import datetime
from typing import Sequence

from flask_wtf import FlaskForm
from sqlalchemy.inspection import inspect
from werkzeug.datastructures import ImmutableMultiDict

from atlas_um.helpers.common import safe_strip
from atlas_um.pgdb import pgdb


class BaseForm(FlaskForm):
    """
    Base form, extended with some helpful features.

    Allows comparison by data and provides some default
    values.
    """

    FIELD_REQUIRED_MESSAGE = "This field is required"

    class Meta:
        def bind_field(self, form, unbound_field, options):
            filters = unbound_field.kwargs.get("filters", [])
            if safe_strip not in filters:
                filters.append(safe_strip)

            return unbound_field.bind(form=form, filters=filters, **options)

    def __init__(self, *args, **kwargs):
        self._obj = kwargs.get("obj")
        super().__init__(*args, **kwargs)

    def __eq__(self, other):
        try:
            return self.data == other.data and self.obj == other.obj
        except Exception:
            return False

    @property
    def obj(self):
        return self._obj

    def dump(
        self,
        cleanup: bool = False,
        fields: Sequence[str] = None,
        exclude: Sequence[str] = None,
        cleanup_fields: Sequence[str] = None,
    ) -> ImmutableMultiDict:
        """
        Helper method to dump form as request body.

        Allows to cleanup values and respects relations fields
        and their usage in selects.
        """
        fields = fields or []
        exclude = exclude or []
        cleanup_fields = cleanup_fields or []

        data = {}
        for k, v in self.data.items():
            if (fields and k not in fields) or (exclude and k in exclude):
                continue
            if isinstance(v, pgdb.Model):
                identity = inspect(v).identity
                if cleanup or k in cleanup_fields:
                    data[k] = "__None"
                else:
                    data[k] = str(identity[0]) if identity else "__None"
            elif isinstance(v, datetime.date):
                data[k] = v.strftime("%m/%d/%y")
            else:
                if cleanup or k in cleanup_fields:
                    data[k] = ""
                else:
                    data[k] = str(v) if v else ""
        return ImmutableMultiDict(data)