# -*- mode: python -*-
# -*- coding: utf-8 -*-

##############################################################################
#
# Gestion scolarite IUT
#
# Copyright (c) 1999 - 2021 Emmanuel Viennet.  All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#   Emmanuel Viennet      emmanuel.viennet@viennet.net
#
##############################################################################


""" Common definitions
"""
import base64
import bisect
import copy
import datetime
import json
from hashlib import md5
import numbers
import os
import pydot
import re
import requests
import six
import six.moves._thread
import sys
import time
import traceback
import types
import unicodedata
import urllib
from xml.etree import ElementTree

from flask import g, current_app

from PIL import Image as PILImage

from flask import g, url_for, request, make_response
from werkzeug.wrappers import response

from config import Config
from app import log
from app.scodoc.sco_vdi import ApoEtapeVDI
from app.scodoc.sco_xml import quote_xml_attr
from app.scodoc.sco_codes_parcours import NOTES_TOLERANCE, CODES_EXPL
from app.scodoc import sco_exceptions
from app.scodoc import sco_xml
import sco_version


# ----- CALCUL ET PRESENTATION DES NOTES
NOTES_PRECISION = 1e-4  # evite eventuelles erreurs d'arrondis
NOTES_MIN = 0.0  # valeur minimale admise pour une note (sauf malus, dans [-20, 20])
NOTES_MAX = 1000.0
NOTES_NEUTRALISE = -1000.0  # notes non prises en comptes dans moyennes
NOTES_SUPPRESS = -1001.0  # note a supprimer
NOTES_ATTENTE = -1002.0  # note "en attente" (se calcule comme une note neutralisee)


# Types de modules
MODULE_STANDARD = 0
MODULE_MALUS = 1

MALUS_MAX = 20.0
MALUS_MIN = -20.0

APO_MISSING_CODE_STR = "----"  # shown in HTML pages in place of missing code Apogée
EDIT_NB_ETAPES = 6  # Nombre max de codes étapes / semestre presentés dans l'UI

IT_SITUATION_MISSING_STR = (
    "____"  # shown on ficheEtud (devenir) in place of empty situation
)

RANG_ATTENTE_STR = "(attente)"  #  rang affiché sur bulletins quand notes en attente

# borne supérieure de chaque mention
NOTES_MENTIONS_TH = (
    NOTES_TOLERANCE,
    7.0,
    10.0,
    12.0,
    14.0,
    16.0,
    18.0,
    20.0 + NOTES_TOLERANCE,
)
NOTES_MENTIONS_LABS = (
    "Nul",
    "Faible",
    "Insuffisant",
    "Passable",
    "Assez bien",
    "Bien",
    "Très bien",
    "Excellent",
)

EVALUATION_NORMALE = 0
EVALUATION_RATTRAPAGE = 1
EVALUATION_SESSION2 = 2


def fmt_note(val, note_max=None, keep_numeric=False):
    """conversion note en str pour affichage dans tables HTML ou PDF.
    Si keep_numeric, laisse les valeur numeriques telles quelles (pour export Excel)
    """
    if val is None:
        return "ABS"
    if val == NOTES_NEUTRALISE:
        return "EXC"  # excuse, note neutralise
    if val == NOTES_ATTENTE:
        return "ATT"  # attente, note neutralisee
    if isinstance(val, float) or isinstance(val, int):
        if note_max != None and note_max > 0:
            val = val * 20.0 / note_max
        if keep_numeric:
            return val
        else:
            s = "%2.2f" % round(float(val), 2)  # 2 chiffres apres la virgule
            s = "0" * (5 - len(s)) + s  # padding: 0 à gauche pour longueur 5: "12.34"
            return s
    else:
        return val.replace("NA0", "-")  # notes sans le NA0


def fmt_coef(val):
    """Conversion valeur coefficient (float) en chaine"""
    if val < 0.01:
        return "%g" % val  # unusually small value
    return "%g" % round(val, 2)


