use chrono::prelude::*;
use log::Level;
use rs_data_formats_derive::Name;
use serde::{Deserialize, Serialize};
use serde_json::json;

pub const TOPIC_PREFIX: &str = concat!("tg/", env!("CARGO_PKG_VERSION_MAJOR"), "/");

pub trait Name {
    fn name(&self) -> &'static str;
}

#[derive(Serialize, Deserialize, Debug)]
pub struct Common {
    pub sender: String,
    pub application: String,
    pub time: DateTime<Utc>,
    pub payload: String,
}

#[derive(Serialize, Deserialize, Debug, Name)]
pub struct Log {
    severity: Level,
    msg: String,
}

#[derive(Serialize, Deserialize, Debug, Name)]
pub struct Kovaak {
    score: f32,
    scenario: String,
    hash: String,
    game_version: String,
}

fn topic_name<T: Name>(prefix: &str, sym: &T) -> String {
    format!("{}{}", prefix, sym.name().to_lowercase())
}

pub fn build_msg<T: Name + Serialize>(sender: &str, data: T) -> (String, String) {
    (
        topic_name(TOPIC_PREFIX, &data),
        json!(Common {
            sender: sender.to_string(),
            time: Utc::now(),
            application: data.name().to_lowercase(),
            payload: json!(&data).to_string(),
        })
        .to_string(),
    )
}

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

    #[test]
    fn test_topic_name() {
        let k = Kovaak {
            score: 0.0,
            scenario: format!(""),
            hash: format!(""),
            game_version: format!(""),
        };
        assert_eq!("Kovaak", topic_name(TOPIC_PREFIX, &k));
    }
}