{{!

  Copyright (c) Meta Platforms, Inc. and affiliates.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

}}{{!
Generates a top-level file to be imported in the user's service code. It provides
wrappers for each of the service handlers that the user is then able to extend.
}}
{{> common/auto_generated_py}}

from abc import ABCMeta
import typing as _typing

import folly.iobuf as _fbthrift_iobuf

import apache.thrift.metadata.thrift_types as _fbthrift_metadata
{{#program:generate_immutable_types}}
from {{program:base_library_package}}.serializer import serialize_iobuf, deserialize, Protocol
{{/program:generate_immutable_types}}
{{#program:generate_mutable_types}}
from {{program:base_library_package}}.mutable_serializer import serialize_iobuf, deserialize, Protocol
{{/program:generate_mutable_types}}
from {{program:base_library_package}}.server import ServiceInterface, RpcKind, PythonUserException

import {{program:module_path}}.{{>types/types_import_path}}
import {{program:module_path}}.thrift_metadata
{{#program:include_namespaces}}
{{#has_services?}}
import {{included_module_path}}.thrift_services
{{/has_services?}}
{{#has_types?}}
import {{included_module_path}}.{{>types/types_import_path}}
{{/has_types?}}
{{/program:include_namespaces}}
{{#program:adapter_modules}}
import {{module_path}}
{{/program:adapter_modules}}
{{#program:adapter_type_hint_modules}}
import {{module_path}}
{{/program:adapter_type_hint_modules}}

{{#program:services}}
class {{service:name}}Interface(
  {{#service:extends}}{{#service:external_program?}}
    {{service:module_path}}.thrift_services.{{/service:external_program?}}{{service:name}}Interface,
    {{/service:extends}}
    {{^service:extends?}}
    ServiceInterface,
    {{/service:extends?}}
    metaclass=ABCMeta
):

    @staticmethod
    def service_name() -> bytes:
        return b"{{service:name}}"

    def getFunctionTable(self) -> _typing.Mapping[bytes, _typing.Callable[..., object]]:
        functionTable = {
        {{#service:supported_service_functions}}
            b"{{function:name}}": ({{> services/function_kind }}, self._fbthrift__handler_{{function:name}}),
        {{/service:supported_service_functions}}
        }
        return {**super().getFunctionTable(), **functionTable}

    @staticmethod
    def __get_thrift_name__() -> str:
        return "{{program:name}}.{{service:name}}"

    @staticmethod
    def __get_metadata__() -> _fbthrift_metadata.ThriftMetadata:
        return {{program:module_path}}.thrift_metadata.gen_metadata_service_{{service:name}}()

    @staticmethod
    def __get_metadata_service_response__() -> _fbthrift_metadata.ThriftServiceMetadataResponse:
        return {{program:module_path}}.thrift_metadata._fbthrift_metadata_service_response_{{service:name}}()


{{#service:supported_service_functions}}

    {{^function:stream?}}async {{/function:stream?}}{{#function:stream_has_first_response?}}async {{/function:stream_has_first_response?}}def {{function:name}}(
            self{{#function:args}},
            {{field:py_name}}: {{#field:type}}{{> types/pep484_type}}{{/field:type}}{{/function:args}}
        ) -> {{#function:return_type}}{{> services/service_func_return_type }}{{/function:return_type}}:
        raise NotImplementedError("async def {{function:name}} is not implemented")

    {{#function:stream?}}
    async def _fbthrift__stream_wrapper_{{function:name}}(self, stream_generator: _typing.AsyncIterator[{{#function:stream_elem_type}}{{> types/pep484_type}}{{/function:stream_elem_type}}], protocol: Protocol) -> _typing.AsyncIterator[_fbthrift_iobuf.IOBuf]:
        {{#function:stream_exceptions?}}
        try:
            async for item in stream_generator:
                yield serialize_iobuf({{> types/function_second_return_type}}(success=item), protocol)
        {{#function:stream_exceptions}}{{#field:type}}
        except {{type:module_path}}.{{#type:struct}}{{> structs/unadapted_name}}{{/type:struct}} as e:
            return_struct = {{> types/function_second_return_type}}({{field:py_name}}=e)
            buf = serialize_iobuf(return_struct, protocol)
            exp = PythonUserException('{{type:py3_namespace}}{{#type:struct}}{{> structs/unadapted_name}}{{/type:struct}}', str(e), buf)
            raise exp
        {{/field:type}}
        {{/function:stream_exceptions}}
        {{/function:stream_exceptions?}}
        {{^function:stream_exceptions?}}
        async for item in stream_generator:
            yield serialize_iobuf({{> types/function_second_return_type}}(success=item), protocol)
        {{/function:stream_exceptions?}}

    {{/function:stream?}}
    async def _fbthrift__handler_{{function:name}}(self, args: _fbthrift_iobuf.IOBuf, protocol: Protocol) {{!
            }}-> {{> services/service_handler_return_type }}:
        args_struct = deserialize({{> types/function_args_type}}, args, protocol)
        {{! TODO: call the postWrite hook here }}
        {{#function:exceptions?}}
        try:
            {{> services/get_handler_result }}
        {{#function:exceptions}}{{#field:type}}
        except {{type:module_path}}.{{#type:struct}}{{> structs/unadapted_name}}{{/type:struct}} as e:
            return_struct = {{> types/function_return_type}}({{field:py_name}}=e)
            buf = serialize_iobuf(return_struct, protocol)
            exp = PythonUserException('{{type:py3_namespace}}{{#type:struct}}{{> structs/unadapted_name}}{{/type:struct}}', str(e), buf)
            raise exp
        {{/field:type}}
        {{/function:exceptions}}
        {{/function:exceptions?}}
        {{^function:exceptions?}}
        {{> services/get_handler_result }}
        {{/function:exceptions?}}
        {{^function:oneway?}}
        {{^function:stream?}}
        return serialize_iobuf(return_struct, protocol)
        {{/function:stream?}}
        {{#function:stream?}}
        return (serialize_iobuf(return_struct, protocol), return_stream)
        {{/function:stream?}}
        {{/function:oneway?}}

{{/service:supported_service_functions}}
{{/program:services}}
