from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
from django.contrib.auth.models import User as BaseUser, Permission as BasePermission
from django.utils.text import slugify
from django.db.models import Q
from allianceauth.services.hooks import ServicesHook
from django.db.models.signals import pre_save, post_save, pre_delete, post_delete, m2m_changed
from django.dispatch import receiver
from allianceauth.authentication.models import State, get_guest_state, CharacterOwnership, UserProfile
from allianceauth.hooks import get_hooks
from allianceauth.eveonline.models import EveCharacter
from django.forms import ModelForm


def make_service_hooks_update_groups_action(service):
    """
    Make a admin action for the given service
    :param service: services.hooks.ServicesHook
    :return: fn to update services groups for the selected users
    """
    def update_service_groups(modeladmin, request, queryset):
        for user in queryset:  # queryset filtering doesn't work here?
            service.update_groups(user)

    update_service_groups.__name__ = str('update_{}_groups'.format(slugify(service.name)))
    update_service_groups.short_description = "Sync groups for selected {} accounts".format(service.title)
    return update_service_groups


def make_service_hooks_sync_nickname_action(service):
    """
    Make a sync_nickname admin action for the given service
    :param service: services.hooks.ServicesHook
    :return: fn to sync nickname for the selected users
    """
    def sync_nickname(modeladmin, request, queryset):
        for user in queryset:  # queryset filtering doesn't work here?
            service.sync_nickname(user)

    sync_nickname.__name__ = str('sync_{}_nickname'.format(slugify(service.name)))
    sync_nickname.short_description = "Sync nicknames for selected {} accounts".format(service.title)
    return sync_nickname


class QuerysetModelForm(ModelForm):
    # allows specifying FK querysets through kwarg
    def __init__(self, querysets=None, *args, **kwargs):
        querysets = querysets or {}
        super().__init__(*args, **kwargs)
        for field, qs in querysets.items():
            self.fields[field].queryset = qs


class UserProfileInline(admin.StackedInline):
    model = UserProfile
    readonly_fields = ('state',)
    form = QuerysetModelForm
    verbose_name = ''
    verbose_name_plural = 'Profile'

    def get_formset(self, request, obj=None, **kwargs):
        # main_character field can only show current value or unclaimed alts
        # if superuser, allow selecting from any unclaimed main
        query = Q()
        if obj and obj.profile.main_character:
            query |= Q(pk=obj.profile.main_character_id)
            if request.user.is_superuser:
                query |= Q(userprofile__isnull=True)
            else:
                query |= Q(character_ownership__user=obj)
        qs = EveCharacter.objects.filter(query)
        formset = super().get_formset(request, obj=obj, **kwargs)

        def get_kwargs(self, index):
            return {'querysets': {'main_character': EveCharacter.objects.filter(query)}}
        formset.get_form_kwargs = get_kwargs
        return formset

    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return False


class UserAdmin(BaseUserAdmin):
    """
    Extending Django's UserAdmin model
    """
    def get_actions(self, request):
        actions = super(BaseUserAdmin, self).get_actions(request)

        for hook in get_hooks('services_hook'):
            svc = hook()
            # Check update_groups is redefined/overloaded
            if svc.update_groups.__module__ != ServicesHook.update_groups.__module__:
                action = make_service_hooks_update_groups_action(svc)
                actions[action.__name__] = (action,
                                            action.__name__,
                                            action.short_description)
            # Create sync nickname action if service implements it
            if svc.sync_nickname.__module__ != ServicesHook.sync_nickname.__module__:
                action = make_service_hooks_sync_nickname_action(svc)
                actions[action.__name__] = (action,
                                            action.__name__,
                                            action.short_description)

        return actions
    list_filter = BaseUserAdmin.list_filter + ('profile__state',)
    inlines = BaseUserAdmin.inlines + [UserProfileInline]
    list_display = BaseUserAdmin.list_display + ('get_main_character',)

    def get_main_character(self, obj):
        return obj.profile.main_character
    get_main_character.short_description = "Main Character"

    def has_change_permission(self, request, obj=None):
        return request.user.has_perm('auth.change_user')

    def has_add_permission(self, request, obj=None):
        return request.user.has_perm('auth.add_user')

    def has_delete_permission(self, request, obj=None):
        return request.user.has_perm('auth.delete_user')


@admin.register(State)
class StateAdmin(admin.ModelAdmin):
    fieldsets = (
        (None, {
            'fields': ('name', 'permissions', 'priority'),
        }),
        ('Membership', {
            'fields': ('public', 'member_characters', 'member_corporations', 'member_alliances'),
        })
    )
    filter_horizontal = ['member_characters', 'member_corporations', 'member_alliances', 'permissions']
    list_display = ('name', 'priority', 'user_count')

    def has_delete_permission(self, request, obj=None):
        if obj == get_guest_state():
            return False
        return super(StateAdmin, self).has_delete_permission(request, obj=obj)

    def get_fieldsets(self, request, obj=None):
        if obj == get_guest_state():
            return (
                (None, {
                    'fields': ('permissions', 'priority'),
                }),
            )
        return super(StateAdmin, self).get_fieldsets(request, obj=obj)

    @staticmethod
    def user_count(obj):
        return obj.userprofile_set.all().count()


@admin.register(CharacterOwnership)
class CharacterOwnershipAdmin(admin.ModelAdmin):
    list_display = ('user', 'character')
    search_fields = ('user__username', 'character__character_name', 'character__corporation_name', 'character__alliance_name')
    readonly_fields = ('owner_hash', 'character')


class PermissionAdmin(admin.ModelAdmin):
    actions = None
    readonly_fields = [field.name for field in BasePermission._meta.fields]
    list_display = ('admin_name', 'name', 'codename', 'content_type')
    list_filter = ('content_type__app_label',)

    @staticmethod
    def admin_name(obj):
        return str(obj)

    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return False

    def has_module_permission(self, request):
        return True

    def has_change_permission(self, request, obj=None):
        # can see list but not edit it
        return not obj


# Hack to allow registration of django.contrib.auth models in our authentication app
class User(BaseUser):
    class Meta:
        proxy = True
        verbose_name = BaseUser._meta.verbose_name
        verbose_name_plural = BaseUser._meta.verbose_name_plural


class Permission(BasePermission):
    class Meta:
        proxy = True
        verbose_name = BasePermission._meta.verbose_name
        verbose_name_plural = BasePermission._meta.verbose_name_plural


try:
    admin.site.unregister(BaseUser)
finally:
    admin.site.register(User, UserAdmin)
    admin.site.register(Permission, PermissionAdmin)


@receiver(pre_save, sender=User)
def redirect_pre_save(sender, signal=None, *args, **kwargs):
    pre_save.send(BaseUser, *args, **kwargs)


@receiver(post_save, sender=User)
def redirect_post_save(sender, signal=None, *args, **kwargs):
    post_save.send(BaseUser, *args, **kwargs)


@receiver(pre_delete, sender=User)
def redirect_pre_delete(sender, signal=None, *args, **kwargs):
    pre_delete.send(BaseUser, *args, **kwargs)


@receiver(post_delete, sender=User)
def redirect_post_delete(sender, signal=None, *args, **kwargs):
    post_delete.send(BaseUser, *args, **kwargs)


@receiver(m2m_changed, sender=User.groups.through)
def redirect_m2m_changed_groups(sender, signal=None, *args, **kwargs):
    m2m_changed.send(BaseUser, *args, **kwargs)


@receiver(m2m_changed, sender=User.user_permissions.through)
def redirect_m2m_changed_permissions(sender, signal=None, *args, **kwargs):
    m2m_changed.send(BaseUser, *args, **kwargs)