use crate::Response;
use rustls::{ClientConfig, ClientSession, Stream, TLSError};
use std::{io::prelude::*, net::TcpStream, sync::Arc};
use url::Url;

fn config() -> ClientConfig {
    let mut config = ClientConfig::new();
    config
        .root_store
        .add_server_trust_anchors(&webpki_roots::TLS_SERVER_ROOTS);
    config
}

#[derive(thiserror::Error, Debug)]
pub enum Error {
    #[error("TLS error: {0:?}")]
    TLS(#[from] TLSError),

    #[error("URL error: {0:?}")]
    URL(#[from] url::ParseError),

    #[error("Invalid DNS name: {0:?}")]
    InvalidDNSName(#[from] webpki::InvalidDNSNameError),

    #[error("IO error: {0:?}")]
    IO(#[from] std::io::Error),

    #[error("Response parsing error: {0:?}")]
    ResponseParse(#[from] crate::ResponseError),

    #[error("Invalid URL scheme {0:?}")]
    InvalidScheme(String),
}

pub fn get<T>(u: T) -> Result<crate::Response, Error>
where
    T: Into<String>,
{
    let u = u.into();
    let mut ur = Url::parse(&u.clone())?;
    if ur.port().is_none() {
        ur.set_port(Some(1965)).unwrap();
    }

    if ur.scheme() == "" {
        let _ = ur.set_scheme("gemini");
    }

    if ur.scheme() != "gemini" {
        return Err(Error::InvalidScheme(ur.scheme().to_string()));
    }

    let cfg = Arc::new(config());
    let host = ur.host_str().unwrap();
    let mut sock = TcpStream::connect(&format!("{}:{}", host, ur.port().unwrap()))?;
    let name_ref = webpki::DNSNameRef::try_from_ascii_str(host)?;
    let mut client = ClientSession::new(&cfg, name_ref);
    let mut tls = Stream::new(&mut client, &mut sock);

    let req = format!("{}\r\n", u);
    log::trace!("writing request {:?}", req);
    tls.write(req.as_bytes())?;
    Ok(Response::parse(&mut tls)?)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::*;

    #[test]
    fn gemini_homepage() -> Result<(), Error> {
        let _ = pretty_env_logger::try_init();
        let resp = get("gemini://gemini.circumlunar.space/".to_string())?;

        assert_eq!(resp.status, StatusCode::Success);
        assert_eq!(resp.meta, "text/gemini");
        assert_ne!(resp.body.len(), 0);

        Ok(())
    }
}