import re
from typing import List, Sequence, Set

from django.http import HttpRequest, HttpResponse
from django.utils.translation import ugettext as _

from zerver.decorator import require_member_or_admin, require_realm_admin
from zerver.lib.actions import (
    do_create_multiuse_invite_link,
    do_get_user_invites,
    do_invite_users,
    do_resend_user_invite_email,
    do_revoke_multi_use_invite,
    do_revoke_user_invite,
)
from zerver.lib.exceptions import OrganizationAdministratorRequired, OrganizationOwnerRequired
from zerver.lib.request import REQ, JsonableError, has_request_variables
from zerver.lib.response import json_error, json_success
from zerver.lib.streams import access_stream_by_id
from zerver.lib.validator import check_int, check_list
from zerver.models import MultiuseInvite, PreregistrationUser, Stream, UserProfile


def check_if_owner_required(invited_as: int, user_profile: UserProfile) -> None:
    if invited_as == PreregistrationUser.INVITE_AS['REALM_OWNER'] and not user_profile.is_realm_owner:
        raise OrganizationOwnerRequired()

@require_member_or_admin
@has_request_variables
def invite_users_backend(request: HttpRequest, user_profile: UserProfile,
                         invitee_emails_raw: str=REQ("invitee_emails"),
                         invite_as: int=REQ(
                             validator=check_int, default=PreregistrationUser.INVITE_AS['MEMBER']),
                         stream_ids: List[int]=REQ(validator=check_list(check_int)),
                         ) -> HttpResponse:

    if user_profile.realm.invite_by_admins_only and not user_profile.is_realm_admin:
        raise OrganizationAdministratorRequired()
    if invite_as not in PreregistrationUser.INVITE_AS.values():
        return json_error(_("Must be invited as an valid type of user"))
    check_if_owner_required(invite_as, user_profile)
    if invite_as == PreregistrationUser.INVITE_AS['REALM_ADMIN'] and not user_profile.is_realm_admin:
        return json_error(_("Must be an organization administrator"))
    if not invitee_emails_raw:
        return json_error(_("You must specify at least one email address."))
    if not stream_ids:
        return json_error(_("You must specify at least one stream for invitees to join."))

    invitee_emails = get_invitee_emails_set(invitee_emails_raw)

    streams: List[Stream] = []
    for stream_id in stream_ids:
        try:
            (stream, recipient, sub) = access_stream_by_id(user_profile, stream_id)
        except JsonableError:
            return json_error(
                _("Stream does not exist with id: {}. No invites were sent.").format(stream_id))
        streams.append(stream)

    do_invite_users(user_profile, invitee_emails, streams, invite_as)
    return json_success()

def get_invitee_emails_set(invitee_emails_raw: str) -> Set[str]:
    invitee_emails_list = set(re.split(r'[,\n]', invitee_emails_raw))
    invitee_emails = set()
    for email in invitee_emails_list:
        is_email_with_name = re.search(r'<(?P<email>.*)>', email)
        if is_email_with_name:
            email = is_email_with_name.group('email')
        invitee_emails.add(email.strip())
    return invitee_emails

@require_member_or_admin
def get_user_invites(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:
    all_users = do_get_user_invites(user_profile)
    return json_success({'invites': all_users})

@require_member_or_admin
@has_request_variables
def revoke_user_invite(request: HttpRequest, user_profile: UserProfile,
                       prereg_id: int) -> HttpResponse:
    try:
        prereg_user = PreregistrationUser.objects.get(id=prereg_id)
    except PreregistrationUser.DoesNotExist:
        raise JsonableError(_("No such invitation"))

    if prereg_user.referred_by.realm != user_profile.realm:
        raise JsonableError(_("No such invitation"))

    if prereg_user.referred_by_id != user_profile.id:
        check_if_owner_required(prereg_user.invited_as, user_profile)
        if not user_profile.is_realm_admin:
            raise JsonableError(_("Must be an organization administrator"))

    do_revoke_user_invite(prereg_user)
    return json_success()

@require_realm_admin
@has_request_variables
def revoke_multiuse_invite(request: HttpRequest, user_profile: UserProfile,
                           invite_id: int) -> HttpResponse:

    try:
        invite = MultiuseInvite.objects.get(id=invite_id)
    except MultiuseInvite.DoesNotExist:
        raise JsonableError(_("No such invitation"))

    if invite.realm != user_profile.realm:
        raise JsonableError(_("No such invitation"))

    check_if_owner_required(invite.invited_as, user_profile)

    do_revoke_multi_use_invite(invite)
    return json_success()

@require_member_or_admin
@has_request_variables
def resend_user_invite_email(request: HttpRequest, user_profile: UserProfile,
                             prereg_id: int) -> HttpResponse:
    try:
        prereg_user = PreregistrationUser.objects.get(id=prereg_id)
    except PreregistrationUser.DoesNotExist:
        raise JsonableError(_("No such invitation"))

    # Structurally, any invitation the user can actually access should
    # have a referred_by set for the user who created it.
    if prereg_user.referred_by is None or prereg_user.referred_by.realm != user_profile.realm:
        raise JsonableError(_("No such invitation"))

    if prereg_user.referred_by_id != user_profile.id:
        check_if_owner_required(prereg_user.invited_as, user_profile)
        if not user_profile.is_realm_admin:
            raise JsonableError(_("Must be an organization administrator"))

    timestamp = do_resend_user_invite_email(prereg_user)
    return json_success({'timestamp': timestamp})

@require_realm_admin
@has_request_variables
def generate_multiuse_invite_backend(
        request: HttpRequest, user_profile: UserProfile,
        invite_as: int=REQ(validator=check_int, default=PreregistrationUser.INVITE_AS['MEMBER']),
        stream_ids: Sequence[int]=REQ(validator=check_list(check_int), default=[])) -> HttpResponse:
    check_if_owner_required(invite_as, user_profile)

    streams = []
    for stream_id in stream_ids:
        try:
            (stream, recipient, sub) = access_stream_by_id(user_profile, stream_id)
        except JsonableError:
            return json_error(_("Invalid stream id {}. No invites were sent.").format(stream_id))
        streams.append(stream)

    invite_link = do_create_multiuse_invite_link(user_profile, invite_as, streams)
    return json_success({'invite_link': invite_link})