# copyright 2022-2024 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact https://www.logilab.fr -- mailto:contact@logilab.fr
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.

import json
import logging
from functools import partial
from enum import Enum

from cubicweb import AuthenticationError, Binary
from cubicweb.schema_exporters import JSONSchemaExporter
from cubicweb.sobjects.services import StatsService, GcStatsService
from pyramid.config import Configurator
from pyramid.request import Request
from pyramid.response import Response
from pyramid.security import remember, forget
from pyramid.settings import asbool

from cubicweb_api.auth.jwt_auth import setup_jwt
from cubicweb_api.constants import (
    API_ROUTE_NAME_PREFIX,
)
from cubicweb_api.httperrors import get_http_error
from cubicweb_api.openapi.openapi import setup_openapi, custom_openapi_validation_error
from cubicweb_api.util import get_cw_repo
from cubicweb_api.transaction import Transaction, BinaryResolver
from cubicweb.pyramid.core import Connection
from cubicweb.entities import AnyEntity
from cubicweb._exceptions import UnknownEid
from yams.schema import RelationDefinitionSchema
from yams.types import DefinitionName
from openapi_core import validate_request
from os import path
from openapi_spec_validator import validate_spec
from openapi_spec_validator.readers import read_from_filename
from openapi_core import Spec
from pyramid_openapi3.wrappers import PyramidOpenAPIRequest
from pyramid_openapi3.exceptions import RequestValidationError

log = logging.getLogger(__name__)


class ApiRoutes(Enum):
    """
    All the available routes as listed in the openapi/openapi_template.yml file.
    """

    schema = "schema"
    rql = "rql"
    binary = "binary"
    login = "login"
    logout = "logout"
    current_user = "current_user"
    siteinfo = "siteinfo"
    help = "help"


def get_route_name(route_name: ApiRoutes) -> str:
    """
    Generates a unique route name using the api
    prefix to prevent clashes with routes from other cubes.

    :param route_name: The route name base
    :return: The generated route name
    """
    return f"{API_ROUTE_NAME_PREFIX}{route_name.value}"


def schema_view(request: Request):
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    repo = get_cw_repo(request)
    exporter = JSONSchemaExporter()
    exported_schema = exporter.export_as_dict(repo.schema)
    return exported_schema


def rql_multipart_view(request: Request):
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    body = request.openapi_validated.body

    # As we can't validate params in the multipart, we convert the request to JSON
    # and manually validate it
    request.content_type = "application/json"
    request.body = body["queries"].encode()
    spec_path = path.join(request.cw_cnx.repo.config.apphome, "openapi.yaml")
    spec_dict, _ = read_from_filename(spec_path)
    validate_spec(spec_dict)
    spec = Spec.create(spec_dict)

    # Manually run the request validation
    openapi_request = PyramidOpenAPIRequest(request)
    try:
        validate_request(request=openapi_request, spec=spec)
    except Exception as e:
        return custom_openapi_validation_error(
            RequestValidationError(errors=[e]), request
        )

    queries = json.loads(body["queries"])
    transaction = Transaction(queries, BinaryResolver(body))
    rsets = [rset.rows for rset in transaction.execute(request.cw_cnx)]
    return rsets


def rql_view(request: Request):
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    queries = request.openapi_validated.body
    transaction = Transaction(queries)
    rsets = [rset.rows for rset in transaction.execute(request.cw_cnx)]
    return rsets


def binary_view(request: Request):
    request_params = request.openapi_validated.parameters.query
    eid: int = request_params["eid"]
    attribute_name: DefinitionName = request_params["attribute"]
    cw_cnx: Connection = request.cw_cnx

    try:
        entity: AnyEntity = cw_cnx.entity_from_eid(eid)
        rel_def: RelationDefinitionSchema = entity.e_schema.relation_definition(
            attribute_name
        )
    except (UnknownEid, KeyError) as e:
        return get_http_error(
            400,
            "KeyError",
            str(e),
        )

    if rel_def.object.type != "Bytes":
        return get_http_error(
            400,
            "KeyError",
            f"Attribute '{attribute_name}' of "
            f"entity '{entity.cw_etype}' is not of type Bytes",
        )
    attribute = getattr(entity, attribute_name)
    if attribute is None:
        request.response.status_code = 204
        request.response.content_type = None
    else:
        binary: Binary = attribute
        request.response.content_type = "application/octet-stream"
        request.response.body = binary.read()
    return request.response


