dav: Migrate WebDav routes into a resource formalism

crates/dav/src/resource.rs

@@ -0,0 +1,70 @@
+use std::io::Write;
+
+use actix_web::{http::StatusCode, HttpRequest};
+use anyhow::{anyhow, Result};
+use async_trait::async_trait;
+use quick_xml::Writer;
+use rustical_auth::AuthInfo;
+
+use crate::propfind::{write_invalid_props_response, write_propstat_response};
+
+// A resource is identified by a URI and has properties
+// A resource can also be a collection
+// A resource cannot be none, only Methods like PROPFIND, GET, REPORT, etc. can be exposed
+// A resource exists
+#[async_trait(?Send)]
+pub trait Resource: Sized {
+    type MemberType: Resource;
+    type UriComponents: Sized; // defines how the resource URI maps to parameters, i.e. /{principal}/{calendar} -> (String, String)
+
+    async fn acquire_from_request(
+        req: HttpRequest,
+        auth_info: AuthInfo,
+        uri_components: Self::UriComponents,
+        prefix: String,
+    ) -> Result<Self>;
+
+    fn get_path(&self) -> &str;
+    async fn get_members(&self) -> Result<Vec<Self::MemberType>>;
+
+    fn list_dead_props() -> Vec<&'static str>;
+    fn write_prop<W: Write>(&self, writer: &mut Writer<W>, prop: &str) -> Result<()>;
+}
+
+pub trait HandlePropfind {
+    fn propfind(&self, props: Vec<&str>) -> Result<String>;
+}
+
+impl<R: Resource> HandlePropfind for R {
+    fn propfind(&self, props: Vec<&str>) -> Result<String> {
+        let mut props = props;
+        if props.contains(&"allprops") {
+            if props.len() != 1 {
+                // allprops MUST be the only queried prop per spec
+                return Err(anyhow!("allprops MUST be the only quereid prop"));
+            }
+            props = R::list_dead_props();
+        }
+
+        let mut invalid_props = Vec::<&str>::new();
+
+        let mut output_buffer = Vec::new();
+        let mut writer = Writer::new_with_indent(&mut output_buffer, b' ', 2);
+
+        write_propstat_response(&mut writer, self.get_path(), StatusCode::OK, |writer| {
+            for prop in props {
+                // TODO: Fix error types
+                match self
+                    .write_prop(writer, prop)
+                    .map_err(|_e| quick_xml::Error::TextNotFound)
+                {
+                    Ok(_) => {}
+                    Err(_) => invalid_props.push(prop),
+                };
+            }
+            Ok(())
+        })?;
+        write_invalid_props_response(&mut writer, self.get_path(), invalid_props)?;
+        Ok(std::str::from_utf8(&output_buffer)?.to_string())
+    }
+}