from django import forms
from django.contrib import admin
from django.db import models
from django.utils.html import format_html
from django.utils.safestring import mark_safe
from django.utils.translation import gettext_lazy as _
from django.utils import timezone
from unfold.admin import ModelAdmin, TabularInline
from import_export.admin import ImportExportModelAdmin
from unfold.contrib.import_export.forms import ExportForm, ImportForm
from core.models import Directory
from .models import Location, Pharmacy, PharmacyPhone, PharmacyHistory, DislocationColumnPreset


# ---------------------------------------------------------------------------
# Shared
# ---------------------------------------------------------------------------

class HierarchicalRegionChoiceField(forms.ModelChoiceField):
    """Поле выбора региона с отступами по иерархии в выпадающем списке."""

    def __init__(self, *args, **kwargs):
        queryset = kwargs.get('queryset') or Directory.objects.filter(
            directory_type__code__in=['region', 'district', 'city', 'city_district'],
            is_active=True,
        ).select_related('directory_type').order_by('_path')
        kwargs['queryset'] = queryset
        kwargs.setdefault('required', True)
        super().__init__(*args, **kwargs)

    def label_from_instance(self, obj):
        depth = (getattr(obj, '_path', '') or '').count('.')
        indent = '\u00A0\u00A0' * depth + ('└ ' if depth else '')
        return f'{indent}{obj.name}'


class HasCoordinatesFilter(admin.SimpleListFilter):
    """Записи, які так і лишились на дефолтних координатах поля (центр Одеси) —
    тобто піну ніхто не ставив і геокодування по адресі не спрацювало."""
    title = _('Координаты на карте')
    parameter_name = 'has_coordinates'

    def lookups(self, request, model_admin):
        return [
            ('no',  _('Без координат')),
            ('yes', _('С координатами')),
        ]

    def queryset(self, request, queryset):
        default = queryset.model._meta.get_field('location').default
        if self.value() == 'no':
            return queryset.filter(models.Q(location=default) | models.Q(location=''))
        if self.value() == 'yes':
            return queryset.exclude(location=default).exclude(location='')
        return queryset


# ---------------------------------------------------------------------------
# Location
# ---------------------------------------------------------------------------

class LocationAdminForm(forms.ModelForm):
    location_region = HierarchicalRegionChoiceField(
        label=_('Город/район'),
        empty_label=_('— Выберите регион —'),
        widget=forms.Select(attrs={'class': 'hierarchy-region-select'}),
        help_text=_('Выберите из списка. Уровни вложенности отображаются отступами.'),
    )

    class Meta:
        model = Location
        fields = '__all__'


@admin.register(Location)
class LocationAdmin(ModelAdmin, ImportExportModelAdmin):
    form = LocationAdminForm
    import_form_class = ImportForm
    export_form_class = ExportForm
    class Media:
        css = {'all': ('locations/css/location_admin.css',)}
        js = ('assets/js/admin_leaflet_resize_fix.js',)

    list_display = ['address_display', 'location_type', 'location_region',
                    'coordinates_display', 'is_active', 'updated_at']
    list_filter  = ['location_type', 'is_active', HasCoordinatesFilter]
    search_fields = ['address', 'street', 'house_number', 'comments']
    list_select_related = ['location_region']
    ordering = ['location_region', 'address']

    # address тепер лише генерується в Location.save() з street/house_number/building/
    # apartment — ручний ввід сюди все одно перезатреться при збереженні
    readonly_fields = ['address', 'created_at', 'updated_at']

    fieldsets = (
        (_('Тип и регион'), {
            'fields': ('location_type', 'location_region', 'is_active'),
        }),
        (_('Адрес'), {
            'fields': ('street', 'house_number', 'building', 'apartment', 'address'),
        }),
        (_('Координаты'), {
            'fields': ('location',),
        }),
        (_('Прочее'), {
            'fields': ('comments',),
            'classes': ('collapse',),
        }),
        (_('Служебное'), {
            'fields': ('created_at', 'updated_at'),
            'classes': ('collapse',),
        }),
    )

    def get_form(self, request, obj=None, **kwargs):
        form = super().get_form(request, obj, **kwargs)
        if 'location_type' in form.base_fields:
            # Аптеки создаются только через «Аптеки» (там номер, лицензия и т.д.)
            form.base_fields['location_type'].choices = [
                (k, v) for k, v in form.base_fields['location_type'].choices
                if k != 'pharmacy'
            ]
        return form

    def address_display(self, obj):
        region = obj.location_region.name if obj.location_region else '—'
        addr = obj.get_full_address() or obj.address or '—'
        return format_html(
            '<strong>{}</strong><br><span style="color:#666;font-size:12px;">{}</span>',
            region, addr,
        )
    address_display.short_description = _('Регион / Адрес')
    address_display.admin_order_field = 'address'

    def coordinates_display(self, obj):
        if obj.has_coordinates and obj.latitude is not None and obj.longitude is not None:
            return format_html('📍 {}', f'{float(obj.latitude):.5f}, {float(obj.longitude):.5f}')
        return mark_safe('<span style="color:#dc2626;">⚠ немає координат</span>')
    coordinates_display.short_description = _('Координаты')
    coordinates_display.admin_order_field = 'location'


