feat(fapp): add FappRouter for mesh integration

New fapp_router.rs module:
- FappAction enum (Ignore, Dropped, Forward, QueryResponse)
- Wire format: 1-byte tag (0x01-0x05) + CBOR body
- FappRouter with shared RoutingTable and TransportManager
- handle_incoming() decodes and dispatches FAPP frames
- process_slot_announce() with relay/flood logic
- process_slot_query() answers from local FappStore
- broadcast_announce() / send_query() for outbound floods
- drain_pending_sends() for async send integration
- 3 unit tests

Also fixed borrow checker issue in FappStore::store

crates/quicprochat-p2p/src/fapp.rs

@@ -426,14 +426,14 @@ impl FappStore {
             }
         }
 
-        // Capacity check per therapist.
+        let addr = announce.therapist_address;
-        let queue = self
+
-            .announces
+        // Capacity check per therapist (evict oldest if needed).
-            .entry(announce.therapist_address)
+        {
-            .or_default();
+            let queue = self.announces.entry(addr).or_default();
-        if queue.len() >= MAX_PER_THERAPIST {
+            if queue.len() >= MAX_PER_THERAPIST {
-            // Evict oldest.
+                queue.remove(0);
-            queue.remove(0);
+            }
         }
 
         // Total capacity check.
@@ -452,10 +452,9 @@ impl FappStore {
         }
 
         // Update latest sequence.
-        self.latest_sequence
+        self.latest_sequence.insert(addr, announce.sequence);
-            .insert(announce.therapist_address, announce.sequence);
 
-        queue.push(announce);
+        self.announces.entry(addr).or_default().push(announce);
         true
     }
 

