plexor-core 0.1.0-alpha.2

// Copyright 2025 Alecks Gates
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

use crate::codec::{Codec, CodecName};
use crate::erasure::payload::{PayloadErased, PayloadRawErased};
use crate::erasure::reactant::{ErrorReactantErased, ReactantErased, ReactantRawErased};
use crate::erasure::synapse::{SynapseInternalErased, erase_synapse_internal};
use crate::logging::LogTrace;
use crate::neuron::{Neuron, NeuronError};
use crate::synapse::SynapseInprocess;
use crate::utils::struct_name_of_type;
use std::collections::{HashMap, HashSet};
use std::fmt::Debug;
use std::future::Future;
use std::pin::Pin;
use std::sync::Arc;
use parking_lot::RwLock;
use thiserror::Error;
use tokio::sync::Mutex;
use tracing::Instrument;
use uuid::Uuid;

#[derive(Error, Debug)]
pub enum GanglionError {
    #[error("Synapse not found: {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})")]
    SynapseNotFound {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
    #[error(
        "Failed to acquire lock on synapse: {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})"
    )]
    SynapseLock {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
    #[error(
        "Transmission error for neuron {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id}): {message}"
    )]
    Transmit {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
        message: String,
    },
    #[error("Encode error for neuron {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})")]
    Encode {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
    #[error("Decode error for neuron {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})")]
    Decode {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
    #[error(
        "Adaptation error for neuron {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})"
    )]
    Adapt {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
    #[error("Queue full for neuron {neuron_name} (ganglion: {ganglion_name}, id: {ganglion_id})")]
    QueueFull {
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    },
}

impl GanglionError {
    /// Convert a NeuronError to a GanglionError with additional context
    pub fn from_neuron_error(
        neuron_error: NeuronError,
        ganglion_name: String,
        ganglion_id: Uuid,
    ) -> Self {
        match neuron_error {
            NeuronError::Encode { neuron_name, .. } => GanglionError::Encode {
                neuron_name,
                ganglion_name,
                ganglion_id,
            },
            NeuronError::Decode { neuron_name, .. } => GanglionError::Decode {
                neuron_name,
                ganglion_name,
                ganglion_id,
            },
        }
    }

    /// Convert a PlexusError to a GanglionError with additional context
    pub fn from_plexus_error(
        plexus_error: crate::plexus::PlexusError,
        neuron_name: String,
        ganglion_name: String,
        ganglion_id: Uuid,
    ) -> Self {
        match plexus_error {
            // If the PlexusError already contains a GanglionError, return it as-is
            crate::plexus::PlexusError::Ganglion(ganglion_error) => ganglion_error,
            // For all other PlexusError variants, convert to Adapt error
            _ => GanglionError::Adapt {
                neuron_name,
                ganglion_name,
                ganglion_id,
            },
        }
    }
}

pub trait Ganglion {
    fn capable<T, C>(&mut self, neuron: Arc<dyn Neuron<T, C> + Send + Sync>) -> bool
    where
        C: Codec<T> + CodecName + Send + Sync + 'static,
        T: Send + Sync + 'static;

    fn adapt<T, C>(
        &mut self,
        neuron: Arc<dyn Neuron<T, C> + Send + Sync>,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>>
    where
        C: Codec<T> + CodecName + Send + Sync + 'static,
        T: Send + Sync + 'static;
}

/// Internal interface for Ganglion that handles type-erased payloads and reactants.
pub trait GanglionInternal {
    fn transmit(
        &mut self,
        payload: Arc<dyn PayloadErased + Send + Sync + 'static>,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<()>, GanglionError>> + Send + 'static>>;

    fn react(
        &mut self,
        neuron_name: String,
        reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
        error_reactants: Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>>;

    /// React to multiple neurons at once.
    fn react_many(
        &mut self,
        reactions: HashMap<
            String,
            (
                Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
                Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
            ),
        >,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>> {
        let mut futures = Vec::new();
        for (name, (rs, ers)) in reactions {
            futures.push(self.react(name, rs, ers));
        }
        Box::pin(async move {
            for f in futures {
                f.await?;
            }
            Ok(())
        })
    }

    fn unique_id(&self) -> Uuid;
}

/// External interface for Ganglion that handles network-level type-erased data.
pub trait GanglionExternal {
    fn transmit(
        &mut self,
        payload: Arc<dyn PayloadErased + Send + Sync + 'static>,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<()>, GanglionError>> + Send + 'static>>;

    #[allow(clippy::type_complexity)]
    fn transmit_encoded(
        &mut self,
        payload: Arc<dyn PayloadRawErased + Send + Sync + 'static>,
    ) -> Pin<Box<dyn Future<Output = Result<(Vec<()>, Vec<()>), GanglionError>> + Send + 'static>>;

    fn react(
        &mut self,
        neuron_name: String,
        reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
        raw_reactants: Vec<Arc<dyn ReactantRawErased + Send + Sync + 'static>>,
        error_reactants: Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>>;

    /// React to multiple neurons at once.
    fn react_many(
        &mut self,
        reactions: HashMap<
            String,
            (
                Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
                Vec<Arc<dyn ReactantRawErased + Send + Sync + 'static>>,
                Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
            ),
        >,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>> {
        let mut futures = Vec::new();
        for (name, (rs, rrs, ers)) in reactions {
            futures.push(self.react(name, rs, rrs, ers));
        }
        Box::pin(async move {
            for f in futures {
                f.await?;
            }
            Ok(())
        })
    }

    fn unique_id(&self) -> Uuid;
}

/// Helper function to adapt a single neuron to multiple ganglia at once.
/// Note: All ganglia in the slice must be of the same type G.
/// For heterogeneous ganglia, use the `adapt_all!` macro instead.
pub async fn adapt_all<T, C, G>(
    ganglia: &[Arc<Mutex<G>>],
    neuron: Arc<dyn Neuron<T, C> + Send + Sync>,
) -> Result<(), GanglionError>
where
    C: Codec<T> + CodecName + Send + Sync + 'static,
    T: Send + Sync + 'static,
    G: Ganglion + ?Sized,
{
    for ganglion_mutex in ganglia {
        let mut ganglion = ganglion_mutex.lock().await;
        ganglion.adapt(neuron.clone()).await?;
    }
    Ok(())
}

