main.py

# SPDX-License-Identifier: LGPL-2.1-or-later
#
# Copyright (C) 2021-2023 Collabora Limited
# Author: Guillaume Tucker <guillaume.tucker@collabora.com>
# Author: Jeny Sadadia <jeny.sadadia@collabora.com>

# pylint: disable=unused-argument disable=global-statement

"""KernelCI API main module"""

import os
import re
from typing import List, Union, Optional
from fastapi import (
    Depends,
    FastAPI,
    HTTPException,
    status,
    Request,
    Form,
    Header,
    Query
)
from fastapi.responses import JSONResponse, PlainTextResponse, FileResponse
from fastapi.security import OAuth2PasswordRequestForm
from fastapi_pagination import add_pagination
from fastapi_versioning import VersionedFastAPI
from bson import ObjectId, errors
from pymongo.errors import DuplicateKeyError
from fastapi_users import FastAPIUsers
from beanie import PydanticObjectId
from kernelci.api.models import (
    Node,
    Hierarchy,
    PublishEvent,
    parse_node_obj,
    KernelVersion,
)
from .auth import Authentication
from .db import Database
from .pubsub import PubSub
from .user_manager import get_user_manager, create_user_manager
from .models import (
    PageModel,
    Subscription,
    SubscriptionStats,
    User,
    UserRead,
    UserCreate,
    UserUpdate,
    UserGroup,
)


# List of all the supported API versions.  This is a placeholder until the API
# actually supports multiple versions with different sets of endpoints and
# models etc.
API_VERSIONS = ['v0']

app = FastAPI()
db = Database(service=(os.getenv('MONGO_SERVICE') or 'mongodb://db:27017'))
auth = Authentication(token_url="user/login")
pubsub = None  # pylint: disable=invalid-name

auth_backend = auth.get_user_authentication_backend()
fastapi_users_instance = FastAPIUsers[User, PydanticObjectId](
    get_user_manager,
    [auth_backend],
)
user_manager = create_user_manager()


@app.on_event('startup')
async def pubsub_startup():
    """Startup event handler to create Pub/Sub object"""
    global pubsub  # pylint: disable=invalid-name
    pubsub = await PubSub.create()


@app.on_event('startup')
async def create_indexes():
    """Startup event handler to create database indexes"""
    await db.create_indexes()


@app.on_event('startup')
async def initialize_beanie():
    """Startup event handler to initialize Beanie"""
    await db.initialize_beanie()


@app.exception_handler(ValueError)
async def value_error_exception_handler(request: Request, exc: ValueError):
    """Global exception handler for 'ValueError'"""
    return JSONResponse(
        status_code=status.HTTP_400_BAD_REQUEST,
        content={"detail": str(exc)},
    )


@app.exception_handler(errors.InvalidId)
async def invalid_id_exception_handler(
        request: Request,
        exc: errors.InvalidId):
    """Global exception handler for `errors.InvalidId`
    The exception is raised from Database when invalid ObjectId is received"""
    return JSONResponse(
        status_code=status.HTTP_400_BAD_REQUEST,
        content={"detail": str(exc)},
    )


@app.get('/')
async def root():
    """Root endpoint handler"""
    return {"message": "KernelCI API"}

# -----------------------------------------------------------------------------
# Users


def get_current_user(user: User = Depends(
        fastapi_users_instance.current_user(active=True))):
    """Get current active user"""
    return user


def get_current_superuser(user: User = Depends(
        fastapi_users_instance.current_user(active=True, superuser=True))):
    """Get current active superuser"""
    return user


app.include_router(
    fastapi_users_instance.get_auth_router(auth_backend,
                                           requires_verification=True),
    prefix="/user",
    tags=["user"]
)

register_router = fastapi_users_instance.get_register_router(
    UserRead, UserCreate)


@app.post("/user/register", response_model=UserRead, tags=["user"],
          response_model_by_alias=False)
async def register(request: Request, user: UserCreate,
                   current_user: User = Depends(get_current_superuser)):
    """User registration route

