feat: add rust actions

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/cuddle-please-actions/src/config.rs

@@ -0,0 +1,49 @@
+use std::ops::Deref;
+
+use anyhow::Context;
+
+pub enum ActionConfig {
+    Actual { doc: yaml_rust2::Yaml },
+    None,
+}
+
+impl Deref for ActionConfig {
+    type Target = yaml_rust2::Yaml;
+
+    fn deref(&self) -> &Self::Target {
+        match &self {
+            ActionConfig::Actual { doc } => doc,
+            ActionConfig::None => &yaml_rust2::Yaml::BadValue,
+        }
+    }
+}
+
+impl TryFrom<&str> for ActionConfig {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        let mut cuddle = yaml_rust2::YamlLoader::load_from_str(value)?;
+
+        if cuddle.len() != 1 {
+            anyhow::bail!("cuddle.yaml can only be 1 document wide");
+        }
+
+        let doc = cuddle.pop().unwrap();
+        let doc = doc["please"]["actions"].clone();
+
+        if doc.is_badvalue() {
+            return Ok(Self::None);
+        }
+
+        Ok(Self::Actual { doc })
+    }
+}
+
+impl ActionConfig {
+    pub fn parse() -> anyhow::Result<Self> {
+        let cuddle_yaml =
+            std::fs::read_to_string("cuddle.yaml").context("failed to read cuddle.yaml")?;
+
+        Self::try_from(cuddle_yaml.as_str())
+    }
+}