def fmt_abs(val):
    """Conversion absences en chaine. val est une list [nb_abs_total, nb_abs_justifiees
    => NbAbs / Nb_justifiees
    """
    return "%s / %s" % (val[0], val[1])


def isnumber(x):
    "True if x is a number (int, float, etc.)"
    return isinstance(x, numbers.Number)


def join_words(*words):
    words = [str(w).strip() for w in words if w is not None]
    return " ".join([w for w in words if w])


def get_mention(moy):
    """Texte "mention" en fonction de la moyenne générale"""
    try:
        moy = float(moy)
    except:
        return ""
    return NOTES_MENTIONS_LABS[bisect.bisect_right(NOTES_MENTIONS_TH, moy)]


class DictDefault(dict):  # obsolete, use collections.defaultdict
    """A dictionnary with default value for all keys
    Each time a non existent key is requested, it is added to the dict.
    (used in python 2.4, can't use new __missing__ method)
    """

    defaultvalue = 0

    def __init__(self, defaultvalue=0, kv_dict={}):
        dict.__init__(self)
        self.defaultvalue = defaultvalue
        self.update(kv_dict)

    def __getitem__(self, k):
        if k in self:
            return self.get(k)
        value = copy.copy(self.defaultvalue)
        self[k] = value
        return value


class WrapDict(object):
    """Wrap a dict so that getitem returns '' when values are None"""

    def __init__(self, adict, NoneValue=""):
        self.dict = adict
        self.NoneValue = NoneValue

    def __getitem__(self, key):
        value = self.dict[key]
        if value is None:
            return self.NoneValue
        else:
            return value


def group_by_key(d, key):
    gr = DictDefault(defaultvalue=[])
    for e in d:
        gr[e[key]].append(e)
    return gr


# ----- Global lock for critical sections (except notes_tables caches)
GSL = six.moves._thread.allocate_lock()  # Global ScoDoc Lock

SCODOC_DIR = Config.SCODOC_DIR

# ----- Repertoire "config" modifiable
#        /opt/scodoc-data/config
SCODOC_CFG_DIR = os.path.join(Config.SCODOC_VAR_DIR, "config")
# ----- Version information
SCODOC_VERSION_DIR = os.path.join(SCODOC_CFG_DIR, "version")
# ----- Repertoire tmp : /opt/scodoc-data/tmp
SCO_TMP_DIR = os.path.join(Config.SCODOC_VAR_DIR, "tmp")
if not os.path.exists(SCO_TMP_DIR):
    os.mkdir(SCO_TMP_DIR, 0o755)
# ----- Les logos: /opt/scodoc-data/config/logos
SCODOC_LOGOS_DIR = os.path.join(SCODOC_CFG_DIR, "logos")
LOGOS_IMAGES_ALLOWED_TYPES = ("jpg", "jpeg", "png")  # remind that PIL does not read pdf


# ----- Les outils distribués
SCO_TOOLS_DIR = os.path.join(Config.SCODOC_DIR, "tools")


# ----- Lecture du fichier de configuration
from app.scodoc import sco_config
from app.scodoc import sco_config_load

sco_config_load.load_local_configuration(SCODOC_CFG_DIR)
CONFIG = sco_config.CONFIG
if hasattr(CONFIG, "CODES_EXPL"):
    CODES_EXPL.update(
        CONFIG.CODES_EXPL
    )  # permet de customiser les explications de codes

if CONFIG.CUSTOM_HTML_HEADER:
    CUSTOM_HTML_HEADER = open(CONFIG.CUSTOM_HTML_HEADER).read()
else:
    CUSTOM_HTML_HEADER = ""

if CONFIG.CUSTOM_HTML_HEADER_CNX:
    CUSTOM_HTML_HEADER_CNX = open(CONFIG.CUSTOM_HTML_HEADER_CNX).read()
else:
    CUSTOM_HTML_HEADER_CNX = ""

if CONFIG.CUSTOM_HTML_FOOTER:
    CUSTOM_HTML_FOOTER = open(CONFIG.CUSTOM_HTML_FOOTER).read()
else:
    CUSTOM_HTML_FOOTER = ""

if CONFIG.CUSTOM_HTML_FOOTER_CNX:
    CUSTOM_HTML_FOOTER_CNX = open(CONFIG.CUSTOM_HTML_FOOTER_CNX).read()
else:
    CUSTOM_HTML_FOOTER_CNX = ""

SCO_ENCODING = "utf-8"  # used by Excel, XML, PDF, ...


