from app import db
from werkzeug.datastructures import MultiDict
from app.dao import DAOClass
from app.models import (
    Permission,
    Service,
    User,
    MANAGE_USERS,
    MANAGE_TEMPLATES,
    MANAGE_SETTINGS,
    SEND_TEXTS,
    SEND_EMAILS,
    SEND_LETTERS,
    MANAGE_API_KEYS,
    VIEW_ACTIVITY)


# Default permissions for a service
default_service_permissions = [
    MANAGE_USERS,
    MANAGE_TEMPLATES,
    MANAGE_SETTINGS,
    SEND_TEXTS,
    SEND_EMAILS,
    SEND_LETTERS,
    MANAGE_API_KEYS,
    VIEW_ACTIVITY]


class PermissionDAO(DAOClass):

    class Meta:
        model = Permission

    def get_query(self, filter_by_dict=None):
        if filter_by_dict is None:
            filter_by_dict = MultiDict()
        else:
            filter_by_dict = MultiDict(filter_by_dict)
        query = self.Meta.model.query
        if 'id' in filter_by_dict:
            query = query.filter(Permission.id.in_(filter_by_dict.getlist('id')))
        if 'service' in filter_by_dict:
            service_ids = filter_by_dict.getlist('service')
            if len(service_ids) == 1:
                query.filter_by(service=Service.query.get(service_ids[0]))
            # TODO the join method for multiple services
        if 'user' in filter_by_dict:
            user_ids = filter_by_dict.getlist('user')
            if len(user_ids) == 1:
                query = query.filter_by(user=User.query.get(user_ids[0]))
            # TODO the join method for multiple users
        if 'permission' in filter_by_dict:
            query = query.filter(Permission.permission.in_(filter_by_dict.getlist('permission')))
        return query

    def add_default_service_permissions_for_user(self, user, service):
        for name in default_service_permissions:
            permission = Permission(permission=name, user=user, service=service)
            self.create_instance(permission, _commit=False)

    def remove_user_service_permissions(self, user, service):
        query = self.get_query(filter_by_dict={'user': user.id, 'service': service.id})
        query.delete()

    def set_user_service_permission(self, user, service, permissions, _commit=False):
        try:
            query = self.get_query(filter_by_dict={'user': user.id, 'service': service.id})
            query.delete()
            for p in permissions:
                p.user = user
                p.service = service
                self.create_instance(p, _commit=False)
        except Exception as e:
            if _commit:
                db.session.rollback()
            raise e
        else:
            if _commit:
                db.session.commit()


permission_dao = PermissionDAO()