experiENS/avisstage/views_search.py

import json
import logging
from datetime import date

from django import forms
from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.core.cache import cache
from django.core.paginator import Paginator
from django.db.models import Case, Q, When
from django.http import HttpResponseBadRequest, JsonResponse
from django.shortcuts import get_object_or_404, redirect, render

USE_ELASTICSEARCH = getattr(settings, "USE_ELASTICSEARCH", True)

if USE_ELASTICSEARCH:
    from .documents import StageDocument

from .decorators import en_scolarite_required
from .models import Stage
from .statics import NIVEAU_SCOL_OPTIONS, TYPE_LIEU_OPTIONS, TYPE_STAGE_OPTIONS

logger = logging.getLogger("recherche")

# Recherche
class SearchForm(forms.Form):
    generique = forms.CharField(required=False)
    sujet = forms.CharField(label=u"À propos de", required=False)
    contexte = forms.CharField(
        label=u"Contexte (lieu, encadrant⋅e⋅s, structure)", required=False
    )

    apres_annee = forms.IntegerField(label=u"Après cette année", required=False)
    avant_annee = forms.IntegerField(label=u"Avant cette année", required=False)

    type_stage = forms.ChoiceField(
        label="Type de stage",
        choices=([("", u"")] + list(TYPE_STAGE_OPTIONS)),
        required=False,
    )
    niveau_scol = forms.ChoiceField(
        label="Année d'étude",
        choices=([("", u"")] + list(NIVEAU_SCOL_OPTIONS)),
        required=False,
    )

    type_lieu = forms.ChoiceField(
        label="Type de lieu d'accueil",
        choices=([("", u"")] + list(TYPE_LIEU_OPTIONS)),
        required=False,
    )
    tri = forms.ChoiceField(
        label=u"Tri par",
        choices=[("pertinence", u"Pertinence"), ("-date_maj", u"Dernière mise à jour")],
        required=False,
        initial="pertinence",
    )


def cherche(**kwargs):
    filtres = Q(public=True)
    use_dsl = False

    def field_relevant(field, test_string=True):
        return (
            field in kwargs
            and kwargs[field] is not None
            and ((not test_string) or kwargs[field].strip() != "")
        )

    if USE_ELASTICSEARCH:
        dsl = StageDocument.search()

        #
        # Recherche libre AVEC ELASTICSEARCH
        #

        # Champ générique : recherche dans tous les champs
        if field_relevant("generique"):
            # print("Filtre generique", kwargs['generique'])
            dsl = dsl.query(
                "match", _all={"query": kwargs["generique"], "fuzziness": "auto"}
            )
            use_dsl = True

        # Sujet -> Recherche dan les noms de sujets et les thématiques
        if field_relevant("sujet"):
            dsl = dsl.query(
                "multi_match",
                query=kwargs["sujet"],
                fields=["sujet^2", "thematiques", "matieres"],
                fuzziness="auto",
            )
            use_dsl = True

        # Contexte -> Encadrants, structure, lieu
        if field_relevant("contexte"):
            dsl = dsl.query(
                "multi_match",
                query=kwargs["contexte"],
                fields=[
                    "encadrants",
                    "structure^2",
                    "lieux.nom",
                    "lieux.pays",
                    "lieux.ville",
                ],
                fuzziness="auto",
            )
            use_dsl = True

    else:
        # Sans ElasticSearch, on active quand même une approximation de
        # recherche en base de données
        if field_relevant("generique"):
            generique = kwargs["generique"]
            filtres = (
                Q(sujet__icontains=generique)
                | Q(thematiques__name__icontains=generique)
                | Q(matieres__nom__icontains=generique)
                | Q(lieux__nom__icontains=generique)
            )

        # Autres champs -> non fonctionnels
        if field_relevant("sujet") or field_relevant("contexte"):
            raise NotImplementedError(
                "ElasticSearch doit être activé pour ce type de recherche"
            )

    #
    # Filtres directs db
    #

    # Dates
    if field_relevant("avant_annee", False):
        dte = date(kwargs["avant_annee"] + 1, 1, 1)
        filtres &= Q(date_fin__lt=dte)

    if field_relevant("apres_annee", False):
        dte = date(kwargs["apres_annee"], 1, 1)
        filtres &= Q(date_debut__gte=dte)