SCO_DEFAULT_SQL_USER = "scodoc"  # should match Zope process UID
SCO_DEFAULT_SQL_PORT = "5432"
SCO_DEFAULT_SQL_USERS_CNX = "dbname=SCOUSERS port=%s" % SCO_DEFAULT_SQL_PORT

# Valeurs utilisées pour affichage seulement, pas de requetes ni de mails envoyés:
SCO_WEBSITE = "https://scodoc.org"
SCO_USER_MANUAL = "https://scodoc.org/GuideUtilisateur"
SCO_ANNONCES_WEBSITE = "https://listes.univ-paris13.fr/mailman/listinfo/scodoc-annonces"
SCO_DEVEL_LIST = "scodoc-devel@listes.univ-paris13.fr"
SCO_USERS_LIST = "notes@listes.univ-paris13.fr"

# Mails avec exceptions (erreurs) anormales envoyés à cette adresse:
# mettre '' pour désactiver completement l'envois de mails d'erreurs.
# (ces mails sont précieux pour corriger les erreurs, ne les désactiver que si
#  vous avez de bonnes raisons de le faire: vous pouvez me contacter avant)
SCO_EXC_MAIL = "scodoc-exception@viennet.net"

# L'adresse du mainteneur (non utilisée automatiquement par ScoDoc: ne pas changer)
SCO_DEV_MAIL = "emmanuel.viennet@gmail.com"  # SVP ne pas changer

# Adresse pour l'envoi des dumps (pour assistance technnique):
#   ne pas changer (ou vous perdez le support)
SCO_DUMP_UP_URL = "https://scodoc.iutv.univ-paris13.fr/scodoc-installmgr/upload-dump"
# SCO_DUMP_UP_URL = "http://192.168.56.1:5000/upload_dump"

CSV_FIELDSEP = ";"
CSV_LINESEP = "\n"
CSV_MIMETYPE = "text/comma-separated-values"
CSV_SUFFIX = ".csv"
JSON_MIMETYPE = "application/json"
JSON_SUFFIX = ".json"
PDF_MIMETYPE = "application/pdf"
PDF_SUFFIX = ".pdf"
XLS_MIMETYPE = "application/vnd.ms-excel"
XLSX_MIMETYPE = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
XLSX_SUFFIX = ".xlsx"
XML_MIMETYPE = "text/xml"
XML_SUFFIX = ".xml"


def get_mime_suffix(format_code: str) -> tuple[str, str]:
    """Returns (MIME, SUFFIX) from format_code == "xls", "xml", ...
    SUFFIX includes the dot: ".xlsx", ".xml", ...
    "xls" and "xlsx" format codes give XLSX
    """
    d = {
        "csv": (CSV_MIMETYPE, CSV_SUFFIX),
        "xls": (XLSX_MIMETYPE, XLSX_SUFFIX),
        "xlsx": (XLSX_MIMETYPE, XLSX_SUFFIX),
        "pdf": (PDF_MIMETYPE, PDF_SUFFIX),
        "xml": (XML_MIMETYPE, XML_SUFFIX),
        "json": (JSON_MIMETYPE, JSON_SUFFIX),
    }
    return d[format_code]


# Admissions des étudiants
# Différents types de voies d'admission:
# (stocké en texte libre dans la base, mais saisie par menus pour harmoniser)
TYPE_ADMISSION_DEFAULT = "Inconnue"
TYPES_ADMISSION = (TYPE_ADMISSION_DEFAULT, "APB", "APB-PC", "CEF", "Direct")

BULLETINS_VERSIONS = ("short", "selectedevals", "long")

