proxy_cfg 0.4.2

use std::env;

use super::{ProxyConfig, Result};

pub(crate) fn get_proxy_config() -> Result<Option<ProxyConfig>> {
    let vars: Vec<(String, String)> = env::vars().collect();
    let mut proxy_config: ProxyConfig = Default::default();

    for (key, value) in vars {
        let key = key.to_lowercase();
        if key.ends_with("_proxy") {
            let scheme = &key[..key.len() - 6];
            if scheme == "no" {
                for url in value.split(",").map(|s| s.trim()) {
                    if !url.is_empty() {
                        proxy_config.whitelist.insert(url.to_owned().to_lowercase());
                    }
                }
            } else {
                proxy_config.proxies.insert(scheme.to_owned().to_lowercase(), value);
            }
        }
    }

    if proxy_config.proxies.is_empty() {
        return Ok(None);
    }

    Ok(Some(proxy_config))
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;
    use std::env;
    use std::sync::Mutex;

    use url::Url;

    use super::get_proxy_config;

    // Mutex to serialize tests that modify environment variables.
    static ENV_MUTEX: Mutex<()> = Mutex::new(());

    #[test]
    #[allow(clippy::multiple_unsafe_ops_per_block, reason = "same rationale for all operations")]
    fn test_env_basic() {
        let _guard = ENV_MUTEX.lock().unwrap();

        // SAFETY: The mutex ensures only one test at a time modifies environment variables.
        unsafe {
            env::set_var("HTTP_PROXY", "127.0.0.1");
            env::set_var("HTTPS_PROXY", "candybox2.github.io");
            env::set_var("FTP_PROXY", "http://9-eyes.com");
            env::set_var("NO_PROXY", "");
        };

        let mut proxies = HashMap::new();
        proxies.insert("http".into(), "127.0.0.1".to_owned());
        proxies.insert("https".into(), "candybox2.github.io".to_owned());
        proxies.insert("ftp".into(), "http://9-eyes.com".to_owned());

        let env_var_proxies = get_proxy_config().unwrap().unwrap().proxies;
        if env_var_proxies.len() != 3 {
            // Other proxies are present on the host machine.
            for (k, ..) in proxies.iter() {
                assert_eq!(env_var_proxies.get(k), proxies.get(k));
            }
        } else {
            assert_eq!(env_var_proxies, proxies);
        }
    }

    #[test]
    #[allow(clippy::multiple_unsafe_ops_per_block, reason = "same rationale for all operations")]
    fn test_env_whitelist() {
        let _guard = ENV_MUTEX.lock().unwrap();

        // SAFETY: The mutex ensures only one test at a time modifies environment variables.
        unsafe {
            env::set_var("HTTP_PROXY", "127.0.0.1");
            env::set_var("HTTPS_PROXY", "candybox2.github.io");
            env::set_var("FTP_PROXY", "http://9-eyes.com");
            env::set_var("NO_PROXY", "google.com, 192.168.0.1, localhost, https://github.com/");
        };

        let proxy_config = get_proxy_config().unwrap().unwrap();

        assert_eq!(
            proxy_config.get_proxy_for_url(&Url::parse("http://google.com").unwrap()),
            None
        );
        assert_eq!(
            proxy_config.get_proxy_for_url(&Url::parse("https://localhost").unwrap()),
            None
        );
        assert_eq!(
            proxy_config
                .get_proxy_for_url(&Url::parse("https://bitbucket.org").unwrap())
                .unwrap(),
            "candybox2.github.io"
        );
    }
}