crates/quicprochat-p2p/src/fapp_router.rs

@@ -0,0 +1,335 @@
+//! FAPP routing: decode wire frames, integrate with [`RoutingTable`](crate::routing_table::RoutingTable)
+//! and [`TransportManager`](crate::transport_manager::TransportManager).
+//!
+//! [`FappRouter::broadcast_announce`](FappRouter::broadcast_announce) and
+//! [`FappRouter::send_query`](FappRouter::send_query) enqueue outbound frames; call
+//! [`FappRouter::drain_pending_sends`](FappRouter::drain_pending_sends) and pass each
+//! payload to [`TransportManager::send`](crate::transport_manager::TransportManager::send)
+//! from an async context.
+
+use std::collections::HashSet;
+use std::sync::{Arc, Mutex, RwLock};
+
+use anyhow::{bail, Result};
+
+use crate::fapp::{
+    FappStore, SlotAnnounce, SlotQuery, SlotResponse, CAP_FAPP_PATIENT, CAP_FAPP_RELAY,
+    CAP_FAPP_THERAPIST,
+};
+use crate::routing_table::RoutingTable;
+use crate::transport::TransportAddr;
+use crate::transport_manager::TransportManager;
+
+// ---------------------------------------------------------------------------
+// Wire message tags (CBOR body follows the tag byte)
+// ---------------------------------------------------------------------------
+
+/// [`SlotAnnounce`] frame.
+pub const FAPP_WIRE_ANNOUNCE: u8 = 0x01;
+/// [`SlotQuery`] frame.
+pub const FAPP_WIRE_QUERY: u8 = 0x02;
+/// [`SlotResponse`] frame.
+pub const FAPP_WIRE_RESPONSE: u8 = 0x03;
+/// [`SlotReserve`](crate::fapp::SlotReserve) frame (handled later).
+pub const FAPP_WIRE_RESERVE: u8 = 0x04;
+/// [`SlotConfirm`](crate::fapp::SlotConfirm) frame (handled later).
+pub const FAPP_WIRE_CONFIRM: u8 = 0x05;
+
+// ---------------------------------------------------------------------------
+// FappAction — what to do after handling an incoming FAPP frame
+// ---------------------------------------------------------------------------
+
+/// Result of processing an incoming FAPP payload (mirrors [`IncomingAction`](crate::mesh_router::IncomingAction) style).
+#[derive(Debug)]
+pub enum FappAction {
+    /// No application-visible effect.
+    Ignore,
+    /// Invalid frame, unknown tag, or rejected message.
+    Dropped(String),
+    /// Flood this wire payload to each listed next hop.
+    Forward {
+        wire: Vec<u8>,
+        next_hops: Vec<TransportAddr>,
+    },
+    /// Relay answered from [`FappStore`] (matches may be empty).
+    QueryResponse(SlotResponse),
+}
+
+// ---------------------------------------------------------------------------
+// Wire helpers
+// ---------------------------------------------------------------------------
+
+fn encode_tagged(tag: u8, cbor_body: &[u8]) -> Vec<u8> {
+    let mut out = Vec::with_capacity(1 + cbor_body.len());
+    out.push(tag);
+    out.extend_from_slice(cbor_body);
+    out
+}
+
+fn slot_query_to_wire(query: &SlotQuery) -> Vec<u8> {
+    let mut buf = Vec::new();
+    ciborium::into_writer(query, &mut buf).expect("SlotQuery CBOR");
+    buf
+}
+
+fn slot_query_from_wire(bytes: &[u8]) -> Result<SlotQuery> {
+    let q: SlotQuery = ciborium::from_reader(bytes)?;
+    Ok(q)
+}
+
+/// Unique next-hop addresses from the routing table (flood fan-out).
+fn flood_targets(table: &RoutingTable) -> Vec<TransportAddr> {
+    let mut seen = HashSet::new();
+    let mut out = Vec::new();
+    for e in table.entries() {
+        if seen.insert(e.next_hop_addr.clone()) {
+            out.push(e.next_hop_addr.clone());
+        }
+    }
+    out
+}
+
+fn enqueue_flood(
+    pending: &Mutex<Vec<(TransportAddr, Vec<u8>)>>,
+    wire: Vec<u8>,
+    table: &RoutingTable,
+) -> Result<()> {
+    let hops = flood_targets(table);
+    if hops.is_empty() {
+        bail!("no mesh neighbors in routing table for flood");
+    }
+    let mut q = pending
+        .lock()
+        .map_err(|e| anyhow::anyhow!("pending_sends lock poisoned: {e}"))?;
+    for addr in hops {
+        q.push((addr, wire.clone()));
+    }
+    Ok(())
+}
+
+// ---------------------------------------------------------------------------
+// FappRouter
+// ---------------------------------------------------------------------------
+
+/// FAPP message router integrated with the mesh [`RoutingTable`] and transports.