    Custom user registration router to ensure unique username.
    `user` from request has a list of user group name strings.
    This handler will convert them to `UserGroup` objects and
    insert user object to database.
    """
    existing_user = await db.find_one(User, username=user.username)
    if existing_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already exists",
        )
    groups = []
    if user.groups:
        for group_name in user.groups:
            group = await db.find_one(UserGroup, name=group_name)
            if not group:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail=f"User group does not exist with name: \
    {group_name}")
            groups.append(group)
    user.groups = groups
    created_user = await register_router.routes[0].endpoint(
        request, user, user_manager)
    # Update user to be an admin user explicitly if requested as
    # `fastapi-users` register route does not allow it
    if user.is_superuser:
        user_from_id = await db.find_by_id(User, created_user.id)
        user_from_id.is_superuser = True
        created_user = await db.update(user_from_id)
    return created_user


app.include_router(
    fastapi_users_instance.get_reset_password_router(),
    prefix="/user",
    tags=["user"],
)
app.include_router(
    fastapi_users_instance.get_verify_router(UserRead),
    prefix="/user",
    tags=["user"],
)

users_router = fastapi_users_instance.get_users_router(
    UserRead, UserUpdate, requires_verification=True)

app.add_api_route(
    path="/whoami",
    tags=["user"],
    methods=["GET"],
    description="Get current user information",
    endpoint=users_router.routes[0].endpoint)
app.add_api_route(
    path="/user/{id}",
    tags=["user"],
    methods=["GET"],
    description="Get user information by ID",
    dependencies=[Depends(get_current_user)],
    endpoint=users_router.routes[2].endpoint)
app.add_api_route(
    path="/user/{id}",
    tags=["user"],
    methods=["DELETE"],
    description="Delete user by ID",
    dependencies=[Depends(get_current_superuser)],
    endpoint=users_router.routes[4].endpoint)


@app.patch("/user/me", response_model=UserRead, tags=["user"],
           response_model_by_alias=False)
async def update_me(request: Request, user: UserUpdate,
                    current_user: User = Depends(get_current_user)):
    """User update route

    Custom user update router handler will only allow users to update
    its own profile.
    """
    if user.username and user.username != current_user.username:
        existing_user = await db.find_one(User, username=user.username)
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Username already exists: {user.username}",
            )
    groups = []
    if user.groups:
        for group_name in user.groups:
            group = await db.find_one(UserGroup, name=group_name)
            if not group:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail=f"User group does not exist with name: \
    {group_name}")
            groups.append(group)
    if groups:
        user.groups = groups
    return await users_router.routes[1].endpoint(
        request, user, current_user, user_manager)


@app.patch("/user/{user_id}", response_model=UserRead, tags=["user"],
           response_model_by_alias=False)
async def update_user(user_id: str, request: Request, user: UserUpdate,
                      current_user: User = Depends(get_current_superuser)):
    """Router to allow admin users to update other user account"""
    user_from_id = await db.find_by_id(User, user_id)
    if not user_from_id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"User not found with id: {user_id}",
        )

    if user.username and user.username != user_from_id.username:
        existing_user = await db.find_one(User, username=user.username)
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Username already exists: {user.username}",
            )

    groups = []
    if user.groups:
        for group_name in user.groups:
            group = await db.find_one(UserGroup, name=group_name)
            if not group:
                raise HTTPException(
                    status_code=status.HTTP_400_BAD_REQUEST,
                    detail=f"User group does not exist with name: \
    {group_name}")
            groups.append(group)
    if groups:
        user.groups = groups

    updated_user = await users_router.routes[3].endpoint(
        user, request, user_from_id, user_manager
    )
    # Update user to be an admin user explicitly if requested as
    # `fastapi-users` user update route does not allow it
    if user.is_superuser:
        user_from_id = await db.find_by_id(User, updated_user.id)
        user_from_id.is_superuser = True
        updated_user = await db.update(user_from_id)
    return updated_user


async def authorize_user(node_id: str,
                         user: User = Depends(get_current_user)):
    """Return the user if active, authenticated, and authorized"""

    # Only the user that created the node or any other user from the permitted
    # user groups will be allowed to update the node
    node_from_id = await db.find_by_id(Node, node_id)
    if not node_from_id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with id: {node_id}"
        )
    if not user.username == node_from_id.owner:
        if not any(group.name in node_from_id.user_groups
                   for group in user.groups):
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Unauthorized to complete the operation"
            )
    return user


