env.rs

use crate::util::cli::{Report, Reportable};
use std::{collections::HashMap, ffi::OsString, fmt::Debug, path::Path};
use thiserror::Error;

pub trait ExplicitEnv: Debug {
    fn explicit_env(&self) -> HashMap<String, OsString>;
}

#[derive(Debug, Error)]
pub enum Error {
    #[error("The `{0}` environment variable isn't set, which is quite weird")]
    NotSet(&'static str),
}

impl Reportable for Error {
    fn report(&self) -> Report {
        Report::error("Failed to initialize base environment", self)
    }
}

#[derive(Clone, Debug)]
pub struct Env {
    vars: HashMap<String, std::ffi::OsString>,
}

impl Env {
    pub fn new() -> Result<Self, Error> {
        let mut vars = HashMap::new();

        let home = std::env::var_os("HOME").ok_or(Error::NotSet("HOME"))?;
        let path = std::env::var_os("PATH").ok_or(Error::NotSet("PATH"))?;
        if let Some(term) = std::env::var_os("TERM") {
            vars.insert("TERM".into(), term);
        }
        if let Some(ssh_auth_sock) = std::env::var_os("SSH_AUTH_SOCK") {
            vars.insert("SSH_AUTH_SOCK".into(), ssh_auth_sock);
        }

        vars.insert("HOME".into(), home);
        vars.insert("PATH".into(), path);

        Ok(Self { vars })
    }

    pub fn path(&self) -> &OsString {
        self.vars.get("PATH").unwrap()
    }

    pub fn prepend_to_path(mut self, path: impl AsRef<Path>) -> Self {
        let mut path = path.as_ref().as_os_str().to_os_string();
        path.push(":");
        path.push(self.path().clone());
        self.vars.insert("PATH".into(), path);
        self
    }

    pub fn insert_env_var(&mut self, key: String, value: OsString) {
        self.vars.insert(key, value);
    }

    pub fn explicit_env_vars(mut self, vars: HashMap<String, OsString>) -> Self {
        self.vars.extend(vars);
        self
    }
}

impl ExplicitEnv for Env {
    fn explicit_env(&self) -> HashMap<String, OsString> {
        self.vars.clone()
    }
}