WIP: refactor Element type - namespace work

1 files changed, 236 insertions, 163 deletions

diff --git a/src/stanza/mod.rs b/src/stanza/mod.rs
index e96ae9c..1bb3fc2 100644
--- a/src/stanza/mod.rs
+++ b/src/stanza/mod.rs
@@ -17,23 +17,17 @@ use tokio::io::{AsyncBufRead, AsyncWrite};
 
 use crate::{JabberError, Result};
 
-// #[derive(Clone, Debug)]
-// pub struct EventTree<'e> {
-//     pub event: Event<'e>,
-//     pub children: Option<Vec<Element<'e>>>,
-// }
-
 pub type Prefix<'s> = Option<&'s str>;
 
 #[derive(Clone, Debug)]
 /// represents an xml element as a tree of nodes
-pub struct Element<'s> {
+pub struct Element {
     /// element prefix
     /// e.g. `foo` in `<foo:bar />`.
-    prefix: Option<&'s str>,
+    prefix: Option<String>,
     /// element name
     /// e.g. `bar` in `<foo:bar />`.
-    localname: &'s str,
+    localname: String,
     /// qualifying namespace
     /// an element must be qualified by a namespace
     /// e.g. for `<stream:features>` in
@@ -61,7 +55,7 @@ pub struct Element<'s> {
     /// </stream:stream>
     /// ```
     /// would be `"jabber:client"`
-    namespace: &'s str,
+    namespace: String,
     /// all namespaces applied to element
     /// e.g. for `<bind>` in
     /// ```
@@ -75,22 +69,49 @@ pub struct Element<'s> {
     /// ```
     /// would be `[(None, "urn:ietf:params:xml:ns:xmpp-bind")]` despite
     /// `(Some("stream"), "http://etherx.jabber.org/streams")` also being available
-    namespace_declarations: Box<BTreeMap<Option<&'s str>, &'s str>>,
+    // TODO: maybe not even needed, as can calculate when writing which namespaces need to be declared
+    // but then can't have unused namespace on element, confusing.
+    namespace_declarations: Box<BTreeMap<Option<String>, String>>,
     /// element attributes
-    attributes: Box<BTreeMap<&'s str, &'s str>>,
+    attributes: Box<BTreeMap<String, String>>,
     // children elements namespaces contain their parents' namespaces
-    children: Box<Vec<Node<'s>>>,
+    children: Box<Vec<Node>>,
+}
+
+impl Element {
+    pub fn new_empty<S: ToString, C: Into<Node>>(
+        prefix: Option<S>,
+        localname: S,
+        namespace: S,
+        namespace_declarations: BTreeMap<Option<S>, S>,
+        attributes: BTreeMap<S, S>,
+        children: Vec<C>,
+    ) {
+    }
+    pub fn push_child<C: Into<Node>>(&mut self, node: C) {}
 }
 
 #[derive(Clone, Debug)]
-pub enum Node<'s> {
-    Element(Element<'s>),
-    Text(&'s str),
+pub enum Node {
+    Element(Element),
+    Text(String),
     Unknown,
 }
 
-impl<'s> From<&Node<'s>> for Vec<Event<'s>> {
-    fn from(node: &Node<'s>) -> Self {
+impl From<Element> for Node {
+    fn from(element: Element) -> Self {
+        Self::Element(element)
+    }
+}
+
+impl<S: ToString> From<S> for Node {
+    fn from(text: S) -> Self {
+        Self::Text(text.to_string())
+    }
+}
+
+impl<'s> From<&Node> for Vec<Event<'s>> {
+    fn from(node: &Node) -> Self {
         match node {
             Node::Element(e) => e.into(),
             Node::Text(t) => vec![Event::Text(BytesText::new(t))],
@@ -99,7 +120,7 @@ impl<'s> From<&Node<'s>> for Vec<Event<'s>> {
     }
 }
 
-impl<'s> Element<'s> {
+impl Element {
     /// returns the fully qualified name
     /// e.g. `foo:bar` in
     /// `<foo:bar>`.
@@ -107,14 +128,14 @@ impl<'s> Element<'s> {
         if let Some(prefix) = self.prefix {
             format!("{}:{}", prefix, self.localname).as_str()
         } else {
-            self.localname
+            &self.localname
         }
     }
 
     /// returns the localname.
     /// e.g. `bar` in `<foo:bar>`
     pub fn localname(&self) -> &str {
-        self.localname
+        &self.localname
     }
 
     /// returns the prefix.
@@ -130,12 +151,12 @@ impl<'s> Element<'s> {
     /// `<bar:element xmlns='foo' xmlns:bar='bar'>`
     /// it will be `bar`.
     pub fn namespace(&self) -> &str {
-        self.namespace
+        &self.namespace
     }
 }
 