@app.get('/users', response_model=PageModel, tags=["user"],
         response_model_exclude={"items": {"__all__": {
                                    "hashed_password"}}})
async def get_users(request: Request,
                    current_user: User = Depends(get_current_user)):
    """Get all the users if no request parameters have passed.
       Get the matching users otherwise."""
    query_params = dict(request.query_params)
    # Drop pagination parameters from query as they're already in arguments
    for pg_key in ['limit', 'offset']:
        query_params.pop(pg_key, None)
    paginated_resp = await db.find_by_attributes(User, query_params)
    paginated_resp.items = serialize_paginated_data(
        User, paginated_resp.items)
    return paginated_resp


@app.post("/user/update-password", tags=["user"])
async def update_password(request: Request,
                          credentials: OAuth2PasswordRequestForm = Depends(),
                          new_password: str = Form(None)):
    """Update user password"""
    user = await user_manager.authenticate(credentials)
    if user is None or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="LOGIN_BAD_CREDENTIALS",
        )
    user_update = UserUpdate(password=new_password)
    user_from_username = await db.find_one(User, username=credentials.username)
    await users_router.routes[3].endpoint(
        user_update, request, user_from_username, user_manager
    )


# -----------------------------------------------------------------------------
# User groups


@app.post('/group', response_model=UserGroup, response_model_by_alias=False)
async def post_user_group(
        group: UserGroup,
        current_user: User = Depends(get_current_superuser)):
    """Create new user group"""
    try:
        obj = await db.create(group)
    except DuplicateKeyError as error:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Group '{group.name}' already exists. \
Use a different group name."
        ) from error
    await pubsub.publish_cloudevent('user_group', {'op': 'created',
                                                   'id': str(obj.id)})
    return obj


@app.get('/groups', response_model=PageModel)
async def get_user_groups(request: Request):
    """Get all the user groups if no request parameters have passed.
       Get all the matching user groups otherwise."""
    query_params = dict(request.query_params)

    # Drop pagination parameters from query as they're already in arguments
    for pg_key in ['limit', 'offset']:
        query_params.pop(pg_key, None)

    paginated_resp = await db.find_by_attributes(UserGroup, query_params)
    paginated_resp.items = serialize_paginated_data(
        UserGroup, paginated_resp.items)
    return paginated_resp


@app.get('/group/{group_id}', response_model=Union[UserGroup, None],
         response_model_by_alias=False)
async def get_group(group_id: str):
    """Get user group information from the provided group id"""
    return await db.find_by_id(UserGroup, group_id)


@app.delete('/group/{group_id}', response_model=PageModel)
async def delete_group(group_id: str,
                       current_user: User = Depends(get_current_superuser)):
    """Delete user group matching the provided group id"""
    group_from_id = await db.find_by_id(UserGroup, group_id)
    if not group_from_id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Group not found with id: {group_id}"
        )
    # Remove users from the group before deleting it
    users = await db.find_by_attributes(
        User, {"groups.name": group_from_id.name})
    for user in users.items:
        user['groups'].remove(group_from_id)
        await db.update(User(**user))

    # Remove group from user groups that are permitted to update node
    nodes = await db.find_by_attributes(
        Node, {"user_groups": group_from_id.name})
    for node in nodes.items:
        node['user_groups'].remove(group_from_id.name)
        await db.update(Node(**node))

    await db.delete_by_id(UserGroup, group_id)


# -----------------------------------------------------------------------------
# Nodes

def _get_node_event_data(operation, node, is_hierarchy=False):
    return {
        'op': operation,
        'id': str(node.id),
        'kind': node.kind,
        'name': node.name,
        'path': node.path,
        'group': node.group,
        'state': node.state,
        'result': node.result,
        'owner': node.owner,
        'data': node.data,
        'is_hierarchy': is_hierarchy,
    }


async def translate_null_query_params(query_params: dict):
    """Translate null query parameters to None"""
    translated = query_params.copy()
    for key, value in query_params.items():
        if value == 'null':
            translated[key] = None
    return translated


