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use std::io;
use common::{msg::*, send_msg, Handler};
use serde::{Deserialize, Serialize};
use serde_json::Deserializer;
#[derive(Debug, Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum EchoBody {
#[serde(rename = "echo")]
Echo { msg_id: usize, echo: String },
#[serde(rename = "echo_ok")]
EchoOk {
msg_id: usize,
in_reply_to: usize,
echo: String,
},
}
fn main() {
let mut stdout = io::stdout();
let deser = Deserializer::from_reader(io::stdin());
let mut deser = deser.into_iter::<Message<()>>();
let Some(msg) = deser.next() else {
panic!("stream ended before init message");
};
let Ok(msg) = msg else {
panic!("{}", msg.unwrap_err());
};
let (node_id, node_ids, msg_id) = match msg.body {
MaelstromBodyOr::MaelstromBody {
inner:
MaelstromBody::Init {
node_id,
node_ids,
msg_id,
},
} => (node_id, node_ids, msg_id),
_ => {
panic!("expected init message to be first message");
}
};
send_msg(
&mut stdout,
&Message {
header: msg.header.flip(),
body: MaelstromBodyOr::MaelstromBody::<()> {
inner: MaelstromBody::InitOk {
msg_id: 0,
in_reply_to: msg_id,
},
},
},
);
let mut handler = EchoHandler::init(node_id, node_ids, msg_id);
drop(deser);
let deser = Deserializer::from_reader(io::stdin());
for msg in deser.into_iter::<Message<EchoBody>>() {
let msg = msg.unwrap();
match msg.body {
MaelstromBodyOr::Other { inner } => {
if let Some(out) = handler.handle(msg.header, inner) {
send_msg(&mut stdout, &out);
}
}
_ => todo!(),
};
}
}
pub struct EchoHandler {
next_msg_id: usize,
}
impl Handler for EchoHandler {
type Body = EchoBody;
fn init(_node_id: String, _node_ids: Vec<String>, _msg_id: usize) -> Self {
EchoHandler { next_msg_id: 1 }
}
fn handle(&mut self, header: MessageHeader, body: Self::Body) -> Option<Message<EchoBody>> {
match body {
EchoBody::Echo { msg_id, echo } => {
let msg = Message {
header: header.flip(),
body: MaelstromBodyOr::Other {
inner: EchoBody::EchoOk {
msg_id: self.next_msg_id,
in_reply_to: msg_id,
echo,
},
},
};
self.next_msg_id += 1;
Some(msg)
}
EchoBody::EchoOk { .. } => None,
}
}
}
|
