use std::str::FromStr;
use url::Url;

#[derive(Clone, Debug)]
pub(crate) struct HttpOrigin {
    pub origin: String,
    pub host_idx: usize,
}

impl HttpOrigin {
    /// Returns the Host header value (e.g. `example.com` for the origin `https://example.com`).
    pub fn host(&self) -> &str {
        &self.origin[self.host_idx..]
    }
}

impl FromStr for HttpOrigin {
    type Err = &'static str;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let url = Url::parse(s).map_err(|_| "invalid URL")?;
        if url.scheme() != "http" && url.scheme() != "https" {
            return Err("expected http:// or https:// scheme");
        }
        if url.path() != "/" {
            return Err("path must be /");
        }
        Ok(HttpOrigin {
            origin: url.origin().ascii_serialization(),
            host_idx: url.scheme().len() + "://".len(),
        })
    }
}