cln-plugin: Add options to the getmanifest call

plugins/src/options.rs

@@ -0,0 +1,122 @@
+use serde::ser::{SerializeStruct, Serializer};
+use serde::{Serialize};
+
+#[derive(Clone, Debug)]
+pub enum Value {
+    String(String),
+    Integer(i64),
+    Boolean(bool),
+}
+
+/// An stringly typed option that is passed to
+#[derive(Clone, Debug)]
+pub struct ConfigOption {
+    name: String,
+    pub(crate) value: Option<Value>,
+    default: Value,
+    description: String,
+}
+
+impl ConfigOption {
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+    pub fn default(&self) -> &Value {
+        &self.default
+    }
+}
+
+// When we serialize we don't add the value. This is because we only
+// ever serialize when we pass the option back to lightningd during
+// the getmanifest call.
+impl Serialize for ConfigOption {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_struct("ConfigOption", 4)?;
+        s.serialize_field("name", &self.name)?;
+        match &self.default {
+            Value::String(ss) => {
+                s.serialize_field("type", "string")?;
+                s.serialize_field("default", ss)?;
+            }
+            Value::Integer(i) => {
+                s.serialize_field("type", "int")?;
+                s.serialize_field("default", i)?;
+            }
+
+            Value::Boolean(b) => {
+                s.serialize_field("type", "bool")?;
+                s.serialize_field("default", b)?;
+            }
+        }
+
+        s.serialize_field("description", &self.description)?;
+        s.end()
+    }
+}
+impl ConfigOption {
+    pub fn new(name: &str, default: Value, description: &str) -> Self {
+        Self {
+            name: name.to_string(),
+            default,
+            description: description.to_string(),
+            value: None,
+        }
+    }
+
+    pub fn value(&self) -> Value {
+        match &self.value {
+            None => self.default.clone(),
+            Some(v) => v.clone(),
+        }
+    }
+
+    pub fn description(&self) -> String {
+        self.description.clone()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_option_serialize() {
+        let tests = vec![
+            (
+                ConfigOption::new("name", Value::String("default".to_string()), "description"),
+                json!({
+                "name": "name",
+                        "description":"description",
+                        "default": "default",
+                        "type": "string",
+                    }),
+            ),
+            (
+                ConfigOption::new("name", Value::Integer(42), "description"),
+                json!({
+                "name": "name",
+                        "description":"description",
+                        "default": 42,
+                        "type": "int",
+                    }),
+            ),
+            (
+                ConfigOption::new("name", Value::Boolean(true), "description"
+                json!({
+                "name": "name",
+                        "description":"description",
+                        "default": true,
+                        "type": "booltes",
+                    }),
+            )),
+        ];
+
+        for (input, expected) in tests.iter() {
+            let res = serde_json::to_value(input).unwrap();
+            assert_eq!(&res, expected);
+        }
+    }
+}