# Support for ScoDoc7 compatibility


def ScoURL():
    """base URL for this sco instance.
    e.g. https://scodoc.xxx.fr/ScoDoc/DEPT/Scolarite
    = page accueil département
    """
    return url_for("scolar.index_html", scodoc_dept=g.scodoc_dept)[
        : -len("/index_html")
    ]


def NotesURL():
    """URL of Notes
    e.g. https://scodoc.xxx.fr/ScoDoc/DEPT/Scolarite/Notes
    = url de base des méthodes de notes
    (page accueil programmes).
    """
    return url_for("notes.index_html", scodoc_dept=g.scodoc_dept)[: -len("/index_html")]


def EntreprisesURL():
    """URL of Enterprises
    e.g. https://scodoc.xxx.fr/ScoDoc/DEPT/Scolarite/Entreprises
    = url de base des requêtes de ZEntreprises
    et page accueil Entreprises
    """
    return "NotImplemented"
    # url_for("entreprises.index_html", scodoc_dept=g.scodoc_dept)[
    #    : -len("/index_html")
    # ]


def AbsencesURL():
    """URL of Absences"""
    return url_for("absences.index_html", scodoc_dept=g.scodoc_dept)[
        : -len("/index_html")
    ]


def UsersURL():
    """URL of Users
    e.g. https://scodoc.xxx.fr/ScoDoc/DEPT/Scolarite/Users
    = url de base des requêtes ZScoUsers
    et page accueil users
    """
    return url_for("users.index_html", scodoc_dept=g.scodoc_dept)[: -len("/index_html")]


# ---- Simple python utilities


def simplesqlquote(s, maxlen=50):
    """simple SQL quoting to avoid most SQL injection attacks.
    Note: we use this function in the (rare) cases where we have to
    construct SQL code manually"""
    s = s[:maxlen]
    s.replace("'", r"\'")
    s.replace(";", r"\;")
    for bad in ("select", "drop", ";", "--", "insert", "delete", "xp_"):
        s = s.replace(bad, "")
    return s


def unescape_html(s):
    """un-escape html entities"""
    s = s.strip().replace("&amp;", "&")
    s = s.replace("&lt;", "<")
    s = s.replace("&gt;", ">")
    return s


# test if obj is iterable (but not a string)
isiterable = lambda obj: getattr(obj, "__iter__", False)


def unescape_html_dict(d):
    """un-escape all dict values, recursively"""
    try:
        indices = list(d.keys())
    except:
        indices = list(range(len(d)))
    for k in indices:
        v = d[k]
        if isinstance(v, bytes):
            d[k] = unescape_html(v)
        elif isiterable(v):
            unescape_html_dict(v)


# Expressions used to check noms/prenoms
FORBIDDEN_CHARS_EXP = re.compile(r"[*\|~\(\)\\]")
ALPHANUM_EXP = re.compile(r"^[\w-]+$", re.UNICODE)


def is_valid_code_nip(s):
    """True si s peut être un code NIP: au moins 6 chiffres décimaux"""
    if not s:
        return False
    return re.match(r"^[0-9]{6,32}$", s)


def strnone(s):
    "convert s to string, '' if s is false"
    if s:
        return str(s)
    else:
        return ""


def stripquotes(s):
    "strip s from spaces and quotes"
    s = s.strip()
    if s and ((s[0] == '"' and s[-1] == '"') or (s[0] == "'" and s[-1] == "'")):
        s = s[1:-1]
    return s


def suppress_accents(s):
    "remove accents and suppress non ascii characters from string s"
    if isinstance(s, str):
        return (
            unicodedata.normalize("NFD", s)
            .encode("ascii", "ignore")
            .decode(SCO_ENCODING)
        )
    return s  # may be int


def sanitize_string(s):
    """s is an ordinary string, encoding given by SCO_ENCODING"
    suppress accents and chars interpreted in XML
    Irreversible (not a quote)

    For ids and some filenames
    """
    # Table suppressing some chars:
    trans = str.maketrans("", "", "'`\"<>!&\\ ")
    return suppress_accents(s.translate(trans)).replace(" ", "_").replace("\t", "_")


