# -*- coding: UTF-8 -*
"""
auth.cas.py
"""
import datetime

import flask
from flask import current_app, flash, url_for
from flask_login import current_user, login_user

from app import db
from app.auth import bp
from app.auth.models import User
from app.models.config import ScoDocSiteConfig
from app.scodoc import sco_excel
from app.scodoc.sco_exceptions import ScoValueError, AccessDenied
import app.scodoc.sco_utils as scu

# after_cas_login/after_cas_logout : routes appelées par redirect depuis le serveur CAS.


@bp.route("/after_cas_login")
def after_cas_login():
    "Called by CAS after CAS authentication"
    # Ici on a les infos dans flask.session["CAS_ATTRIBUTES"]
    if ScoDocSiteConfig.is_cas_enabled() and ("CAS_ATTRIBUTES" in flask.session):
        # Lookup user:
        cas_id = flask.session["CAS_ATTRIBUTES"].get(
            "cas:" + ScoDocSiteConfig.get("cas_attribute_id"),
            flask.session.get("CAS_USERNAME"),
        )
        if cas_id is not None:
            user: User = User.query.filter_by(cas_id=cas_id).first()
            if user and user.active:
                if user.cas_allow_login:
                    current_app.logger.info(f"CAS: login {user.user_name}")
                    if login_user(user):
                        flask.session[
                            "scodoc_cas_login_date"
                        ] = datetime.datetime.now().isoformat()
                        user.cas_last_login = datetime.datetime.utcnow()
                        db.session.add(user)
                        db.session.commit()
                        return flask.redirect(url_for("scodoc.index"))
                else:
                    current_app.logger.info(
                        f"CAS login denied for {user.user_name} (not allowed to use CAS)"
                    )
            else:
                current_app.logger.info(
                    f"""CAS login denied for {
                        user.user_name if user else ""
                    } cas_id={cas_id} (unknown or inactive)"""
                )
        else:
            current_app.logger.info(
                f"""CAS attribute '{ScoDocSiteConfig.get("cas_attribute_id")}' not found !
                    (check your ScoDoc config)"""
            )

    # Echec:
    flash("échec de l'authentification")
    return flask.redirect(url_for("auth.login"))


@bp.route("/after_cas_logout")
def after_cas_logout():
    "Called by CAS after CAS logout"
    flash("Vous êtes déconnecté")
    current_app.logger.info("after_cas_logout")
    return flask.redirect(url_for("scodoc.index"))


def cas_error_callback(message):
    "Called by CAS when an error occurs, with a message"
    raise ScoValueError(f"Erreur authentification CAS: {message}")


def set_cas_configuration(app: flask.app.Flask = None):
    """Force la configuration du module flask_cas à partir des paramètres de
    la config de ScoDoc.
    Appelé au démarrage et à chaque modif des paramètres.
    """
    app = app or current_app
    if ScoDocSiteConfig.is_cas_enabled():
        current_app.logger.debug("CAS: set_cas_configuration")
        app.config["CAS_SERVER"] = ScoDocSiteConfig.get("cas_server")
        app.config["CAS_LOGIN_ROUTE"] = ScoDocSiteConfig.get("cas_login_route", "/cas")
        app.config["CAS_LOGOUT_ROUTE"] = ScoDocSiteConfig.get(
            "cas_logout_route", "/cas/logout"
        )
        app.config["CAS_VALIDATE_ROUTE"] = ScoDocSiteConfig.get(
            "cas_validate_route", "/cas/serviceValidate"
        )
        app.config["CAS_AFTER_LOGIN"] = "auth.after_cas_login"
        app.config["CAS_AFTER_LOGOUT"] = "auth.after_cas_logout"
        app.config["CAS_ERROR_CALLBACK"] = cas_error_callback
        app.config["CAS_SSL_VERIFY"] = ScoDocSiteConfig.get("cas_ssl_verify")
        app.config["CAS_SSL_CERTIFICATE"] = ScoDocSiteConfig.get("cas_ssl_certificate")
    else:
        app.config.pop("CAS_SERVER", None)
        app.config.pop("CAS_AFTER_LOGIN", None)
        app.config.pop("CAS_AFTER_LOGOUT", None)
        app.config.pop("CAS_SSL_VERIFY", None)
        app.config.pop("CAS_SSL_CERTIFICATE", None)


