use std::collections::HashMap;

use reqwest::Client;
use serde::Deserialize;

#[derive(Deserialize)]
struct ForgeVersionResponse {
    promos: HashMap<String, String>,
}

/// Queries the newest version of forge for a given minecraft version from the
/// forge api
pub async fn newest_forge_version(
    http: &Client,
    mcversion: &str,
) -> anyhow::Result<Option<String>> {
    let resp = http
        .get("https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json")
        .send()
        .await?
        .bytes()
        .await?;

    let mut resp = json5::from_str::<ForgeVersionResponse>(std::str::from_utf8(&resp)?)?;

    Ok(resp.promos.remove(&format!("{}-latest", mcversion)))
}

/// Parses the strange forge version format found in modpack.json files to the
/// actual forge version number which is used in other places such as the twitch
/// manifest.
#[inline]
pub fn parse_version(version: &str) -> Option<&str> {
    version.split('-').nth(1).map(|s| s.trim_end_matches(']'))
}

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

    #[test]
    fn parse_version_valid() {
        assert_eq!(parse_version("[1.16.5-420.69-1.16.5]"), Some("420.69"));
        assert_eq!(parse_version("[1.16.5-420.69]"), Some("420.69"));
    }
}