@app.get('/node/{node_id}', response_model=Union[Node, None],
         response_model_by_alias=False)
async def get_node(node_id: str):
    """Get node information from the provided node id"""
    try:
        return await db.find_by_id(Node, node_id)
    except KeyError as error:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with the kind: {str(error)}"
        ) from error


def serialize_paginated_data(model, data: list):
    """
    Serialize models to generate response without using alias.
    This is required to get models with `id` field in the response
    instead of `_id`.
    In usual cases providing `response_model_by_alias` to endpoint
    definition serves the purpose. However, that doesn't work in case
    of paginated data. Hence, need to serialize it manually.
    """
    serialized_data = []
    for obj in data:
        serialized_data.append(model(**obj).dict())
    return serialized_data


@app.get('/nodes', response_model=PageModel)
async def get_nodes(request: Request):
    """Get all the nodes if no request parameters have passed.
       Get all the matching nodes otherwise, within the pagination limit."""
    query_params = dict(request.query_params)

    # Drop pagination parameters from query as they're already in arguments
    for pg_key in ['limit', 'offset']:
        query_params.pop(pg_key, None)

    query_params = await translate_null_query_params(query_params)

    try:
        # Query using the base Node model, regardless of the specific
        # node type
        model = Node
        translated_params = model.translate_fields(query_params)
        paginated_resp = await db.find_by_attributes(model, translated_params)
        paginated_resp.items = serialize_paginated_data(
            model, paginated_resp.items)
        return paginated_resp
    except KeyError as error:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with the kind: {str(error)}"
        ) from error

add_pagination(app)


@app.get('/count', response_model=int)
async def get_nodes_count(request: Request):
    """Get the count of all the nodes if no request parameters have passed.
       Get the count of all the matching nodes otherwise."""
    query_params = dict(request.query_params)

    query_params = await translate_null_query_params(query_params)

    try:
        # Query using the base Node model, regardless of the specific
        # node type
        model = Node
        translated_params = model.translate_fields(query_params)
        return await db.count(model, translated_params)
    except KeyError as error:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with the kind: {str(error)}"
        ) from error


async def _verify_user_group_existence(user_groups: List[str]):
    """Check if user group exists"""
    for group_name in user_groups:
        if not await db.find_one(UserGroup, name=group_name):
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"User group does not exist with name: {group_name}")


def _translate_version_fields(node: Node):
    """Translate Node version fields"""
    data = node.data
    if data:
        version = data.get('kernel_revision', {}).get('version')
        if version:
            version = KernelVersion.translate_version_fields(version)
            node.data['kernel_revision']['version'] = version
    return node


@app.post('/node', response_model=Node, response_model_by_alias=False)
async def post_node(node: Node,
                    authorization: str | None = Header(default=None),
                    current_user: User = Depends(get_current_user)):
    """Create a new node"""
    # [TODO] Remove translation below once we can use it in the pipeline
    node = _translate_version_fields(node)

    # Explicit pydantic model validation
    parse_node_obj(node)

    # [TODO] Implement sanity checks depending on the node kind
    if node.parent:
        parent = await db.find_by_id(Node, node.parent)
        if not parent:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail=f"Parent not found with id: {node.parent}"
            )

    await _verify_user_group_existence(node.user_groups)
    node.owner = current_user.username
    # if node.submitter is not set, set it to "pipeline"
    if not node.submitter:
        node.submitter = "service:pipeline"

    # The node is handled as a generic Node by the DB, regardless of its
    # specific kind. The concrete Node submodel (Kbuild, Checkout, etc.)
    # is only used for data format validation
    obj = await db.create(node)
    data = _get_node_event_data('created', obj)
    attributes = {}
    if data.get('owner', None):
        attributes['owner'] = data['owner']
    await pubsub.publish_cloudevent('node', data, attributes)
    return obj


@app.put('/node/{node_id}', response_model=Node, response_model_by_alias=False)
async def put_node(node_id: str, node: Node,
                   user: str = Depends(authorize_user)):
    """Update an already added node"""
    node.id = ObjectId(node_id)
    node_from_id = await db.find_by_id(Node, node_id)
    if not node_from_id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with id: {node.id}"
        )

    # [TODO] Remove translation below once we can use it in the pipeline
    node = _translate_version_fields(node)

    # Sanity checks
    # Note: do not update node ownership fields, don't update 'state'
    # until we've checked the state transition is valid.
    update_data = node.dict(exclude={'user', 'user_groups', 'state'})
    new_node_def = node_from_id.copy(update=update_data)
    # 1- Parse and validate node to specific subtype
    specialized_node = parse_node_obj(new_node_def)

