use sha2::{Sha256, Digest};
use hex::ToHex;

/// A unique description of an origin, from where a domain might be served.
pub enum Descr<'a> {
    Git{url: &'a str, branch: &'a str},
}

impl<'a> Descr<'a> {

    /// Returns a globally unique string for the Descr.
    pub fn id(&'a self) -> String {

        let mut h = Sha256::new();

        let mut h_update = |b: &str| {
            h.update(b);
            h.update("\n");
        };

        match self {
            Descr::Git{url, branch} => {
                h_update("git");
                h_update(url);
                h_update(branch);
            }
        }

        h.finalize().encode_hex::<String>()
    }
}

#[cfg(test)]
mod descr_tests {

    #[test]
    fn id() {

        assert_eq!(
            super::Descr::Git{url:"foo", branch:"bar"}.id(),
            "424130b9e6c1675c983b4b97579877e16d8a6377e4fe10970e6d210811c3b7ac",
        )
    }
//}