from django import forms

from application.org_mgnt.models import PrimaryDepartment, SecondaryDepartment


class DepartmentSelectionForm(forms.Form):
    primary_department = forms.ModelChoiceField(
        queryset=PrimaryDepartment.objects.all(),
        widget=forms.Select(attrs={'class': 'form-control'}),
        empty_label="选择一级部门",
        label="一级部门"
    )
    secondary_department = forms.ModelChoiceField(
        queryset=SecondaryDepartment.objects.none(),
        widget=forms.Select(attrs={'class': 'form-control'}),
        empty_label="选择二级部门",
        label="二级部门"
    )

    def __init__(self, *args, **kwargs):
        super(DepartmentSelectionForm, self).__init__(*args, **kwargs)
        if 'primary_department' in self.data:
            try:
                primary_department_id = int(self.data.get('primary_department'))
                self.fields['secondary_department'].queryset = SecondaryDepartment.objects.filter(primary_department_id=primary_department_id).order_by('secondary_department_name')
            except (ValueError, TypeError):
                pass
        elif 'instance' in kwargs and kwargs['instance']:
            instance = kwargs['instance']
            if hasattr(instance, 'primary_department') and isinstance(instance.primary_department, PrimaryDepartment):
                self.fields['secondary_department'].queryset = instance.primary_department.secondarydepartment_set.order_by('secondary_department_name')
            else:
                try:
                    primary_department = PrimaryDepartment.objects.get(department_name=instance.primary_department)
                    self.fields['secondary_department'].queryset = primary_department.secondarydepartment_set.order_by('secondary_department_name')
                except PrimaryDepartment.DoesNotExist:
                    self.fields['secondary_department'].queryset = SecondaryDepartment.objects.none()