    # 2 - State transition checks
    is_valid, message = specialized_node.validate_node_state_transition(
        node.state)
    if not is_valid:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=message
        )
    # Now we can update the state
    new_node_def.state = node.state

    # Update node in the DB
    obj = await db.update(new_node_def)
    data = _get_node_event_data('updated', obj)
    attributes = {}
    if data.get('owner', None):
        attributes['owner'] = data['owner']
    await pubsub.publish_cloudevent('node', data, attributes)
    return obj


async def _set_node_ownership_recursively(user: User, hierarchy: Hierarchy,
                                          submitter: str, treeid: str):
    """Set node ownership information for a hierarchy of nodes"""
    if not hierarchy.node.owner:
        hierarchy.node.owner = user.username
    hierarchy.node.submitter = submitter
    hierarchy.node.treeid = treeid
    for node in hierarchy.child_nodes:
        await _set_node_ownership_recursively(user, node, submitter, treeid)


@app.put('/nodes/{node_id}', response_model=List[Node],
         response_model_by_alias=False)
async def put_nodes(
        node_id: str, nodes: Hierarchy,
        authorization: str | None = Header(default=None),
        user: str = Depends(authorize_user)):
    """Add a hierarchy of nodes to an existing root node"""
    nodes.node.id = ObjectId(node_id)
    # Retrieve the root node from the DB and submitter
    node_from_id = await db.find_by_id(Node, node_id)
    if not node_from_id:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Node not found with id: {node_id}"
        )
    submitter = node_from_id.submitter
    treeid = node_from_id.treeid

    await _set_node_ownership_recursively(user, nodes, submitter, treeid)
    obj_list = await db.create_hierarchy(nodes, Node)
    data = _get_node_event_data('updated', obj_list[0], True)
    attributes = {}
    if data.get('owner', None):
        attributes['owner'] = data['owner']
    await pubsub.publish_cloudevent('node', data, attributes)
    return obj_list


# -----------------------------------------------------------------------------
# Pub/Sub

@app.post('/subscribe/{channel}', response_model=Subscription)
async def subscribe(channel: str, user: User = Depends(get_current_user),
                    promisc: Optional[bool] = Query(None)):
    """Subscribe handler for Pub/Sub channel"""
    options = {}
    if promisc:
        options['promiscuous'] = promisc
    return await pubsub.subscribe(channel, user.username, options)


@app.post('/unsubscribe/{sub_id}')
async def unsubscribe(sub_id: int, user: User = Depends(get_current_user)):
    """Unsubscribe handler for Pub/Sub channel"""
    try:
        await pubsub.unsubscribe(sub_id, user.username)
    except KeyError as error:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Subscription id not found: {str(error)}"
        ) from error
    except RuntimeError as error:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(error)
        ) from error


@app.get('/listen/{sub_id}')
async def listen(sub_id: int, user: User = Depends(get_current_user)):
    """Listen messages from a subscribed Pub/Sub channel"""
    try:
        return await pubsub.listen(sub_id, user.username)
    except KeyError as error:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Subscription id not found: {str(error)}"
        ) from error
    except RuntimeError as error:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Error while listening to sub id {sub_id}: {str(error)}"
        ) from error


@app.post('/publish/{channel}')
async def publish(event: PublishEvent, channel: str,
                  user: User = Depends(get_current_user)):
    """Publish an event on the provided Pub/Sub channel"""
    event_dict = PublishEvent.dict(event)
    # 1 - Extract data and attributes from the event
    # 2 - Add the owner as an extra attribute
    # 3 - Collect all the other extra attributes, if available, without
    #     overwriting any of the standard ones in the dict
    data = event_dict.pop('data')
    extra_attributes = event_dict.pop("attributes")
    attributes = event_dict
    attributes['owner'] = user.username
    if extra_attributes:
        for k in extra_attributes:
            if k not in attributes:
                attributes[k] = extra_attributes[k]
    await pubsub.publish_cloudevent(channel, data, attributes)


