use serde::{Deserialize, Serialize};

#[derive(Debug, Deserialize, Serialize)]
pub struct Message {
    src: String,
    #[serde(rename = "dest")]
    dst: String,
    body: MessageBody,
}
#[derive(Debug, Deserialize, Serialize)]
pub struct MessageBody {
    #[serde(rename = "msg_id")]
    id: Option<u64>,
    in_reply_to: Option<u64>,

    #[serde(flatten)]
    data: MessagePayload,
}

#[derive(Debug, Deserialize, Serialize, PartialEq)]
#[serde(tag = "type")]
#[serde(rename_all = "snake_case")]
pub enum MessagePayload {
    Init {
        node_id: String,
        #[serde(rename = "node_ids")]
        nodes: Vec<String>,
    },
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn protocol_decode_init() -> color_eyre::Result<()> {
        let json_input = r###"{
        "src":      "c1",
        "dest":     "n3",
        "body": {
            "type":     "init",
            "msg_id":   1,
            "node_id":  "n3",
            "node_ids": ["n1", "n2", "n3"]
        }
      }
    "###;

        let msg = serde_json::from_str::<Message>(json_input)?;

        assert!(matches!(msg.body.data, MessagePayload::Init { .. }));
        Ok(())
    }
}