# Library code for use in management commands
from __future__ import absolute_import
from __future__ import print_function

import sys

from argparse import ArgumentParser
from django.core.exceptions import MultipleObjectsReturned
from django.core.management.base import BaseCommand, CommandError
from typing import Any, Dict, Optional, Text, List

from zerver.models import Realm, UserProfile

def is_integer_string(val):
    # type: (str) -> bool
    try:
        int(val)
        return True
    except ValueError:
        return False

class ZulipBaseCommand(BaseCommand):
    def add_realm_args(self, parser, required=False, help=None):
        # type: (ArgumentParser, bool, Optional[str]) -> None
        if help is None:
            help = """The numeric or string ID (subdomain) of the Zulip organization to modify.
You can use the command list_realms to find ID of the realms in this server."""

        parser.add_argument(
            '-r', '--realm',
            dest='realm_id',
            required=required,
            type=str,
            help=help)

    def add_user_list_args(self, parser, required=False, help=None, all_users_arg=True, all_users_help=None):
        # type: (ArgumentParser, bool, Optional[str], bool, Optional[str]) -> None
        if help is None:
            help = 'A comma-separated list of email addresses.'

        parser.add_argument(
            '-u', '--users',
            dest='users',
            required=required,
            type=str,
            help=help)

        if all_users_arg:
            if all_users_help is None:
                all_users_help = "All users in realm."

            parser.add_argument(
                '-a', '--all-users',
                dest='all_users',
                action="store_true",
                default=False,
                help=all_users_help)

    def get_realm(self, options):
        # type: (Dict[str, Any]) -> Optional[Realm]
        val = options["realm_id"]
        if val is None:
            return None

        # If they specified a realm argument, we need to ensure the
        # realm exists.  We allow two formats: the numeric ID for the
        # realm and the string ID of the realm.
        try:
            if is_integer_string(val):
                return Realm.objects.get(id=val)
            return Realm.objects.get(string_id=val)
        except Realm.DoesNotExist:
            raise CommandError("There is no realm with id '%s'. Aborting." %
                               (options["realm_id"],))

    def get_users(self, options, realm):
        # type: (Dict[str, Any], Optional[Realm]) -> List[UserProfile]
        if "all_users" in options:
            all_users = options["all_users"]

            # User should pass either user list or all_users flag
            if bool(options["users"]) == all_users:
                raise CommandError("You can't use both -u/--users and -a/--all-users.")

            if all_users and realm is None:
                raise CommandError("The --all-users option requires a realm; please pass --realm.")

            if all_users:
                return UserProfile.objects.filter(realm=realm)

        if options["users"] is None:
            return []
        emails = set([email.strip() for email in options["users"].split(",")])
        user_profiles = []
        for email in emails:
            user_profiles.append(self.get_user(email, realm))
        return user_profiles

    def get_user(self, email, realm):
        # type: (Text, Optional[Realm]) -> UserProfile

        # If a realm is specified, try to find the user there, and
        # throw an error if they don't exist.
        if realm is not None:
            try:
                return UserProfile.objects.select_related().get(email__iexact=email.strip(), realm=realm)
            except UserProfile.DoesNotExist:
                raise CommandError("The realm '%s' does not contain a user with email '%s'" % (realm, email))

        # Realm is None in the remaining code path.  Here, we
        # optimistically try to see if there is exactly one user with
        # that email; if so, we'll return it.
        try:
            return UserProfile.objects.select_related().get(email__iexact=email.strip())
        except MultipleObjectsReturned:
            raise CommandError("This Zulip server contains multiple users with that email " +
                               "(in different realms); please pass `--realm` to specify which one to modify.")
        except UserProfile.DoesNotExist:
            raise CommandError("This Zulip server does not contain a user with email '%s'" % (email,))