CAS_USER_INFO_IDS = (
    "user_name",
    "nom",
    "prenom",
    "email",
    "roles_string",
    "active",
    "dept",
    "cas_id",
    "cas_allow_login",
    "cas_allow_scodoc_login",
)
CAS_USER_INFO_COMMENTS = (
    """user_name:
    L'identifiant (login).
    """,
    "",
    "",
    "",
    "Pour info: 0 si compte inactif",
    """Pour info: roles:
    chaînes séparées par _:
    1. Le rôle (Ens, Secr ou Admin)
    2. Le département (en majuscule)
    """,
    """dept:
    Le département d'appartenance de l'utilisateur. Vide si l'utilisateur
    intervient dans plusieurs départements.
    """,
    """cas_id:
    identifiant de l'utilisateur sur CAS (requis pour CAS).
    """,
    """cas_allow_login:
    autorise la connexion via CAS (optionnel, faux par défaut)
    """,
    """cas_allow_scodoc_login
    autorise connexion via ScoDoc même si CAS obligatoire (optionnel, faux par défaut)
    """,
)


def cas_users_generate_excel_sample() -> bytes:
    """generate an excel document suitable to import users CAS information"""
    style = sco_excel.excel_make_style(bold=True)
    titles = CAS_USER_INFO_IDS
    titles_styles = [style] * len(titles)
    # Extrait tous les utilisateurs (tous dept et statuts)
    rows = []
    for user in User.query.order_by(User.user_name):
        u_dict = user.to_dict()
        rows.append([u_dict.get(k) for k in CAS_USER_INFO_IDS])
    return sco_excel.excel_simple_table(
        lines=rows,
        titles=titles,
        titles_styles=titles_styles,
        sheet_name="Utilisateurs ScoDoc",
        comments=CAS_USER_INFO_COMMENTS,
    )


def cas_users_import_excel_file(datafile) -> int:
    """
    Import users CAS configuration from Excel file.
    May change cas_id, cas_allow_login, cas_allow_scodoc_login
    :param datafile:  stream to be imported
    :return: nb de comptes utilisateurs modifiés
    """
    from app.scodoc import sco_import_users

    if not current_user.is_administrator():
        raise AccessDenied(f"invalid user ({current_user}) must be SuperAdmin")
    current_app.logger.info("cas_users_import_excel_file by {current_user}")

    users_infos = sco_import_users.read_users_excel_file(
        datafile, titles=CAS_USER_INFO_IDS
    )

    return cas_users_import_data(users_infos=users_infos)


def cas_users_import_data(users_infos: list[dict]) -> int:
    """Import informations configuration CAS
    users est une liste de dict, on utilise seulement les champs:
    - user_name : la clé, l'utilisateur DOIT déjà exister
    - cas_id : l'ID CAS a enregistrer.
    - cas_allow_login
    - cas_allow_scodoc_login
    Les éventuels autres champs sont ignorés.

    Return: nb de comptes modifiés.
    """
    nb_modif = 0
    users = []
    for info in users_infos:
        user: User = User.query.filter_by(user_name=info["user_name"]).first()
        if not user:
            return False, f"utilisateur {info['user_name']} inexistant", 0
        modif = False
        if info["cas_id"].strip() != (user.cas_id or ""):
            user.cas_id = info["cas_id"].strip() or None
            modif = True
        val = scu.to_bool(info["cas_allow_login"])
        if val != user.cas_allow_login:
            user.cas_allow_login = val
            modif = True
        val = scu.to_bool(info["cas_allow_scodoc_login"])
        if val != user.cas_allow_scodoc_login:
            user.cas_allow_scodoc_login = val
            modif = True
        if modif:
            nb_modif += 1
    # Record modifications
    for user in users:
        try:
            db.session.add(user)
        except Exception as exc:
            db.session.rollback()
            raise ScoValueError(
                "Erreur (1) durant l'importation des modifications"
            ) from exc
    try:
        db.session.commit()
    except Exception as exc:
        db.session.rollback()
        raise ScoValueError(
            "Erreur (2) durant l'importation des modifications"
        ) from exc
    return nb_modif