    # Type de stage
    if field_relevant("type_stage"):
        filtres &= Q(type_stage=kwargs["type_stage"])

    if field_relevant("niveau_scol"):
        filtres &= Q(niveau_scol=kwargs["niveau_scol"])

    # Type de lieu
    if field_relevant("type_lieu"):
        filtres &= Q(lieux__type_lieu=kwargs["type_lieu"])

    # Application
    if USE_ELASTICSEARCH and use_dsl:
        filtres &= Q(id__in=[s.meta.id for s in dsl.scan()])

    # print(filtres)
    resultat = Stage.objects.filter(filtres)
    tri = "pertinence"

    if not use_dsl:
        kwargs["tri"] = "-date_maj"

    if field_relevant("tri") and kwargs["tri"] in ["-date_maj"]:
        tri = kwargs["tri"]
        resultat = resultat.order_by(tri)

    return resultat, tri


@login_required
@en_scolarite_required
def recherche(request):
    form = SearchForm()
    return render(request, "avisstage/recherche/recherche.html", {"form": form})


@login_required
@en_scolarite_required
def recherche_resultats(request):
    stages = []
    tri = ""
    vue = "vue-liste"
    lieux = []
    stageids = []
    if request.method == "GET":
        form = SearchForm(request.GET)
        if form.is_valid():
            page = request.GET.get("page", 1)
            search_args = form.cleaned_data

            # Gestion du cache
            lsearch_args = {
                key: val
                for key, val in search_args.items()
                if val != "" and val is not None
            }
            cache_key = json.dumps(lsearch_args, sort_keys=True)
            cached = cache.get(cache_key)
            if cached is None:
                # Requête effective
                stages, tri = cherche(**search_args)
                stageids = list(stages.values_list("id", flat=True))
                lieux = [
                    [stageid, lieuid]
                    for (stageid, lieuid) in stages.values_list("id", "lieux")
                    if lieuid is not None
                ]

                # Sauvegarde dans le cache
                to_cache = {"stages": stageids, "lieux": lieux, "tri": tri}
                cache.set(cache_key, to_cache, 600)
                logger.info(cache_key)
            else:
                # Lecture du cache
                stageids = cached["stages"]
                lieux = cached["lieux"]
                tri = cached["tri"]
                logger.info("recherche en cache")

            # Pagination
            paginator = Paginator(stageids, 25)
            try:
                stageids = paginator.page(page)
            except InvalidPage:
                stageids = []

            if cached is None:
                stages = stages[
                    max(0, stageids.start_index() - 1) : stageids.end_index()
                ]
            else:
                orderer = Case(
                    *[When(pk=pk, then=pos) for pos, pk in enumerate(stageids)]
                )
                stages = Stage.objects.filter(id__in=stageids).order_by(orderer)

            stages = stages.prefetch_related(
                "lieux", "auteur", "matieres", "thematiques"
            )
    else:
        form = SearchForm()
    if stages:
        vue = "vue-hybride"

    # Version JSON pour recherche dynamique
    if request.GET.get("format") == "json":
        return JsonResponse(
            {"stages": stages, "page": page, "num_pages": paginator.num_pages}
        )

    template_name = "avisstage/recherche/resultats.html"
    if request.GET.get("format") == "raw":
        template_name = "avisstage/recherche/stage_items.html"
    return render(
        request,
        template_name,
        {
            "form": form,
            "stages": stages,
            "paginator": stageids,
            "tri": tri,
            "vue": vue,
            "lieux": lieux,
            "MAPBOX_API_KEY": settings.MAPBOX_API_KEY,
        },
    )


@login_required
@en_scolarite_required
def stage_items(request):
    try:
        stageids = [int(a) for a in request.GET.get("ids", "").split(";")]
    except ValueError:
        return HttpResponseBadRequest("Paramètre incorrect")
    stages = Stage.objects.filter(id__in=stageids).prefetch_related(
        "lieux", "auteur", "matieres", "thematiques"
    )
    return render(request, "avisstage/recherche/stage_items.html", {"stages": stages})