{{!

  Copyright (c) Facebook, Inc. and its 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.

}}
    {{#service:interactions}}{{>lib/server}}
    {{/service:interactions}}

    {{#service:docs?}}
    #[doc = {{service:docs}}]
    {{/service:docs?}}
    #[::async_trait::async_trait]
    pub trait {{service:name}}: ::std::marker::Send + ::std::marker::Sync + 'static {{>lib/block}}{{!
    }}{{#service:requestContext?}}
        type RequestContext: ::std::marker::Sync;{{!
    }}{{/service:requestContext?}}
    {{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}
        {{#function:docs?}}
        #[doc = {{function:docs}}]
        {{/function:docs?}}
        async fn {{function:rust_name}}(
            &self,{{!
            }}{{#service:requestContext?}}
            _request_context: &Self::RequestContext,{{!
            }}{{/service:requestContext?}}{{!
            }}{{#function:args}}
            _{{field:name}}: {{#field:type}}{{>lib/type}}{{/field:type}},{{!
            }}{{/function:args}}
        ) -> ::std::result::Result<{{!
            }}{{#function:return_type}}{{>lib/type}}{{/function:return_type}}, {{!
            }}{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn{{!
        }}> {
            ::std::result::Result::Err({{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::ApplicationException(
                ::fbthrift::ApplicationException::unimplemented_method(
                    "{{service:name}}",
                    "{{function:name}}",
                ),
            ))
        }
    {{/function:returns_streams?}}{{#function:returns_streams?}}
        // {{function:rust_name}}: server-side streaming not yet implemented
    {{/function:returns_streams?}}
    {{/function:starts_interaction?}}{{#function:starts_interaction?}}
        {{#function:docs?}}
        #[doc = {{function:docs}}]
        {{/function:docs?}}
        fn {{function:rust_name}}(
            &self,
        ) -> ::anyhow::Result<::std::boxed::Box<dyn {{function:interaction_name}}>> {
            ::anyhow::bail!("{{service:name}}.{{function:name}} not implemented");
        }
    {{/function:starts_interaction?}}{{/service:rustFunctions}}
    }

    #[::async_trait::async_trait]
    impl<T> {{service:name}} for ::std::boxed::Box<T>
    where
        T: {{service:name}} + Send + Sync + ?Sized,
    {{>lib/block}}
    {{#service:requestContext?}}
        type RequestContext = T::RequestContext;{{!
    }}{{/service:requestContext?}}
    {{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}
        async fn {{function:rust_name}}(
            &self,{{!
            }}{{#service:requestContext?}}
            request_context: &Self::RequestContext,{{!
            }}{{/service:requestContext?}}{{!
            }}{{#function:args}}
            {{field:rust_name}}: {{#field:type}}{{>lib/type}}{{/field:type}},{{!
            }}{{/function:args}}
        ) -> ::std::result::Result<{{!
            }}{{#function:return_type}}{{>lib/type}}{{/function:return_type}}, {{!
            }}{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn{{!
        }}> {
            (**self).{{function:rust_name}}({{!
                }}{{#service:requestContext?}}
                request_context, {{!
                }}{{/service:requestContext?}}{{!
                }}{{#function:args}}
                {{field:rust_name}}, {{!
                }}{{/function:args}}
            ).await
        }
    {{/function:returns_streams?}}{{#function:returns_streams?}}
        // {{function:rust_name}}: server-side streaming not yet implemented
    {{/function:returns_streams?}}
    {{/function:starts_interaction?}}{{#function:starts_interaction?}}
        fn {{function:rust_name}}(
            &self,
        ) -> ::anyhow::Result<::std::boxed::Box<dyn {{function:interaction_name}}>> {
            (**self).{{function:rust_name}}()
        }
    {{/function:starts_interaction?}}{{/service:rustFunctions}}
    }

    /// Processor for {{service:name}}'s methods.
    #[derive(Clone, Debug)]
    pub struct {{service:name}}Processor<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
        }}{{!
    }}> {
        service: H,{{!
        }}{{#service:extends?}}
        supa: SS,{{!
        }}{{/service:extends?}}{{!
        }}{{^service:extends?}}
        supa: ::fbthrift::NullServiceProcessor<P, R>,{{!
        }}{{/service:extends?}}
        _phantom: ::std::marker::PhantomData<(P, H, R)>,
    }