/// Macro to adapt a single neuron to multiple heterogeneous ganglia at once.
///
/// # Examples
///
/// ```rust
/// # use std::sync::Arc;
/// # use tokio::sync::Mutex;
/// # use plexor_core::adapt_all;
/// # use plexor_core::neuron::{Neuron, NeuronImpl};
/// # use plexor_core::ganglion::{Ganglion, GanglionInprocess};
/// # use plexor_core::namespace::NamespaceImpl;
/// # use plexor_core::codec::{Codec, CodecError, CodecName};
/// #
/// # #[derive(Debug)]
/// # struct Dummy;
/// # impl CodecName for Dummy { fn name() -> &'static str { "dummy" } }
/// # impl Codec<Dummy> for Dummy {
/// #     fn encode(_: &Dummy) -> Result<Vec<u8>, CodecError> { Ok(vec![]) }
/// #     fn decode(_: &[u8]) -> Result<Dummy, CodecError> { Ok(Dummy) }
/// # }
/// #
/// # tokio::runtime::Runtime::new().unwrap().block_on(async {
/// let ns = Arc::new(NamespaceImpl { delimiter: ".", parts: vec!["test"] });
/// let neuron = Arc::new(NeuronImpl::<Dummy, Dummy>::new(ns));
/// let g1 = Arc::new(Mutex::new(GanglionInprocess::new()));
/// let g2 = Arc::new(Mutex::new(GanglionInprocess::new()));
///
/// adapt_all!(neuron, g1, g2).await.unwrap();
/// # });
/// ```
#[macro_export]
macro_rules! adapt_all {
    ($neuron:expr, $($ganglion:expr),+ $(,)?) => {
        async {
            $(
                $ganglion.lock().await.adapt($neuron.clone()).await?;
            )+
            Result::<(), $crate::ganglion::GanglionError>::Ok(())
        }
    };
}

/// Macro to adapt multiple neurons to multiple heterogeneous ganglia at once.
///
/// This locks each ganglion once and adapts all provided neurons to it.
///
/// # Examples
///
/// ```rust
/// # use std::sync::Arc;
/// # use tokio::sync::Mutex;
/// # use plexor_core::adapt_many;
/// # use plexor_core::neuron::{Neuron, NeuronImpl};
/// # use plexor_core::ganglion::{Ganglion, GanglionInprocess};
/// # use plexor_core::namespace::NamespaceImpl;
/// # use plexor_core::codec::{Codec, CodecError, CodecName};
/// #
/// # #[derive(Debug, Clone)]
/// # struct Dummy;
/// # impl CodecName for Dummy { fn name() -> &'static str { "dummy" } }
/// # impl Codec<Dummy> for Dummy {
/// #     fn encode(_: &Dummy) -> Result<Vec<u8>, CodecError> { Ok(vec![]) }
/// #     fn decode(_: &[u8]) -> Result<Dummy, CodecError> { Ok(Dummy) }
/// # }
/// #
/// # tokio::runtime::Runtime::new().unwrap().block_on(async {
/// let ns = Arc::new(NamespaceImpl { delimiter: ".", parts: vec!["test"] });
/// let n1 = Arc::new(NeuronImpl::<Dummy, Dummy>::new(ns.clone()));
/// let n2 = Arc::new(NeuronImpl::<Dummy, Dummy>::new(ns));
/// let g1 = Arc::new(Mutex::new(GanglionInprocess::new()));
/// let g2 = Arc::new(Mutex::new(GanglionInprocess::new()));
///
/// let res: Result<(), plexor_core::ganglion::GanglionError> = adapt_many!([n1, n2], g1, g2).await;
/// res.unwrap();
/// # });
/// ```
#[macro_export]
macro_rules! adapt_many {
    // Base case: simple expansion for a single ganglion
    ([$($neuron:expr),+ $(,)?], $ganglion:expr $(,)?) => {
        async {
            let mut g = $ganglion.lock().await;
            $(
                g.adapt($neuron.clone()).await?;
            )+
            Result::<(), $crate::ganglion::GanglionError>::Ok(())
        }
    };

    // Recursive step: handle head ganglion, then recurse for tail
    ([$($neuron:expr),+ $(,)?], $head_ganglion:expr, $($tail_ganglion:expr),+ $(,)?) => {
        async {
            {
                let mut g = $head_ganglion.lock().await;
                $(
                    g.adapt($neuron.clone()).await?;
                )+
            }
            $crate::adapt_many!([$($neuron),+], $($tail_ganglion),+).await
        }
    };
}

pub struct GanglionInprocess {
    id: Uuid,
    synapses_by_name:
        HashMap<String, Arc<RwLock<dyn SynapseInternalErased + Send + Sync + 'static>>>,
    /// Neurons that this ganglion will handle (if empty, handles all)
    relevant_neurons: HashSet<String>,
    /// Neurons that this ganglion will ignore
    ignored_neurons: HashSet<String>,
}

impl GanglionInprocess {
    pub fn new() -> Self {
        Self {
            id: Uuid::now_v7(),
            synapses_by_name: HashMap::new(),
            relevant_neurons: HashSet::new(),
            ignored_neurons: HashSet::new(),
        }
    }

    /// Helper to create an Arc<Mutex<GanglionInprocess>>
    pub fn new_shared() -> Arc<Mutex<Self>> {
        Arc::new(Mutex::new(Self::new()))
    }

    pub fn new_with_filters(
        relevant_neurons: HashSet<String>,
        ignored_neurons: HashSet<String>,
    ) -> Self {
        Self {
            id: Uuid::now_v7(),
            synapses_by_name: HashMap::new(),
            relevant_neurons,
            ignored_neurons,
        }
    }

    fn get_synapse_by_name(
        &self,
        name: &str,
    ) -> Option<Arc<RwLock<dyn SynapseInternalErased + Send + Sync + 'static>>> {
        self.synapses_by_name.get(name).cloned()
    }
}

impl Default for GanglionInprocess {
    fn default() -> Self {
        Self::new()
    }
}

impl Ganglion for GanglionInprocess {
    fn capable<T, C>(&mut self, neuron: Arc<dyn Neuron<T, C> + Send + Sync>) -> bool
    where
        C: Codec<T> + CodecName + Send + Sync + 'static,
        T: Send + Sync + 'static,
    {
        let neuron_name = neuron.name();

        if !self.relevant_neurons.is_empty() && !self.relevant_neurons.contains(&neuron_name) {
            return false;
        }

        if !self.ignored_neurons.is_empty() && self.ignored_neurons.contains(&neuron_name) {
            return false;
        }

        true
    }

    fn adapt<T, C>(
        &mut self,
        neuron: Arc<dyn Neuron<T, C> + Send + Sync>,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>>
    where
        C: Codec<T> + CodecName + Send + Sync + 'static,
        T: Send + Sync + 'static,
    {
        // Call capable and return early if false
        if !self.capable(neuron.clone()) {
            return Box::pin(async move {
                Ok(()) // Not an error, just not capable
            });
        }

        let neuron_name = neuron.name();

        // Check if the synapse already exists
        if self.synapses_by_name.contains_key(&neuron_name) {
            return Box::pin(async move {
                Ok(()) // Not an error, synapse already exists
            });
        }

