1 files changed, 182 insertions, 0 deletions
diff --git a/sip/src/encoding/headers.rs b/sip/src/encoding/headers.rs
new file mode 100644
index 0000000..e880739
--- /dev/null
+++ b/sip/src/encoding/headers.rs
@@ -0,0 +1,182 @@
+use super::{headermap::HeaderMap, method::Method, uri::Uri};
+use anyhow::{anyhow, bail, Result};
+use std::{fmt::Display, str::FromStr};
+
+macro_rules! header {
+    ($hname:literal, struct $name:ident($type:ty)) => {
+        #[derive(Debug)]
+        pub struct $name(pub $type);
+        impl Header for $name {
+            const NAME: &'static str = $hname;
+        }
+        impl Display for $name {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                write!(f, "{}", self.0)
+            }
+        }
+        impl FromStr for $name {
+            type Err = anyhow::Error;
+            fn from_str(s: &str) -> Result<Self, Self::Err> {
+                Ok($name(<$type>::from_str(s)?))
+            }
+        }
+    };
+}
+
+pub trait Header: FromStr<Err = anyhow::Error> + Display {
+    const NAME: &'static str;
+}
+
+header!("Content-Length", struct ContentLength(usize));
+header!("Content-Type", struct ContentType(String));
+header!("Call-ID", struct CallID(String));
+header!("Via", struct Via(String));
+header!("Max-Forwards", struct MaxForwards(usize));
+header!("From", struct From(String));
+header!("To", struct To(String));
+header!("User-Agent", struct UserAgent(String));
+header!("Allow", struct Allow(String));
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
+pub struct CSeq(pub u32, pub Method);
+
+impl Header for CSeq {
+    const NAME: &'static str = "CSeq";
+}
+impl Display for CSeq {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{} {}", self.0, self.1)
+    }
+}
+impl FromStr for CSeq {
+    type Err = anyhow::Error;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let (seq, method) = s.split_once(" ").ok_or(anyhow!("method missing"))?;
+        Ok(CSeq(seq.parse()?, method.parse()?))
+    }
+}
+
+#[derive(Debug)]
+pub struct WWWAuthenticate {
+    pub realm: String,
+    pub nonce: String,
+}
+impl Header for WWWAuthenticate {
+    const NAME: &'static str = "WWW-Authenticate";
+}
+impl Display for WWWAuthenticate {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Digest realm={:?}, nonce={:?}", self.realm, self.nonce)
+    }
+}
+impl FromStr for WWWAuthenticate {
+    type Err = anyhow::Error;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        // TODO this is totally wrong
+        let kvs = s
+            .strip_prefix("Digest ")
+            .ok_or(anyhow!("type not digest"))?
+            .split(",")
+            .map(|e| {
+                let Some((k, v)) = e.split_once("=") else {
+                    bail!("not a KV-pair")
+                };
+                Ok((k.trim().to_string(), v.trim().to_string()))
+            })
+            .try_collect::<HeaderMap>()?;
+        Ok(WWWAuthenticate {
+            realm: unquote(
+                &kvs.get_raw("realm")
+                    .ok_or(anyhow!("realm missing"))?
+                    .to_string(),
+            )?,
+            nonce: unquote(
+                &kvs.get_raw("nonce")
+                    .ok_or(anyhow!("nonce missing"))?
+                    .to_string(),
+            )?,
+        })
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Authorization {
+    pub username: String,
+    pub realm: String,
+    pub uri: String,
+    pub nonce: String,
+    pub response: String,
+}
+impl Header for Authorization {
+    const NAME: &'static str = "Authorization";
+}
+impl Display for Authorization {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self {
+            username,
+            realm,
+            nonce,
+            uri,
+            response,
+        } = self;
+        write!(
+            f,
+            "Digest username={username:?},\r\n  realm={realm:?},\r\n  nonce={nonce:?},\r\n  uri={uri:?},\r\n  response={response:?},\r\n  algorithm=MD5"
+        )
+    }
+}
+impl FromStr for Authorization {
+    type Err = anyhow::Error;
+    fn from_str(_s: &str) -> Result<Self, Self::Err> {
+        todo!()
+    }
+}
+
+pub fn unquote(v: &str) -> Result<String> {
+    Ok(v.strip_prefix("\"")
+        .ok_or(anyhow!("start quote missing"))?
+        .strip_suffix("\"")
+        .ok_or(anyhow!("end quote missing"))?
+        .to_string())
+}
+
+#[derive(Debug)]
+pub struct Contact {
+    pub display_name: Option<String>,
+    pub uri: Uri,
+    pub params: String,
+}
+
+impl Header for Contact {
+    const NAME: &'static str = "Contact";
+}
+impl Display for Contact {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let Self {
+            display_name,
+            uri,
+            params,
+        } = self;
+        if let Some(display_name) = display_name {
+            write!(f, "{display_name} <{uri}>{params}")
+        } else {
+            write!(f, "<{uri}>{params}")
+        }
+    }
+}
+impl FromStr for Contact {
+    type Err = anyhow::Error;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let (display_name, rest) = s.split_once("<").ok_or(anyhow!("malformed contact"))?;
+        let (uri, params) = rest.split_once(">;").ok_or(anyhow!("malformed contact"))?;
+        Ok(Self {
+            display_name: if display_name.is_empty() {
+                None
+            } else {
+                Some(display_name.to_string())
+            },
+            params: params.to_string(),
+            uri: Uri::from_str(uri)?,
+        })
+    }
+}