From 78e8a06ec2a75159774535d182a90ad7b25b3889 Mon Sep 17 00:00:00 2001
From: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Date: Sun, 23 Apr 2017 17:30:23 +0100
Subject: [PATCH] Add a presence parser.

---
 src/lib.rs      |   2 +
 src/presence.rs | 179 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 181 insertions(+)
 create mode 100644 src/presence.rs

diff --git a/src/lib.rs b/src/lib.rs
index 7be94346..79b7d1da 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -19,6 +19,8 @@ pub mod ns;
 /// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
 pub mod message;
 /// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
+pub mod presence;
+/// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
 pub mod body;
 
 /// XEP-0004: Data Forms
diff --git a/src/presence.rs b/src/presence.rs
new file mode 100644
index 00000000..51e5854e
--- /dev/null
+++ b/src/presence.rs
@@ -0,0 +1,179 @@
+use std::str::FromStr;
+
+use minidom::Element;
+use minidom::IntoAttributeValue;
+
+use jid::Jid;
+
+use error::Error;
+
+use ns;
+
+use delay;
+
+/// Lists every known payload of a `<presence/>`.
+#[derive(Debug, Clone)]
+pub enum PresencePayload {
+    Delay(delay::Delay),
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum PresenceType {
+    /// This value is not an acceptable 'type' attribute, it is only used
+    /// internally to signal the absence of 'type'.
+    Available,
+    Error,
+    Probe,
+    Subscribe,
+    Subscribed,
+    Unavailable,
+    Unsubscribe,
+    Unsubscribed,
+}
+
+impl Default for PresenceType {
+    fn default() -> PresenceType {
+        PresenceType::Available
+    }
+}
+
+impl FromStr for PresenceType {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<PresenceType, Error> {
+        Ok(match s {
+            "error" => PresenceType::Error,
+            "probe" => PresenceType::Probe,
+            "subscribe" => PresenceType::Subscribe,
+            "subscribed" => PresenceType::Subscribed,
+            "unavailable" => PresenceType::Unavailable,
+            "unsubscribe" => PresenceType::Unsubscribe,
+            "unsubscribed" => PresenceType::Unsubscribed,
+
+            _ => return Err(Error::ParseError("Invalid 'type' attribute on presence element.")),
+        })
+    }
+}
+
+impl IntoAttributeValue for PresenceType {
+    fn into_attribute_value(self) -> Option<String> {
+        Some(match self {
+            PresenceType::Available => return None,
+
+            PresenceType::Error => "error",
+            PresenceType::Probe => "probe",
+            PresenceType::Subscribe => "subscribe",
+            PresenceType::Subscribed => "subscribed",
+            PresenceType::Unavailable => "unavailable",
+            PresenceType::Unsubscribe => "unsubscribe",
+            PresenceType::Unsubscribed => "unsubscribed",
+        }.to_owned())
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum PresencePayloadType {
+    XML(Element),
+    Parsed(PresencePayload),
+}
+
+#[derive(Debug, Clone)]
+pub struct Presence {
+    pub from: Option<Jid>,
+    pub to: Option<Jid>,
+    pub id: Option<String>,
+    pub type_: PresenceType,
+    pub payloads: Vec<PresencePayloadType>,
+}
+
+pub fn parse_presence(root: &Element) -> Result<Presence, Error> {
+    if !root.is("presence", ns::JABBER_CLIENT) {
+        return Err(Error::ParseError("This is not a presence element."));
+    }
+    let from = root.attr("from")
+        .and_then(|value| value.parse().ok());
+    let to = root.attr("to")
+        .and_then(|value| value.parse().ok());
+    let id = root.attr("id")
+        .and_then(|value| value.parse().ok());
+    let type_ = match root.attr("type") {
+        Some(type_) => type_.parse()?,
+        None => Default::default(),
+    };
+    let mut payloads = vec!();
+    for elem in root.children() {
+        let payload = if let Ok(delay) = delay::parse_delay(elem) {
+            Some(PresencePayload::Delay(delay))
+        } else {
+            None
+        };
+        payloads.push(match payload {
+            Some(payload) => PresencePayloadType::Parsed(payload),
+            None => PresencePayloadType::XML(elem.clone()),
+        });
+    }
+    Ok(Presence {
+        from: from,
+        to: to,
+        id: id,
+        type_: type_,
+        payloads: payloads,
+    })
+}
+
+pub fn serialise_payload(payload: &PresencePayload) -> Element {
+    match *payload {
+        PresencePayload::Delay(ref delay) => delay::serialise(delay),
+    }
+}
+
+pub fn serialise(presence: &Presence) -> Element {
+    let mut stanza = Element::builder("presence")
+                             .ns(ns::JABBER_CLIENT)
+                             .attr("from", presence.from.clone().and_then(|value| Some(String::from(value))))
+                             .attr("to", presence.to.clone().and_then(|value| Some(String::from(value))))
+                             .attr("id", presence.id.clone())
+                             .attr("type", presence.type_.clone())
+                             .build();
+    for child in presence.payloads.clone() {
+        let elem = match child {
+            PresencePayloadType::XML(elem) => elem,
+            PresencePayloadType::Parsed(payload) => serialise_payload(&payload),
+        };
+        stanza.append_child(elem);
+    }
+    stanza
+}
+
+#[cfg(test)]
+mod tests {
+    use minidom::Element;
+    use presence;
+
+    #[test]
+    fn test_simple() {
+        let elem: Element = "<presence xmlns='jabber:client'/>".parse().unwrap();
+        let presence = presence::parse_presence(&elem).unwrap();
+        assert_eq!(presence.from, None);
+        assert_eq!(presence.to, None);
+        assert_eq!(presence.id, None);
+        assert_eq!(presence.type_, presence::PresenceType::Available);
+        assert!(presence.payloads.is_empty());
+    }
+
+    #[test]
+    fn test_serialise() {
+        let elem: Element = "<presence xmlns='jabber:client' type='unavailable'/>".parse().unwrap();
+        let presence = presence::parse_presence(&elem).unwrap();
+        let presence2 = presence::Presence {
+            from: None,
+            to: None,
+            id: None,
+            type_: presence::PresenceType::Unavailable,
+            payloads: vec!(),
+        };
+        let elem2 = presence::serialise(&presence2);
+        assert_eq!(elem, elem2);
+        println!("{:#?}", presence);
+    }
+}