from urllib.parse import parse_qs

from django.apps import apps
from django.urls import re_path as url
from django.contrib import admin, messages
from django.contrib.contenttypes.admin import GenericTabularInline
from django.contrib.contenttypes.forms import BaseGenericInlineFormSet
from django.contrib.admin.utils import unquote
from django.urls import reverse
from django.db.models import Q
from django.shortcuts import redirect
from django.templatetags.static import static
from django.utils.functional import cached_property
from django.utils.html import format_html
from django.utils.safestring import mark_safe
from django.utils.translation import ngettext, gettext_lazy as _

from orchestra.admin import ExtendedModelAdmin
from orchestra.admin.utils import insertattr, get_modeladmin, admin_link, admin_date
from orchestra.contrib.orchestration.models import Route
from orchestra.core import services
from orchestra.utils import db, sys
from orchestra.utils.functional import cached

from .actions import run_monitor, show_history
from .api import history_data
from .filters import ResourceDataListFilter
from .forms import ResourceForm
from .models import Resource, ResourceData, MonitorData


class ResourceAdmin(ExtendedModelAdmin):
    list_display = (
        'id', 'verbose_name', 'content_type', 'aggregation', 'on_demand',
        'default_allocation', 'unit', 'crontab', 'is_active'
    )
    list_display_links = ('id', 'verbose_name')
    list_editable = ('default_allocation', 'crontab', 'is_active',)
    list_filter = (
        ('content_type', admin.RelatedOnlyFieldListFilter), 'aggregation', 'on_demand',
        'disable_trigger'
    )
    fieldsets = (
        (None, {
            'fields': ('verbose_name', 'name', 'content_type', 'aggregation'),
        }),
        (_("Configuration"), {
            'fields': ('unit', 'scale', 'on_demand', 'default_allocation', 'disable_trigger',
                       'is_active'),
        }),
        (_("Monitoring"), {
            'fields': ('monitors', 'crontab'),
        }),
    )
    actions = (run_monitor,)
    change_view_actions = actions
    change_readonly_fields = ('name', 'content_type')
    prepopulated_fields = {
        'name': ('verbose_name',)
    }
    list_select_related = ('content_type', 'crontab',)

    def change_view(self, request, object_id, form_url='', extra_context=None):
        """ Remaind user when monitor routes are not configured """
        if request.method == 'GET':
            resource = self.get_object(request, unquote(object_id))
            backends = Route.objects.values_list('backend', flat=True)
            not_routed = []
            for monitor in resource.monitors:
                if monitor not in backends:
                    not_routed.append(monitor)
            if not_routed:
                messages.warning(request, ngettext(
                    _("%(not_routed)s monitor doesn't have any configured route."),
                    _("%(not_routed)s monitors don't have any configured route."),
                    len(not_routed),
                ) % {
                    'not_routed': ', '.join(not_routed)
                })
        return super(ResourceAdmin, self).change_view(request, object_id, form_url=form_url,
                extra_context=extra_context)

    def save_model(self, request, obj, form, change):
        super(ResourceAdmin, self).save_model(request, obj, form, change)
        # best-effort
        model = obj.content_type.model_class()
        modeladmin = type(get_modeladmin(model))
        resources = obj.content_type.resource_set.filter(is_active=True)
        inlines = []
        for inline in modeladmin.inlines:
            if inline.model is ResourceData:
                inline = resource_inline_factory(resources)
            inlines.append(inline)
        modeladmin.inlines = inlines
        # reload Not always work
        sys.touch_wsgi()

    def formfield_for_dbfield(self, db_field, **kwargs):
        """ filter service content_types """
        if db_field.name == 'content_type':
            models = [ model._meta.model_name for model in services.get() ]
            kwargs['queryset'] = db_field.remote_field.model.objects.filter(model__in=models)
        return super(ResourceAdmin, self).formfield_for_dbfield(db_field, **kwargs)


def content_object_link(data):
    ct = data.content_type
    url = reverse('admin:%s_%s_change' % (ct.app_label, ct.model), args=(data.object_id,))
    return format_html('<a href="{}">{}</a>', url, data.content_object_repr)
content_object_link.short_description = _("Content object")
content_object_link.admin_order_field = 'content_object_repr'