_BAD_FILENAME_CHARS = str.maketrans("", "", ":/\\&")


def make_filename(name):
    """Try to convert name to a reasonable filename
    without spaces, (back)slashes, : and without accents
    """
    return suppress_accents(name.translate(_BAD_FILENAME_CHARS)).replace(" ", "_")


VALID_CARS = (
    "-abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.!"  # no / !
)
VALID_CARS_SET = set(VALID_CARS)
VALID_EXP = re.compile("^[" + VALID_CARS + "]+$")


def sanitize_filename(filename):
    """Keep only valid chars
    used for archives filenames
    """
    filename = suppress_accents(filename.replace(" ", "_"))
    sane = "".join([c for c in filename if c in VALID_CARS_SET])
    if len(sane) < 2:
        sane = time.strftime("%Y-%m-%d-%H%M%S") + "-" + sane
    return sane


def is_valid_filename(filename):
    """True if filename is safe"""
    return VALID_EXP.match(filename)


def bul_filename(sem, etud, format):
    """Build a filename for this bulletin"""
    dt = time.strftime("%Y-%m-%d")
    filename = f"bul-{sem['titre_num']}-{dt}-{etud['nom']}.{format}"
    filename = make_filename(filename)
    return filename


def sendCSVFile(REQUEST, data, filename):  # DEPRECATED ne plus utiliser
    """publication fichier.
    (on ne doit rien avoir émis avant, car ici sont générés les entetes)
    """
    filename = (
        unescape_html(suppress_accents(filename)).replace("&", "").replace(" ", "_")
    )
    REQUEST.RESPONSE.setHeader("content-type", CSV_MIMETYPE)
    REQUEST.RESPONSE.setHeader(
        "content-disposition", 'attachment; filename="%s"' % filename
    )
    return data


def sendPDFFile(REQUEST, data, filename):
    filename = (
        unescape_html(suppress_accents(filename)).replace("&", "").replace(" ", "_")
    )
    if REQUEST:
        REQUEST.RESPONSE.setHeader("content-type", PDF_MIMETYPE)
        REQUEST.RESPONSE.setHeader(
            "content-disposition", 'attachment; filename="%s"' % filename
        )
    return data


class ScoDocJSONEncoder(json.JSONEncoder):
    def default(self, o):  # pylint: disable=E0202
        if isinstance(o, (datetime.date, datetime.datetime)):
            return o.isoformat()
        elif isinstance(o, ApoEtapeVDI):
            return str(o)
        else:
            return json.JSONEncoder.default(self, o)


def sendJSON(REQUEST, data):
    js = json.dumps(data, indent=1, cls=ScoDocJSONEncoder)
    return send_file(js, filename="sco_data.json", mime=JSON_MIMETYPE, attached=False)


def sendXML(REQUEST, data, tagname=None, force_outer_xml_tag=True):
    if type(data) != list:
        data = [data]  # always list-of-dicts
    if force_outer_xml_tag:
        data = [{tagname: data}]
        tagname += "_list"
    doc = sco_xml.simple_dictlist2xml(data, tagname=tagname)
    if REQUEST:
        REQUEST.RESPONSE.setHeader("content-type", XML_MIMETYPE)
    return doc


def sendResult(REQUEST, data, name=None, format=None, force_outer_xml_tag=True):
    if (format is None) or (format == "html"):
        return data
    elif format == "xml":  # name is outer tagname
        return sendXML(
            REQUEST, data, tagname=name, force_outer_xml_tag=force_outer_xml_tag
        )
    elif format == "json":
        return sendJSON(REQUEST, data)
    else:
        raise ValueError("invalid format: %s" % format)


def send_file(data, filename, suffix="", mime=None, attached=True):
    "Build Flask Response for file download of given type"
    if suffix:
        filename += suffix
    filename = make_filename(filename)
    response = make_response(data)
    response.headers["Content-Type"] = mime
    if attached:
        response.headers["Content-Disposition"] = 'attachment; filename="%s"' % filename
    return response


def get_scodoc_version():
    "return a string identifying ScoDoc version"
    return sco_version.SCOVERSION


def check_scodoc7_password(scodoc7_hash, password):
    """Check a password vs scodoc7 hash
    used only during old databases migrations"""
    m = md5()
    m.update(password.encode("utf-8"))
    h = base64.encodebytes(m.digest()).decode("utf-8").strip()
    return h == scodoc7_hash


