# Copyright The IETF Trust 2014-2020, All Rights Reserved
# -*- coding: utf-8 -*-


import json

from django.utils.html import escape
from django import forms
from django.db.models import Q
from django.urls import reverse as urlreverse

import debug                            # pyflakes:ignore

from ietf.doc.models import Document, DocAlias
from ietf.doc.utils import uppercase_std_abbreviated_name
from ietf.utils.fields import SearchableField

def select2_id_doc_name(objs):
    return [{
        "id": o.pk,
        "text": escape(uppercase_std_abbreviated_name(o.name)),
    } for o in objs]


def select2_id_doc_name_json(objs):
    return json.dumps(select2_id_doc_name(objs))


class SearchableDocumentsField(SearchableField):
    """Server-based multi-select field for choosing documents using select2.js. """
    model = Document
    default_hint_text = "Type name to search for document"

    def __init__(self, doc_type="draft", *args, **kwargs):
        super(SearchableDocumentsField, self).__init__(*args, **kwargs)
        self.doc_type = doc_type

    def doc_type_filter(self, queryset):
        """Filter to include only desired doc type"""
        return queryset.filter(type=self.doc_type)

    def get_model_instances(self, item_ids):
        """Get model instances corresponding to item identifiers in select2 field value

        Accepts both names and pks as IDs
        """
        names = [ i for i in item_ids if not i.isdigit() ]
        ids   = [ i for i in item_ids if i.isdigit() ]
        objs = self.model.objects.filter(
            Q(name__in=names)|Q(id__in=ids)
        )
        return self.doc_type_filter(objs)

    def make_select2_data(self, model_instances):
        """Get select2 data items"""
        return select2_id_doc_name(model_instances)

    def ajax_url(self):
        """Get the URL for AJAX searches"""
        return urlreverse('ietf.doc.views_search.ajax_select2_search_docs', kwargs={
            "doc_type": self.doc_type,
            "model_name": self.model.__name__.lower()
        })


class SearchableDocumentField(SearchableDocumentsField):
    """Specialized to only return one Document"""
    max_entries = 1


class SearchableDocAliasesField(SearchableDocumentsField):
    """Search DocAliases instead of Documents"""
    model = DocAlias
    
    def doc_type_filter(self, queryset):
        """Filter to include only desired doc type

        For DocAlias, pass through to the docs to check type.
        """
        return queryset.filter(docs__type=self.doc_type)

class SearchableDocAliasField(SearchableDocAliasesField):
    """Specialized to only return one DocAlias"""
    max_entries = 1