"""
Script de migration des données de la base "absences" -> "assiduites"/"justificatifs"

Ecrit par Matthias HARTMANN
"""
from datetime import date, datetime, time, timedelta
from json import dump, dumps
from sqlalchemy import not_

from flask import g

from app import db
from app.models import (
    Absence,
    Assiduite,
    Departement,
    Identite,
    Justificatif,
    ModuleImplInscription,
)

from app.models.config import ScoDocSiteConfig

from app.models.assiduites import (
    compute_assiduites_justified,
)
from app.profiler import Profiler
from app.scodoc.sco_utils import (
    EtatAssiduite,
    EtatJustificatif,
    TerminalColor,
    localize_datetime,
    print_progress_bar,
)
from app.scodoc import notesdb as ndb


class _glob:
    """variables globales du script"""

    DEBUG: bool = False
    PROBLEMS: dict[int, list[str]] = {}
    DEPT_ETUDIDS: dict[int, Identite] = {}
    COMPTE: list[int, int] = []
    ERR_ETU: list[int] = []
    MERGER_ASSI: "_Merger" = None
    MERGER_JUST: "_Merger" = None

    MORNING: time = None
    NOON: time = None
    EVENING: time = None


class _Merger:
    def __init__(self, abs_: Absence, est_abs: bool) -> None:
        self.deb = (abs_.jour, abs_.matin)
        self.fin = (abs_.jour, abs_.matin)
        self.moduleimpl = abs_.moduleimpl_id
        self.etudid = abs_.etudid
        self.est_abs = est_abs
        self.raison = abs_.description
        self.entry_date = abs_.entry_date

    def merge(self, abs_: Absence) -> bool:
        """Fusionne les absences.
        Return False si pas de fusion.
        """

        if self.etudid != abs_.etudid:
            return False

        # Cas d'une même absence enregistrée plusieurs fois
        if self.fin == (abs_.jour, abs_.matin):
            self.moduleimpl = None
        else:
            if self.fin[1]:
                if abs_.jour != self.fin[0]:
                    return False
            else:
                day_after: date = abs_.jour - timedelta(days=1) == self.fin[0]
                if not (day_after and abs_.matin):
                    return False

        self.fin = (abs_.jour, abs_.matin)
        return True

    @staticmethod
    def _tuple_to_date(couple: tuple[date, bool], end=False):
        if couple[1]:
            time_ = _glob.NOON if end else _glob.MORNING
            date_ = datetime.combine(couple[0], time_)
        else:
            time_ = _glob.EVENING if end else _glob.NOON
            date_ = datetime.combine(couple[0], time_)
        d = localize_datetime(date_)
        return d

    def _to_justif(self):
        date_deb = _Merger._tuple_to_date(self.deb)
        date_fin = _Merger._tuple_to_date(self.fin, end=True)

        _glob.cursor.execute(
            """INSERT INTO justificatifs
            (etudid,date_debut,date_fin,etat,raison,entry_date)
            VALUES (%(etudid)s,%(date_debut)s,%(date_fin)s,%(etat)s,%(raison)s,%(entry_date)s)
            """,
            {
                "etudid": self.etudid,
                "date_debut": date_deb,
                "date_fin": date_fin,
                "etat": EtatJustificatif.VALIDE,
                "raison": self.raison,
                "entry_date": self.entry_date,
            },
        )
        # retour = Justificatif.fast_create_justificatif(
        #     etudid=self.etudid,
        #     date_debut=date_deb,
        #     date_fin=date_fin,
        #     etat=EtatJustificatif.VALIDE,
        #     raison=self.raison,
        #     entry_date=self.entry_date,
        # )
        # return retour

    def _to_assi(self):
        date_deb = _Merger._tuple_to_date(self.deb)
        date_fin = _Merger._tuple_to_date(self.fin, end=True)

        _glob.cursor.execute(
            """INSERT INTO assiduites
            (etudid,date_debut,date_fin,etat,moduleimpl_id,"description",entry_date)
            VALUES (%(etudid)s,%(date_debut)s,%(date_fin)s,%(etat)s,%(moduleimpl_id)s,%(description)s,%(entry_date)s)
            """,
            {
                "etudid": self.etudid,
                "date_debut": date_deb,
                "date_fin": date_fin,
                "etat": EtatAssiduite.ABSENT,
                "moduleimpl_id": self.moduleimpl,
                "description": self.raison,
                "entry_date": self.entry_date,
            },
        )