-impl<'s> From<&Element<'s>> for Vec<Event<'s>> {
-    fn from(element: &Element<'s>) -> Self {
+impl<'s> From<&Element> for Vec<Event<'s>> {
+    fn from(element: &Element) -> Self {
         let name = element.name();
 
         let event = BytesStart::new(name);
@@ -183,9 +204,9 @@ impl<'s> From<&Element<'s>> for Vec<Event<'s>> {
     }
 }
 
-impl<'s> Element<'s> {
+impl Element {
     /// if there is only one child in the vec of children, will return that element
-    pub fn child(&self) -> Result<&Node<'s>> {
+    pub fn child(&self) -> Result<&Node> {
         if self.children.len() == 1 {
             Ok(&self.children[0])
         } else if self.children.len() > 1 {
@@ -196,7 +217,7 @@ impl<'s> Element<'s> {
     }
 
     /// returns reference to children
-    pub fn children(&self) -> Result<&Vec<Node<'s>>> {
+    pub fn children(&self) -> Result<&Vec<Node>> {
         if !self.children.is_empty() {
             Ok(&self.children)
         } else {
@@ -206,7 +227,7 @@ impl<'s> Element<'s> {
 
     /// returns text content, error if there is none
     pub fn text_content(&self) -> Result<Vec<&str>> {
-        let text = Vec::new();
+        let mut text = Vec::new();
         for node in *self.children {
             match node {
                 Node::Text(t) => text.push(t),
@@ -214,43 +235,86 @@ impl<'s> Element<'s> {
             }
         }
         if text.is_empty() {
-            Err(ElementError::NotText)
+            return Err(ElementError::NotText.into());
         }
         Ok(text)
     }
 
-    pub async fn write<W: AsyncWrite + Unpin + Send>(&self, writer: &mut Writer<W>) -> Result<()> {
-        let events: Vec<Event> = self.into();
-        for event in events {
-            writer.write_event_async(event).await?
+    /// returns whether or not the element is qualified by a namespace, either declared
+    /// by a parent, or itself.
+    fn namespace_qualified<S: AsRef<str>>(
+        &self,
+        local_namespaces: &BTreeMap<Option<S>, S>,
+    ) -> bool {
+        if let Some(namespace) = local_namespaces.get(self.prefix) {
+            if namespace != self.namespace {
+                return false;
+            }
+        };
+
+        if let Some(namespace) = self.namespace_declarations.get(&self.prefix) {
+            if namespace != self.namespace {
+                return false;
+            }
+        }
+
+        for child in *self.children {
+            if child.namespace_qualified(local_namespaces) == false {
+                return false;
+            }
         }
-        Ok(())
+
+        true
     }
 
-    pub async fn write_start<W: AsyncWrite + Unpin + Send>(
+    /// writes an element to a writer. the element's namespace must be qualified by the
+    /// context given in `local_namespaces` or the element's internal namespace declarations
+    pub async fn write<S: AsRef<str>, W: AsyncWrite + Unpin + Send>(
         &self,
         writer: &mut Writer<W>,
+        local_namespaces: &BTreeMap<Option<S>, S>,
     ) -> Result<()> {
-        let mut event = BytesStart::new(self.name());
+        // TODO: NEXT: instead of having a check if namespace qualified function, have the namespace declarations be added if needed given the context when converting from `Element` to `Event`s
+        if self.namespace_qualified(local_namespaces) {
+            let events: Vec<Event> = self.into();
+            for event in events {
+                writer.write_event_async(event).await?
+            }
+            Ok(())
+        } else {
+            Err(ElementError::NamespaceNotQualified.into())
+        }
+    }
 
-        // namespace declarations
-        self.namespace_declarations.iter().for_each(|declaration| {
-            let (prefix, namespace) = declaration;
-            match prefix {
-                Some(prefix) => {
-                    event.push_attribute((format!("xmlns:{}", prefix).as_str(), *namespace))
+    pub async fn write_start<S: AsRef<str>, W: AsyncWrite + Unpin + Send>(
+        &self,
+        writer: &mut Writer<W>,
+        local_namespaces: &BTreeMap<Option<S>, S>,
+    ) -> Result<()> {
+        if self.namespace_qualified(local_namespaces) {
+            let mut event = BytesStart::new(self.name());
+
+            // namespace declarations
+            self.namespace_declarations.iter().for_each(|declaration| {
+                let (prefix, namespace) = declaration;
+                match prefix {
+                    Some(prefix) => {
+                        event.push_attribute((format!("xmlns:{}", prefix).as_str(), *namespace))
+                    }
+                    None => event.push_attribute(("xmlns", *namespace)),
                 }
-                None => event.push_attribute(("xmlns", *namespace)),
-            }
-        });
+            });
 
