flask_crud_app/functions/validate_values.py

from datetime import datetime
import re
from typing import Dict, Any, Optional
from definitions.attribute import *
from config import item_attributes

def _is_int(value: Any) -> bool:
    """Check if a value is a valid integer (including string representations)."""
    if isinstance(value, int):
        return True
    if isinstance(value, str):
        try:
            int(value)
            return True
        except ValueError:
            return False
    return False

def _is_float(value: Any) -> bool:
    """Check if a value is a valid float (including string representations)."""
    if isinstance(value, (int, float)):
        return True
    if isinstance(value, str):
        try:
            float(value)
            return True
        except ValueError:
            return False
    return False

def _is_date(value: Any) -> bool:
    """Check if a value is a valid date in YYYY-MM-DD format."""
    if not isinstance(value, str):
        return False
    try:
        datetime.strptime(value, "%Y-%m-%d")
        return True
    except ValueError:
        return False

def validate_values(form_data: Dict[str, Any]) -> Optional[str]:
    """
    Validate form data against the configuration in item_attributes.
    Returns an error message if invalid, otherwise None.
    """
    # Check if all required fields are present
    for attrib in item_attributes:
        if attrib.required and attrib.attrib_name not in form_data:
            return f"Missing required field: {attrib.display_name}."

    # Check for unexpected fields
    submitted_fields = set(form_data.keys())
    expected_fields = {attrib.attrib_name for attrib in item_attributes}
    if unexpected_fields := submitted_fields - expected_fields:
        return f"Unexpected fields submitted: {', '.join(unexpected_fields)}."

    # Validate each field
    for attrib in item_attributes:
        if attrib.attrib_name not in form_data:
            continue  # Skip optional fields that are not submitted

        value = form_data[attrib.attrib_name]

        # Validate based on attribute type
        if isinstance(attrib, textAttribute):
            if attrib.regex is not None and not re.match(attrib.regex, str(value)):
                return f"Invalid value for {attrib.display_name}. Must match pattern: {attrib.regex}."

        elif isinstance(attrib, intAttribute):
            if not _is_int(value):
                return f"Invalid value for {attrib.display_name}. Must be an integer."
            value_int = int(value)  # Convert to integer for range checks
            if attrib.min_val is not None and value_int < attrib.min_val:
                return f"Invalid value for {attrib.display_name}. Must be at least {attrib.min_val}."
            if attrib.max_val is not None and value_int > attrib.max_val:
                return f"Invalid value for {attrib.display_name}. Must be at most {attrib.max_val}."

        elif isinstance(attrib, floatAttribute):
            if not _is_float(value):
                return f"Invalid value for {attrib.display_name}. Must be a number."
            value_float = float(value)  # Convert to float for range checks
            if attrib.min_val is not None and value_float < attrib.min_val:
                return f"Invalid value for {attrib.display_name}. Must be at least {attrib.min_val}."
            if attrib.max_val is not None and value_float > attrib.max_val:
                return f"Invalid value for {attrib.display_name}. Must be at most {attrib.max_val}."

        elif isinstance(attrib, dateAttribute):
            if not _is_date(value):
                return f"Invalid value for {attrib.display_name}. Must be a valid date (YYYY-MM-DD)."
            if attrib.min_val is not None:
                min_date = datetime.strptime(attrib.min_val, "%Y-%m-%d")
                if datetime.strptime(value, "%Y-%m-%d") < min_date:
                    return f"Invalid value for {attrib.display_name}. Must be on or after {attrib.min_val}."
            if attrib.max_val is not None:
                max_date = datetime.strptime(attrib.max_val, "%Y-%m-%d")
                if datetime.strptime(value, "%Y-%m-%d") > max_date:
                    return f"Invalid value for {attrib.display_name}. Must be on or before {attrib.max_val}."

        elif isinstance(attrib, selectAttribute):
            if value not in attrib.options:
                return f"Invalid value for {attrib.display_name}. Must be one of: {', '.join(attrib.options)}."

    return None  # No errors