use crate::app_config::AppConfig;
use crate::libvirt_rest_structures::net::{NetworkInfo, NetworkName};
use crate::nat::nat_definition::NetNat;

#[derive(thiserror::Error, Debug)]
enum NatLibError {
    #[error("Could not save nat definition, because network bridge name was not specified!")]
    MissingNetworkBridgeName,
}

/// Save nat definition
pub fn save_nat_def(net: &NetworkInfo) -> anyhow::Result<()> {
    let nat = match net.has_nat_def() {
        true => NetNat {
            interface: net
                .bridge_name
                .as_ref()
                .ok_or(NatLibError::MissingNetworkBridgeName)?
                .to_string(),
            ipv4: net
                .ip_v4
                .as_ref()
                .map(|i| i.nat.clone())
                .unwrap_or_default(),
            ipv6: net
                .ip_v6
                .as_ref()
                .map(|i| i.nat.clone())
                .unwrap_or_default(),
        },
        false => NetNat::default(),
    };

    let json = serde_json::to_string(&nat)?;

    std::fs::write(AppConfig::get().net_nat_path(&net.name), json)?;

    Ok(())
}

/// Remove nat definition, if existing
pub fn remove_nat_def(name: &NetworkName) -> anyhow::Result<()> {
    let nat_file = AppConfig::get().net_nat_path(name);
    if nat_file.exists() {
        std::fs::remove_file(nat_file)?;
    }

    Ok(())
}

/// Load nat definition, if available
pub fn load_nat_def(name: &NetworkName) -> anyhow::Result<NetNat> {
    let nat_file = AppConfig::get().net_nat_path(name);
    if !nat_file.exists() {
        return Ok(NetNat::default());
    }

    let file = std::fs::read_to_string(nat_file)?;

    Ok(serde_json::from_str(&file)?)
}