1 files changed, 34 insertions, 0 deletions
diff --git a/src/runtime.rs b/src/runtime.rs
new file mode 100644
index 0000000..96ffd0d
--- /dev/null
+++ b/src/runtime.rs
@@ -0,0 +1,34 @@
+use crate::model::Trojan;
+use anyhow::{Result, bail};
+use async_trait::async_trait;
+
+#[async_trait]
+pub trait Runtime: Send {
+    /// Protection must be installed before durable enabled intent changes.
+    async fn arm(&mut self) -> Result<()>;
+    async fn apply(&mut self, connection: Option<&Trojan>, generation: u64) -> Result<()>;
+    async fn maintain(&mut self, connection: Option<&Trojan>, generation: u64) -> Result<()> {
+        self.apply(connection, generation).await
+    }
+    /// Called only after disabled intent has been durably recorded.
+    async fn disable(&mut self) -> Result<()>;
+    fn routing(&self) -> &str;
+}
+
+/// Allows managing saved subscriptions without claiming that host capture is available.
+pub struct OfflineRuntime;
+#[async_trait]
+impl Runtime for OfflineRuntime {
+    async fn arm(&mut self) -> Result<()> {
+        bail!("Host networking is unavailable; install and start the Roentgen service")
+    }
+    async fn apply(&mut self, _: Option<&Trojan>, _: u64) -> Result<()> {
+        bail!("Host networking is unavailable")
+    }
+    async fn disable(&mut self) -> Result<()> {
+        Ok(())
+    }
+    fn routing(&self) -> &str {
+        "unavailable"
+    }
+}