# -*- coding: utf-8 -*-
from smtplib import SMTPException

import transaction
import typing as typing

from sqlalchemy import or_
from sqlalchemy.orm import Session
from sqlalchemy.orm import Query
from sqlalchemy.orm.exc import NoResultFound

from tracim_backend.config import CFG
from tracim_backend.models.auth import User
from tracim_backend.models.auth import Group
from tracim_backend.exceptions import NoUserSetted
from tracim_backend.exceptions import EmailAlreadyExistInDb
from tracim_backend.exceptions import TooShortAutocompleteString
from tracim_backend.exceptions import PasswordDoNotMatch
from tracim_backend.exceptions import EmailValidationFailed
from tracim_backend.exceptions import UserDoesNotExist
from tracim_backend.exceptions import WrongUserPassword
from tracim_backend.exceptions import AuthenticationFailed
from tracim_backend.exceptions import NotificationNotSend
from tracim_backend.exceptions import UserNotActive
from tracim_backend.models.context_models import UserInContext
from tracim_backend.lib.mail_notifier.notifier import get_email_manager
from tracim_backend.models.context_models import TypeUser
from tracim_backend.models.data import UserRoleInWorkspace


class UserApi(object):

    def __init__(
            self,
            current_user: typing.Optional[User],
            session: Session,
            config: CFG,
            show_deleted: bool = False,
    ) -> None:
        self._session = session
        self._user = current_user
        self._config = config
        self._show_deleted = show_deleted

    def _base_query(self):
        query = self._session.query(User)
        if not self._show_deleted:
            query = query.filter(User.is_deleted == False)
        return query

    def get_user_with_context(self, user: User) -> UserInContext:
        """
        Return UserInContext object from User
        """
        user = UserInContext(
            user=user,
            dbsession=self._session,
            config=self._config,
        )
        return user

    # Getters

    def get_one(self, user_id: int) -> User:
        """
        Get one user by user id
        """
        try:
            user = self._base_query().filter(User.user_id == user_id).one()
        except NoResultFound as exc:
            raise UserDoesNotExist('User "{}" not found in database'.format(user_id)) from exc  # nopep8
        return user

    def get_one_by_email(self, email: str) -> User:
        """
        Get one user by email
        :param email: Email of the user
        :return: one user
        """
        try:
            user = self._base_query().filter(User.email == email).one()
        except NoResultFound as exc:
            raise UserDoesNotExist('User "{}" not found in database'.format(email)) from exc  # nopep8
        return user

    def get_one_by_public_name(self, public_name: str) -> User:
        """
        Get one user by public_name
        """
        try:
            user = self._base_query().filter(User.display_name == public_name).one()
        except NoResultFound as exc:
            raise UserDoesNotExist('User "{}" not found in database'.format(public_name)) from exc  # nopep8
        return user
    # FIXME - G.M - 24-04-2018 - Duplicate method with get_one.

    def get_one_by_id(self, id: int) -> User:
        return self.get_one(user_id=id)

    def get_current_user(self) -> User:
        """
        Get current_user
        """
        if not self._user:
            raise UserDoesNotExist('There is no current user')
        return self._user

    def _get_all_query(self) -> Query:
        return self._session.query(User).order_by(User.display_name)

    def get_all(self) -> typing.Iterable[User]:
        return self._get_all_query().all()

    def get_known_user(
            self,
            acp: str,
    ) -> typing.Iterable[User]:
        """
        Return list of know user by current UserApi user.
        :param acp: autocomplete filter by name/email
        :return: List of found users
        """
        if len(acp) < 2:
            raise TooShortAutocompleteString(
                '"{acp}" is a too short string, acp string need to have more than one character'.format(acp=acp)  # nopep8
            )
        query = self._get_all_query()
        query = query.filter(or_(User.display_name.ilike('%{}%'.format(acp)), User.email.ilike('%{}%'.format(acp))))  # nopep8

