//! Payload for ad hoc authentication method for clients that don't support SNI.
//! See the `impl` for [`super::backend::BackendType<ClientCredentials>`].
//! Read more: <https://github.com/neondatabase/cloud/issues/1620#issuecomment-1165332290>.
//! UPDATE (Mon Aug  8 13:20:34 UTC 2022): the payload format has been simplified.

use bstr::ByteSlice;

pub struct PasswordHackPayload {
    pub endpoint: String,
    pub password: Vec<u8>,
}

impl PasswordHackPayload {
    pub fn parse(bytes: &[u8]) -> Option<Self> {
        // The format is `project=<utf-8>;<password-bytes>`.
        let mut iter = bytes.splitn_str(2, ";");
        let endpoint = iter.next()?.to_str().ok()?;
        let endpoint = parse_endpoint_param(endpoint)?.to_owned();
        let password = iter.next()?.to_owned();

        Some(Self { endpoint, password })
    }
}

pub fn parse_endpoint_param(bytes: &str) -> Option<&str> {
    bytes
        .strip_prefix("project=")
        .or_else(|| bytes.strip_prefix("endpoint="))
}

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

    #[test]
    fn parse_endpoint_param_fn() {
        let input = "";
        assert!(parse_endpoint_param(input).is_none());

        let input = "project=";
        assert_eq!(parse_endpoint_param(input), Some(""));

        let input = "project=foobar";
        assert_eq!(parse_endpoint_param(input), Some("foobar"));

        let input = "endpoint=";
        assert_eq!(parse_endpoint_param(input), Some(""));

        let input = "endpoint=foobar";
        assert_eq!(parse_endpoint_param(input), Some("foobar"));

        let input = "other_option=foobar";
        assert!(parse_endpoint_param(input).is_none());
    }

    #[test]
    fn parse_password_hack_payload_project() {
        let bytes = b"";
        assert!(PasswordHackPayload::parse(bytes).is_none());

        let bytes = b"project=";
        assert!(PasswordHackPayload::parse(bytes).is_none());

        let bytes = b"project=;";
        let payload: PasswordHackPayload =
            PasswordHackPayload::parse(bytes).expect("parsing failed");
        assert_eq!(payload.endpoint, "");
        assert_eq!(payload.password, b"");

        let bytes = b"project=foobar;pass;word";
        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
        assert_eq!(payload.endpoint, "foobar");
        assert_eq!(payload.password, b"pass;word");
    }

    #[test]
    fn parse_password_hack_payload_endpoint() {
        let bytes = b"";
        assert!(PasswordHackPayload::parse(bytes).is_none());

        let bytes = b"endpoint=";
        assert!(PasswordHackPayload::parse(bytes).is_none());

        let bytes = b"endpoint=;";
        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
        assert_eq!(payload.endpoint, "");
        assert_eq!(payload.password, b"");

        let bytes = b"endpoint=foobar;pass;word";
        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
        assert_eq!(payload.endpoint, "foobar");
        assert_eq!(payload.password, b"pass;word");
    }
}