    {{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}
    struct Args_{{service:name}}_{{function:name}} {
        {{#function:args}}
        {{field:rust_name}}: {{>lib/fieldtype}},
        {{/function:args}}
    }
    impl<P: ::fbthrift::ProtocolReader> ::fbthrift::Deserialize<P> for self::Args_{{service:name}}_{{function:name}} {
        #[inline]{{! No cost because there's only one caller; with luck will mitigate move cost of args. }}
        #[::tracing::instrument(skip_all, level = "trace", name = "deserialize_args", fields(method = "{{service:name}}.{{function:name}}"))]
        fn read(p: &mut P) -> ::anyhow::Result<Self> {
            static ARGS: &[::fbthrift::Field] = &[
                {{#function:args_by_name}}
                ::fbthrift::Field::new("{{field:name}}", {{#field:type}}{{>lib/ttype}}{{/field:type}}, {{field:key}}),
                {{/function:args_by_name}}
            ];
            {{#function:args}}
            let mut field_{{field:name}} = ::std::option::Option::None;
            {{/function:args}}
            let _ = p.read_struct_begin(|_| ())?;
            loop {
                let (_, fty, fid) = p.read_field_begin(|_| (), ARGS)?;
                match (fty, fid as ::std::primitive::i32) {
                    (::fbthrift::TType::Stop, _) => break,{{!
                    }}{{#function:args}}
                    ({{#field:type}}{{>lib/ttype}}{{/field:type}}, {{field:key}}) => {{!
                        }}field_{{field:name}} = ::std::option::Option::Some({{#field:type}}{{>lib/read}}{{/field:type}}(p)?),{{!
                    }}{{/function:args}}
                    (fty, _) => p.skip(fty)?,
                }
                p.read_field_end()?;
            }
            p.read_struct_end()?;
            {{! Use formatting in errors to try to maximize string sharing }}
            ::std::result::Result::Ok(Self {{>lib/block}}{{!
                }}{{#function:args}}
                {{field:rust_name}}: field_{{field:name}}.ok_or_else(|| ::anyhow::anyhow!("`{}` missing arg `{}`", "{{service:name}}.{{function:name}}", "{{field:name}}"))?,{{!
                }}{{/function:args}}
            })
        }
    }

    {{/function:returns_streams?}}{{/function:starts_interaction?}}{{/service:rustFunctions}}

    impl<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}> {{service:name}}Processor<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}>
    where
        P: ::fbthrift::Protocol + ::std::marker::Send + ::std::marker::Sync + 'static,
        P::Deserializer: ::std::marker::Send,
        H: {{service:name}}{{!
        }}{{#service:requestContext?}}<RequestContext = R>{{/service:requestContext?}},
        R: ::fbthrift::RequestContext<Name = ::std::ffi::CStr> + ::std::marker::Sync,
        <R as ::fbthrift::RequestContext>::ContextStack: ::fbthrift::ContextStack<Name = R::Name, Buffer = ::fbthrift::ProtocolDecoded<P>>
            + ::std::marker::Send + ::std::marker::Sync,{{!
        }}{{#service:extends?}}
        SS: ::fbthrift::ThriftService<P::Frame>,
        SS::Handler: {{>lib/super}},
        P::Frame: ::std::marker::Send + 'static,{{!
        }}{{/service:extends?}}
    {
        pub fn new({{!
            }}service: H{{!
            }}{{#service:extends?}}, supa: SS{{/service:extends?}}{{!
        }}) -> Self {
            Self {
                service,
                supa{{^service:extends?}}{{!
                    }}: ::fbthrift::NullServiceProcessor::new(){{!
                }}{{/service:extends?}},
                _phantom: ::std::marker::PhantomData,
            }
        }

        pub fn into_inner(self) -> H {
            self.service
        }{{!
        }}{{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}

        #[::tracing::instrument(skip_all, fields(method = "{{service:name}}.{{function:name}}"))]
        async fn handle_{{function:name}}<'a>(
            &'a self,
            p: &'a mut P::Deserializer,
            _req_ctxt: &R,
            ctx_stack: &mut R::ContextStack,
        ) -> ::anyhow::Result<{{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn> {
            use ::const_cstr::const_cstr;
            use ::tracing::Instrument as _;
            use ::futures::FutureExt as _;

            const_cstr! {
                SERVICE_NAME = "{{service:name}}";
                METHOD_NAME = "{{service:name}}.{{function:name}}";
            }
            ::fbthrift::ContextStack::pre_read(ctx_stack)?;
            let _args: self::Args_{{service:name}}_{{function:name}} = ::fbthrift::Deserialize::read(p)?;
            ::fbthrift::ContextStack::on_read_data(ctx_stack, &::fbthrift::SerializedMessage {
                protocol: P::PROTOCOL_ID,
                method_name: METHOD_NAME.as_cstr(),
                buffer: ::std::marker::PhantomData, // FIXME P::into_buffer(p).reset(),
            })?;
            ::fbthrift::ContextStack::post_read(ctx_stack, 0)?;