# ---------------------------------------------------------------------------
# Pharmacy filters
# ---------------------------------------------------------------------------

class LicenseStatusFilter(admin.SimpleListFilter):
    title = _('Статус лицензии')
    parameter_name = 'license_status'

    def lookups(self, request, model_admin):
        return [
            ('valid',    _('Действительна')),
            ('expiring', _('Истекает (30 дн.)')),
            ('expired',  _('Истекла')),
            ('none',     _('Нет лицензии')),
        ]

    def queryset(self, request, queryset):
        today = timezone.now().date()
        soon  = today + timezone.timedelta(days=30)
        if self.value() == 'valid':
            return queryset.filter(license_expiry_date__gt=soon)
        if self.value() == 'expiring':
            return queryset.filter(license_expiry_date__gte=today, license_expiry_date__lte=soon)
        if self.value() == 'expired':
            return queryset.filter(license_expiry_date__lt=today)
        if self.value() == 'none':
            return queryset.filter(license_number='') | queryset.filter(license_number__isnull=True)
        return queryset


# ---------------------------------------------------------------------------
# Pharmacy inlines
# ---------------------------------------------------------------------------

class PharmacyPhoneInline(TabularInline):
    model = PharmacyPhone
    extra = 0
    fields = ('phone', 'phone_type', 'is_primary', 'is_active', 'notes')


class PharmacyHistoryInline(TabularInline):
    model = PharmacyHistory
    extra = 0
    readonly_fields = ('changed_field', 'old_value', 'new_value', 'changed_at', 'changed_by')
    fields = ('changed_at', 'changed_by', 'changed_field', 'old_value', 'new_value')
    ordering = ('-changed_at',)

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

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


# ---------------------------------------------------------------------------
# Pharmacy
# ---------------------------------------------------------------------------

class PharmacyAdminForm(forms.ModelForm):
    location_region = HierarchicalRegionChoiceField(
        label=_('Город/район'),
        required=True,
        empty_label=_('— Выберите регион —'),
        widget=forms.Select(attrs={'class': 'hierarchy-region-select'}),
    )

    class Meta:
        model = Pharmacy
        fields = '__all__'

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if 'location_type' in self.fields:
            self.fields['location_type'].initial = 'pharmacy'
            self.fields['location_type'].widget = forms.HiddenInput()


@admin.register(Pharmacy)
class PharmacyAdmin(ModelAdmin, ImportExportModelAdmin):
    form = PharmacyAdminForm
    import_form_class = ImportForm
    export_form_class = ExportForm

    class Media:
        css = {'all': ('locations/css/location_admin.css',)}
        js = ('assets/js/admin_phone_format.js', 'assets/js/admin_leaflet_resize_fix.js')

    # ------------------------------------------------------------------
    # List view
    # ------------------------------------------------------------------

    list_display = [
        'pharmacy_display',
        'organization',
        'category',
        'vat_category',
        'location_region',
        'coordinates_display',
        'phone_numbers_display',
        'status',
        'license_status_display',
        'head_pharmacist',
        'responsible_manager',
        'curator',
        'employees_count_display',
        'working_hours',
        'is_active',
    ]
    list_editable  = ['category', 'vat_category', 'status', 'working_hours']
    list_filter    = ['organization', 'category', 'vat_category', 'status', 'is_active', LicenseStatusFilter, HasCoordinatesFilter]
    search_fields  = ['pharmacy_number', 'address', 'phone', 'license_number',
                      'head_pharmacist__last_name', 'responsible_manager__last_name', 'curator__last_name']
    list_select_related = ['organization', 'location_region', 'head_pharmacist', 'responsible_manager', 'curator']
    ordering = ['organization', 'pharmacy_number']

    # ------------------------------------------------------------------
    # Detail view — tabs
    # ------------------------------------------------------------------