+pub struct FappRouter {
+    /// Local announcement cache and query index (relay nodes).
+    store: Mutex<FappStore>,
+    /// Shared with [`MeshRouter`](crate::mesh_router::MeshRouter).
+    routes: Arc<RwLock<RoutingTable>>,
+    /// Shared transport manager (same as [`MeshRouter`](crate::mesh_router::MeshRouter); wire-up sends via [`Self::drain_pending_sends`] until sync send exists).
+    #[allow(dead_code)]
+    transports: Arc<TransportManager>,
+    /// Bitfield: [`CAP_FAPP_THERAPIST`], [`CAP_FAPP_RELAY`], [`CAP_FAPP_PATIENT`].
+    local_capabilities: u16,
+    /// Frames produced by [`Self::broadcast_announce`] and [`Self::send_query`].
+    pending_sends: Mutex<Vec<(TransportAddr, Vec<u8>)>>,
+}
+
+impl FappRouter {
+    /// Create a router with the given store, shared routing table, transports, and capability mask.
+    pub fn new(
+        store: FappStore,
+        routes: Arc<RwLock<RoutingTable>>,
+        transports: Arc<TransportManager>,
+        local_capabilities: u16,
+    ) -> Self {
+        Self {
+            store: Mutex::new(store),
+            routes,
+            transports,
+            local_capabilities,
+            pending_sends: Mutex::new(Vec::new()),
+        }
+    }
+
+    /// Decode a tagged FAPP wire frame and apply local policy.
+    pub fn handle_incoming(&self, bytes: &[u8]) -> FappAction {
+        if bytes.is_empty() {
+            return FappAction::Dropped("empty FAPP frame".into());
+        }
+        let tag = bytes[0];
+        let body = &bytes[1..];
+        match tag {
+            FAPP_WIRE_ANNOUNCE => match SlotAnnounce::from_wire(body) {
+                Ok(a) => self.process_slot_announce(a),
+                Err(e) => FappAction::Dropped(format!("announce CBOR: {e}")),
+            },
+            FAPP_WIRE_QUERY => match slot_query_from_wire(body) {
+                Ok(q) => self.process_slot_query(q),
+                Err(e) => FappAction::Dropped(format!("query CBOR: {e}")),
+            },
+            FAPP_WIRE_RESPONSE | FAPP_WIRE_RESERVE | FAPP_WIRE_CONFIRM => {
+                FappAction::Dropped(format!("unhandled FAPP tag 0x{tag:02x}"))
+            }
+            _ => FappAction::Dropped(format!("unknown FAPP tag 0x{tag:02x}")),
+        }
+    }
+
+    /// Enqueue a signed [`SlotAnnounce`] to all known next hops (therapist publish / relay re-flood).
+    pub fn broadcast_announce(&self, announce: SlotAnnounce) -> Result<()> {
+        if self.local_capabilities & CAP_FAPP_THERAPIST == 0 {
+            bail!("missing CAP_FAPP_THERAPIST");
+        }
+        let wire = encode_tagged(FAPP_WIRE_ANNOUNCE, &announce.to_wire());
+        let table = self
+            .routes
+            .read()
+            .map_err(|e| anyhow::anyhow!("routing table lock poisoned: {e}"))?;
+        enqueue_flood(&self.pending_sends, wire, &table)
+    }
+
+    /// Enqueue an anonymous [`SlotQuery`] flood (patient discovery).
+    pub fn send_query(&self, query: SlotQuery) -> Result<()> {
+        if self.local_capabilities & CAP_FAPP_PATIENT == 0 {
+            bail!("missing CAP_FAPP_PATIENT");
+        }
+        let body = slot_query_to_wire(&query);
+        let wire = encode_tagged(FAPP_WIRE_QUERY, &body);
+        let table = self
+            .routes
+            .read()
+            .map_err(|e| anyhow::anyhow!("routing table lock poisoned: {e}"))?;
+        enqueue_flood(&self.pending_sends, wire, &table)
+    }
+
+    /// Apply relay / propagation rules to a decoded [`SlotAnnounce`].
+    pub fn process_slot_announce(&self, announce: SlotAnnounce) -> FappAction {
+        if !announce.can_propagate() {
+            return FappAction::Dropped("announce expired or max hops".into());
+        }
+
+        let has_relay = self.local_capabilities & CAP_FAPP_RELAY != 0;
+        if !has_relay {
+            return FappAction::Ignore;
+        }
+
+        let mut store = match self.store.lock() {
+            Ok(g) => g,
+            Err(e) => return FappAction::Dropped(format!("fapp store lock poisoned: {e}")),
+        };
+
+        if store.seen(&announce.id) {
+            return FappAction::Ignore;
+        }
+
+        let stored = store.store(announce.clone());