        // Create the synapse
        let synapse = SynapseInprocess::<T, C>::new(neuron.clone(), vec![], vec![]);
        let erased_synapse = erase_synapse_internal(synapse);

        // Insert the synapse
        self.synapses_by_name
            .insert(neuron_name.clone(), erased_synapse);

        Box::pin(async move { Ok(()) })
    }
}

impl GanglionInternal for GanglionInprocess {
    fn transmit(
        &mut self,
        payload: Arc<dyn PayloadErased + Send + Sync + 'static>,
    ) -> Pin<Box<dyn Future<Output = Result<Vec<()>, GanglionError>> + Send + 'static>> {
        let neuron_name = payload.get_neuron_name();
        tracing::debug!("GanglionInprocess::transmit called for neuron: {neuron_name}");

        if let Some(synapse_lock) = self.get_synapse_by_name(&neuron_name) {
            tracing::debug!("GanglionInprocess::transmit found synapse, acquiring read lock");
            let synapse_guard = synapse_lock.read();
            tracing::debug!(
                "GanglionInprocess::transmit acquired read lock, calling transmit_erased"
            );
            let future = synapse_guard.transmit_erased(payload.clone());
            let ganglion_id = self.id;
            let ganglion_name = struct_name_of_type::<Self>().to_string();
            Box::pin(
                async move {
                    tracing::debug!(
                        "GanglionInprocess::transmit awaiting transmit_erased future"
                    );
                    let result = future.await;
                    tracing::debug!("GanglionInprocess::transmit transmit_erased completed");
                    result.map_err(|e| match e {
                        crate::synapse::SynapseError::QueueFull { neuron_name: _ } => {
                            GanglionError::QueueFull {
                                neuron_name: neuron_name.clone(),
                                ganglion_name: ganglion_name.clone(),
                                ganglion_id,
                            }
                        }
                        _ => GanglionError::Transmit {
                            neuron_name: neuron_name.clone(),
                            ganglion_name: ganglion_name.clone(),
                            ganglion_id,
                            message: e.to_string(),
                        },
                    })
                }
                .instrument(payload.span_debug("GanglionInprocess::transmit")),
            )
        } else {
            tracing::debug!("GanglionInprocess::transmit synapse not found");
            let ganglion_id = self.id;
            let ganglion_name = struct_name_of_type::<GanglionInprocess>().to_string();
            Box::pin(async move {
                Err(GanglionError::SynapseNotFound {
                    neuron_name,
                    ganglion_name,
                    ganglion_id,
                })
            })
        }
    }

    fn react(
        &mut self,
        neuron_name: String,
        reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
        error_reactants: Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>> {
        // Get the synapse by name
        let synapse_lock_opt = self.get_synapse_by_name(&neuron_name);

        // Check if the synapse exists
        if synapse_lock_opt.is_none() {
            let ganglion_id = self.id;
            let ganglion_name = struct_name_of_type::<GanglionInprocess>().to_string();
            return Box::pin(async move {
                Err(GanglionError::SynapseNotFound {
                    neuron_name,
                    ganglion_name,
                    ganglion_id,
                })
            });
        }

        // Get a write lock on the synapse
        let synapse_lock = synapse_lock_opt.unwrap();
        let mut synapse_guard = synapse_lock.write();

        // Call react_erased on the synapse with the reactants
        synapse_guard.react_erased(reactants, error_reactants);

        // The write lock is automatically released when synapse_guard goes out of scope

        Box::pin(async move { Ok(()) })
    }

    fn react_many(
        &mut self,
        reactions: HashMap<
            String,
            (
                Vec<Arc<dyn ReactantErased + Send + Sync + 'static>>,
                Vec<Arc<dyn ErrorReactantErased + Send + Sync>>,
            ),
        >,
    ) -> Pin<Box<dyn Future<Output = Result<(), GanglionError>> + Send + 'static>> {
        for (neuron_name, (reactants, error_reactants)) in reactions {
            if let Some(synapse_lock) = self.get_synapse_by_name(&neuron_name) {
                let mut synapse_guard = synapse_lock.write();
                synapse_guard.react_erased(reactants, error_reactants);
            } else {
                let ganglion_id = self.id;
                let ganglion_name = struct_name_of_type::<GanglionInprocess>().to_string();
                return Box::pin(async move {
                    Err(GanglionError::SynapseNotFound {
                        neuron_name,
                        ganglion_name,
                        ganglion_id,
                    })
                });
            }
        }
        Box::pin(async move { Ok(()) })
    }

    fn unique_id(&self) -> Uuid {
        self.id
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::erasure::payload::{erase_payload, erase_payload_raw};
    use crate::erasure::reactant::{
        ReactantErased, ReactantRawErased, erase_reactant, erase_reactant_raw,
    };
    use crate::namespace::NamespaceImpl;
    use crate::neuron::{Neuron, NeuronImpl};
    use crate::payload::{Payload, PayloadRaw};
    use crate::test_utils::{
        DebugCodec, DebugStruct, GanglionExternalInprocess, PingCodec, PingMsg, PingNeuron,
        TokioMpscReactant, TokioMpscReactantGeneric, TokioMpscReactantRaw, test_namespace,
    };
    use std::collections::HashSet;
    use std::sync::Arc;
    use std::time::Duration;
    use tokio::sync::mpsc::channel;
    use tokio::task;
    use tokio::time::sleep;
    use uuid::Uuid;

    #[test]
    fn test_ganglion_error_with_ganglion_name() {
        let ganglion_id = Uuid::now_v7();
        let ganglion_name = struct_name_of_type::<GanglionInprocess>().to_string();

        // Test SynapseNotFound error
        let synapse_not_found = GanglionError::SynapseNotFound {
            neuron_name: "test_neuron".to_string(),
            ganglion_name: ganglion_name.clone(),
            ganglion_id,
        };
        assert!(synapse_not_found.to_string().contains("test_neuron"));
        assert!(synapse_not_found.to_string().contains("GanglionInprocess"));

        // Test SynapseLockError error
        let synapse_lock_error = GanglionError::SynapseLock {
            neuron_name: "test_neuron".to_string(),
            ganglion_name: ganglion_name.clone(),
            ganglion_id,
        };
        assert!(synapse_lock_error.to_string().contains("test_neuron"));
        assert!(synapse_lock_error.to_string().contains("GanglionInprocess"));