# Simple string manipulations


def abbrev_prenom(prenom):
    "Donne l'abreviation d'un prenom"
    # un peu lent, mais espère traiter tous les cas
    # Jean -> J.
    # Charles -> Ch.
    # Jean-Christophe -> J.-C.
    # Marie Odile -> M. O.
    prenom = prenom.replace(".", " ").strip()
    if not prenom:
        return ""
    d = prenom[:3].upper()
    if d == "CHA":
        abrv = "Ch."  # 'Charles' donne 'Ch.'
        i = 3
    else:
        abrv = prenom[0].upper() + "."
        i = 1
    n = len(prenom)
    while i < n:
        c = prenom[i]
        if c == " " or c == "-" and i < n - 1:
            sep = c
            i += 1
            # gobbe tous les separateurs
            while i < n and (prenom[i] == " " or prenom[i] == "-"):
                if prenom[i] == "-":
                    sep = "-"
                i += 1
            if i < n:
                abrv += sep + prenom[i].upper() + "."
        i += 1
    return abrv


#
def timedate_human_repr():
    "representation du temps courant pour utilisateur: a localiser"
    return time.strftime("%d/%m/%Y à %Hh%M")


def annee_scolaire_repr(year, month):
    """representation de l'annee scolaire : '2009 - 2010'
    à partir d'une date.
    """
    if month > 7:  # apres le 1er aout
        return "%s - %s" % (year, year + 1)
    else:
        return "%s - %s" % (year - 1, year)


def annee_scolaire_debut(year, month):
    """Annee scolaire de debut (septembre): heuristique pour l'hémisphère nord..."""
    if int(month) > 7:
        return int(year)
    else:
        return int(year) - 1


def sem_decale_str(sem):
    """'D' si semestre decalé, ou ''"""
    # considère "décalé" les semestre impairs commençant entre janvier et juin
    # et les pairs entre juillet et decembre
    if sem["semestre_id"] <= 0:
        return ""
    if (sem["semestre_id"] % 2 and sem["mois_debut_ord"] <= 6) or (
        not sem["semestre_id"] % 2 and sem["mois_debut_ord"] > 6
    ):
        return "D"
    else:
        return ""


def is_valid_mail(email):
    """True if well-formed email address"""
    return re.match(r"^.+@.+\..{2,3}$", email)


def graph_from_edges(edges, graph_name="mygraph"):
    """Crée un graph pydot
    à partir d'une liste d'arêtes [ (n1, n2), (n2, n3), ... ]
    où n1, n2, ... sont des chaînes donnant l'id des nœuds.

    Fonction remplaçant celle de pydot qui est buggée.
    """
    nodes = set([it for tup in edges for it in tup])
    graph = pydot.Dot(graph_name)
    for n in nodes:
        graph.add_node(pydot.Node(n))
    for e in edges:
        graph.add_edge(pydot.Edge(src=e[0], dst=e[1]))
    return graph


ICONSIZES = {}  # name : (width, height) cache image sizes


def icontag(name, file_format="png", no_size=False, **attrs):
    """tag HTML pour un icone.
    (dans les versions anterieures on utilisait Zope)
    Les icones sont des fichiers PNG dans .../static/icons
    Si la taille (width et height) n'est pas spécifiée, lit l'image
    pour la mesurer (et cache le résultat).
    """
    if (not no_size) and (("width" not in attrs) or ("height" not in attrs)):
        if name not in ICONSIZES:
            img_file = os.path.join(
                Config.SCODOC_DIR,
                "app/static/icons/%s.%s"
                % (
                    name,
                    file_format,
                ),
            )
            im = PILImage.open(img_file)
            width, height = im.size[0], im.size[1]
            ICONSIZES[name] = (width, height)  # cache
        else:
            width, height = ICONSIZES[name]
        attrs["width"] = width
        attrs["height"] = height
    if "border" not in attrs:
        attrs["border"] = 0
    if "alt" not in attrs:
        attrs["alt"] = "logo %s" % name
    s = " ".join(['%s="%s"' % (k, attrs[k]) for k in attrs])
    return '<img class="%s" %s src="/ScoDoc/static/icons/%s.%s" />' % (
        name,
        s,
        name,
        file_format,
    )


