[COMPLETE] MTP-MIGRATION [Some errors to be found]

omikron-connector/src/omega_discovery.rs

@@ -0,0 +1,88 @@
+use std::env;
+use std::time::Duration;
+
+use mtp::crypto::PublicKeyBundle;
+
+const OMEGA_API_BASE_DEFAULT: &str = "https://tensamin.net:9188";
+const REQUEST_TIMEOUT: Duration = Duration::from_secs(10);
+
+pub struct OmikronEndpoint {
+    pub id: i64,
+    pub host: String,
+    pub port: u16,
+    pub public_key: PublicKeyBundle,
+}
+
+fn api_base() -> String {
+    env::var("OMEGA_API_URL").unwrap_or_else(|_| OMEGA_API_BASE_DEFAULT.to_string())
+}
+
+/* The Omega host as stored in `.tu` files: no `https://` scheme, but with port. */
+pub fn omega_host() -> String {
+    api_base()
+        .trim_start_matches("https://")
+        .trim_start_matches("http://")
+        .to_string()
+}
+
+/* `GET /api/get/omikron` - random connected Omikron. Used on first-ever run;
+ * the only discovery endpoint with a liveness guarantee. */
+pub async fn discover_random() -> Result<OmikronEndpoint, String> {
+    fetch(&format!("{}/api/get/omikron", api_base())).await
+}
+
+/* `GET /api/get/omikron/{iota_id}` - this Iota's primary Omikron.
+ * No liveness guarantee (may 404 after restart or point at a stale Omikron);
+ * fall back to `discover_random`. */
+pub async fn discover_primary(iota_id: u64) -> Result<OmikronEndpoint, String> {
+    fetch(&format!("{}/api/get/omikron/{}", api_base(), iota_id)).await
+}
+
+async fn fetch(url: &str) -> Result<OmikronEndpoint, String> {
+    let client = reqwest::Client::builder()
+        .timeout(REQUEST_TIMEOUT)
+        .build()
+        .map_err(|e| format!("Failed to build HTTP client: {}", e))?;
+
+    let body = client
+        .get(url)
+        .send()
+        .await
+        .map_err(|e| format!("Request to {} failed: {}", url, e))?
+        .text()
+        .await
+        .map_err(|e| format!("Failed to read response body from {}: {}", url, e))?;
+
+    let json = json::parse(&body).map_err(|e| format!("Invalid JSON from {}: {}", url, e))?;
+
+    if json["status"].as_str() != Some("success") {
+        return Err(format!(
+            "Omega returned status {:?} for {}",
+            json["status"].as_str(),
+            url
+        ));
+    }
+
+    let id = json["id"]
+        .as_i64()
+        .ok_or_else(|| format!("Missing/invalid \"id\" in response from {}", url))?;
+    let host = json["ip_address"]
+        .as_str()
+        .ok_or_else(|| format!("Missing/invalid \"ip_address\" in response from {}", url))?
+        .to_string();
+    let port = json["port"]
+        .as_u16()
+        .ok_or_else(|| format!("Missing/invalid \"port\" in response from {}", url))?;
+    let public_key_b64 = json["public_key"]
+        .as_str()
+        .ok_or_else(|| format!("Missing/invalid \"public_key\" in response from {}", url))?;
+    let public_key = PublicKeyBundle::from_base64(public_key_b64)
+        .map_err(|e| format!("Failed to decode public key from {}: {}", url, e))?;
+
+    Ok(OmikronEndpoint {
+        id,
+        host,
+        port,
+        public_key,
+    })
+}