use std::process::Command;

pub fn from_setting(setting: Option<String>) -> Backend {
    // Git is the default setting until further notice
    setting.map_or(Backend::Git, |name| match name.as_ref() {
        "git" => Backend::Git,
        "mercurial" => Backend::Mercurial,
        _ => Backend::Unknown(name.to_string())
    })
}

#[derive(Debug)]
pub enum Backend {
    Git,
    Mercurial,
    Unknown(String)
}

impl Backend {
    pub fn clone(&self, source: &str) -> bool {
        match self {
            Backend::Git => {
                let status = Command::new("git")
                    .arg("clone")
                    .arg("--recursive")
                    .arg(source)
                    .status().expect("PROCESS ERROR!");
                status.success()
            },
            Backend::Mercurial => {
                unreachable!("Unimplemented");
            },
            Backend::Unknown(name) => {
                eprintln!("Unknown DVCS: {}", name);
                false
            }
        }
    }

    pub fn update(&self) -> bool {
        match self {
            Backend::Git => {
                let status = Command::new("git")
                    .arg("pull")
                    .status()
                    .expect("Failed to pull on git repo.");
                status.success()
            },
            Backend::Mercurial => {
                unreachable!("Unimplemented");
            },
            Backend::Unknown(name) => {
                eprintln!("Unknown DVCS: {}", name);
                false
            }
        }
    }
}