ICON_PDF = icontag("pdficon16x20_img", title="Version PDF")
ICON_XLS = icontag("xlsicon_img", title="Version tableur")


def sort_dates(L, reverse=False):
    """Return sorted list of dates, allowing None items (they are put at the beginning)"""
    mindate = datetime.datetime(datetime.MINYEAR, 1, 1)
    try:
        return sorted(L, key=lambda x: x or mindate, reverse=reverse)
    except:
        # Helps debugging
        log("sort_dates( %s )" % L)
        raise


def query_portal(req, msg="Portail Apogee", timeout=3):
    """Retreives external data using HTTP request
    (used to connect to Apogee portal, or ScoDoc server)
    returns a string,  "" on error
    """
    log("query_portal: %s" % req)

    try:
        r = requests.get(req, timeout=timeout)  # seconds / request
    except:
        log("query_portal: can't connect to %s" % msg)
        return ""
    if r.status_code != 200:
        log(f"query_portal: http error {r.status_code}")
        return ""  # XXX ou raise exception ?

    return r.text


def AnneeScolaire(sco_year=None):
    "annee de debut de l'annee scolaire courante"
    if sco_year:
        year = sco_year
        try:
            year = int(year)
            if year > 1900 and year < 2999:
                return year
        except:
            raise sco_exceptions.ScoValueError("invalid sco_year")
    t = time.localtime()
    year, month = t[0], t[1]
    if month < 8:  # le "pivot" est le 1er aout
        year = year - 1
    return year


def return_text_if_published(val, REQUEST):
    """Pour les méthodes publiées qui ramènent soit du texte (HTML) soit du JSON
    sauf quand elles sont appellées depuis python.
    La présence de l'argument REQUEST indique la publication.
    """
    if REQUEST and not isinstance(val, str):
        return sendJSON(REQUEST, val)
    return val


def confirm_dialog(
    message="<p>Confirmer ?</p>",
    OK="OK",
    Cancel="Annuler",
    dest_url="",
    cancel_url="",
    target_variable="dialog_confirmed",
    parameters={},
    add_headers=True,  # complete page
    helpmsg=None,
):
    from app.scodoc import html_sco_header

    # dialog de confirmation simple
    parameters[target_variable] = 1
    # Attention: la page a pu etre servie en GET avec des parametres
    # si on laisse l'url "action" vide, les parametres restent alors que l'on passe en POST...
    if not dest_url:
        action = ""
    else:
        # strip remaining parameters from destination url:
        dest_url = urllib.parse.splitquery(dest_url)[0]
        action = f'action="{dest_url}"'

    H = [
        f"""<form {action} method="post">""",
        message,
        """<input type="submit" value="%s"/>""" % OK,
    ]
    if cancel_url:
        H.append(
            """<input type ="button" value="%s"
            onClick="document.location='%s';"/>"""
            % (Cancel, cancel_url)
        )
    for param in parameters.keys():
        if parameters[param] is None:
            parameters[param] = ""
        if type(parameters[param]) == type([]):
            for e in parameters[param]:
                H.append('<input type="hidden" name="%s" value="%s"/>' % (param, e))
        else:
            H.append(
                '<input type="hidden" name="%s" value="%s"/>'
                % (param, parameters[param])
            )
    H.append("</form>")
    if helpmsg:
        H.append('<p class="help">' + helpmsg + "</p>")
    if add_headers:
        return (
            html_sco_header.sco_header() + "\n".join(H) + html_sco_header.sco_footer()
        )
    else:
        return "\n".join(H)