        // Test new Transmit error
        let transmit_error = GanglionError::Transmit {
            neuron_name: "test_neuron".to_string(),
            ganglion_name: ganglion_name.clone(),
            ganglion_id,
            message: "test failure".to_string(),
        };
        assert!(transmit_error.to_string().contains("test_neuron"));
        assert!(transmit_error.to_string().contains("GanglionInprocess"));
        assert!(transmit_error.to_string().contains("test failure"));
    }
    // test_ganglion_inprocess_neuron_by_name has been removed as part of removing get_neuron_by_name and neurons_by_name

    #[tokio::test]
    async fn test_ganglion_inprocess_get_synapse_by_name() {
        let ns = test_namespace();
        let neuron_impl_instance: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns.clone());
        let neuron_name_str = neuron_impl_instance.name();

        let neuron: Arc<dyn Neuron<DebugStruct, DebugCodec> + Send + Sync + 'static> =
            Arc::new(neuron_impl_instance);

        let mut ganglion = GanglionInprocess::new();

        // Use adapt instead of add_neuron and populate_synapse
        ganglion
            .adapt(neuron.clone())
            .await
            .expect("Failed to adapt neuron for test");

        let result_by_name1 = ganglion.get_synapse_by_name(&neuron_name_str);
        assert!(result_by_name1.is_some());
        let synapse_by_name1 = result_by_name1.unwrap();

        let result_by_name2 = ganglion.get_synapse_by_name(&neuron_name_str);
        assert!(result_by_name2.is_some());
        let synapse_by_name2 = result_by_name2.unwrap();

        assert!(
            Arc::ptr_eq(&synapse_by_name1, &synapse_by_name2),
            "Repeated calls to get_synapse_by_name should yield the same Arc instance."
        );

        let non_existent_result = ganglion.get_synapse_by_name("non_existent_neuron");
        assert!(non_existent_result.is_none());
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_transmit_via_adapt() {
        let ns = test_namespace();

        let (tx1, mut rx1) = channel::<Arc<Payload<PingMsg, PingCodec>>>(10);
        let (tx2, mut rx2) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(10);

        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns.clone());

        let neuron_arc = neuron_impl.clone_to_arc();

        let mut ganglion: GanglionInprocess = GanglionInprocess::new();

        // Use adapt instead of add_neuron and populate_synapse
        ganglion
            .adapt(neuron_arc.clone())
            .await
            .expect("Failed to adapt neuron");

        let ping_neuron = Arc::new(PingNeuron::new(test_namespace()));
        ganglion
            .adapt(ping_neuron.clone())
            .await
            .expect("Failed to adapt ping neuron");

        let reactants1: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>> =
            vec![erase_reactant::<PingMsg, PingCodec, _>(Box::new(
                TokioMpscReactantGeneric::new(tx1.clone()),
            ))];
        let reactants2: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>> =
            vec![erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(
                TokioMpscReactantGeneric::new(tx2.clone()),
            ))];

        ganglion
            .react(ping_neuron.name(), reactants1, vec![])
            .await
            .expect("Failed to react ping");
        ganglion
            .react(neuron_arc.name(), reactants2, vec![])
            .await
            .expect("Failed to react debug");

        let correlation_uuid1 = Uuid::now_v7();
        let payload1 = Payload::builder()
            .value(PingMsg { seq: 1 })
            .correlation_id(correlation_uuid1)
            .neuron(ping_neuron)
            .build()
            .unwrap();

        let erased_payload1 = erase_payload(payload1);
        ganglion
            .transmit(erased_payload1)
            .await
            .expect("Failed to transmit payload1");

        assert_eq!(
            rx1.len(),
            1,
            "Reactant 1 should have received the first message (ping)"
        );
        let received_p1_ch1 = rx1.recv().await.unwrap();
        assert_eq!(
            received_p1_ch1.value.seq, 1,
            "Payload value mismatch for reactant 1"
        );
        assert_eq!(
            received_p1_ch1.correlation_id(), correlation_uuid1,
            "Correlation ID mismatch for reactant 1"
        );

        let debug_struct_arc_2 = Arc::new(DebugStruct {
            foo: 456,
            bar: "ganglion_test_payload_2".to_string(),
        });
        let correlation_uuid2 = Uuid::now_v7();
        let payload2 = Payload::builder()
            .value((*debug_struct_arc_2).clone())
            .correlation_id(correlation_uuid2)
            .neuron(neuron_arc.clone())
            .build()
            .unwrap();

        let erased_payload2 = erase_payload(payload2);
        ganglion
            .transmit(erased_payload2)
            .await
            .expect("Failed to transmit payload2");

        assert_eq!(
            rx2.len(),
            1,
            "Reactant 2 should have received the second message (debug)"
        );
        let received_p2_ch1 = rx2.recv().await.unwrap();
        assert_eq!(
            received_p2_ch1.value, debug_struct_arc_2,
            "Second payload value mismatch for reactant 2"
        );
        assert_eq!(
            received_p2_ch1.correlation_id(), correlation_uuid2,
            "Second correlation ID mismatch for reactant 2"
        );

        // Ensure channels are empty now, indicating no unexpected messages
        assert_eq!(
            rx1.len(),
            0,
            "Reactant 1 channel should be empty after all expected messages"
        );
        assert_eq!(
            rx2.len(),
            0,
            "Reactant 2 channel should be empty after all expected messages"
        );
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_across_threads() {
        // Create a struct to hold the shared state
        struct SharedState {
            // Channels to receive payloads from reactants
            tx1: tokio::sync::mpsc::Sender<Arc<Payload<DebugStruct, DebugCodec>>>,
            tx2: tokio::sync::mpsc::Sender<Arc<Payload<DebugStruct, DebugCodec>>>,
            // Counter for received payloads
            received_count: std::sync::atomic::AtomicUsize,
        }

        // Create channels with large buffer to avoid blocking
        let (tx1, mut rx1) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(100);
        let (tx2, mut rx2) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(100);

        // Create shared state
        let shared_state = Arc::new(SharedState {
            tx1,
            tx2,
            received_count: std::sync::atomic::AtomicUsize::new(0),
        });

        // Number of threads and payloads per thread
        let num_threads = 10;
        let payloads_per_thread = 10;
        let total_payloads = num_threads * payloads_per_thread;

        // Create a vector to store all task handles
        let mut handles = Vec::new();

        // Spawn a task to receive payloads and count them
        let receiver_state = shared_state.clone();
        let receiver_handle = task::spawn(async move {
            let mut received_payloads = Vec::new();

            // Collect payloads from both channels
            for _ in 0..total_payloads * 2 {
                tokio::select! {
                    Some(payload) = rx1.recv() => {
                        received_payloads.push(payload);
                        receiver_state.received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                    Some(payload) = rx2.recv() => {
                        received_payloads.push(payload);
                        receiver_state.received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                }
            }

            received_payloads
        });

