from django.contrib import admin
from django.forms import ModelForm, CharField, TextInput
from django.utils.html import format_html
from django.utils.translation import gettext, gettext_lazy as _, ungettext
from django.contrib.auth.admin import UserAdmin as OldUserAdmin
from django.core.exceptions import ValidationError

from django_ace import AceWidget

from judge.models import Profile, ProfileInfo
from judge.widgets import AdminPagedownWidget, AdminSelect2Widget

from reversion.admin import VersionAdmin

import re


class ProfileForm(ModelForm):
    def __init__(self, *args, **kwargs):
        super(ProfileForm, self).__init__(*args, **kwargs)
        if "current_contest" in self.base_fields:
            # form.fields['current_contest'] does not exist when the user has only view permission on the model.
            self.fields[
                "current_contest"
            ].queryset = self.instance.contest_history.select_related("contest").only(
                "contest__name", "user_id", "virtual"
            )
            self.fields["current_contest"].label_from_instance = (
                lambda obj: "%s v%d" % (obj.contest.name, obj.virtual)
                if obj.virtual
                else obj.contest.name
            )

    class Meta:
        widgets = {
            "timezone": AdminSelect2Widget,
            "language": AdminSelect2Widget,
            "ace_theme": AdminSelect2Widget,
            "current_contest": AdminSelect2Widget,
        }
        if AdminPagedownWidget is not None:
            widgets["about"] = AdminPagedownWidget


class TimezoneFilter(admin.SimpleListFilter):
    title = _("timezone")
    parameter_name = "timezone"

    def lookups(self, request, model_admin):
        return (
            Profile.objects.values_list("timezone", "timezone")
            .distinct()
            .order_by("timezone")
        )

    def queryset(self, request, queryset):
        if self.value() is None:
            return queryset
        return queryset.filter(timezone=self.value())


class ProfileInfoInline(admin.StackedInline):
    model = ProfileInfo
    can_delete = False
    verbose_name_plural = "profile info"
    fk_name = "profile"


class ProfileAdmin(VersionAdmin):
    fields = (
        "user",
        "display_rank",
        "about",
        "organizations",
        "timezone",
        "language",
        "ace_theme",
        "last_access",
        "ip",
        "mute",
        "is_unlisted",
        "notes",
        "is_totp_enabled",
        "current_contest",
    )
    readonly_fields = ("user",)
    list_display = (
        "admin_user_admin",
        "email",
        "is_totp_enabled",
        "timezone_full",
        "date_joined",
        "last_access",
        "ip",
        "show_public",
    )
    ordering = ("user__username",)
    search_fields = ("user__username", "ip", "user__email")
    list_filter = ("language", TimezoneFilter)
    actions = ("recalculate_points",)
    actions_on_top = True
    actions_on_bottom = True
    form = ProfileForm
    inlines = (ProfileInfoInline,)

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

    def get_fields(self, request, obj=None):
        if request.user.has_perm("judge.totp"):
            fields = list(self.fields)
            fields.insert(fields.index("is_totp_enabled") + 1, "totp_key")
            return tuple(fields)
        else:
            return self.fields

    def get_readonly_fields(self, request, obj=None):
        fields = self.readonly_fields
        if not request.user.has_perm("judge.totp"):
            fields += ("is_totp_enabled",)
        return fields

    def show_public(self, obj):
        return format_html(
            '<a href="{0}" style="white-space:nowrap;">{1}</a>',
            obj.get_absolute_url(),
            gettext("View on site"),
        )

    show_public.short_description = ""

    def admin_user_admin(self, obj):
        return obj.username

    admin_user_admin.admin_order_field = "user__username"
    admin_user_admin.short_description = _("User")

    def email(self, obj):
        return obj.email

    email.admin_order_field = "user__email"
    email.short_description = _("Email")

    def timezone_full(self, obj):
        return obj.timezone

    timezone_full.admin_order_field = "timezone"
    timezone_full.short_description = _("Timezone")

    def date_joined(self, obj):
        return obj.user.date_joined

    date_joined.admin_order_field = "user__date_joined"
    date_joined.short_description = _("date joined")

    def recalculate_points(self, request, queryset):
        count = 0
        for profile in queryset:
            profile.calculate_points()
            count += 1
        self.message_user(
            request,
            ungettext(
                "%d user have scores recalculated.",
                "%d users have scores recalculated.",
                count,
            )
            % count,
        )

    recalculate_points.short_description = _("Recalculate scores")


class UserForm(ModelForm):
    username = CharField(
        max_length=150,
        help_text=_("Username can only contain letters, digits, and underscores."),
        widget=TextInput(attrs={"class": "vTextField"}),
    )

    def clean_username(self):
        username = self.cleaned_data.get("username")
        if not re.match(r"^\w+$", username):
            raise ValidationError(
                _("Username can only contain letters, digits, and underscores.")
            )
        return username


class UserAdmin(OldUserAdmin):
    # Customize the fieldsets for adding and editing users
    form = UserForm
    fieldsets = (
        (None, {"fields": ("username", "password")}),
        ("Personal Info", {"fields": ("first_name", "last_name", "email")}),
        (
            "Permissions",
            {
                "fields": (
                    "is_active",
                    "is_staff",
                    "is_superuser",
                    "groups",
                    "user_permissions",
                )
            },
        ),
        ("Important dates", {"fields": ("last_login", "date_joined")}),
    )

    readonly_fields = ("last_login", "date_joined")

    def get_readonly_fields(self, request, obj=None):
        fields = self.readonly_fields
        if not request.user.is_superuser:
            fields += (
                "is_staff",
                "is_active",
                "is_superuser",
                "groups",
                "user_permissions",
            )
        return fields