/*! A Van is a moving van, or an installation ISO */

use tokio::process::Command;
use std::process::ExitStatus;
use std::os::unix::process::ExitStatusExt;
use std::str::FromStr;

use crate::errors::Error;

/// Describes a hash of a file
pub struct Sha256(pub String);

impl FromStr for Sha256 {
    type Err = Error;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let sum = s.clone();

        Ok(Sha256(sum.to_string()))
    }
}

impl ToString for Sha256 {
    fn to_string(&self) -> String {
        self.0.clone()
    }
}

/// Describes a moving Van, or a way to install a distribution
pub struct Van {
    /// The common name of the distribution (e.g "Arch Linux")
    pub name: String,
    /// The SHA-256 hash of the downloaded file
    pub shasum: Sha256,
    /// Where the ISO can be downloaded from
    pub download_url: String,
    /// The commonly accepted version (e.g "rolling", "21.11", "unstable")
    pub version: String,
}

impl Van {
    pub fn new(name: String,
               shasum: String,
               download_url: String,
               version: String
               ) -> Self {
        Self {
            name,
            shasum: Sha256(shasum),
            download_url,
            version
        }
    }

    pub async fn download(&self, target: String) -> Result<(), Error> {
        let mut output = Command::new("ssh")
            .args([
                  "-oStrictHostKeyChecking=accept-new",
                  &target.clone(),
                  "wget",
                  "-O",
                  &self.download_url.clone(),
                  &format!("/var/lib/libvirt/images/{}", self.make_pretty_name().clone())
            ])
            .output()
            .await?;

        if output.status != ExitStatus::from_raw(0) {
            Err(Error::RemoteCommand(String::from_utf8(output.stdout).unwrap()))
        } else {
            Ok(())
        }
    }

    pub fn make_pretty_name(&self) -> String {
        let safe_name = self.name.clone().to_lowercase().replace(" ", "-");
        let file_name = format!("{}-{}-{}.van", safe_name, self.version.clone(), self.shasum.0.clone());

        file_name
    }
}