from django import forms

from django.conf import settings

from django.utils.safestring import mark_safe

from django.utils.text import truncate_words

from django.template.loader import render_to_string

from django.contrib.admin.widgets import ForeignKeyRawIdWidget

class ForeignKeySearchInput(ForeignKeyRawIdWidget):

    """

    A Widget for displaying ForeignKeys in an autocomplete search input 

    instead in a <select> box.

    """

    # Set in subclass to render the widget with a different template

    widget_template = None

    # Set this to the patch of the search view

    search_path = '../foreignkey_autocomplete/'

    class Media:

        css = {

            'all': ('django_extensions/css/jquery.autocomplete.css',)

        }

        js = (

            'django_extensions/js/jquery.js',

            'django_extensions/js/jquery.bgiframe.min.js',

            'django_extensions/js/jquery.ajaxQueue.js',

            'django_extensions/js/jquery.autocomplete.js',

        )

    def label_for_value(self, value):

        key = self.rel.get_related_field().name

        obj = self.rel.to._default_manager.get(**{key: value})

        return truncate_words(obj, 14)

    def __init__(self, rel, search_fields, attrs=None):

        self.search_fields = search_fields

        super(ForeignKeySearchInput, self).__init__(rel, attrs)

    def render(self, name, value, attrs=None):

        if attrs is None:

            attrs = {}

        output = [super(ForeignKeySearchInput, self).render(name, value, attrs)]

        opts = self.rel.to._meta

        app_label = opts.app_label

        model_name = opts.object_name.lower()

        related_url = '../../../%s/%s/' % (app_label, model_name)

        params = self.url_parameters()

        if params:

            url = '?' + '&'.join(['%s=%s' % (k, v) for k, v in params.items()])

        else:

            url = ''

        if not attrs.has_key('class'):

            attrs['class'] = 'vForeignKeyRawIdAdminField'

        # Call the TextInput render method directly to have more control

        output = [forms.TextInput.render(self, name, value, attrs)]

        if value:

            label = self.label_for_value(value)

        else:

            label = u''

        context = {

            'url': url,

            'related_url': related_url,

            'admin_media_prefix': settings.ADMIN_MEDIA_PREFIX,

            'search_path': self.search_path,

            'search_fields': ','.join(self.search_fields),

            'model_name': model_name,

            'app_label': app_label,

            'label': label,

            'name': name,

        }

        output.append(render_to_string(self.widget_template or (

            'django_extensions/widgets/%s/%s/foreignkey_searchinput.html' % (app_label, model_name),

            'django_extensions/widgets/%s/foreignkey_searchinput.html' % app_label,

            'django_extensions/widgets/foreignkey_searchinput.html',

        ), context))

        output.reverse()

        return mark_safe(u''.join(output))