from random import choice
from string import ascii_letters, digits

from flask import flash
from flask_security import current_user

from advlabdb import db
from advlabdb.models import Semester


def randomPassword():
    return "".join(choice(ascii_letters + digits) for i in range(12))


def userActiveSemester(flashWarning=False):
    lastSemesterId = (
        Semester.query.order_by(Semester.year.desc()).order_by(Semester.label.desc()).first().id
    )  # "WS" > "SS"
    if current_user.active_semester_id is None:
        current_user.active_semester_id = lastSemesterId
        db.session.commit()
    elif current_user.active_semester_id != lastSemesterId:
        activeSemester = Semester.query.get(current_user.active_semester_id)
        if activeSemester:
            if flashWarning:
                flash(f"You are in the old semester {activeSemester.repr()}!", "warning")
        else:
            current_user.active_semester_id = lastSemesterId
            db.session.commit()
            flash("Semester changed!", "warning")

    return Semester.query.get(current_user.active_semester_id)


def setUserActiveSemester(semesterId):
    if current_user.active_semester_id != semesterId:
        semester = Semester.query.get(semesterId)
        if semester:
            try:
                current_user.active_semester_id = semesterId
                db.session.commit()
            except Exception as ex:
                flash(str(ex), "error")

                db.session.rollback()
            else:
                flash(f"Active semester changed to {semester.repr()}!", "warning")
        else:
            flash(f"No semester with ID {semesterId}!", "error")