        # retour = Assiduite.fast_create_assiduite(
        #     etudid=self.etudid,
        #     date_debut=date_deb,
        #     date_fin=date_fin,
        #     etat=EtatAssiduite.ABSENT,
        #     moduleimpl_id=self.moduleimpl,
        #     description=self.raison,
        #     entry_date=self.entry_date,
        # )
        # return retour

    def export(self):
        """Génère un nouvel objet Assiduité ou Justificatif"""
        obj: Assiduite or Justificatif = None
        if self.est_abs:
            _glob.COMPTE[0] += 1
            self._to_assi()
        else:
            _glob.COMPTE[1] += 1
            self._to_justif()


class _Statistics:
    def __init__(self) -> None:
        self.object: dict[str, dict or int] = {"total": 0}
        self.year: int = None

    def __set_year(self, year: int):
        if year not in self.object:
            self.object[year] = {
                "etuds_inexistant": [],
                "abs_invalide": {},
            }
        self.year = year
        return self

    def __add_etud(self, etudid: int):
        if etudid not in self.object[self.year]["etuds_inexistant"]:
            self.object[self.year]["etuds_inexistant"].append(etudid)
        return self

    def __add_abs(self, abs_: int, err: str):
        if abs_ not in self.object[self.year]["abs_invalide"]:
            self.object[self.year]["abs_invalide"][abs_] = [err]
        else:
            self.object[self.year]["abs_invalide"][abs_].append(err)

        return self

    def add_problem(self, abs_: Absence, err: str):
        """Ajoute un nouveau problème dans les statistiques"""
        abs_.jour: date
        pivot: date = date(abs_.jour.year, 9, 15)
        year: int = abs_.jour.year
        if pivot < abs_.jour:
            year += 1
        self.__set_year(year)

        if err == "Etudiant inexistant":
            self.__add_etud(abs_.etudid)
        else:
            self.__add_abs(abs_.id, err)

        self.object["total"] += 1

    def compute_stats(self) -> dict:
        """Comptage des statistiques"""
        stats: dict = {"total": self.object["total"]}
        for year, item in self.object.items():
            if year == "total":
                continue

            stats[year] = {}
            stats[year]["etuds_inexistant"] = len(item["etuds_inexistant"])
            stats[year]["abs_invalide"] = len(item["abs_invalide"])

        return stats

    def export(self, file):
        """Sérialise les statistiques dans un fichier"""
        dump(self.object, file, indent=2)


def migrate_abs_to_assiduites(
    dept: str = None,
    morning: str = None,
    noon: str = None,
    evening: str = None,
    debug: bool = False,
):
    """
    une absence à 3 états:

    |.estabs|.estjust|
    |1|0| -> absence non justifiée
    |1|1| -> absence justifiée
    |0|1| -> justifié

    dualité des temps :

    .matin: bool (0:00 -> time_pref | time_pref->23:59:59)
    .jour : date (jour de l'absence/justificatif)
    .moduleimpl_id: relation -> moduleimpl_id
    description:str -> motif abs / raison justif

    .entry_date: datetime -> timestamp d'entrée de l'abs
    .etudid: relation -> Identite
    """
    Profiler.clear()

    _glob.DEBUG = debug

    if morning is None:
        morning = ScoDocSiteConfig.get("assi_morning_time", time(8, 0))

    morning: list[str] = str(morning).split(":")
    _glob.MORNING = time(int(morning[0]), int(morning[1]))

    if noon is None:
        noon = ScoDocSiteConfig.get("assi_lunch_time", time(13, 0))

    noon: list[str] = str(noon).split(":")
    _glob.NOON = time(int(noon[0]), int(noon[1]))

    if evening is None:
        evening = ScoDocSiteConfig.get("assi_afternoon_time", time(18, 0))

    evening: list[str] = str(evening).split(":")
    _glob.EVENING = time(int(evening[0]), int(evening[1]))

    ndb.open_db_connection()
    _glob.cnx = g.db_conn
    _glob.cursor = _glob.cnx.cursor()

    if dept is None:
        prof_total = Profiler("MigrationTotal")
        prof_total.start()
        depart: Departement
        for depart in Departement.query.order_by(Departement.id):
            migrate_dept(
                depart.acronym, _Statistics(), Profiler(f"Migration_{depart.acronym}")
            )
        prof_total.stop()

        print(
            TerminalColor.GREEN
            + f"Fin de la migration, elle a durée {prof_total.elapsed():.2f}"
            + TerminalColor.RESET
        )

    else:
        migrate_dept(dept, _Statistics(), Profiler("Migration"))


def migrate_dept(dept_name: str, stats: _Statistics, time_elapsed: Profiler):
    time_elapsed.start()

    absences_query = Absence.query
    dept: Departement = Departement.query.filter_by(acronym=dept_name).first()

    if dept is None:
        raise ValueError(f"Département inexistant: {dept_name}")

    etuds_id: list[int] = [etud.id for etud in dept.etudiants]
    absences_query = absences_query.filter(Absence.etudid.in_(etuds_id))
    absences: Absence = absences_query.order_by(
        Absence.etudid, Absence.jour, not_(Absence.matin)
    )

    absences_len: int = absences.count()

    if absences_len == 0:
        print(
            f"{TerminalColor.BLUE}Le département {dept_name} ne possède aucune absence.{TerminalColor.RESET}"
        )
        return