def login_view(request: Request):
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    request_params = request.openapi_validated.body
    login: str = request_params["login"]
    pwd: str = request_params["password"]

    repo = get_cw_repo(request)
    with repo.internal_cnx() as cnx:
        try:
            cwuser = repo.authenticate_user(cnx, login, password=pwd)
        except AuthenticationError:
            raise AuthenticationError("Invalid credentials")

        headers = remember(
            request,
            cwuser.eid,
        )
        return Response(headers=headers, status=204)


def logout_view(request: Request):
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    headers = forget(request)
    return Response(headers=headers, status=204)


def current_user_view(request: Request) -> dict:
    """
    See the openapi/openapi_template.yml
    file for more information about this route.
    """
    user = request.cw_cnx.user
    return {"eid": user.eid, "login": user.login, "dcTitle": user.dc_title()}


def siteinfo_view(request: Request):
    """
    display debugging information about the current website
    """
    repo = get_cw_repo(request)
    version_configuration = repo.get_versions()

    pyvalue = {
        "config_type": repo.vreg.config.name,
        "config_mode": repo.vreg.config.mode,
        "instance_home": repo.vreg.config.apphome,
        "cubicweb": version_configuration.get("cubicweb", "no version configuration"),
        "cubes": {
            pk.replace("system.version.", ""): version
            for pk, version in request.cw_cnx.execute(
                "Any K,V WHERE P is CWProperty, P value V, P pkey K, "
                'P pkey ~="system.version.%"',
                build_descr=False,
            )
        },
        "base_url": repo.config["base-url"],
        "datadir_url": getattr(repo.vreg.config, "datadir_url", None),
    }

    return {
        "info": {
            "pyvalue": pyvalue,
            "stats": StatsService(request.cw_cnx).call(),
        },
        "registry": {
            x: {a: [str(klass) for klass in b] for a, b in y.items()}
            for x, y in repo.vreg.items()
        },
        "gc": GcStatsService(request.cw_cnx).call(),
    }


def includeme(config: Configurator):
    enable_login = asbool(
        config.registry.settings.get("cubicweb_api.enable_login_route", False)
    )
    if enable_login:
        setup_jwt(config)

    setup_openapi(config, enable_login=enable_login)
    config.pyramid_openapi3_register_routes()

    view_defaults = dict(
        request_method="POST",
        renderer="cubicweb_api_json",
        # CSRF protection using tokens only apply if the api is used by <form/> HTML components
        # This API is more generic thus we use custom HTTP headers
        # Each request expects the header "X-Client-Name: <YOUR_CLIENT>" to be set
        #
        # More information about CSRF protection in the OWASP cheatsheet:
        # https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html#custom-request-headers
        # Note: Only the multipart route is subject to CSRF, but we add the custom
        #       header on all routes for consistency
        require_csrf=False,
        openapi=True,
        use_api_exceptions=True,
        anonymous_or_connected=True,
    )
    add_view = partial(config.add_view, **view_defaults)

    add_view(
        view=schema_view,
        route_name=get_route_name(ApiRoutes.schema),
        request_method="GET",
    )

    add_view(
        view=rql_multipart_view,
        route_name=get_route_name(ApiRoutes.rql),
        header="Content-Type:multipart/form-data",
    )

    add_view(
        view=rql_view,
        route_name=get_route_name(ApiRoutes.rql),
    )

    add_view(
        view=binary_view,
        route_name=get_route_name(ApiRoutes.binary),
        request_method="GET",
        renderer=None,
    )

    if enable_login:
        add_view(
            view=login_view,
            route_name=get_route_name(ApiRoutes.login),
            anonymous_or_connected=None,
        )
        add_view(
            view=logout_view,
            route_name=get_route_name(ApiRoutes.logout),
            anonymous_or_connected=None,
        )

    add_view(
        view=current_user_view,
        route_name=get_route_name(ApiRoutes.current_user),
        request_method="GET",
    )

    add_view(
        view=siteinfo_view,
        route_name=get_route_name(ApiRoutes.siteinfo),
        request_method="GET",
    )