-        // attributes
-        let event =
-            event.with_attributes(self.attributes.iter().map(|(attr, value)| (*attr, *value)));
+            // attributes
+            let event =
+                event.with_attributes(self.attributes.iter().map(|(attr, value)| (*attr, *value)));
 
-        writer.write_event_async(Event::Start(event)).await?;
+            writer.write_event_async(Event::Start(event)).await?;
 
-        Ok(())
+            Ok(())
+        } else {
+            Err(ElementError::NamespaceNotQualified.into())
+        }
     }
 
     pub async fn write_end<W: AsyncWrite + Unpin + Send>(
@@ -263,9 +327,9 @@ impl<'s> Element<'s> {
     }
 
     #[async_recursion]
-    pub async fn read<R: AsyncBufRead + Unpin + Send>(
+    pub async fn read<S: AsRef<str>, R: AsyncBufRead + Unpin + Send>(
         reader: &mut Reader<R>,
-        local_namespaces: &BTreeMap<Option<&str>, &str>,
+        local_namespaces: &BTreeMap<Option<S>, S>,
     ) -> Result<Self> {
         let node = Node::read_recursive(reader, local_namespaces)
             .await?
@@ -276,21 +340,25 @@ impl<'s> Element<'s> {
             Node::Unknown => Err(JabberError::UnexpectedElement),
         }
     }
-    pub async fn read_start<R: AsyncBufRead + Unpin + Send>(
+
+    pub async fn read_start<S: AsRef<str>, R: AsyncBufRead + Unpin + Send>(
         reader: &mut Reader<R>,
-        local_namespaces: &BTreeMap<Option<&str>, &str>,
-    ) -> Result<Self> {
-        let mut buf = Vec::new();
+        local_namespaces: &BTreeMap<Option<S>, S>,
+    ) -> Result<Element> {
+        let buf = Vec::new();
         let event = reader.read_event_into_async(&mut buf).await?;
         match event {
             Event::Start(e) => {
-                let prefix = e
-                    .name()
-                    .prefix()
-                    .map(|prefix| str::from_utf8(prefix.into_inner())?);
-                let localname = str::from_utf8(e.local_name().into_inner())?;
+                let prefix = e.name().prefix().map(|prefix| prefix.into_inner());
+                let converted_prefix;
+                if let Some(raw_prefix) = prefix {
+                    converted_prefix = Some(str::from_utf8(raw_prefix)?)
+                }
+                let prefix = converted_prefix;
+
+                let localname = str::from_utf8(e.local_name().into_inner())?.to_owned();
 
-                let mut namespaces = local_namespaces.clone();
+                let mut local_namespaces = local_namespaces.clone();
                 let mut namespace_declarations = BTreeMap::new();
                 let attributes = BTreeMap::new();
 
@@ -300,62 +368,70 @@ impl<'s> Element<'s> {
                         match prefix_declaration {
                             PrefixDeclaration::Default => {
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations.try_insert(None, value);
-                                namespaces.insert(None, value);
+                                if let Some(_) = namespace_declarations.insert(None, value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(None, value);
                             }
                             PrefixDeclaration::Named(prefix) => {
                                 let key = str::from_utf8(prefix)?;
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations
-                                    .try_insert(Some(key), value)
-                                    .map_err(ParseError::DuplicateAttribute)?;
-                                namespaces.insert(Some(key), value);
+                                if let Some(_) = namespace_declarations.insert(Some(key), value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(Some(key), value);
                             }
                         }
                     } else {
-                        attributes
-                            .try_insert(
-                                str::from_utf8(attribute.key.into_inner())?,
-                                str::from_utf8(attribute.value.as_ref())?,
-                            )
-                            .map_err(ParseError::DuplicateAttribute)?;
+                        if let Some(_) = attributes.insert(
+                            str::from_utf8(attribute.key.into_inner())?,
+                            str::from_utf8(attribute.value.as_ref())?,
+                        ) {
+                            return Err(ElementParseError::DuplicateAttribute.into());
+                        };
                     }
                 }
 
-                let namespace = *namespaces.get(&prefix).ok_or(ParseError::NoNamespace)?;
+                let namespace = *local_namespaces
+                    .get(&prefix)
+                    .ok_or(ElementParseError::NoNamespace)?;
 
                 let mut children = Vec::new();
 