class ResourceDataAdmin(ExtendedModelAdmin):
    list_display = (
        'id', 'resource_link', content_object_link, 'allocated', 'display_used',
        'display_updated'
    )
    list_filter = ('resource',)
    fields = (
        'resource_link', 'content_type', content_object_link, 'display_updated', 'display_used',
        'allocated',
    )
    search_fields = ('content_object_repr',)
    readonly_fields = fields
    actions = (run_monitor, show_history)
    change_view_actions = actions
    ordering = ('-updated_at',)
    list_select_related = ('resource__content_type', 'content_type')

    resource_link = admin_link('resource')
    display_updated = admin_date('updated_at', short_description=_("Updated"))

    def get_urls(self):
        """Returns the additional urls for the change view links"""
        urls = super(ResourceDataAdmin, self).get_urls()
        admin_site = self.admin_site
        opts = self.model._meta
        return [
            url('^(\d+)/used-monitordata/$',
                admin_site.admin_view(self.used_monitordata_view),
                name='%s_%s_used_monitordata' % (opts.app_label, opts.model_name)
            ),
            url('^history_data/$',
                admin_site.admin_view(history_data),
                name='%s_%s_history_data' % (opts.app_label, opts.model_name)
            ),
            url('^list-related/(.+)/(.+)/(\d+)/$',
                admin_site.admin_view(self.list_related_view),
                name='%s_%s_list_related' % (opts.app_label, opts.model_name)
            ),
        ] + urls

    def display_used(self, rdata):
        if rdata.used is None:
            return ''
        url = reverse('admin:resources_resourcedata_used_monitordata', args=(rdata.pk,))
        return format_html('<a href="{}">{} {}</a>', url, rdata.used, rdata.unit)
    display_used.short_description = _("Used")
    display_used.admin_order_field = 'used'

    def has_add_permission(self, *args, **kwargs):
        return False

    def used_monitordata_view(self, request, object_id):
        url = reverse('admin:resources_monitordata_changelist')
        url += '?resource_data=%s' % object_id
        return redirect(url)

    def list_related_view(self, request, app_name, model_name, object_id):
        resources = Resource.objects.select_related('content_type')
        resource_models = {r.content_type.model_class(): r.content_type_id for r in resources}
        # Self
        model = apps.get_model(app_name, model_name)
        obj = model.objects.get(id=int(object_id))
        ct_id = resource_models[model]
        qset = Q(content_type_id=ct_id, object_id=obj.id, resource__is_active=True)
        # Related
        for field, rel in obj._meta.fields_map.items():
            try:
                ct_id = resource_models[rel.related_model]
            except KeyError:
                pass
            else:
                manager = getattr(obj, field)
                ids = manager.values_list('id', flat=True)
                qset = Q(qset) | Q(content_type_id=ct_id, object_id__in=ids, resource__is_active=True)
        related = ResourceData.objects.filter(qset)
        related_ids = related.values_list('id', flat=True)
        related_ids = ','.join(map(str, related_ids))
        url = reverse('admin:resources_resourcedata_changelist')
        url += '?id__in=%s' % related_ids
        return redirect(url)


class MonitorDataAdmin(ExtendedModelAdmin):
    list_display = ('id', 'monitor', content_object_link, 'display_created', 'value')
    list_filter = ('monitor', ResourceDataListFilter)
    add_fields = ('monitor', 'content_type', 'object_id', 'created_at', 'value')
    fields = ('monitor', 'content_type', content_object_link, 'display_created', 'value', 'state')
    change_readonly_fields = fields
    list_select_related = ('content_type',)
    search_fields = ('content_object_repr',)
    date_hierarchy = 'created_at'

    display_created = admin_date('created_at', short_description=_("Created"))

    def filter_used_monitordata(self, request, queryset):
        query_string = parse_qs(request.META['QUERY_STRING'])
        resource_data = query_string.get('resource_data')
        if resource_data:
            mdata = ResourceData.objects.get(pk=int(resource_data[0]))
            resource = mdata.resource
            ids = []
            for monitor, dataset in mdata.get_monitor_datasets():
                dataset = resource.aggregation_instance.filter(dataset)
                if isinstance(dataset, MonitorData):
                    ids.append(dataset.id)
                else:
                    ids += dataset.values_list('id', flat=True)
            return queryset.filter(id__in=ids)
        return queryset

    def get_queryset(self, request):
        queryset = super(MonitorDataAdmin, self).get_queryset(request)
        queryset = self.filter_used_monitordata(request, queryset)
        return queryset.prefetch_related('content_object')


admin.site.register(Resource, ResourceAdmin)
admin.site.register(ResourceData, ResourceDataAdmin)
admin.site.register(MonitorData, MonitorDataAdmin)