+        if !stored {
+            return FappAction::Ignore;
+        }
+
+        let forwarded = announce.forwarded();
+        if !forwarded.can_propagate() {
+            return FappAction::Ignore;
+        }
+
+        let wire = encode_tagged(FAPP_WIRE_ANNOUNCE, &forwarded.to_wire());
+        let next_hops = {
+            let table = match self.routes.read() {
+                Ok(t) => t,
+                Err(e) => {
+                    return FappAction::Dropped(format!("routing table lock poisoned: {e}"));
+                }
+            };
+            flood_targets(&table)
+        };
+
+        if next_hops.is_empty() {
+            return FappAction::Ignore;
+        }
+
+        FappAction::Forward {
+            wire,
+            next_hops,
+        }
+    }
+
+    /// Answer from cache and/or ignore (query flooding is a separate [`Self::send_query`] path).
+    pub fn process_slot_query(&self, query: SlotQuery) -> FappAction {
+        if self.local_capabilities & CAP_FAPP_RELAY == 0 {
+            return FappAction::Ignore;
+        }
+
+        let store = match self.store.lock() {
+            Ok(g) => g,
+            Err(e) => return FappAction::Dropped(format!("fapp store lock poisoned: {e}")),
+        };
+
+        let response = store.query(&query);
+        FappAction::QueryResponse(response)
+    }
+
+    /// Take queued outbound frames (typically sent with `TransportManager::send` in async code).
+    pub fn drain_pending_sends(&self) -> Result<Vec<(TransportAddr, Vec<u8>)>> {
+        let mut q = self
+            .pending_sends
+            .lock()
+            .map_err(|e| anyhow::anyhow!("pending_sends lock poisoned: {e}"))?;
+        let out = std::mem::take(&mut *q);
+        Ok(out)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::Duration;
+
+    use crate::fapp::{Fachrichtung, Kostentraeger, Modalitaet, SlotType, TimeSlot};
+    use crate::identity::MeshIdentity;
+
+    #[test]
+    fn handle_incoming_unknown_tag_dropped() {
+        let routes = Arc::new(RwLock::new(RoutingTable::new(Duration::from_secs(300))));
+        let transports = Arc::new(TransportManager::new());
+        let r = FappRouter::new(FappStore::new(), routes, transports, CAP_FAPP_RELAY);
+
+        match r.handle_incoming(&[0xFF]) {
+            FappAction::Dropped(msg) => assert!(msg.contains("unknown")),
+            other => panic!("expected Dropped, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn process_slot_query_requires_relay_cap() {
+        let routes = Arc::new(RwLock::new(RoutingTable::new(Duration::from_secs(300))));
+        let transports = Arc::new(TransportManager::new());
+        let r = FappRouter::new(FappStore::new(), routes, transports, 0);
+
+        let q = SlotQuery {
+            query_id: [1u8; 16],
+            fachrichtung: None,
+            modalitaet: None,
+            kostentraeger: None,
+            plz_prefix: None,
+            earliest: None,
+            latest: None,
+            slot_type: None,
+            max_results: 5,
+        };
+        assert!(matches!(r.process_slot_query(q), FappAction::Ignore));
+    }
+
+    #[test]
+    fn broadcast_announce_requires_therapist_cap() {
+        let routes = Arc::new(RwLock::new(RoutingTable::new(Duration::from_secs(300))));
+        let transports = Arc::new(TransportManager::new());
+        let r = FappRouter::new(FappStore::new(), routes, transports, CAP_FAPP_RELAY);
+        let id = MeshIdentity::generate();
+        let a = SlotAnnounce::new(
+            &id,
+            vec![Fachrichtung::Verhaltenstherapie],
+            vec![Modalitaet::Praxis],
+            vec![Kostentraeger::GKV],
+            "80331".into(),
+            vec![TimeSlot {
+                start_unix: 1,
+                duration_minutes: 50,
+                slot_type: SlotType::Therapie,
+            }],
+            [0xAA; 32],
+            1,
+        );
+        assert!(r.broadcast_announce(a).is_err());
+    }
+}

crates/quicprochat-p2p/src/lib.rs

@@ -16,6 +16,7 @@ pub mod address;
 pub mod announce;
 pub mod announce_protocol;
 pub mod fapp;
+pub mod fapp_router;
 pub mod broadcast;
 pub mod envelope;
 pub mod envelope_v2;