from django.contrib import admin
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth.models import User
from django.core.paginator import Paginator

from .models import Band, Child, Event, Parent, Swallow

site = admin.AdminSite(name="admin")

site.register(User, UserAdmin)


class CustomPaginator(Paginator):
    def __init__(self, queryset, page_size, orphans=0, allow_empty_first_page=True):
        super().__init__(queryset, 5, orphans=2, allow_empty_first_page=allow_empty_first_page)


class EventAdmin(admin.ModelAdmin):
    date_hierarchy = 'date'
    list_display = ['event_date_func']

    @admin.display
    def event_date_func(self, event):
        return event.date

    def has_add_permission(self, request):
        return False


site.register(Event, EventAdmin)


class ParentAdmin(admin.ModelAdmin):
    list_filter = ['child__name']
    search_fields = ['child__name']


class ChildAdmin(admin.ModelAdmin):
    list_display = ['name', 'parent']
    list_per_page = 10
    list_filter = ['parent', 'age']

    def get_queryset(self, request):
        return super().get_queryset(request).select_related("parent")


class CustomPaginationAdmin(ChildAdmin):
    paginator = CustomPaginator


class FilteredChildAdmin(admin.ModelAdmin):
    list_display = ['name', 'parent']
    list_per_page = 10

    def get_queryset(self, request):
        return super().get_queryset(request).filter(name__contains='filtered')


class BandAdmin(admin.ModelAdmin):
    list_filter = ['genres']


class NrOfMembersFilter(admin.SimpleListFilter):
    title = 'number of members'
    parameter_name = 'nr_of_members_partition'

    def lookups(self, request, model_admin):
        return [
            ('5', '0 - 5'),
            ('more', 'more than 5'),
        ]

    def queryset(self, request, queryset):
        value = self.value()
        if value == '5':
            return queryset.filter(nr_of_members__lte=5)
        if value == 'more':
            return queryset.filter(nr_of_members__gt=5)


class BandCallableFilterAdmin(admin.ModelAdmin):
    list_filter = [NrOfMembersFilter]


site.register(Band, BandCallableFilterAdmin)


class GroupAdmin(admin.ModelAdmin):
    list_filter = ['members']


class ConcertAdmin(admin.ModelAdmin):
    list_filter = ['group__members']
    search_fields = ['group__members__name']


class QuartetAdmin(admin.ModelAdmin):
    list_filter = ['members']


class ChordsBandAdmin(admin.ModelAdmin):
    list_filter = ['members']


class InvitationAdmin(admin.ModelAdmin):
    list_display = ('band', 'player')
    list_select_related = ('player',)


class DynamicListDisplayChildAdmin(admin.ModelAdmin):
    list_display = ('parent', 'name', 'age')

    def get_list_display(self, request):
        my_list_display = super().get_list_display(request)
        if request.user.username == 'noparents':
            my_list_display = list(my_list_display)
            my_list_display.remove('parent')
        return my_list_display


class DynamicListDisplayLinksChildAdmin(admin.ModelAdmin):
    list_display = ('parent', 'name', 'age')
    list_display_links = ['parent', 'name']

    def get_list_display_links(self, request, list_display):
        return ['age']


site.register(Child, DynamicListDisplayChildAdmin)


class NoListDisplayLinksParentAdmin(admin.ModelAdmin):
    list_display_links = None
    list_display = ['name']
    list_editable = ['name']


site.register(Parent, NoListDisplayLinksParentAdmin)


class SwallowAdmin(admin.ModelAdmin):
    actions = None  # prevent ['action_checkbox'] + list(list_display)
    list_display = ('origin', 'load', 'speed', 'swallowonetoone')
    list_editable = ['load', 'speed']
    list_per_page = 3


site.register(Swallow, SwallowAdmin)


class DynamicListFilterChildAdmin(admin.ModelAdmin):
    list_filter = ('parent', 'name', 'age')

    def get_list_filter(self, request):
        my_list_filter = super().get_list_filter(request)
        if request.user.username == 'noparents':
            my_list_filter = list(my_list_filter)
            my_list_filter.remove('parent')
        return my_list_filter


class DynamicSearchFieldsChildAdmin(admin.ModelAdmin):
    search_fields = ('name',)

    def get_search_fields(self, request):
        search_fields = super().get_search_fields(request)
        search_fields += ('age',)
        return search_fields


class EmptyValueChildAdmin(admin.ModelAdmin):
    empty_value_display = '-empty-'
    list_display = ('name', 'age_display', 'age')

    @admin.display(empty_value='&dagger;')
    def age_display(self, obj):
        return obj.age
