// Copyright (c) 2017 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 std::convert::TryFrom;
use std::str::FromStr;

use minidom::{Element, IntoAttributeValue};
use jid::Jid;

use error::Error;

use ns;

generate_attribute!(Type, "type", {
    Assisted => "assisted",
    Direct => "direct",
    Proxy => "proxy",
    Tunnel => "tunnel",
}, Default = Direct);

generate_attribute!(Mode, "mode", {
    Tcp => "tcp",
    Udp => "udp",
}, Default = Tcp);

generate_id!(CandidateId);

generate_id!(StreamId);

#[derive(Debug, Clone)]
pub struct Candidate {
    pub cid: CandidateId,
    pub host: String,
    pub jid: Jid,
    pub port: Option<u16>,
    pub priority: u32,
    pub type_: Type,
}

impl Into<Element> for Candidate {
    fn into(self) -> Element {
        Element::builder("candidate")
                .ns(ns::JINGLE_S5B)
                .attr("cid", self.cid)
                .attr("host", self.host)
                .attr("jid", String::from(self.jid))
                .attr("port", self.port)
                .attr("priority", self.priority)
                .attr("type", self.type_)
                .build()
    }
}

#[derive(Debug, Clone)]
pub enum TransportPayload {
    Activated(String),
    Candidates(Vec<Candidate>),
    CandidateError,
    CandidateUsed(String),
    ProxyError,
    None,
}

#[derive(Debug, Clone)]
pub struct Transport {
    pub sid: StreamId,
    pub dstaddr: Option<String>,
    pub mode: Mode,
    pub payload: TransportPayload,
}

impl TryFrom<Element> for Transport {
    type Error = Error;

    fn try_from(elem: Element) -> Result<Transport, Error> {
        if elem.is("transport", ns::JINGLE_S5B) {
            let sid = get_attr!(elem, "sid", required);
            let dstaddr = get_attr!(elem, "dstaddr", optional);
            let mode = get_attr!(elem, "mode", default);

            let mut payload = None;
            for child in elem.children() {
                payload = Some(if child.is("candidate", ns::JINGLE_S5B) {
                    let mut candidates = match payload {
                        Some(TransportPayload::Candidates(candidates)) => candidates,
                        Some(_) => return Err(Error::ParseError("Non-candidate child already present in JingleS5B transport element.")),
                        None => vec!(),
                    };
                    candidates.push(Candidate {
                        cid: get_attr!(child, "cid", required),
                        host: get_attr!(child, "host", required),
                        jid: get_attr!(child, "jid", required),
                        port: get_attr!(child, "port", optional),
                        priority: get_attr!(child, "priority", required),
                        type_: get_attr!(child, "type", default),
                    });
                    TransportPayload::Candidates(candidates)
                } else if child.is("activated", ns::JINGLE_S5B) {
                    if payload.is_some() {
                        return Err(Error::ParseError("Non-activated child already present in JingleS5B transport element."));
                    }
                    let cid = get_attr!(child, "cid", required);
                    TransportPayload::Activated(cid)
                } else if child.is("candidate-error", ns::JINGLE_S5B) {
                    if payload.is_some() {
                        return Err(Error::ParseError("Non-candidate-error child already present in JingleS5B transport element."));
                    }
                    TransportPayload::CandidateError
                } else if child.is("candidate-used", ns::JINGLE_S5B) {
                    if payload.is_some() {
                        return Err(Error::ParseError("Non-candidate-used child already present in JingleS5B transport element."));
                    }
                    let cid = get_attr!(child, "cid", required);
                    TransportPayload::CandidateUsed(cid)
                } else if child.is("proxy-error", ns::JINGLE_S5B) {
                    if payload.is_some() {
                        return Err(Error::ParseError("Non-proxy-error child already present in JingleS5B transport element."));
                    }
                    TransportPayload::ProxyError
                } else {
                    return Err(Error::ParseError("Unknown child in JingleS5B transport element."));
                });
            }
            let payload = payload.unwrap_or(TransportPayload::None);
            Ok(Transport {
                sid: sid,
                dstaddr: dstaddr,
                mode: mode,
                payload: payload,
            })
        } else {
            Err(Error::ParseError("This is not an JingleS5B transport element."))
        }
    }
}

impl Into<Element> for Transport {
    fn into(self) -> Element {
        Element::builder("transport")
                .ns(ns::JINGLE_S5B)
                .attr("sid", self.sid)
                .attr("dstaddr", self.dstaddr)
                .attr("mode", self.mode)
                .append(match self.payload {
                     TransportPayload::Candidates(mut candidates) => {
                         candidates.drain(..)
                                   .map(|candidate| candidate.into())
                                   .collect::<Vec<Element>>()
                     },
                     TransportPayload::Activated(cid) => {
                         vec!(Element::builder("activated")
                                      .ns(ns::JINGLE_S5B)
                                      .attr("cid", cid)
                                      .build())
                     },
                     TransportPayload::CandidateError => {
                         vec!(Element::builder("candidate-error")
                                      .ns(ns::JINGLE_S5B)
                                      .build())
                     },
                     TransportPayload::CandidateUsed(ref cid) => {
                         vec!(Element::builder("candidate-used")
                                      .ns(ns::JINGLE_S5B)
                                      .attr("cid", cid)
                                      .build())
                     },
                     TransportPayload::ProxyError => {
                         vec!(Element::builder("proxy-error")
                                      .ns(ns::JINGLE_S5B)
                                      .build())
                     },
                     TransportPayload::None => vec!(),
                 })
                .build()
    }
}

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

    #[test]
    fn test_simple() {
        let elem: Element = "<transport xmlns='urn:xmpp:jingle:transports:s5b:1' sid='coucou'/>".parse().unwrap();
        let transport = Transport::try_from(elem).unwrap();
        assert_eq!(transport.sid, StreamId(String::from("coucou")));
        assert_eq!(transport.dstaddr, None);
        assert_eq!(transport.mode, Mode::Tcp);
        match transport.payload {
            TransportPayload::None => (),
            _ => panic!("Wrong element inside transport!"),
        }
    }

    #[test]
    fn test_serialise_activated() {
        let elem: Element = "<transport xmlns='urn:xmpp:jingle:transports:s5b:1' sid='coucou'><activated cid='coucou'/></transport>".parse().unwrap();
        let transport = Transport {
            sid: StreamId(String::from("coucou")),
            dstaddr: None,
            mode: Mode::Tcp,
            payload: TransportPayload::Activated(String::from("coucou")),
        };
        let elem2: Element = transport.into();
        assert_eq!(elem, elem2);
    }

    #[test]
    fn test_serialise_candidate() {
        let elem: Element = "<transport xmlns='urn:xmpp:jingle:transports:s5b:1' sid='coucou'><candidate cid='coucou' host='coucou' jid='coucou@coucou' priority='0'/></transport>".parse().unwrap();
        let transport = Transport {
            sid: StreamId(String::from("coucou")),
            dstaddr: None,
            mode: Mode::Tcp,
            payload: TransportPayload::Candidates(vec!(Candidate {
                cid: CandidateId(String::from("coucou")),
                host: String::from("coucou"),
                jid: Jid::from_str("coucou@coucou").unwrap(),
                port: None,
                priority: 0u32,
                type_: Type::Direct,
            })),
        };
        let elem2: Element = transport.into();
        assert_eq!(elem, elem2);
    }
}