,
            "formula": formula
        }
        
    except (ValidationError, CalculationError) as e:
        logger.error(str(e))
        raise
    except Exception as e:
        logger.error(f"Failed to apply formula: {e}")
        raise CalculationError(str(e))