        # INFO - G.M - 2018-07-27 - if user is set and is simple user, we
        # should show only user in same workspace as user
        if self._user and self._user.profile.id <= Group.TIM_USER:
            user_workspaces_id_query = self._session.\
                query(UserRoleInWorkspace.workspace_id).\
                distinct(UserRoleInWorkspace.workspace_id).\
                filter(UserRoleInWorkspace.user_id == self._user.user_id)
            users_in_workspaces = self._session.\
                query(UserRoleInWorkspace.user_id).\
                distinct(UserRoleInWorkspace.user_id).\
                filter(UserRoleInWorkspace.workspace_id.in_(user_workspaces_id_query.subquery())).subquery()  # nopep8
            query = query.filter(User.user_id.in_(users_in_workspaces))
        return query.all()

    def find(
            self,
            user_id: int=None,
            email: str=None,
            public_name: str=None
    ) -> typing.Tuple[TypeUser, User]:
        """
        Find existing user from all theses params.
        Check is made in this order: user_id, email, public_name
        If no user found raise UserDoesNotExist exception
        """
        user = None

        if user_id:
            try:
                user = self.get_one(user_id)
                return TypeUser.USER_ID, user
            except UserDoesNotExist:
                pass
        if email:
            try:
                user = self.get_one_by_email(email)
                return TypeUser.EMAIL, user
            except UserDoesNotExist:
                pass
        if public_name:
            try:
                user = self.get_one_by_public_name(public_name)
                return TypeUser.PUBLIC_NAME, user
            except UserDoesNotExist:
                pass

        raise UserDoesNotExist('User not found with any of given params.')

    # Check methods

    def user_with_email_exists(self, email: str) -> bool:
        try:
            self.get_one_by_email(email)
            return True
        # TODO - G.M - 09-04-2018 - Better exception
        except:
            return False

    def authenticate_user(self, email: str, password: str) -> User:
        """
        Authenticate user with email and password, raise AuthenticationFailed
        if uncorrect.
        :param email: email of the user
        :param password: cleartext password of the user
        :return: User who was authenticated.
        """
        try:
            user = self.get_one_by_email(email)
            if not user.is_active:
                raise UserNotActive('User "{}" is not active'.format(email))
            if user.validate_password(password):
                return user
            else:
                raise WrongUserPassword('User "{}" password is incorrect'.format(email))  # nopep8
        except (WrongUserPassword, UserDoesNotExist) as exc:
            raise AuthenticationFailed('User "{}" authentication failed'.format(email)) from exc  # nopep8

    # Actions
    def set_password(
            self,
            user: User,
            loggedin_user_password: str,
            new_password: str,
            new_password2: str,
            do_save: bool=True
    ):
        """
        Set User password if loggedin user password is correct
        and both new_password are the same.
        :param user: User who need password changed
        :param loggedin_user_password: cleartext password of logged user (not
        same as user)
        :param new_password: new password for user
        :param new_password2: should be same as new_password
        :param do_save: should we save new user password ?
        :return:
        """
        if not self._user:
            raise NoUserSetted('Current User should be set in UserApi to use this method')  # nopep8
        if not self._user.validate_password(loggedin_user_password):  # nopep8
            raise WrongUserPassword(
                'Wrong password for authenticated user {}'. format(self._user.user_id)  # nopep8
            )
        if new_password != new_password2:
            raise PasswordDoNotMatch('Passwords given are different')

        self.update(
            user=user,
            password=new_password,
            do_save=do_save,
        )
        if do_save:
            # TODO - G.M - 2018-07-24 - Check why commit is needed here
            self.save(user)
        return user

    def set_email(
            self,
            user: User,
            loggedin_user_password: str,
            email: str,
            do_save: bool = True
    ):
        """
        Set email address of user if loggedin user password is correct
        :param user: User who need email changed
        :param loggedin_user_password: cleartext password of logged user (not
        same as user)
        :param email:
        :param do_save:
        :return:
        """
        if not self._user:
            raise NoUserSetted('Current User should be set in UserApi to use this method')  # nopep8
        if not self._user.validate_password(loggedin_user_password):  # nopep8
            raise WrongUserPassword(
                'Wrong password for authenticated user {}'. format(self._user.user_id)  # nopep8
            )
        self.update(
            user=user,
            email=email,
            do_save=do_save,
        )
        return user

