system-pri/backend/app/students/routes/registrations.py

from apiflask import APIBlueprint
from flask import abort

from ...project_supervisor.models import ProjectSupervisor
from ..models import Group
from ...dependencies import db
from ..schemas import ProjectSupervisorPaginationSchema, ProjectSupervisorQuerySchema
from ...base.utils import paginate_models

bp = APIBlueprint("registrations", __name__, url_prefix="/registrations")


@bp.route('/', methods=['GET'])
@bp.input(ProjectSupervisorQuerySchema, location='query')
@bp.output(ProjectSupervisorPaginationSchema)
def list_available_groups(query: dict) -> dict:
    mode = 0 if query.get('mode') else 1
    page = query.get('page')
    per_page = query.get('per_page')

    available_groups = (ProjectSupervisor.limit_group - ProjectSupervisor.count_groups)
    ps_query = db.session.query(ProjectSupervisor, available_groups).join(Group, isouter=True)

    if mode is not None:
        ps_query = ps_query.filter(ProjectSupervisor.mode != 1-mode)

    ps_query = ps_query.group_by(ProjectSupervisor.id). \
        having(available_groups > 0)

    data = paginate_models(page, ps_query, per_page)

    project_supervisors = []
    for project_supervisor, available_groups in data['items']:
        setattr(project_supervisor, 'available_groups', available_groups)
        project_supervisors.append(project_supervisor)

    return {
        "project_supervisors": project_supervisors,
        "max_pages": data['max_pages']
    }