import re
from typing import Dict, Union


class WallAttributes:

    def __init__(self, description: str):
        """
        :param description: Description of the walls.
        """
        self.description: str = description

    def process(self) -> Dict[str, Union[float, str, bool, None]]:
        result: Dict[str, Union[float, str, bool, None]] = {}
        description = self.description.lower()

        # thermal transmittance - it can be negative which is errneous however we'll still pull it out
        match = re.search(r"average thermal transmittance (-?\d+\.\d+)\s(w/m-¦k)", description)
        if match:
            result['thermal_transmittance'] = float(match.group(1))
            result['thermal_transmittance_unit'] = match.group(2)
        else:
            result['thermal_transmittance'] = None
            result['thermal_transmittance_unit'] = None

        # wall type
        result['is_cavity_wall'] = 'cavity wall' in description
        result['has_filled_cavity'] = 'filled cavity' in description
        result['is_solid_brick'] = 'solid brick' in description
        result['is_system_built'] = 'system built' in description
        result['is_timber_frame'] = 'timber frame' in description
        result['is_granite_or_whinstone'] = 'granite' in description or 'whinstone' in description
        result['as_built'] = 'as built' in description
        result['is_cob'] = 'cob' in description
        result['assumed'] = 'assumed' in description
        result['is_sandstone_or_limestone'] = 'sandstone or limestone' in description

        # insulation thickness - this is far from a perfect approach and we'd likely need to use nlp to do this
        # generally however this is sufficient for mvp
        thickness_map = {
            "external insulation": "average",
            "internal insulation": "average",
            "partial insulation": "below average",
            "no insulation": "none",
            "additional insulation": "above average",
            "insulated": "average"
        }
        for key, value in thickness_map.items():
            if key in description:
                result['insulation_thickness'] = value
                break
        else:
            result['insulation_thickness'] = None

        # insulation type
        result['external_insulation'] = 'external insulation' in description
        result['internal_insulation'] = 'internal insulation' in description

        return result