        // Create shared namespace, neuron, and ganglion outside the tasks
        let ns = test_namespace();
        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns);
        let neuron = neuron_impl.clone_to_arc();

        let reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>> = vec![
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: shared_state.tx1.clone(),
            })),
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: shared_state.tx2.clone(),
            })),
        ];

        let mut shared_ganglion = GanglionInprocess::new();
        // Use adapt instead of add_neuron and populate_synapse
        shared_ganglion
            .adapt(neuron.clone())
            .await
            .expect("Failed to adapt neuron");
        shared_ganglion
            .react(neuron.name(), reactants, vec![])
            .await
            .expect("Failed to react");

        let shared_ganglion = Arc::new(tokio::sync::Mutex::new(shared_ganglion));

        // Spawn multiple tasks that will transmit payloads using the shared ganglion
        for thread_id in 0..num_threads {
            let ganglion = shared_ganglion.clone();
            let neuron_clone = neuron.clone();

            // Spawn a new task
            let handle = task::spawn(async move {
                // Transmit payloads through this task's ganglion
                for i in 0..payloads_per_thread {
                    // Create a unique payload for this thread and iteration
                    let payload_id = thread_id * payloads_per_thread + i;
                    let debug_struct = Arc::new(DebugStruct {
                        foo: payload_id as i32,
                        bar: format!("thread_{thread_id}_payload_{i}"),
                    });

                    let correlation_uuid = Uuid::now_v7();
                    let payload = Payload::builder()
                        .value((*debug_struct).clone())
                        .correlation_id(correlation_uuid)
                        .neuron(neuron_clone.clone())
                        .build()
                        .unwrap();

                    // Add a small delay to increase the chance of thread interleaving
                    sleep(Duration::from_millis(1)).await;

                    // Transmit the payload through the shared ganglion
                    let mut ganglion_guard = ganglion.lock().await;
                    let erased_payload = erase_payload(payload);
                    let _ = ganglion_guard.transmit(erased_payload).await;
                }
            });

            handles.push(handle);
        }

        // Wait for all transmitter tasks to complete
        for handle in handles {
            handle.await.unwrap();
        }

        // Wait for the receiver task to complete and get the received payloads
        let received_payloads = receiver_handle.await.unwrap();

        // Verify that we received the expected number of payloads
        assert_eq!(
            shared_state
                .received_count
                .load(std::sync::atomic::Ordering::SeqCst),
            total_payloads * 2,
            "Should have received all payloads on both reactants"
        );

        // Verify that we received payloads from all threads
        let mut foo_values = received_payloads
            .iter()
            .map(|p| p.value.foo)
            .collect::<Vec<_>>();
        foo_values.sort();
        foo_values.dedup();

        assert_eq!(
            foo_values.len(),
            total_payloads,
            "Should have received payloads with all expected foo values"
        );

        // Check that the foo values match the expected range
        for i in 0..total_payloads {
            assert!(
                foo_values.contains(&(i as i32)),
                "Should have received a payload with foo={i}"
            );
        }

        // Verify that all correlation_ids are preserved
        let mut correlation_ids = received_payloads
            .iter()
            .map(|p| p.correlation_id())
            .collect::<Vec<_>>();

        // Each correlation_id should appear exactly twice (once from each reactant)
        // So we should have total_payloads unique correlation_ids
        correlation_ids.sort();

        // Count occurrences of each correlation_id
        let mut correlation_id_counts = std::collections::HashMap::new();
        for id in &correlation_ids {
            *correlation_id_counts.entry(*id).or_insert(0) += 1;
        }

        // Verify we have the expected number of unique correlation_ids
        assert_eq!(
            correlation_id_counts.len(),
            total_payloads,
            "Should have received payloads with all expected correlation_ids"
        );

        // Verify each correlation_id appears exactly twice (once from each reactant)
        for (id, count) in correlation_id_counts {
            assert_eq!(
                count, 2,
                "Correlation ID {id} should appear exactly twice (once from each reactant)"
            );
        }
    }

    #[tokio::test]
    async fn test_ganglion_external_unique_id() {
        use crate::test_utils::GanglionExternalInprocess;
        let ganglion1 = GanglionExternalInprocess::new();
        let ganglion2 = GanglionExternalInprocess::new();

        // Each ganglion should have a unique ID
        assert_ne!(ganglion1.unique_id(), ganglion2.unique_id());

        // The same ganglion should return the same ID consistently
        assert_eq!(ganglion1.unique_id(), ganglion1.unique_id());
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_capable_with_relevant_neurons() {
        // Create neurons
        let neuron1 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "1"],
            },
        )));
        let neuron2 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "2"],
            },
        )));
        // Create ganglion with only neuron1 in relevant_neurons
        let mut relevant_neurons = HashSet::new();
        relevant_neurons.insert("dev.plexo.1.DebugStruct.debug".to_string());
        let mut ganglion = GanglionInprocess::new_with_filters(relevant_neurons, HashSet::new());

        // Test that neuron1 is capable
        assert!(ganglion.capable(neuron1.clone()));

        // Test that neuron2 is not capable
        assert!(!ganglion.capable(neuron2.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_capable_with_ignored_neurons() {
        // Create neurons
        let neuron1 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "1"],
            },
        )));
        let neuron2 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "2"],
            },
        )));

        // Create ganglion with neuron1 in ignored_neurons
        let mut ignored_neurons = HashSet::new();
        ignored_neurons.insert("dev.plexo.1.DebugStruct.debug".to_string());
        let mut ganglion = GanglionInprocess::new_with_filters(HashSet::new(), ignored_neurons);

        // Test that neuron1 is not capable (ignored)
        assert!(!ganglion.capable(neuron1.clone()));

        // Test that neuron2 is capable (not ignored)
        assert!(ganglion.capable(neuron2.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_external_inprocess_capable_with_relevant_neurons() {
        // Create neurons
        let neuron1 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "1"],
            },
        )));
        let neuron2 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "2"],
            },
        )));

        // Create ganglion with only neuron1 in relevant_neurons
        let mut relevant_neurons = HashSet::new();
        relevant_neurons.insert("dev.plexo.1.DebugStruct.debug".to_string());
        let mut ganglion =
            GanglionExternalInprocess::new_with_filters(relevant_neurons, HashSet::new());

        // Test that neuron1 is capable
        assert!(ganglion.capable(neuron1.clone()));

        // Test that neuron2 is not capable
        assert!(!ganglion.capable(neuron2.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_external_inprocess_capable_with_ignored_neurons() {
        // Create neurons
        let neuron1 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "1"],
            },
        )));
        let neuron2 = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo", "2"],
            },
        )));