    _glob.DEPT_ETUDIDS = {e.id for e in Identite.query.filter_by(dept_id=dept.id)}
    _glob.COMPTE = [0, 0]
    _glob.ERR_ETU = []
    _glob.MERGER_ASSI = None
    _glob.MERGER_JUST = None

    print(
        f"{TerminalColor.BLUE}{absences_len} absences du département {dept_name} vont être migrées{TerminalColor.RESET}"
    )

    print_progress_bar(0, absences_len, "Progression", "effectué", autosize=True)

    etuds_modimpl_ids = {}
    for i, abs_ in enumerate(absences):
        etud_modimpl_ids = etuds_modimpl_ids.get(abs_.etudid)
        if etud_modimpl_ids is None:
            etud_modimpl_ids = {
                ins.moduleimpl_id
                for ins in ModuleImplInscription.query.filter_by(etudid=abs_.etudid)
            }
            etuds_modimpl_ids[abs_.etudid] = etud_modimpl_ids
        try:
            _from_abs_to_assiduite_justificatif(abs_, etud_modimpl_ids)
        except ValueError as e:
            stats.add_problem(abs_, e.args[0])

        if i % 10 == 0:
            print_progress_bar(
                i,
                absences_len,
                "Progression",
                "effectué",
                autosize=True,
            )

        if i % 1000 == 0:
            print_progress_bar(
                i,
                absences_len,
                "Progression",
                "effectué",
                autosize=True,
            )
            _glob.cnx.commit()

    if _glob.MERGER_ASSI is not None:
        _glob.MERGER_ASSI.export()
    if _glob.MERGER_JUST is not None:
        _glob.MERGER_JUST.export()

    _glob.cnx.commit()

    print_progress_bar(
        absences_len,
        absences_len,
        "Progression",
        "effectué",
        autosize=True,
    )

    print(
        TerminalColor.RED
        + f"Justification des absences du département {dept_name}, veuillez patienter, ceci peut prendre un certain temps."
        + TerminalColor.RESET
    )

    justifs: Justificatif = Justificatif.query.join(Identite).filter_by(dept_id=dept.id)
    compute_assiduites_justified(justifs, reset=True)

    time_elapsed.stop()

    statistiques: dict = stats.compute_stats()
    print(
        f"{TerminalColor.GREEN}La migration a pris {time_elapsed.elapsed():.2f} secondes {TerminalColor.RESET}"
    )

    filename = f"/opt/scodoc-data/log/{datetime.now().strftime('%Y-%m-%dT%H:%M:%S')}scodoc_migration_abs_{dept_name}.json"
    if statistiques["total"] > 0:
        print(
            f"{TerminalColor.RED}{statistiques['total']} absences qui n'ont pas pu être migrées."
        )
        print(
            f"Vous retrouverez un fichier json {TerminalColor.GREEN}{filename}{TerminalColor.RED} contenant les problèmes de migrations"
        )

    with open(
        filename,
        "w",
        encoding="utf-8",
    ) as file:
        stats.export(file)

    print(
        f"{TerminalColor.CYAN}{_glob.COMPTE[0]} assiduités et {_glob.COMPTE[1]} justificatifs ont été générés pour le département {dept_name}.{TerminalColor.RESET}"
    )

    if _glob.DEBUG:
        print(dumps(statistiques, indent=2))


def _from_abs_to_assiduite_justificatif(_abs: Absence, etud_modimpl_ids: set[int]):
    if _abs.etudid not in _glob.DEPT_ETUDIDS:
        raise ValueError("Etudiant inexistant")

    if _abs.estabs:
        if (_abs.moduleimpl_id is not None) and (
            _abs.moduleimpl_id not in etud_modimpl_ids
        ):
            raise ValueError("Moduleimpl_id incorrect ou étudiant non inscrit")

        if _glob.MERGER_ASSI is None:
            _glob.MERGER_ASSI = _Merger(_abs, True)
            return True
        elif _glob.MERGER_ASSI.merge(_abs):
            return True
        else:
            _glob.MERGER_ASSI.export()
            _glob.MERGER_ASSI = _Merger(_abs, True)
            return False

    if _glob.MERGER_JUST is None:
        _glob.MERGER_JUST = _Merger(_abs, False)
        return True
    elif _glob.MERGER_JUST.merge(_abs):
        return True
    else:
        _glob.MERGER_JUST.export()
        _glob.MERGER_JUST = _Merger(_abs, False)
        return False