# -*- coding: utf-8 -*-

"""
 (c) 2014-2017 - Copyright Red Hat Inc

 Authors:
   Pierre-Yves Chibon <pingou@pingoured.fr>
   Farhaan Bukhsh <farhaan.bukhsh@gmail.com>

"""

from __future__ import absolute_import, unicode_literals

import datetime
import logging

import flask
from six.moves.urllib.parse import urljoin
from sqlalchemy.exc import SQLAlchemyError

import pagure.config
import pagure.lib.login
import pagure.lib.model as model
import pagure.lib.model_base
import pagure.lib.notify
import pagure.lib.query
import pagure.login_forms as forms
from pagure.lib.login import check_password, generate_hashed_value
from pagure.ui import UI_NS
from pagure.utils import login_required

_log = logging.getLogger(__name__)


@UI_NS.route("/user/new/", methods=["GET", "POST"])
@UI_NS.route("/user/new", methods=["GET", "POST"])
def new_user():
    """Create a new user."""
    if not pagure.config.config.get("ALLOW_USER_REGISTRATION", True):
        flask.flash("User registration is disabled.", "error")
        return flask.redirect(flask.url_for("auth_login"))
    form = forms.NewUserForm()
    if form.validate_on_submit():

        username = form.user.data
        if pagure.lib.query.search_user(flask.g.session, username=username):
            flask.flash("Username already taken.", "error")
            return flask.redirect(flask.request.url)

        email = form.email_address.data
        if pagure.lib.query.search_user(flask.g.session, email=email):
            flask.flash("Email address already taken.", "error")
            return flask.redirect(flask.request.url)

        form.password.data = generate_hashed_value(form.password.data)

        token = pagure.lib.login.id_generator(40)

        user = model.User()
        user.token = token
        form.populate_obj(obj=user)
        user.default_email = form.email_address.data
        flask.g.session.add(user)
        flask.g.session.flush()

        try:
            pagure.lib.query.add_email_to_user(
                flask.g.session, user, form.email_address.data
            )
            flask.g.session.commit()
            send_confirmation_email(user)
            flask.flash(
                "User created, please check your email to activate the "
                "account"
            )
        except pagure.exceptions.PagureException as err:
            flask.flash(str(err), "error")
            _log.exception(err)
        except SQLAlchemyError:  # pragma: no cover
            flask.g.session.rollback()
            flask.flash("Could not create user.")
            _log.exception("Could not create user.")

        return flask.redirect(flask.url_for("auth_login"))

    return flask.render_template("login/user_new.html", form=form)


@UI_NS.route("/dologin", methods=["POST"])
def do_login():
    """Log in the user."""
    logout()

    form = forms.LoginForm()
    next_url = flask.request.form.get("next_url")
    if not next_url or next_url == "None":
        next_url = flask.url_for("ui_ns.index")
    else:
        next_url = urljoin(flask.request.host_url, next_url)

    if form.validate_on_submit():
        username = form.username.data
        try:
            pagure.lib.login.check_username_and_password(
                flask.g.session, username, form.password.data
            )
        except pagure.exceptions.PagureException as ex:
            _log.exception(ex)
            flask.flash(str(ex), "error")
            return flask.redirect(flask.url_for("auth_login"))

        user_obj = pagure.lib.query.search_user(
            flask.g.session, username=username
        )
        visit_key = pagure.lib.login.id_generator(40)
        now = datetime.datetime.utcnow()
        expiry = now + datetime.timedelta(days=30)
        session = model.PagureUserVisit(
            user_id=user_obj.id,
            user_ip=flask.request.remote_addr,
            visit_key=visit_key,
            expiry=expiry,
        )
        flask.g.session.add(session)
        try:
            flask.g.session.commit()
            flask.g.fas_user = user_obj
            flask.g.fas_session_id = visit_key
            flask.g.fas_user.login_time = now
            flask.flash("Welcome %s" % user_obj.username)
        except SQLAlchemyError as err:  # pragma: no cover
            flask.flash(
                "Could not set the session in the db, "
                "please report this error to an admin",
                "error",
            )
            _log.exception(err)

        return flask.redirect(next_url)
    else:
        flask.flash("Insufficient information provided", "error")
    return flask.redirect(flask.url_for("auth_login"))