            let res = ::std::panic::AssertUnwindSafe(
                self.service.{{function:rust_name}}({{!
                    }}{{#service:requestContext?}}
                    _req_ctxt,{{!
                    }}{{/service:requestContext?}}{{!
                    }}{{#function:args}}
                    _args.{{field:rust_name}},{{!
                    }}{{/function:args}}
                )
            )
            .catch_unwind()
            .instrument(::tracing::info_span!("service_handler", method = "{{service:name}}.{{function:name}}"))
            .await;

            // nested results - panic catch on the outside, method on the inside
            let res = match res {
                ::std::result::Result::Ok(::std::result::Result::Ok(res)) => {
                    ::tracing::info!(method = "{{service:name}}.{{function:name}}", "success");
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::Success(res)
                }
                ::std::result::Result::Ok(::std::result::Result::Err({{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::Success(_))) => {
                    panic!(
                        "{} attempted to return success via error",
                        "{{function:rust_name}}",
                    )
                }
                ::std::result::Result::Ok(::std::result::Result::Err(exn)) => {
                    ::tracing::error!(method = "{{service:name}}.{{function:name}}", exception = ?exn);
                    exn
                }
                ::std::result::Result::Err(exn) => {
                    let aexn = ::fbthrift::ApplicationException::handler_panic("{{service:name}}.{{function:name}}", exn);
                    {{program:crate}}::services::{{service:snake}}::{{function:upcamel}}Exn::ApplicationException(aexn)
                }
            };

            ::std::result::Result::Ok(res)
        }{{!
        }}{{/function:returns_streams?}}{{/function:starts_interaction?}}{{#function:starts_interaction?}}

        fn handle_{{function:name}}(
            &self,
        ) -> ::anyhow::Result<::std::boxed::Box<dyn {{function:interaction_name}}>> {
            self.service.{{function:rust_name}}()
        }{{!
        }}{{/function:starts_interaction?}}{{!
        }}{{/service:rustFunctions}}
    }

    #[::async_trait::async_trait]
    impl<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}> ::fbthrift::ServiceProcessor<P> for {{service:name}}Processor<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}>
    where
        P: ::fbthrift::Protocol + ::std::marker::Send + ::std::marker::Sync + 'static,
        P::Deserializer: ::std::marker::Send,
        H: {{service:name}}{{!
        }}{{#service:requestContext?}}<RequestContext = R>{{/service:requestContext?}},{{!
        }}{{#service:extends?}}
        SS: ::fbthrift::ThriftService<P::Frame>,
        SS::Handler: {{>lib/super}},{{!
        }}{{/service:extends?}}
        P::Frame: ::std::marker::Send + 'static,
        R: ::fbthrift::RequestContext<Name = ::std::ffi::CStr> + ::std::marker::Send + ::std::marker::Sync + 'static,
        <R as ::fbthrift::RequestContext>::ContextStack: ::fbthrift::ContextStack<Name = R::Name, Buffer = ::fbthrift::ProtocolDecoded<P>>
            + ::std::marker::Send + ::std::marker::Sync + 'static
    {
        type RequestContext = R;

        #[inline]
        fn method_idx(&self, name: &[::std::primitive::u8]) -> ::std::result::Result<::std::primitive::usize, ::fbthrift::ApplicationException> {
            match name {{>lib/block}}{{!
                }}{{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}
                b"{{#service:interaction?}}{{service:name}}.{{/service:interaction?}}{{function:name}}" => ::std::result::Result::Ok({{function:index}}usize),{{!
                }}{{/function:returns_streams?}}{{/function:starts_interaction?}}{{/service:rustFunctions}}
                _ => ::std::result::Result::Err(::fbthrift::ApplicationException::unknown_method()),
            }
        }