        // Create ganglion with neuron1 in ignored_neurons
        let mut ignored_neurons = HashSet::new();
        ignored_neurons.insert("dev.plexo.1.DebugStruct.debug".to_string());
        let mut ganglion =
            GanglionExternalInprocess::new_with_filters(HashSet::new(), ignored_neurons);

        // Test that neuron1 is not capable (ignored)
        assert!(!ganglion.capable(neuron1.clone()));

        // Test that neuron2 is capable (not ignored)
        assert!(ganglion.capable(neuron2.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_capable_default_behavior() {
        // Create neuron
        let neuron = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(Arc::new(
            NamespaceImpl {
                delimiter: ".",
                parts: vec!["dev", "plexo"],
            },
        )));

        // Create ganglion with default constructor (no filters)
        let mut ganglion = GanglionInprocess::new();

        // Test that neuron is capable (default behavior should accept all)
        assert!(ganglion.capable(neuron.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_external_inprocess_capable_default_behavior() {
        // Create neuron
        let neuron = Arc::new(NeuronImpl::<DebugStruct, DebugCodec>::new(test_namespace()));

        // Create ganglion with default constructor (no filters)
        let mut ganglion = GanglionExternalInprocess::new();

        // Test that neuron is capable (default behavior should accept all)
        assert!(ganglion.capable(neuron.clone()));
    }

    #[tokio::test]
    async fn test_ganglion_external_transmit_encoded() {
        let ns = test_namespace();
        let mut ganglion = GanglionExternalInprocess::new();
        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns.clone());
        let neuron: Arc<dyn Neuron<DebugStruct, DebugCodec> + Send + Sync + 'static> =
            Arc::new(neuron_impl.clone());

        // Adapt the neuron to the ganglion first
        ganglion
            .adapt(neuron.clone())
            .await
            .expect("Failed to adapt neuron");

        let debug_struct_value = DebugStruct {
            foo: 42,
            bar: "test_value".to_owned(),
        };
        let debug_struct_arc = Arc::new(debug_struct_value);
        let correlation_id = Uuid::now_v7();
        let encoded = neuron_impl
            .encode(debug_struct_arc.as_ref())
            .expect("Encoding should succeed in test");

        let payload_raw =
            PayloadRaw::with_correlation(encoded, neuron.clone(), Some(correlation_id));

        let erased_payload = erase_payload_raw(payload_raw);
        let result = ganglion
            .transmit_encoded(erased_payload)
            .await
            .expect("Failed to transmit encoded payload");

        // For the test implementation, we expect empty vectors since no reactants were added
        assert_eq!(result.0.len(), 0);
        assert_eq!(result.1.len(), 0);
    }

    #[tokio::test]
    async fn test_ganglion_external_adapt() {
        let mut ganglion = GanglionExternalInprocess::new();
        let ns = test_namespace();
        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns);
        let neuron: Arc<dyn Neuron<DebugStruct, DebugCodec> + Send + Sync + 'static> =
            Arc::new(neuron_impl);

        // This should complete without error
        ganglion
            .adapt(neuron)
            .await
            .expect("Failed to adapt neuron");
    }

    #[tokio::test]
    async fn test_ganglion_external_inprocess_transmit_via_adapt() {
        let ns = test_namespace();

        let (tx1, mut rx1) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(2);
        let (tx2, mut rx2) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(2);
        let (raw_tx1, mut raw_rx1) = channel::<Arc<PayloadRaw<DebugStruct, DebugCodec>>>(2);
        let (raw_tx2, mut raw_rx2) = channel::<Arc<PayloadRaw<DebugStruct, DebugCodec>>>(2);

        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns.clone());
        let neuron_arc = neuron_impl.clone_to_arc();

        let reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>> = vec![
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: tx1.clone(),
            })),
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: tx2.clone(),
            })),
        ];

        let raw_reactants: Vec<Arc<dyn ReactantRawErased + Send + Sync + 'static>> = vec![
            erase_reactant_raw::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactantRaw {
                sender: raw_tx1.clone(),
            })),
            erase_reactant_raw::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactantRaw {
                sender: raw_tx2.clone(),
            })),
        ];

        let mut ganglion: GanglionExternalInprocess = GanglionExternalInprocess::new();

        ganglion
            .adapt(neuron_arc.clone())
            .await
            .expect("Failed to adapt neuron");
        ganglion
            .react(neuron_arc.name(), reactants, raw_reactants, vec![])
            .await
            .expect("Failed to react");

        let debug_struct_arc = Arc::new(DebugStruct {
            foo: 123,
            bar: "ganglion_external_test_payload_1".to_string(),
        });
        let correlation_uuid1 = Uuid::now_v7();
        let encoded = neuron_impl
            .encode(debug_struct_arc.as_ref())
            .expect("Encoding should succeed in test");
        let payload_raw1 = PayloadRaw::with_correlation(
            encoded,
            neuron_arc.clone(),
            Some(correlation_uuid1),
        );

        let erased_payload1 = erase_payload_raw(payload_raw1);
        ganglion
            .transmit_encoded(erased_payload1)
            .await
            .expect("Failed to transmit encoded payload1");

        // Check that raw reactants received the payload
        let received_raw_p1_ch1 =
            tokio::time::timeout(std::time::Duration::from_millis(100), raw_rx1.recv())
                .await
                .expect("Timeout raw_rx1")
                .expect("Closed raw_rx1");
        assert_eq!(
            received_raw_p1_ch1.correlation_id(), correlation_uuid1,
            "Raw correlation ID mismatch for reactant 1"
        );

        let received_raw_p1_ch2 =
            tokio::time::timeout(std::time::Duration::from_millis(100), raw_rx2.recv())
                .await
                .expect("Timeout raw_rx2")
                .expect("Closed raw_rx2");
        assert_eq!(
            received_raw_p1_ch2.correlation_id(), correlation_uuid1,
            "Raw correlation ID mismatch for reactant 2"
        );

        // Check that regular reactants also received the decoded payload
        let received_p1_ch1 =
            tokio::time::timeout(std::time::Duration::from_millis(100), rx1.recv())
                .await
                .expect("Timeout rx1")
                .expect("Closed rx1");
        assert_eq!(
            received_p1_ch1.value, debug_struct_arc,
            "Payload value mismatch for reactant 1"
        );
        assert_eq!(
            received_p1_ch1.correlation_id(), correlation_uuid1,
            "Correlation ID mismatch for reactant 1"
        );

        let received_p1_ch2 =
            tokio::time::timeout(std::time::Duration::from_millis(100), rx2.recv())
                .await
                .expect("Timeout rx2")
                .expect("Closed rx2");
        assert_eq!(
            received_p1_ch2.value, debug_struct_arc,
            "Payload value mismatch for reactant 2"
        );
        assert_eq!(
            received_p1_ch2.correlation_id(), correlation_uuid1,
            "Correlation ID mismatch for reactant 2"
        );