    # address тепер лише генерується в Location.save() з street/house_number/building/
    # apartment — ручний ввід сюди все одно перезатреться при збереженні
    # is_active тепер похідне поле від status (Pharmacy.save()) — ручне
    # редагування нічого не дасть, тому лише readonly-показ.
    readonly_fields = [
        'address', 'employees_count_display', 'license_status_display',
        'is_active', 'created_at', 'updated_at',
        'carbonio_account_id', 'carbonio_sync_status', 'carbonio_last_sync',
        'carbonio_sync_error', 'carbonio_password',
    ]

    fieldsets = (
        (_('Основное'), {
            'classes': ('tab',),
            'fields': (
                'organization', 'pharmacy_number', 'category', 'vat_category',
                'status', 'is_active', 'working_hours',
                'location_type',
            ),
        }),
        (_('Адрес'), {
            'classes': ('tab',),
            'fields': (
                'location_region',
                'street', 'house_number', 'building', 'apartment',
                'address',
                'location',
            ),
        }),
        (_('Контакты'), {
            'classes': ('tab',),
            'fields': ('phone',),
        }),
        (_('Лицензия'), {
            'classes': ('tab',),
            'fields': (
                'license_number', 'license_expiry_date',
                'license_status_display',
            ),
        }),
        (_('Персонал'), {
            'classes': ('tab',),
            'fields': (
                'head_pharmacist', 'responsible_manager', 'curator',
                'pharmacists_count', 'employees_count_display',
            ),
        }),
        (_('Почта Carbonio'), {
            'classes': ('tab',),
            'fields': (
                'carbonio_sync_enabled', 'carbonio_email', 'carbonio_password',
                'carbonio_account_id', 'carbonio_sync_status', 'carbonio_last_sync',
                'carbonio_sync_error',
            ),
            'description': _('Пусто в «Почта Carbonio» — адрес сгенерируется как '
                             '<префикс организации><номер>@домен. Можно задать вручную.'),
        }),
        (_('Примечания'), {
            'classes': ('tab',),
            'fields': ('comments', 'created_at', 'updated_at'),
        }),
    )

    inlines = [PharmacyPhoneInline, PharmacyHistoryInline]

    # ------------------------------------------------------------------
    # Queryset
    # ------------------------------------------------------------------

    def get_queryset(self, request):
        return super().get_queryset(request).prefetch_related('phones')

    # ------------------------------------------------------------------
    # List display methods
    # ------------------------------------------------------------------

    def pharmacy_display(self, obj):
        org = obj.organization.name if obj.organization else ''
        addr = obj.get_full_address() or obj.address or ''
        short_addr = addr[:70] + '…' if len(addr) > 70 else addr
        return format_html(
            '<strong>№{} {}</strong>'
            '<br><span style="color:#6b7280;font-size:12px;">{}</span>',
            obj.pharmacy_number, org, short_addr,
        )
    pharmacy_display.short_description = _('Аптека')
    pharmacy_display.admin_order_field = 'pharmacy_number'

    def coordinates_display(self, obj):
        if obj.has_coordinates and obj.latitude is not None and obj.longitude is not None:
            return format_html('📍 {}', f'{float(obj.latitude):.5f}, {float(obj.longitude):.5f}')
        return mark_safe('<span style="color:#dc2626;">⚠ немає координат</span>')
    coordinates_display.short_description = _('Координаты')
    coordinates_display.admin_order_field = 'location'

    def license_status_display(self, obj):
        status = obj.license_status
        color = {
            'Действительна': '#16a34a',
            'Истекла':        '#dc2626',
            'Бессрочная':     '#6b7280',
            'Нет лицензии':   '#6b7280',
        }.get(status, '#ca8a04' if 'Истекает' in status else '#6b7280')
        return format_html('<span style="color:{};">{}</span>', color, status)
    license_status_display.short_description = _('Лицензия')
    license_status_display.admin_order_field = 'license_expiry_date'

    def employees_count_display(self, obj):
        count = obj.employees_count
        color = '#16a34a' if count else '#9ca3af'
        return format_html(
            '<span style="color:{};font-weight:bold;">{}</span>',
            color, count or 0,
        )
    employees_count_display.short_description = _('Сотрудников')

    def phone_numbers_display(self, obj):
        from django.utils.safestring import mark_safe
        numbers = []
        if obj.phone:
            numbers.append(obj.phone)
        numbers.extend(
            p.phone for p in obj.phones.all()
            if p.phone and p.phone != obj.phone
        )
        if not numbers:
            return '—'
        return mark_safe('<br>'.join(numbers))
    phone_numbers_display.short_description = _('Телефоны')


@admin.register(DislocationColumnPreset)
class DislocationColumnPresetAdmin(ModelAdmin):
    list_display = ['name', 'code', 'is_default', 'department', 'updated_at']
    list_filter = ['is_default']
    search_fields = ['name', 'code']
    list_select_related = ['department']
    ordering = ['name']
    readonly_fields = ['created_at', 'updated_at', 'uuid']