@UI_NS.route("/confirm/<token>/")
@UI_NS.route("/confirm/<token>")
def confirm_user(token):
    """Confirm a user account."""
    user_obj = pagure.lib.query.search_user(flask.g.session, token=token)
    if not user_obj:
        flask.flash("No user associated with this token.", "error")
    else:
        user_obj.token = None
        flask.g.session.add(user_obj)

        try:
            flask.g.session.commit()
            flask.flash("Email confirmed, account activated")
            return flask.redirect(flask.url_for("auth_login"))
        except SQLAlchemyError as err:  # pragma: no cover
            flask.flash(
                "Could not set the account as active in the db, "
                "please report this error to an admin",
                "error",
            )
            _log.exception(err)

    return flask.redirect(flask.url_for("ui_ns.index"))


@UI_NS.route("/password/lost/", methods=["GET", "POST"])
@UI_NS.route("/password/lost", methods=["GET", "POST"])
def lost_password():
    """Method to allow a user to change his/her password assuming the email
    is not compromised.
    """
    form = forms.LostPasswordForm()
    if form.validate_on_submit():

        username = form.username.data
        user_obj = pagure.lib.query.search_user(
            flask.g.session, username=username
        )
        if not user_obj:
            flask.flash("Username invalid.", "error")
            return flask.redirect(flask.url_for("auth_login"))
        elif user_obj.token:
            current_time = datetime.datetime.utcnow()
            invalid_period = user_obj.updated_on + datetime.timedelta(
                minutes=3
            )
            if current_time < invalid_period:
                flask.flash(
                    "An email was sent to you less than 3 minutes ago, "
                    "did you check your spam folder? Otherwise, "
                    "try again after some time.",
                    "error",
                )
                return flask.redirect(flask.url_for("auth_login"))

        token = pagure.lib.login.id_generator(40)
        user_obj.token = token
        flask.g.session.add(user_obj)

        try:
            flask.g.session.commit()
            send_lostpassword_email(user_obj)
            flask.flash("Check your email to finish changing your password")
        except SQLAlchemyError:  # pragma: no cover
            flask.g.session.rollback()
            flask.flash(
                "Could not set the token allowing changing a password.",
                "error",
            )
            _log.exception("Password lost change - Error setting token.")

        return flask.redirect(flask.url_for("auth_login"))

    return flask.render_template("login/password_change.html", form=form)


@UI_NS.route("/password/reset/<token>/", methods=["GET", "POST"])
@UI_NS.route("/password/reset/<token>", methods=["GET", "POST"])
def reset_password(token):
    """Method to allow a user to reset his/her password."""
    form = forms.ResetPasswordForm()

    user_obj = pagure.lib.query.search_user(flask.g.session, token=token)
    if not user_obj:
        flask.flash("No user associated with this token.", "error")
        return flask.redirect(flask.url_for("auth_login"))
    elif not user_obj.token:
        flask.flash(
            "Invalid user, this user never asked for a password change",
            "error",
        )
        return flask.redirect(flask.url_for("auth_login"))

    if form.validate_on_submit():

        user_obj.password = generate_hashed_value(form.password.data)

        user_obj.token = None
        flask.g.session.add(user_obj)

        try:
            flask.g.session.commit()
            flask.flash("Password changed")
        except SQLAlchemyError:  # pragma: no cover
            flask.g.session.rollback()
            flask.flash("Could not set the new password.", "error")
            _log.exception("Password lost change - Error setting password.")

        return flask.redirect(flask.url_for("auth_login"))

    return flask.render_template(
        "login/password_reset.html", form=form, token=token
    )


#
# Methods specific to local login.
#


@UI_NS.route("/password/change/", methods=["GET", "POST"])
@UI_NS.route("/password/change", methods=["GET", "POST"])
@login_required
def change_password():
    """Method to change the password for local auth users."""

    form = forms.ChangePasswordForm()
    user_obj = pagure.lib.query.search_user(
        flask.g.session, username=flask.g.fas_user.username
    )

    if not user_obj:
        flask.abort(404, description="User not found")

    if form.validate_on_submit():

        try:
            password_checks = check_password(
                form.old_password.data,
                user_obj.password,
                seed=pagure.config.config.get("PASSWORD_SEED", None),
            )
        except pagure.exceptions.PagureException as err:
            _log.exception(err)
            flask.flash(
                "Could not update your password, either user or password "
                "could not be checked",
                "error",
            )
            return flask.redirect(flask.url_for("auth_login"))

        if password_checks:
            user_obj.password = generate_hashed_value(form.password.data)
            flask.g.session.add(user_obj)

        else:
            flask.flash(
                "Could not update your password, either user or password "
                "could not be checked",
                "error",
            )
            return flask.redirect(flask.url_for("auth_login"))

        try:
            flask.g.session.commit()
            flask.flash("Password changed")
        except SQLAlchemyError:  # pragma: no cover
            flask.g.session.rollback()
            flask.flash("Could not set the new password.", "error")
            _log.exception("Password change  - Error setting new password.")