    def _check_email(self, email: str) -> bool:
        """
        Check if email is completely ok to be used in user db table
        """
        is_email_correct = self._check_email_correctness(email)
        if not is_email_correct:
            raise EmailValidationFailed(
                'Email given form {} is uncorrect'.format(email))  # nopep8
        email_already_exist_in_db = self.check_email_already_in_db(email)
        if email_already_exist_in_db:
            raise EmailAlreadyExistInDb(
                'Email given {} already exist, please choose something else'.format(email)  # nopep8
            )
        return True

    def check_email_already_in_db(self, email: str) -> bool:
        """
        Verify if given email does not already exist in db
        """
        return self._session.query(User.email).filter(User.email==email).count() != 0  # nopep8

    def _check_email_correctness(self, email: str) -> bool:
        """
           Verify if given email is correct:
           - check format
           - futur active check for email ? (dns based ?)
           """
        # TODO - G.M - 2018-07-05 - find a better way to check email
        if not email:
            return False
        email = email.split('@')
        if len(email) != 2:
            return False
        return True

    def update(
            self,
            user: User,
            name: str=None,
            email: str=None,
            password: str=None,
            timezone: str=None,
            groups: typing.Optional[typing.List[Group]]=None,
            do_save=True,
    ) -> User:
        if name is not None:
            user.display_name = name

        if email is not None and email != user.email:
            self._check_email(email)
            user.email = email

        if password is not None:
            user.password = password

        if timezone is not None:
            user.timezone = timezone

        if groups is not None:
            # INFO - G.M - 2018-07-18 - Delete old groups
            for group in user.groups:
                if group not in groups:
                    user.groups.remove(group)
            # INFO - G.M - 2018-07-18 - add new groups
            for group in groups:
                if group not in user.groups:
                    user.groups.append(group)

        if do_save:
            self.save(user)

        return user

    def create_user(
        self,
        email,
        password: str = None,
        name: str = None,
        timezone: str = '',
        groups=[],
        do_save: bool=True,
        do_notify: bool=True,
    ) -> User:
        new_user = self.create_minimal_user(email, groups, save_now=False)
        self.update(
            user=new_user,
            name=name,
            email=email,
            password=password,
            timezone=timezone,
            do_save=False,
        )
        if do_notify:
            try:
                email_manager = get_email_manager(self._config, self._session)
                email_manager.notify_created_account(
                    new_user,
                    password=password
                )
            except SMTPException as e:
                raise NotificationNotSend()
        if do_save:
            self.save(new_user)
        return new_user

    def create_minimal_user(
            self,
            email,
            groups=[],
            save_now=False
    ) -> User:
        """Previous create_user method"""
        self._check_email(email)
        user = User()
        user.email = email
        user.display_name = email.split('@')[0]

        for group in groups:
            user.groups.append(group)

        self._session.add(user)

        if save_now:
            self._session.flush()

        return user

    def enable(self, user: User, do_save=False):
        user.is_active = True
        if do_save:
            self.save(user)

    def disable(self, user:User, do_save=False):
        user.is_active = False
        if do_save:
            self.save(user)

    def delete(self, user: User, do_save=False):
        user.is_deleted = True
        if do_save:
            self.save(user)

    def undelete(self, user: User, do_save=False):
        user.is_deleted = False
        if do_save:
            self.save(user)

    def save(self, user: User):
        self._session.flush()

    def execute_created_user_actions(self, created_user: User) -> None:
        """
        Execute actions when user just been created
        :return:
        """
        # NOTE: Cyclic import
        # TODO - G.M - 28-03-2018 - [Calendar] Reenable Calendar stuff
        #from tracim.lib.calendar import CalendarManager
        #from tracim.model.organisational import UserCalendar

        # TODO - G.M - 04-04-2018 - [auth]
        # Check if this is already needed with
        # new auth system
        created_user.ensure_auth_token(
            session=self._session,
            validity_seconds=self._config.USER_AUTH_TOKEN_VALIDITY
        )

        # Ensure database is up-to-date
        self._session.flush()
        transaction.commit()

        # TODO - G.M - 28-03-2018 - [Calendar] Reenable Calendar stuff
        # calendar_manager = CalendarManager(created_user)
        # calendar_manager.create_then_remove_fake_event(
        #     calendar_class=UserCalendar,
        #     related_object_id=created_user.user_id,
        # )