        async fn handle_method(
            &self,
            idx: ::std::primitive::usize,
            _p: &mut P::Deserializer,
            _r: &R,
            _seqid: ::std::primitive::u32,
        ) -> ::anyhow::Result<::fbthrift::ProtocolEncodedFinal<P>> {
            match idx {{>lib/block}}{{!
                }}{{#service:rustFunctions}}{{^function:starts_interaction?}}{{^function:returns_streams?}}
                {{function:index}}usize => {
                    use const_cstr::const_cstr;
                    const_cstr! {
                        SERVICE_NAME = "{{service:name}}";
                        METHOD_NAME = "{{service:name}}.{{function:name}}";
                    }
                    let mut ctx_stack = _r.get_context_stack(
                        SERVICE_NAME.as_cstr(),
                        METHOD_NAME.as_cstr(),
                    )?;
                    let res = self.handle_{{function:name}}(_p, _r, &mut ctx_stack).await?;
                    let env = ::fbthrift::help::serialize_result_envelope::<P, R, _>(
                        "{{function:name}}",
                        METHOD_NAME.as_cstr(),
                        _seqid,
                        _r,
                        &mut ctx_stack,
                        res
                    )?;
                    Ok(env)
                }{{!
                }}{{/function:returns_streams?}}{{/function:starts_interaction?}}{{/service:rustFunctions}}
                bad => panic!(
                    "{}: unexpected method idx {}",
                    "{{service:name}}Processor",
                    bad
                ),
            }
        }

        #[inline]
        fn create_interaction_idx(&self, name: &str) -> ::anyhow::Result<::std::primitive::usize> {
            match name {{>lib/block}}{{!
                }}{{#service:rustFunctions}}{{#function:starts_interaction?}}
                "{{function:interaction_name}}" => ::std::result::Result::Ok({{function:index}}usize),{{!
                }}{{/function:starts_interaction?}}{{/service:rustFunctions}}
                _ => ::anyhow::bail!("Unknown interaction"),
            }
        }

        fn handle_create_interaction(
            &self,
            idx: ::std::primitive::usize,
        ) -> ::anyhow::Result<
            ::std::sync::Arc<dyn ::fbthrift::ThriftService<P::Frame, Handler = (), RequestContext = Self::RequestContext> + ::std::marker::Send + 'static>
        > {
            match idx {{>lib/block}}{{!
                }}{{#service:rustFunctions}}{{#function:starts_interaction?}}
                {{function:index}}usize => {
                    let handler = self.handle_{{function:name}}()?;
                    let server = ::std::sync::Arc::new({{function:interaction_name}}Processor::<P, ::std::boxed::Box<dyn {{function:interaction_name}}>, R>::new(handler));
                    Ok(server)
                }{{!
                }}{{/function:starts_interaction?}}{{/service:rustFunctions}}
                bad => panic!(
                    "{}: unexpected method idx {}",
                    "{{service:name}}Processor",
                    bad
                ),
            }
        }
    }

    #[::async_trait::async_trait]
    impl<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}> ::fbthrift::ThriftService<P::Frame> for {{service:name}}Processor<P, H, R{{!
        }}{{#service:extends?}}, SS{{/service:extends?}}{{!
    }}>
    where
        P: ::fbthrift::Protocol + ::std::marker::Send + ::std::marker::Sync + 'static,
        P::Deserializer: ::std::marker::Send,
        P::Frame: ::std::marker::Send + 'static,
        H: {{service:name}}{{!
        }}{{#service:requestContext?}}<RequestContext = R>{{/service:requestContext?}},{{!
        }}{{#service:extends?}}
        SS: ::fbthrift::ThriftService<P::Frame, RequestContext = R>,
        SS::Handler: {{>lib/super}},
        P::Frame: ::std::marker::Send + 'static,{{!
        }}{{/service:extends?}}
        R: ::fbthrift::RequestContext<Name = ::std::ffi::CStr> + ::std::marker::Send + ::std::marker::Sync + 'static,
        <R as ::fbthrift::RequestContext>::ContextStack: ::fbthrift::ContextStack<Name = R::Name, Buffer = ::fbthrift::ProtocolDecoded<P>>
            + ::std::marker::Send + ::std::marker::Sync + 'static
    {
        {{#service:interaction?}}
        // Interactions have () as their handler associated type
        // to make `create_interaction` have a common return type.
        type Handler = ();
        {{/service:interaction?}}{{^service:interaction?}}
        type Handler = H;
        {{/service:interaction?}}
        type RequestContext = R;