@app.post('/push/{list_name}')
async def push(raw: dict, list_name: str,
               user: User = Depends(get_current_user)):
    """Push a message on the provided list"""
    attributes = dict(raw)
    data = attributes.pop('data')
    await pubsub.push_cloudevent(list_name, data, attributes)


@app.get('/pop/{list_name}')
async def pop(list_name: str, user: User = Depends(get_current_user)):
    """Pop a message from a given list"""
    return await pubsub.pop(list_name)


@app.get('/stats/subscriptions', response_model=List[SubscriptionStats])
async def stats(user: User = Depends(get_current_superuser)):
    """Get details of all existing subscriptions"""
    return await pubsub.subscription_stats()


@app.get('/viewer')
async def viewer():
    """Serve simple HTML page to view the API /static/viewer.html
    Set various no-cache tag we might update it often"""

    root_dir = os.path.dirname(os.path.abspath(__file__))
    viewer_path = os.path.join(root_dir, 'templates', 'viewer.html')
    with open(viewer_path, 'r', encoding='utf-8') as file:
        # set header to text/html and no-cache stuff
        hdr = {
            'Content-Type': 'text/html',
            'Cache-Control': 'no-cache, no-store, must-revalidate',
            'Pragma': 'no-cache',
            'Expires': '0'
        }
        return PlainTextResponse(file.read(), headers=hdr)


@app.get('/dashboard')
async def dashboard():
    """Serve simple HTML page to view the API dashboard.html
    Set various no-cache tag we might update it often"""

    root_dir = os.path.dirname(os.path.abspath(__file__))
    dashboard_path = os.path.join(root_dir, 'templates', 'dashboard.html')
    with open(dashboard_path, 'r', encoding='utf-8') as file:
        # set header to text/html and no-cache stuff
        hdr = {
            'Content-Type': 'text/html',
            'Cache-Control': 'no-cache, no-store, must-revalidate',
            'Pragma': 'no-cache',
            'Expires': '0'
        }
        return PlainTextResponse(file.read(), headers=hdr)


@app.get('/manage')
async def manage():
    """Serve simple HTML page to submit custom nodes"""

    root_dir = os.path.dirname(os.path.abspath(__file__))
    manage_path = os.path.join(root_dir, 'templates', 'manage.html')
    with open(manage_path, 'r', encoding='utf-8') as file:
        # set header to text/html and no-cache stuff
        hdr = {
            'Content-Type': 'text/html',
            'Cache-Control': 'no-cache, no-store, must-revalidate',
            'Pragma': 'no-cache',
            'Expires': '0'
        }
        return PlainTextResponse(file.read(), headers=hdr)


@app.get('/icons/{icon_name}')
async def icons(icon_name: str):
    """Serve icons from /static/icons"""
    root_dir = os.path.dirname(os.path.abspath(__file__))
    if not re.match(r'^[A-Za-z0-9_.-]+\.png$', icon_name):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid icon name"
        )
    icon_path = os.path.join(root_dir, 'templates', icon_name)
    return FileResponse(icon_path)


versioned_app = VersionedFastAPI(
        app,
        version_format='{major}',
        prefix_format='/v{major}',
        enable_latest=True,
        default_version=(0, 0),
        on_startup=[
            pubsub_startup,
            create_indexes,
            initialize_beanie,
        ]
    )


"""Workaround to use global exception handlers for versioned API.
The issue has already been reported here:
https://github.com/DeanWay/fastapi-versioning/issues/30
"""
for sub_app in versioned_app.routes:
    if hasattr(sub_app.app, "add_exception_handler"):
        sub_app.app.add_exception_handler(
            ValueError, value_error_exception_handler
        )
        sub_app.app.add_exception_handler(
            errors.InvalidId, invalid_id_exception_handler
        )


@versioned_app.middleware("http")
async def redirect_http_requests(request: Request, call_next):
    """Redirect request with version prefix when no version is provided"""
    response = None
    path = request.scope['path']
    match = re.match(r'^/(v[\d.]+)', path)
    if match:
        prefix = match.group(1)
        if prefix not in API_VERSIONS:
            response = PlainTextResponse(
                f"Unsupported API version: {prefix}",
                status_code=status.HTTP_400_BAD_REQUEST
            )
    elif not path.startswith('/latest'):
        request.scope['path'] = '/latest' + path
    return response or await call_next(request)