Periodically verify the status of messages sent over mycelium

Signed-off-by: Lee Smet <lee.smet@hotmail.com>

src/clients/mycelium_client.rs

@@ -0,0 +1,97 @@
+use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
+
+use reqwest::Client as HttpClient;
+use serde::Deserialize;
+use serde_json::{Value, json};
+use thiserror::Error;
+
+use crate::models::TransportStatus;
+
+/// Lightweight client for querying Mycelium transport status
+#[derive(Clone)]
+pub struct MyceliumClient {
+    base_url: String,       // e.g. http://127.0.0.1:9651
+    http: HttpClient,
+    id_counter: Arc<AtomicU64>,
+}
+
+#[derive(Debug, Error)]
+pub enum MyceliumClientError {
+    #[error("HTTP error: {0}")]
+    Http(#[from] reqwest::Error),
+    #[error("JSON error: {0}")]
+    Json(#[from] serde_json::Error),
+    #[error("JSON-RPC error: {0}")]
+    RpcError(String),
+    #[error("Invalid response: {0}")]
+    InvalidResponse(String),
+}
+
+impl MyceliumClient {
+    pub fn new(base_url: impl Into<String>) -> Result<Self, MyceliumClientError> {
+        let url = base_url.into();
+        let http = HttpClient::builder().build()?;
+        Ok(Self {
+            base_url: url,
+            http,
+            id_counter: Arc::new(AtomicU64::new(1)),
+        })
+    }
+
+    fn next_id(&self) -> u64 {
+        self.id_counter.fetch_add(1, Ordering::Relaxed)
+    }
+
+    async fn jsonrpc(&self, method: &str, params: Value) -> Result<Value, MyceliumClientError> {
+        let req = json!({
+            "jsonrpc": "2.0",
+            "id": self.next_id(),
+            "method": method,
+            "params": [ params ]
+        });
+        let resp = self.http.post(&self.base_url).json(&req).send().await?;
+        let status = resp.status();
+        let body: Value = resp.json().await?;
+        if let Some(err) = body.get("error") {
+            let code = err.get("code").and_then(|v| v.as_i64()).unwrap_or(0);
+            let msg = err.get("message").and_then(|v| v.as_str()).unwrap_or("unknown error");
+            return Err(MyceliumClientError::RpcError(format!("code={code} msg={msg}")));
+        }
+        if !status.is_success() {
+            return Err(MyceliumClientError::RpcError(format!("HTTP {status}, body {body}")));
+        }
+        Ok(body)
+    }
+
+    /// Call messageStatus with an outbound message id (hex string)
+    pub async fn message_status(&self, id_hex: &str) -> Result<TransportStatus, MyceliumClientError> {
+        let params = json!({ "id": id_hex });
+        let body = self.jsonrpc("messageStatus", params).await?;
+        let result = body.get("result").ok_or_else(|| {
+            MyceliumClientError::InvalidResponse(format!("missing result in response: {body}"))
+        })?;
+        // Accept both { status: "..."} and bare "..."
+        let status_str = if let Some(s) = result.get("status").and_then(|v| v.as_str()) {
+            s.to_string()
+        } else if let Some(s) = result.as_str() {
+            s.to_string()
+        } else {
+            return Err(MyceliumClientError::InvalidResponse(format!("unexpected result shape: {result}")));
+        };
+        Self::map_status(&status_str).ok_or_else(|| {
+            MyceliumClientError::InvalidResponse(format!("unknown status: {status_str}"))
+        })
+    }
+
+    fn map_status(s: &str) -> Option<TransportStatus> {
+        match s {
+            "queued" => Some(TransportStatus::Queued),
+            "sent" => Some(TransportStatus::Sent),
+            "delivered" => Some(TransportStatus::Delivered),
+            "read" => Some(TransportStatus::Read),
+            "failed" => Some(TransportStatus::Failed),
+            _ => None,
+        }
+    }
+}