        #[tracing::instrument(level="trace", skip_all, fields(service = "{{service:name}}"))]
        async fn call(
            &self,
            req: ::fbthrift::ProtocolDecoded<P>,
            req_ctxt: &R,
        ) -> ::anyhow::Result<::fbthrift::ProtocolEncodedFinal<P>> {
            use ::fbthrift::{BufExt as _, ProtocolReader as _, ServiceProcessor as _};
            let mut p = P::deserializer(req);
            let (idx, mty, seqid) = p.read_message_begin(|name| self.method_idx(name))?;
            if mty != ::fbthrift::MessageType::Call {
                return ::std::result::Result::Err(::std::convert::From::from(::fbthrift::ApplicationException::new(
                    ::fbthrift::ApplicationExceptionErrorCode::InvalidMessageType,
                    format!("message type {:?} not handled", mty)
                )));
            }
            let idx = match idx {
                ::std::result::Result::Ok(idx) => idx,
                ::std::result::Result::Err(_) => {
                    let cur = P::into_buffer(p).reset();
                    return self.supa.call(cur, req_ctxt).await;
                }
            };
            let res = self.handle_method(idx, &mut p, req_ctxt, seqid).await?;
            p.read_message_end()?;

            Ok(res)
        }

        fn create_interaction(
            &self,
            name: &str,
        ) -> ::anyhow::Result<
            ::std::sync::Arc<dyn ::fbthrift::ThriftService<P::Frame, Handler = (), RequestContext = R> + ::std::marker::Send + 'static>
        > {
            use ::fbthrift::{ServiceProcessor as _};
            let idx = self.create_interaction_idx(name);
            let idx = match idx {
                ::anyhow::Result::Ok(idx) => idx,
                ::anyhow::Result::Err(_) => {
                    return self.supa.create_interaction(name);
                }
            };
            self.handle_create_interaction(idx)
        }
    }

    {{^service:interaction?}}
    /// Construct a new instance of a {{service:name}} service.
    ///
    /// This is called when a new instance of a Thrift service Processor
    /// is needed for a particular Thrift protocol.
    #[::tracing::instrument(level="debug", skip_all, fields(proto = ?proto))]
    pub fn make_{{service:name}}_server<F, H, R{{!
        }}{{#service:extends?}}, SMAKE, SS{{/service:extends?}}{{!
    }}>(
        proto: ::fbthrift::ProtocolID,
        handler: H,{{!
        }}{{#service:extends?}}
        supa: SMAKE,{{!
        }}{{/service:extends?}}
    ) -> ::std::result::Result<::std::boxed::Box<dyn ::fbthrift::ThriftService<F, Handler = H, RequestContext = R> + ::std::marker::Send + 'static>, ::fbthrift::ApplicationException>
    where
        F: ::fbthrift::Framing + ::std::marker::Send + ::std::marker::Sync + 'static,
        H: {{service:name}}{{!
        }}{{#service:requestContext?}}<RequestContext = R>{{/service:requestContext?}},{{!
        }}{{#service:extends?}}
        SMAKE: ::std::ops::FnOnce(::fbthrift::ProtocolID) -> ::std::result::Result<SS, ::fbthrift::ApplicationException>,
        SS: ::fbthrift::ThriftService<F, RequestContext = R>,
        SS::Handler: {{>lib/super}},{{!
        }}{{/service:extends?}}
        R: ::fbthrift::RequestContext<Name = ::std::ffi::CStr> + ::std::marker::Send + ::std::marker::Sync + 'static,
        <R as ::fbthrift::RequestContext>::ContextStack: ::fbthrift::ContextStack<Name = R::Name, Buffer = F::DecBuf> + ::std::marker::Send + ::std::marker::Sync + 'static
    {
        match proto {
            ::fbthrift::ProtocolID::BinaryProtocol => {
                ::std::result::Result::Ok(::std::boxed::Box::new({{service:name}}Processor::<::fbthrift::BinaryProtocol<F>, H, R{{!
                    }}{{#service:extends?}}, SS{{/service:extends?}}{{!
                }}>::new(handler{{!
                    }}{{#service:extends?}}, supa(proto)?{{/service:extends?}}{{!
                }})))
            }
            ::fbthrift::ProtocolID::CompactProtocol => {
                ::std::result::Result::Ok(::std::boxed::Box::new({{service:name}}Processor::<::fbthrift::CompactProtocol<F>, H, R{{!
                    }}{{#service:extends?}}, SS{{/service:extends?}}{{!
                }}>::new(handler{{!
                    }}{{#service:extends?}}, supa(proto)?{{/service:extends?}}{{!
                }})))
            }
            bad => {
                ::tracing::error!(method = "{{service:name}}.{{function:name}}", invalid_protocol = ?bad);
                ::std::result::Result::Err(::fbthrift::ApplicationException::invalid_protocol(bad))
            }
        }
    }
    {{/service:interaction?}}
{{!newline}}