import datetime

from django import forms
from django.db import models
from django.core.exceptions import ValidationError

from apps.transactions.widgets import MonthYearWidget


class MonthYearField(models.DateField):
    def to_python(self, value):
        if value is None or isinstance(value, datetime.date):
            return value

        try:
            # Parse the input as year-month
            date = datetime.datetime.strptime(value, "%Y-%m")
            # Set the day to 1
            return date.replace(day=1).date()
        except ValueError:
            raise ValidationError("Invalid date format. Use YYYY-MM.")

    def formfield(self, **kwargs):
        kwargs["widget"] = MonthYearWidget
        kwargs["form_class"] = MonthYearFormField
        return super().formfield(**kwargs)


class MonthYearFormField(forms.DateField):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.input_formats = ["%Y-%m"]

    def to_python(self, value):
        if value in self.empty_values:
            return None
        try:
            date = datetime.datetime.strptime(value, "%Y-%m")
            return date.replace(day=1).date()
        except ValueError:
            raise ValidationError("Invalid date format. Use YYYY-MM.")

    def prepare_value(self, value):
        if isinstance(value, datetime.date):
            return value.strftime("%Y-%m")
        return value