from django.contrib import admin
from django.contrib.auth.models import User, Group
from django.core.urlresolvers import reverse
from django.templatetags.static import static

from .models import Sender, Tag, Document


class MonthListFilter(admin.SimpleListFilter):

    title = "Month"

    # Parameter for the filter that will be used in the URL query.
    parameter_name = "month"

    def lookups(self, request, model_admin):
        r = []
        for document in Document.objects.all():
            r.append((
                document.created.strftime("%Y-%m"),
                document.created.strftime("%B %Y")
            ))
        return sorted(set(r), key=lambda x: x[0], reverse=True)

    def queryset(self, request, queryset):

        if not self.value():
            return None

        year, month = self.value().split("-")
        return queryset.filter(created__year=year, created__month=month)


class TagAdmin(admin.ModelAdmin):

    list_display = ("name", "colour", "match", "matching_algorithm")
    list_filter = ("colour", "matching_algorithm")
    list_editable = ("colour", "match", "matching_algorithm")


class DocumentAdmin(admin.ModelAdmin):

    class Media:
        css = {
            "all": ("paperless.css",)
        }

    search_fields = ("sender__name", "title", "content")
    list_display = ("created_", "sender", "title", "tags_", "document")
    list_filter = ("tags", "sender", MonthListFilter)
    list_per_page = 25

    def created_(self, obj):
        return obj.created.date().strftime("%Y-%m-%d")

    def tags_(self, obj):
        r = ""
        for tag in obj.tags.all():
            r += '<a class="tag" style="background-color: {};" href="{}">{}</a>'.format(
                tag.get_colour_display(),
                "{}?tags__id__exact={}".format(
                    reverse("admin:documents_document_changelist"),
                    tag.pk
                ),
                tag.slug
            )
        return r
    tags_.allow_tags = True

    def document(self, obj):
        return '<a href="{}">' \
                 '<img src="{}" width="22" height="22" alt="{} icon" title="{}">' \
               '</a>'.format(
                    obj.download_url,
                    static("documents/img/{}.png".format(obj.file_type)),
                    obj.file_type,
                    obj.file_name
                )
    document.allow_tags = True

admin.site.register(Sender)
admin.site.register(Tag, TagAdmin)
admin.site.register(Document, DocumentAdmin)

# Unless we implement multi-user, these default registrations don't make sense.
admin.site.unregister(Group)
admin.site.unregister(User)