        // Send a second payload
        let debug_struct_arc_2 = Arc::new(DebugStruct {
            foo: 456,
            bar: "ganglion_external_test_payload_2".to_string(),
        });
        let correlation_uuid2 = Uuid::now_v7();
        let encoded2 = neuron_impl
            .encode(debug_struct_arc_2.as_ref())
            .expect("Encoding should succeed in test");
        let payload_raw2 = PayloadRaw::with_correlation(
            encoded2,
            neuron_arc.clone(),
            Some(correlation_uuid2),
        );

        let erased_payload2 = erase_payload_raw(payload_raw2);
        ganglion
            .transmit_encoded(erased_payload2)
            .await
            .expect("Failed to transmit encoded payload2");

        // Check raw reactants received the second payload
        let received_raw_p2_ch1 =
            tokio::time::timeout(std::time::Duration::from_millis(100), raw_rx1.recv())
                .await
                .expect("Timeout raw_rx1_2")
                .expect("Closed raw_rx1_2");
        assert_eq!(
            received_raw_p2_ch1.correlation_id(), correlation_uuid2,
            "Second raw correlation ID mismatch for reactant 1"
        );

        let received_raw_p2_ch2 =
            tokio::time::timeout(std::time::Duration::from_millis(100), raw_rx2.recv())
                .await
                .expect("Timeout raw_rx2_2")
                .expect("Closed raw_rx2_2");
        assert_eq!(
            received_raw_p2_ch2.correlation_id(), correlation_uuid2,
            "Second raw correlation ID mismatch for reactant 2"
        );

        // Check regular reactants received the second decoded payload
        let received_p2_ch1 =
            tokio::time::timeout(std::time::Duration::from_millis(100), rx1.recv())
                .await
                .expect("Timeout rx1_2")
                .expect("Closed rx1_2");
        assert_eq!(
            received_p2_ch1.value, debug_struct_arc_2,
            "Second payload value mismatch for reactant 1"
        );
        assert_eq!(
            received_p2_ch1.correlation_id(), correlation_uuid2,
            "Second correlation ID mismatch for reactant 1"
        );

        let received_p2_ch2 =
            tokio::time::timeout(std::time::Duration::from_millis(100), rx2.recv())
                .await
                .expect("Timeout rx2_2")
                .expect("Closed rx2_2");
        assert_eq!(
            received_p2_ch2.value, debug_struct_arc_2,
            "Second payload value mismatch for reactant 2"
        );
        assert_eq!(
            received_p2_ch2.correlation_id(), correlation_uuid2,
            "Second correlation ID mismatch for reactant 2"
        );

        // Ensure channels are empty now, indicating no unexpected messages
        assert_eq!(
            rx1.len(),
            0,
            "Reactant 1 channel should be empty after all expected messages"
        );
        assert_eq!(
            rx2.len(),
            0,
            "Reactant 2 channel should be empty after all expected messages"
        );
        assert_eq!(
            raw_rx1.len(),
            0,
            "Raw reactant 1 channel should be empty after all expected messages"
        );
        assert_eq!(
            raw_rx2.len(),
            0,
            "Raw reactant 2 channel should be empty after all expected messages"
        );
    }

    #[tokio::test]
    async fn test_ganglion_inprocess_adapt_erased() {
        let ns = test_namespace();

        // Create a neuron
        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns.clone());
        let neuron: Arc<dyn Neuron<DebugStruct, DebugCodec> + Send + Sync + 'static> =
            Arc::new(neuron_impl);

        // Create a ganglion
        let mut ganglion = GanglionInprocess::new();

        // Use the regular adapt method instead of adapt_erased
        ganglion
            .adapt(neuron.clone())
            .await
            .expect("Failed to adapt neuron");

        // Verify that a synapse was created and stored
        let neuron_name = neuron.name();
        let synapse = ganglion.get_synapse_by_name(&neuron_name);
        assert!(synapse.is_some());
    }

    #[tokio::test]
    async fn test_ganglion_external_inprocess_across_threads() {
        use crate::ganglion::GanglionExternal;
        use crate::neuron::NeuronImpl;
        use crate::payload::PayloadRaw;
        use crate::test_utils::{
            DebugCodec, DebugStruct, GanglionExternalInprocess, TokioMpscReactant,
            TokioMpscReactantRaw, test_namespace,
        };
        use std::sync::Arc;
        use tokio::sync::mpsc::channel;
        use tokio::task;
        use tokio::time::{Duration, sleep};
        use uuid::Uuid;

        // Create a struct to hold the shared state
        struct SharedState {
            // Channels to receive payloads from reactants
            tx1: tokio::sync::mpsc::Sender<Arc<Payload<DebugStruct, DebugCodec>>>,
            tx2: tokio::sync::mpsc::Sender<Arc<Payload<DebugStruct, DebugCodec>>>,
            raw_tx1: tokio::sync::mpsc::Sender<Arc<PayloadRaw<DebugStruct, DebugCodec>>>,
            raw_tx2: tokio::sync::mpsc::Sender<Arc<PayloadRaw<DebugStruct, DebugCodec>>>,
            // Counter for received payloads
            received_count: std::sync::atomic::AtomicUsize,
            raw_received_count: std::sync::atomic::AtomicUsize,
        }

        // Create channels with large buffer to avoid blocking
        let (tx1, mut rx1) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(100);
        let (tx2, mut rx2) = channel::<Arc<Payload<DebugStruct, DebugCodec>>>(100);
        let (raw_tx1, mut raw_rx1) = channel::<Arc<PayloadRaw<DebugStruct, DebugCodec>>>(100);
        let (raw_tx2, mut raw_rx2) = channel::<Arc<PayloadRaw<DebugStruct, DebugCodec>>>(100);

        // Create shared state
        let shared_state = Arc::new(SharedState {
            tx1,
            tx2,
            raw_tx1,
            raw_tx2,
            received_count: std::sync::atomic::AtomicUsize::new(0),
            raw_received_count: std::sync::atomic::AtomicUsize::new(0),
        });

        // Number of threads and payloads per thread
        let num_threads = 10;
        let payloads_per_thread = 10;
        let total_payloads = num_threads * payloads_per_thread;

        // Create a vector to store all task handles
        let mut handles = Vec::new();

        // Spawn a task to receive payloads and count them
        let receiver_state = shared_state.clone();
        let receiver_handle = task::spawn(async move {
            let mut received_payloads = Vec::new();
            let mut received_raw_payloads = Vec::new();

