// Copyright (c) 2018 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

use crate::util::helpers::PlainText;
use digest::Digest;
use sha1::Sha1;

generate_element!(
    /// The main authentication mechanism for components.
    #[derive(Default)]
    Handshake, "handshake", COMPONENT,
    text: (
        /// If Some, contains the hex-encoded SHA-1 of the concatenation of the
        /// stream id and the password, and is used to authenticate against the
        /// server.
        ///
        /// If None, it is the successful reply from the server, the stream is now
        /// fully established and both sides can now exchange stanzas.
        data: PlainText<Option<String>>
    )
);

impl Handshake {
    /// Creates a successful reply from a server.
    pub fn new() -> Handshake {
        Handshake::default()
    }

    /// Creates an authentication request from the component.
    pub fn from_password_and_stream_id(password: &str, stream_id: &str) -> Handshake {
        let input = String::from(stream_id) + password;
        let hash = Sha1::digest(input.as_bytes());
        let content = format!("{:x}", hash);
        Handshake {
            data: Some(content),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use minidom::Element;
    use std::convert::TryFrom;

    #[cfg(target_pointer_width = "32")]
    #[test]
    fn test_size() {
        assert_size!(Handshake, 12);
    }

    #[cfg(target_pointer_width = "64")]
    #[test]
    fn test_size() {
        assert_size!(Handshake, 24);
    }

    #[test]
    fn test_simple() {
        let elem: Element = "<handshake xmlns='jabber:component:accept'/>"
            .parse()
            .unwrap();
        let handshake = Handshake::try_from(elem).unwrap();
        assert_eq!(handshake.data, None);

        let elem: Element = "<handshake xmlns='jabber:component:accept'>Coucou</handshake>"
            .parse()
            .unwrap();
        let handshake = Handshake::try_from(elem).unwrap();
        assert_eq!(handshake.data, Some(String::from("Coucou")));
    }

    #[test]
    fn test_constructors() {
        let handshake = Handshake::new();
        assert_eq!(handshake.data, None);

        let handshake = Handshake::from_password_and_stream_id("123456", "sid");
        assert_eq!(
            handshake.data,
            Some(String::from("9accec263ab84a43c6037ccf7cd48cb1d3f6df8e"))
        );
    }
}