-                Ok(Some(Self::Element(Element {
+                Ok(Self {
                     prefix,
                     localname,
                     namespace,
-                    namespace_declarations,
-                    attributes,
-                    children,
-                })))
+                    namespace_declarations: Box::new(namespace_declarations),
+                    attributes: Box::new(attributes),
+                    children: Box::new(children),
+                })
             }
-            e => Err(ElementError::NotAStart(e)),
+            e => Err(ElementError::NotAStart(e).into()),
         }
     }
 }
 
-impl<'s> Node<'s> {
-    async fn read_recursive<R: AsyncBufRead + Unpin + Send>(
+impl Node {
+    #[async_recursion]
+    async fn read_recursive<S: AsRef<str>, R: AsyncBufRead + Unpin + Send>(
         reader: &mut Reader<R>,
-        local_namespaces: &BTreeMap<Option<&str>, &str>,
-    ) -> Result<Option<Node<'s>>> {
+        local_namespaces: &BTreeMap<Option<S>, S>,
+    ) -> Result<Option<Node>> {
         let mut buf = Vec::new();
         let event = reader.read_event_into_async(&mut buf).await?;
         match event {
             Event::Empty(e) => {
-                let prefix = e
-                    .name()
-                    .prefix()
-                    .map(|prefix| str::from_utf8(prefix.into_inner())?);
-                let localname = str::from_utf8(e.local_name().into_inner())?;
+                let prefix = e.name().prefix().map(|prefix| prefix.into_inner());
+                let converted_prefix;
+                if let Some(raw_prefix) = prefix {
+                    converted_prefix = Some(str::from_utf8(raw_prefix)?)
+                }
+                let prefix = converted_prefix;
+
+                let localname = str::from_utf8(e.local_name().into_inner())?.to_owned();
 
-                let mut namespaces = local_namespaces.clone();
+                let mut local_namespaces = local_namespaces.clone();
                 let mut namespace_declarations = BTreeMap::new();
                 let attributes = BTreeMap::new();
 
@@ -365,49 +441,56 @@ impl<'s> Node<'s> {
                         match prefix_declaration {
                             PrefixDeclaration::Default => {
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations.try_insert(None, value);
-                                namespaces.insert(None, value);
+                                if let Some(_) = namespace_declarations.insert(None, value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(None, value);
                             }
                             PrefixDeclaration::Named(prefix) => {
                                 let key = str::from_utf8(prefix)?;
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations
-                                    .try_insert(Some(key), value)
-                                    .map_err(ParseError::DuplicateAttribute)?;
-                                namespaces.insert(Some(key), value);
+                                if let Some(_) = namespace_declarations.insert(Some(key), value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(Some(key), value);
                             }
                         }
                     } else {
-                        attributes
-                            .try_insert(
-                                str::from_utf8(attribute.key.into_inner())?,
-                                str::from_utf8(attribute.value.as_ref())?,
-                            )
-                            .map_err(ParseError::DuplicateAttribute)?;
+                        if let Some(_) = attributes.insert(
+                            str::from_utf8(attribute.key.into_inner())?,
+                            str::from_utf8(attribute.value.as_ref())?,
+                        ) {
+                            return Err(ElementParseError::DuplicateAttribute.into());
+                        };
                     }
                 }
 
-                let namespace = *namespaces.get(&prefix).ok_or(ParseError::NoNamespace)?;
+                let namespace = *local_namespaces
+                    .get(&prefix)
+                    .ok_or(ElementParseError::NoNamespace)?;
 
-                let children = Vec::new();
+                let mut children = Vec::new();
 
                 Ok(Some(Self::Element(Element {
                     prefix,
                     localname,
                     namespace,
-                    namespace_declarations,
-                    attributes,
-                    children,
+                    namespace_declarations: Box::new(namespace_declarations),
+                    attributes: Box::new(attributes),
+                    children: Box::new(children),
                 })))
             }
             Event::Start(e) => {
-                let prefix = e
-                    .name()
-                    .prefix()
-                    .map(|prefix| str::from_utf8(prefix.into_inner())?);
-                let localname = str::from_utf8(e.local_name().into_inner())?;
+                let prefix = e.name().prefix().map(|prefix| prefix.into_inner());
+                let converted_prefix;
+                if let Some(raw_prefix) = prefix {
+                    converted_prefix = Some(str::from_utf8(raw_prefix)?)
+                }
+                let prefix = converted_prefix;
+
+                let localname = str::from_utf8(e.local_name().into_inner())?.to_owned();
 