            // Collect payloads from all channels
            for _ in 0..total_payloads * 4 {
                // 2 regular + 2 raw channels
                tokio::select! {
                    Some(payload) = rx1.recv() => {
                        received_payloads.push(payload);
                        receiver_state.received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                    Some(payload) = rx2.recv() => {
                        received_payloads.push(payload);
                        receiver_state.received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                    Some(payload) = raw_rx1.recv() => {
                        received_raw_payloads.push(payload);
                        receiver_state.raw_received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                    Some(payload) = raw_rx2.recv() => {
                        received_raw_payloads.push(payload);
                        receiver_state.raw_received_count.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                    }
                }
            }

            (received_payloads, received_raw_payloads)
        });

        // Create shared namespace, neuron, and ganglion outside the tasks
        let ns = test_namespace();
        let neuron_impl: NeuronImpl<DebugStruct, DebugCodec> = NeuronImpl::new(ns);
        let neuron = neuron_impl.clone_to_arc();

        // Create a single shared ganglion with reactants
        let reactants: Vec<Arc<dyn ReactantErased + Send + Sync + 'static>> = vec![
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: shared_state.tx1.clone(),
            })),
            erase_reactant::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactant {
                sender: shared_state.tx2.clone(),
            })),
        ];

        let raw_reactants: Vec<Arc<dyn ReactantRawErased + Send + Sync + 'static>> = vec![
            erase_reactant_raw::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactantRaw {
                sender: shared_state.raw_tx1.clone(),
            })),
            erase_reactant_raw::<DebugStruct, DebugCodec, _>(Box::new(TokioMpscReactantRaw {
                sender: shared_state.raw_tx2.clone(),
            })),
        ];

        let mut shared_ganglion = GanglionExternalInprocess::new();
        shared_ganglion
            .adapt(neuron.clone())
            .await
            .expect("Failed to adapt neuron");
        shared_ganglion
            .react(neuron.name(), reactants, raw_reactants, vec![])
            .await
            .expect("Failed to react");

        let shared_ganglion = Arc::new(tokio::sync::Mutex::new(shared_ganglion));

        // Spawn multiple tasks that will transmit payloads using the shared ganglion
        for thread_id in 0..num_threads {
            let ganglion = shared_ganglion.clone();
            let neuron_clone = neuron.clone();
            let neuron_impl_clone = neuron_impl.clone();

            // Spawn a new task
            let handle = task::spawn(async move {
                // Transmit payloads through this task's ganglion
                for i in 0..payloads_per_thread {
                    // Create a unique payload for this thread and iteration
                    let payload_id = thread_id * payloads_per_thread + i;
                    let debug_struct = Arc::new(DebugStruct {
                        foo: payload_id as i32,
                        bar: format!("external_thread_{thread_id}_payload_{i}"),
                    });

                    let correlation_uuid = Uuid::now_v7();
                    let encoded = neuron_impl_clone
                        .encode(debug_struct.as_ref())
                        .expect("Encoding should succeed in test");
                    let payload_raw = PayloadRaw::with_correlation(
                        encoded,
                        neuron_clone.clone(),
                        Some(correlation_uuid),
                    );

                    // Add a small delay to increase the chance of thread interleaving
                    sleep(Duration::from_millis(1)).await;

                    // Transmit the payload through the shared ganglion
                    let mut ganglion_guard = ganglion.lock().await;
                    let erased_payload = erase_payload_raw(payload_raw);
                    ganglion_guard
                        .transmit_encoded(erased_payload)
                        .await
                        .expect("Failed to transmit encoded payload");
                }
            });

            handles.push(handle);
        }

        // Wait for all transmitter tasks to complete
        for handle in handles {
            handle.await.unwrap();
        }

        // Wait for the receiver task to complete and get the received payloads
        let (received_payloads, received_raw_payloads) = receiver_handle.await.unwrap();

        // Verify that we received the expected number of payloads
        assert_eq!(
            shared_state
                .received_count
                .load(std::sync::atomic::Ordering::SeqCst),
            total_payloads * 2,
            "Should have received all decoded payloads on both regular reactants"
        );

        assert_eq!(
            shared_state
                .raw_received_count
                .load(std::sync::atomic::Ordering::SeqCst),
            total_payloads * 2,
            "Should have received all raw payloads on both raw reactants"
        );

        // Verify that we received payloads from all threads (regular reactants)
        let mut foo_values = received_payloads
            .iter()
            .map(|p| p.value.foo)
            .collect::<Vec<_>>();
        foo_values.sort();
        foo_values.dedup();

        assert_eq!(
            foo_values.len(),
            total_payloads,
            "Should have received payloads with all expected foo values"
        );

        // Check that the foo values match the expected range
        for i in 0..total_payloads {
            assert!(
                foo_values.contains(&(i as i32)),
                "Should have received a payload with foo={i}"
            );
        }

        // Verify that all correlation_ids are preserved (regular reactants)
        let mut correlation_ids = received_payloads
            .iter()
            .map(|p| p.correlation_id())
            .collect::<Vec<_>>();

        // Each correlation_id should appear exactly twice (once from each reactant)
        // So we should have total_payloads unique correlation_ids
        correlation_ids.sort();

        // Count occurrences of each correlation_id
        let mut correlation_id_counts = std::collections::HashMap::new();
        for id in &correlation_ids {
            *correlation_id_counts.entry(*id).or_insert(0) += 1;
        }

        // Verify we have the expected number of unique correlation_ids (regular reactants)
        assert_eq!(
            correlation_id_counts.len(),
            total_payloads,
            "Should have received payloads with all expected correlation_ids"
        );

        // Verify each correlation_id appears exactly twice (once from each reactant)
        for (id, count) in correlation_id_counts {
            assert_eq!(
                count, 2,
                "Correlation ID {id} should appear exactly twice (once from each regular reactant)"
            );
        }

        // Verify that all correlation_ids are preserved (raw reactants)
        let mut raw_correlation_ids = received_raw_payloads
            .iter()
            .map(|p| p.correlation_id())
            .collect::<Vec<_>>();

        raw_correlation_ids.sort();

        // Count occurrences of each correlation_id for raw reactants
        let mut raw_correlation_id_counts = std::collections::HashMap::new();
        for id in &raw_correlation_ids {
            *raw_correlation_id_counts.entry(*id).or_insert(0) += 1;
        }

        // Verify we have the expected number of unique correlation_ids for raw reactants
        assert_eq!(
            raw_correlation_id_counts.len(),
            total_payloads,
            "Should have received raw payloads with all expected correlation_ids"
        );

        // Verify each correlation_id appears exactly twice for raw reactants (once from each raw reactant)
        for (id, count) in raw_correlation_id_counts {
            assert_eq!(
                count, 2,
                "Correlation ID {id} should appear exactly twice (once from each raw reactant)"
            );
        }
    }
}