# Mokey-patching

def resource_inline_factory(resources):
    class ResourceInlineFormSet(BaseGenericInlineFormSet):
        def total_form_count(self, resources=resources):
            return len(resources)

        @cached
        def get_queryset(self):
            """ Filter disabled resources """
            queryset = super(ResourceInlineFormSet, self).get_queryset()
            return queryset.filter(resource__is_active=True).select_related('resource')

        @cached_property
        def forms(self, resources=resources):
            forms = []
            resources_copy = list(resources)
            # Remove queryset disabled objects
            queryset = [rdata for rdata in self.get_queryset() if rdata.resource in resources]
            if self.instance.pk:
                # Create missing resource data
                queryset_resources = [rdata.resource for rdata in queryset]
                for resource in resources:
                    if resource not in queryset_resources:
                        kwargs = {
                            'content_object': self.instance,
                            'content_object_repr': str(self.instance),
                        }
                        if resource.default_allocation:
                            kwargs['allocated'] = resource.default_allocation
                        rdata = resource.dataset.create(**kwargs)
                        queryset.append(rdata)
            # Existing dataset
            for i, rdata in enumerate(queryset):
                forms.append(self._construct_form(i, resource=rdata.resource))
                try:
                    resources_copy.remove(rdata.resource)
                except ValueError:
                    pass
            # Missing dataset
            for i, resource in enumerate(resources_copy, len(queryset)):
                forms.append(self._construct_form(i, resource=resource))
            return forms

    class ResourceInline(GenericTabularInline):
        model = ResourceData
        verbose_name_plural = _("resources")
        form = ResourceForm
        formset = ResourceInlineFormSet
        can_delete = False
        fields = (
            'verbose_name', 'display_used', 'display_updated', 'allocated', 'unit',
        )
        readonly_fields = ('display_used', 'display_updated',)

        class Media:
            css = {
                'all': ('orchestra/css/hide-inline-id.css',)
            }

        display_updated = admin_date('updated_at', default=_("Never"))

        def get_fieldsets(self, request, obj=None):
            if obj:
                opts = self.parent_model._meta
                url = reverse('admin:resources_resourcedata_list_related',
                    args=(opts.app_label, opts.model_name, obj.id))
                link = '<a href="%s">%s</a>' % (url, _("List related"))
                self.verbose_name_plural = mark_safe(_("Resources") + ' ' + link)
            return super(ResourceInline, self).get_fieldsets(request, obj)

        @mark_safe
        def display_used(self, rdata):
            update = ''
            history = ''
            if rdata.pk:
                context = {
                    'title': _("Update"),
                    'url': reverse('admin:resources_resourcedata_monitor', args=(rdata.pk,)),
                    'image': '<img src="%s"></img>' % static('orchestra/images/reload.png'),
                }
                update = '<a href="%(url)s" title="%(title)s">%(image)s</a>' % context
                context.update({
                    'title': _("Show history"),
                    'image': '<img src="%s"></img>' % static('orchestra/images/history.png'),
                    'url': reverse('admin:resources_resourcedata_show_history', args=(rdata.pk,)),
                    'popup': 'onclick="return showAddAnotherPopup(this);"',
                })
                history = '<a href="%(url)s" title="%(title)s" %(popup)s>%(image)s</a>' % context
            if rdata.used is not None:
                used_url = reverse('admin:resources_resourcedata_used_monitordata', args=(rdata.pk,))
                used =  '<a href="%s">%s %s</a>' % (used_url, rdata.used, rdata.unit)
                return ' '.join(map(str, (used, update, history)))
            if rdata.resource.monitors:
                return _("Unknonw %s %s") % (update, history)
            return _("No monitor")
        display_used.short_description = _("Used")

        def has_add_permission(self, *args, **kwargs):
            """ Hidde add another """
            return False

    return ResourceInline


def insert_resource_inlines():
    # Clean previous state
    for related in Resource._related:
        modeladmin = get_modeladmin(related)
        modeladmin_class = type(modeladmin)
        for inline in getattr(modeladmin_class, 'inlines', []):
            if inline.__name__ == 'ResourceInline':
                modeladmin_class.inlines.remove(inline)
    resources = Resource.objects.filter(is_active=True)
    for ct, resources in resources.group_by('content_type').items():
        inline = resource_inline_factory(resources)
        model = ct.model_class()
        insertattr(model, 'inlines', inline)


if db.database_ready():
    insert_resource_inlines()