use bstr::BString;

/// Indicates key or values contain errors that can't be encoded.
#[derive(Debug, thiserror::Error)]
#[allow(missing_docs)]
pub enum Error {
    #[error("{key:?}={value:?} must not contain null bytes or newlines neither in key nor in value.")]
    Encoding { key: String, value: BString },
}

mod access {
    use bstr::BString;

    use crate::protocol::Context;

    impl Context {
        /// Convert all relevant fields into a URL for consumption.
        pub fn to_url(&self) -> Option<BString> {
            use bstr::{ByteSlice, ByteVec};
            let mut buf: BString = self.protocol.clone()?.into();
            buf.push_str(b"://");
            if let Some(user) = &self.username {
                buf.push_str(user);
                buf.push(b'@');
            }
            if let Some(host) = &self.host {
                buf.push_str(host);
            }
            if let Some(path) = &self.path {
                if !path.starts_with_str("/") {
                    buf.push(b'/');
                }
                buf.push_str(path);
            }
            buf.into()
        }
        /// Compute a prompt to obtain the given value.
        pub fn to_prompt(&self, field: &str) -> String {
            match self.to_url() {
                Some(url) => format!("{field} for {url}: "),
                None => format!("{field}: "),
            }
        }
    }
}

mod mutate {
    use bstr::ByteSlice;

    use crate::{protocol, protocol::Context};

    /// In-place mutation
    impl Context {
        /// Destructure the url at our `url` field into parts like protocol, host, username and path and store
        /// them in our respective fields. If `use_http_path` is set, http paths are significant even though
        /// normally this isn't the case.
        #[allow(clippy::result_large_err)]
        pub fn destructure_url_in_place(&mut self, use_http_path: bool) -> Result<&mut Self, protocol::Error> {
            let url = gix_url::parse(self.url.as_ref().ok_or(protocol::Error::UrlMissing)?.as_ref())?;
            self.protocol = Some(url.scheme.as_str().into());
            self.username = url.user().map(ToOwned::to_owned);
            self.host = url.host().map(ToOwned::to_owned).map(|mut host| {
                if let Some(port) = url.port {
                    use std::fmt::Write;
                    write!(host, ":{port}").expect("infallible");
                }
                host
            });
            if !matches!(url.scheme, gix_url::Scheme::Http | gix_url::Scheme::Https) || use_http_path {
                let path = url.path.trim_with(|b| b == '/');
                self.path = (!path.is_empty()).then(|| path.into());
            }
            Ok(self)
        }
    }
}

mod serde;
pub use self::serde::decode;