#!/usr/bin/env python
#
# Copyright (C) 2020 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
API routes for users.
"""

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from uuid import UUID
from typing import List

from gns3server import schemas
from gns3server.controller.controller_error import (
    ControllerBadRequestError,
    ControllerNotFoundError,
    ControllerForbiddenError,
)

from gns3server.db.repositories.users import UsersRepository
from gns3server.db.repositories.rbac import RbacRepository
from gns3server.services import auth_service

from .dependencies.authentication import get_current_active_user
from .dependencies.database import get_repository

import logging

log = logging.getLogger(__name__)

router = APIRouter()


@router.post("/login", response_model=schemas.Token)
async def login(
    users_repo: UsersRepository = Depends(get_repository(UsersRepository)),
    form_data: OAuth2PasswordRequestForm = Depends(),
) -> schemas.Token:
    """
    Default user login method using forms (x-www-form-urlencoded).
    Example: curl http://host:port/v3/users/login -H "Content-Type: application/x-www-form-urlencoded" -d "username=admin&password=admin"
    """

    user = await users_repo.authenticate_user(username=form_data.username, password=form_data.password)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Authentication was unsuccessful.",
            headers={"WWW-Authenticate": "Bearer"},
        )

    token = schemas.Token(access_token=auth_service.create_access_token(user.username), token_type="bearer")
    return token


@router.post("/authenticate", response_model=schemas.Token)
async def authenticate(
    user_credentials: schemas.Credentials,
    users_repo: UsersRepository = Depends(get_repository(UsersRepository)),
) -> schemas.Token:
    """
    Alternative authentication method using json.
    Example: curl http://host:port/v3/users/authenticate -d '{"username": "admin", "password": "admin"}'
    """

    user = await users_repo.authenticate_user(username=user_credentials.username, password=user_credentials.password)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Authentication was unsuccessful.",
            headers={"WWW-Authenticate": "Bearer"},
        )

    token = schemas.Token(access_token=auth_service.create_access_token(user.username), token_type="bearer")
    return token


@router.get("/me", response_model=schemas.User)
async def get_logged_in_user(current_user: schemas.User = Depends(get_current_active_user)) -> schemas.User:
    """
    Get the current active user.
    """

    return current_user


@router.get("/me", response_model=schemas.User)
async def get_logged_in_user(current_user: schemas.User = Depends(get_current_active_user)) -> schemas.User:
    """
    Get the current active user.
    """

    return current_user


@router.get("", response_model=List[schemas.User], dependencies=[Depends(get_current_active_user)])
async def get_users(
        users_repo: UsersRepository = Depends(get_repository(UsersRepository))
) -> List[schemas.User]:
    """
    Get all users.
    """

    return await users_repo.get_users()


@router.post(
    "",
    response_model=schemas.User,
    dependencies=[Depends(get_current_active_user)],
    status_code=status.HTTP_201_CREATED
)
async def create_user(
        user_create: schemas.UserCreate,
        users_repo: UsersRepository = Depends(get_repository(UsersRepository))
) -> schemas.User:
    """
    Create a new user.
    """

    if await users_repo.get_user_by_username(user_create.username):
        raise ControllerBadRequestError(f"Username '{user_create.username}' is already registered")

    if user_create.email and await users_repo.get_user_by_email(user_create.email):
        raise ControllerBadRequestError(f"Email '{user_create.email}' is already registered")

    return await users_repo.create_user(user_create)


@router.get("/{user_id}", dependencies=[Depends(get_current_active_user)], response_model=schemas.User)
async def get_user(
        user_id: UUID,
        users_repo: UsersRepository = Depends(get_repository(UsersRepository)),
) -> schemas.User:
    """
    Get an user.
    """

    user = await users_repo.get_user(user_id)
    if not user:
        raise ControllerNotFoundError(f"User '{user_id}' not found")
    return user


@router.put("/{user_id}", dependencies=[Depends(get_current_active_user)], response_model=schemas.User)
async def update_user(
        user_id: UUID,
        user_update: schemas.UserUpdate,
        users_repo: UsersRepository = Depends(get_repository(UsersRepository))
) -> schemas.User:
    """
    Update an user.
    """

    user = await users_repo.update_user(user_id, user_update)
    if not user:
        raise ControllerNotFoundError(f"User '{user_id}' not found")
    return user


@router.delete(
    "/{user_id}",
    dependencies=[Depends(get_current_active_user)],
    status_code=status.HTTP_204_NO_CONTENT
)
async def delete_user(
    user_id: UUID,
    users_repo: UsersRepository = Depends(get_repository(UsersRepository)),
) -> None:
    """
    Delete an user.
    """

    user = await users_repo.get_user(user_id)
    if not user:
        raise ControllerNotFoundError(f"User '{user_id}' not found")

    if user.is_superadmin:
        raise ControllerForbiddenError("The super admin cannot be deleted")

    success = await users_repo.delete_user(user_id)
    if not success:
        raise ControllerNotFoundError(f"User '{user_id}' could not be deleted")


@router.get(
    "/{user_id}/groups",
    dependencies=[Depends(get_current_active_user)],
    response_model=List[schemas.UserGroup]
)
async def get_user_memberships(
        user_id: UUID,
        users_repo: UsersRepository = Depends(get_repository(UsersRepository))
) -> List[schemas.UserGroup]:
    """
    Get user memberships.
    """

    return await users_repo.get_user_memberships(user_id)


@router.get(
    "/{user_id}/permissions",
    dependencies=[Depends(get_current_active_user)],
    response_model=List[schemas.Permission]
)
async def get_user_permissions(
        user_id: UUID,
        rbac_repo: RbacRepository = Depends(get_repository(RbacRepository))
) -> List[schemas.Permission]:
    """
    Get user permissions.
    """

    return await rbac_repo.get_user_permissions(user_id)


@router.put(
    "/{user_id}/permissions/{permission_id}",
    dependencies=[Depends(get_current_active_user)],
    status_code=status.HTTP_204_NO_CONTENT
)
async def add_permission_to_user(
        user_id: UUID,
        permission_id: UUID,
        rbac_repo: RbacRepository = Depends(get_repository(RbacRepository))
) -> None:
    """
    Add a permission to an user.
    """

    permission = await rbac_repo.get_permission(permission_id)
    if not permission:
        raise ControllerNotFoundError(f"Permission '{permission_id}' not found")

    user = await rbac_repo.add_permission_to_user(user_id, permission)
    if not user:
        raise ControllerNotFoundError(f"User '{user_id}' not found")


@router.delete(
    "/{user_id}/permissions/{permission_id}",
    dependencies=[Depends(get_current_active_user)],
    status_code=status.HTTP_204_NO_CONTENT
)
async def remove_permission_from_user(
    user_id: UUID,
    permission_id: UUID,
    rbac_repo: RbacRepository = Depends(get_repository(RbacRepository)),
) -> None:
    """
    Remove permission from an user.
    """

    permission = await rbac_repo.get_permission(permission_id)
    if not permission:
        raise ControllerNotFoundError(f"Permission '{permission_id}' not found")

    user = await rbac_repo.remove_permission_from_user(user_id, permission)
    if not user:
        raise ControllerNotFoundError(f"User '{user_id}' not found")