        return flask.redirect(flask.url_for("auth_login"))

    return flask.render_template("login/password_recover.html", form=form)


def send_confirmation_email(user):
    """Sends the confirmation email asking the user to confirm its email
    address.
    """
    if not user.emails:
        return

    # The URL of this instance
    instance_url = pagure.config.config.get("APP_URL", flask.request.url_root)

    # A link with a secret token to confirm the registration
    confirmation_url = urljoin(
        instance_url,
        flask.url_for("ui_ns.confirm_user", token=user.token),
    )

    message = """Dear %(username)s,

Thank you for registering on pagure at %(instance_url)s.

To finish your registration, please click on the following link or copy/paste
it in your browser:

    %(confirmation_url)s

Your account will not be activated until you finish this step.

Sincerely,
Your pagure admin.
""" % (
        {
            "username": user.username,
            "instance_url": instance_url,
            "confirmation_url": confirmation_url,
        }
    )

    pagure.lib.notify.send_email(
        text=message,
        subject="Confirm your user account",
        to_mail=user.emails[0].email,
    )


def send_lostpassword_email(user):
    """Sends the email with the information on how to reset his/her password
    to the user.
    """
    if not user.emails:
        return

    url = pagure.config.config.get("APP_URL", flask.request.url_root)

    url = urljoin(
        url or flask.request.url_root,
        flask.url_for("ui_ns.reset_password", token=user.token),
    )

    message = """ Dear %(username)s,

The IP address %(ip)s has requested a password change for this account.

If you wish to change your password, please click on the following link or
copy/paste it in your browser:
  %(url)s

If you did not request this change, please inform an admin immediately!

Sincerely,
Your pagure admin.
""" % (
        {
            "username": user.username,
            "url": url,
            "ip": flask.request.remote_addr,
        }
    )

    pagure.lib.notify.send_email(
        text=message,
        subject="Confirm your password change",
        to_mail=user.emails[0].email,
    )


def logout():
    """Log the user out by expiring the user's session."""
    flask.g.fas_session_id = None
    flask.g.fas_user = None


def _check_session_cookie():
    """Set the user into flask.g if the user is logged in."""
    if not hasattr(flask.g, "session") or not flask.g.session:
        flask.g.session = pagure.lib.model_base.create_session(
            flask.current_app.config["DB_URL"]
        )

    cookie_name = pagure.config.config.get("SESSION_COOKIE_NAME", "pagure")
    cookie_name = "%s_local_cookie" % cookie_name
    session_id = None
    user = None
    login_time = None

    if cookie_name and cookie_name in flask.request.cookies:
        sessionid = flask.request.cookies.get(cookie_name)
        visit_session = pagure.lib.login.get_session_by_visitkey(
            flask.g.session, sessionid
        )
        if visit_session and visit_session.user:
            now = datetime.datetime.now()
            if now > visit_session.expiry:
                flask.flash("Session timed-out", "error")
            elif (
                pagure.config.config.get("CHECK_SESSION_IP", True)
                and visit_session.user_ip != flask.request.remote_addr
            ):
                flask.flash("Session expired", "error")
            else:
                new_expiry = now + datetime.timedelta(days=30)
                session_id = visit_session.visit_key
                user = visit_session.user
                login_time = visit_session.created

                visit_session.expiry = new_expiry
                flask.g.session.add(visit_session)
                try:
                    flask.g.session.commit()
                except SQLAlchemyError as err:  # pragma: no cover
                    flask.flash(
                        "Could not prolong the session in the db, "
                        "please report this error to an admin",
                        "error",
                    )
                    _log.exception(err)

    flask.g.fas_session_id = session_id
    if user:
        flask.g.fas_user = user
        flask.g.fas_user.email = user.default_email
        flask.g.authenticated = pagure.utils.authenticated()
        flask.g.fas_user.login_time = login_time


def _send_session_cookie(response):
    """Set the session cookie if the user is authenticated."""
    cookie_name = pagure.config.config.get("SESSION_COOKIE_NAME", "pagure")
    secure = pagure.config.config.get("SESSION_COOKIE_SECURE", True)

    response.set_cookie(
        key="%s_local_cookie" % cookie_name,
        value=flask.g.get("fas_session_id") or "",
        secure=secure,
        httponly=True,
    )
    return response
