from functools import update_wrapper

from django.conf import settings
from django.contrib import admin
from django.core.urlresolvers import reverse
from django.db import models
from django.utils import importlib
from django.utils.html import escape
from django.utils.safestring import mark_safe
from django.utils.translation import ugettext_lazy as _

from orchestra.models.utils import get_field_value
from orchestra.utils.humanize import naturaldate

from .decorators import admin_field


def get_modeladmin(model, import_module=True):
    """ returns the modeladmin registred for model """
    for k,v in admin.site._registry.iteritems():
        if k is model:
            return v
    if import_module:
        # Sometimes the admin module is not yet imported
        app_label = model._meta.app_label
        for app in settings.INSTALLED_APPS:
            if app.endswith(app_label):
                app_label = app
        importlib.import_module('%s.%s' % (app_label, 'admin'))
        return get_modeladmin(model, import_module=False)


def insertattr(model, name, value, weight=0):
    """ Inserts attribute to a modeladmin """
    modeladmin = model
    if models.Model in model.__mro__:
        modeladmin = type(get_modeladmin(model))
    # Avoid inlines defined on parent class be shared between subclasses
    # Seems that if we use tuples they are lost in some conditions like changing
    # the tuple in modeladmin.__init__
    if not getattr(modeladmin, name):
        setattr(type(modeladmin), name, [])
    
    inserted_attrs = getattr(modeladmin, '__inserted_attrs__', {})
    if not name in inserted_attrs:
        weights = {}
        if hasattr(modeladmin, 'weights') and name in modeladmin.weights:
            weights = modeladmin.weights.get(name)
        inserted_attrs[name] = [
            (attr, weights.get(attr, 0)) for attr in getattr(modeladmin, name)
        ]
    
    inserted_attrs[name].append((value, weight))
    inserted_attrs[name].sort(key=lambda a: a[1])
    setattr(modeladmin, name, [ attr[0] for attr in inserted_attrs[name] ])
    setattr(modeladmin, '__inserted_attrs__', inserted_attrs)


def wrap_admin_view(modeladmin, view):
    """ Add admin authentication to view """
    def wrapper(*args, **kwargs):
        return modeladmin.admin_site.admin_view(view)(*args, **kwargs)
    return update_wrapper(wrapper, view)


def set_default_filter(queryarg, request, value):
    """ set default filters for changelist_view """
    if queryarg not in request.GET:
        request_copy = request.GET.copy()
        if callable(value):
            value = value(request)
        request_copy[queryarg] = value
        request.GET = request_copy
        request.META['QUERY_STRING'] = request.GET.urlencode()


@admin_field
def admin_link(*args, **kwargs):
    instance = args[-1]
    obj = get_field_value(instance, kwargs['field'])
    if not getattr(obj, 'pk', None):
        return '---'
    opts = obj._meta
    view_name = 'admin:%s_%s_change' % (opts.app_label, opts.model_name)
    url = reverse(view_name, args=(obj.pk,))
    extra = ''
    if kwargs['popup']:
        extra = 'onclick="return showAddAnotherPopup(this);"'
    return '<a href="%s" %s>%s</a>' % (url, extra, obj)


@admin_field
def admin_colored(*args, **kwargs):
    instance = args[-1]
    field = kwargs['field']
    value = escape(get_field_value(instance, field))
    color = kwargs.get('colors', {}).get(value, 'black')
    value = getattr(instance, 'get_%s_display' % field)().upper()
    colored_value = '<span style="color: %s;">%s</span>' % (color, value)
    if kwargs.get('bold', True):
        colored_value = '<b>%s</b>' % colored_value
    return mark_safe(colored_value)


@admin_field
def admin_date(*args, **kwargs):
    instance = args[-1]
    value = get_field_value(instance, kwargs['field'])
    if not value:
        return kwargs.get('default', '')
    return '<span title="{0}">{1}</span>'.format(
        escape(str(value)), escape(naturaldate(value)),
    )