from flask import Blueprint, request
from zope import component

from .utils import authz_restrict_to_syscom, create_streaming_response
from ceo_common.errors import BadRequest
from ceo_common.interfaces import ILDAPService, IConfig
from ceod.transactions.members import UpdateMemberPositionsTransaction

bp = Blueprint('positions', __name__)


@bp.route('/', methods=['GET'], strict_slashes=False)
def get_positions():
    ldap_srv = component.getUtility(ILDAPService)

    positions = {}
    for user in ldap_srv.get_users_with_positions():
        for position in user.positions:
            if position not in positions:
                positions[position] = []
            positions[position].append(user.uid)

    return positions


@bp.route('/', methods=['POST'], strict_slashes=False)
@authz_restrict_to_syscom
def update_positions():
    cfg = component.getUtility(IConfig)
    body = request.get_json(force=True)

    required = cfg.get('positions_required')
    available = cfg.get('positions_available')

    # remove falsy values and parse multiple users in each position
    # Example: "user1,user2, user3" -> ["user1","user2","user3"]
    position_to_usernames = {}
    for position, usernames in body.items():
        if not usernames:
            continue
        if type(usernames) is list:
            position_to_usernames[position] = usernames
        elif type(usernames) is str:
            position_to_usernames[position] = usernames.replace(' ', '').split(',')
        else:
            raise BadRequest('usernames must be a list or comma-separated string')

    # check for duplicates (i.e. one username specified twice in the same list)
    for usernames in position_to_usernames.values():
        if len(usernames) != len(set(usernames)):
            raise BadRequest('username may only be specified at most once for a position')

    for position in position_to_usernames.keys():
        if position not in available:
            raise BadRequest(f'unknown position: {position}')

    for position in required:
        if position not in position_to_usernames:
            raise BadRequest(f'missing required position: {position}')

    txn = UpdateMemberPositionsTransaction(position_to_usernames)
    return create_streaming_response(txn)