-                let mut namespaces = local_namespaces.clone();
+                let mut local_namespaces = local_namespaces.clone();
                 let mut namespace_declarations = BTreeMap::new();
                 let attributes = BTreeMap::new();
 
@@ -417,92 +500,82 @@ impl<'s> Node<'s> {
                         match prefix_declaration {
                             PrefixDeclaration::Default => {
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations.try_insert(None, value);
-                                namespaces.insert(None, value);
+                                if let Some(_) = namespace_declarations.insert(None, value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(None, value);
                             }
                             PrefixDeclaration::Named(prefix) => {
                                 let key = str::from_utf8(prefix)?;
                                 let value = str::from_utf8(attribute.value.as_ref())?;
-                                namespace_declarations
-                                    .try_insert(Some(key), value)
-                                    .map_err(ParseError::DuplicateAttribute)?;
-                                namespaces.insert(Some(key), value);
+                                if let Some(_) = namespace_declarations.insert(Some(key), value) {
+                                    return Err(ElementParseError::DuplicateAttribute.into());
+                                };
+                                local_namespaces.insert(Some(key), value);
                             }
                         }
                     } else {
-                        attributes
-                            .try_insert(
-                                str::from_utf8(attribute.key.into_inner())?,
-                                str::from_utf8(attribute.value.as_ref())?,
-                            )
-                            .map_err(ParseError::DuplicateAttribute)?;
+                        if let Some(_) = attributes.insert(
+                            str::from_utf8(attribute.key.into_inner())?,
+                            str::from_utf8(attribute.value.as_ref())?,
+                        ) {
+                            return Err(ElementParseError::DuplicateAttribute.into());
+                        };
                     }
                 }
 
-                let namespace = *namespaces.get(&prefix).ok_or(ParseError::NoNamespace)?;
+                let namespace = *local_namespaces
+                    .get(&prefix)
+                    .ok_or(ElementParseError::NoNamespace)?;
 
                 let mut children = Vec::new();
-                while let Some(child_node) = Node::read_recursive(reader, &namespaces).await? {
+                while let Some(child_node) = Node::read_recursive(reader, &local_namespaces).await?
+                {
                     children.push(child_node)
                 }
 
+                let mut children = Vec::new();
+
                 Ok(Some(Self::Element(Element {
                     prefix,
                     localname,
                     namespace,
-                    namespace_declarations,
-                    attributes,
-                    children,
+                    namespace_declarations: Box::new(namespace_declarations),
+                    attributes: Box::new(attributes),
+                    children: Box::new(children),
                 })))
             }
             Event::End(_) => Ok(None),
-            Event::Text(e) => Ok(Some(Self::Text(e.unescape()?.as_ref()))),
+            Event::Text(e) => Ok(Some(Self::Text(e.unescape()?.as_ref().to_string()))),
             e => Ok(Some(Self::Unknown)),
         }
     }
+
+    fn namespace_qualified<S: AsRef<str>>(
+        &self,
+        local_namespaces: &BTreeMap<Option<S>, S>,
+    ) -> bool {
+        match self {
+            Self::Element(e) => e.namespace_qualified(local_namespaces),
+            _ => true,
+        }
+    }
 }
 
-// #[async_recursion]
-// pub async fn read_start<R: AsyncBufRead + Unpin + Send>(
-//     reader: &mut Reader<R>,
-// ) -> Result<Self, JabberError> {
-//     let mut buf = Vec::new();
-//     let event = reader.read_event_into_async(&mut buf).await?;
-//     match event {
-//         Event::Start(e) => {
-//             return Ok(Self {
-//                 event: Event::Start(e.into_owned()),
-//                 children: None,
-//             })
-//         }
-//         e => Err(ElementError::NotAStart(e.into_owned()).into()),
-//     }
-// }
-
-// pub trait IntoElement<'e> {
-//     fn event(&self) -> Event<'e>;
-//     fn children(&self) -> Option<Vec<Element<'e>>>;
-// }
-
-// impl<'e, T: IntoElement<'e>> From<T> for Element<'e> {
-//     fn from(value: T) -> Self {
-//         Element {
-//             event: value.event(),
-//             children: value.children(),
-//         }
-//     }
-// }
+// the issue is i don't know how to validate that an element always has a namespace when it is being written
+// TODO: ElementBuilder that makes it easier to build an element under a namespace
 
 #[derive(Debug)]
 pub enum ElementError<'e> {
     NotAStart(Event<'e>),
     NotText,
     NoChildren,
+    NamespaceNotQualified,
     MultipleChildren,
 }
 
 #[derive(Debug)]
-pub enum ParseError {
+pub enum ElementParseError {
     DuplicateAttribute,
     NoNamespace,
 }