a2a-rs 0.3.0

//! In-memory task storage implementation

// This module is already conditionally compiled with #[cfg(feature = "server")] in mod.rs

use std::collections::HashMap;
use std::sync::Arc;

use async_trait::async_trait;
use tokio::sync::Mutex; // Changed from std::sync::Mutex

use crate::adapter::business::push_notification::{
    PushNotificationRegistry, PushNotificationSender,
};

#[cfg(feature = "http-client")]
use crate::adapter::business::push_notification::HttpPushNotificationSender;
#[cfg(not(feature = "http-client"))]
use crate::adapter::business::push_notification::NoopPushNotificationSender;
use crate::domain::{
    A2AError, Artifact, Message, Task, TaskArtifactUpdateEvent, TaskPushNotificationConfig,
    TaskState, TaskStatus, TaskStatusUpdateEvent,
};
use crate::port::{
    AsyncNotificationManager, AsyncStreamingHandler, AsyncTaskManager,
    streaming_handler::Subscriber,
};

type StatusSubscribers = Vec<Box<dyn Subscriber<TaskStatusUpdateEvent> + Send + Sync>>;
type ArtifactSubscribers = Vec<Box<dyn Subscriber<TaskArtifactUpdateEvent> + Send + Sync>>;

/// Structure to hold subscribers for a task
pub(crate) struct TaskSubscribers {
    status: StatusSubscribers,
    artifacts: ArtifactSubscribers,
}

impl TaskSubscribers {
    fn new() -> Self {
        Self {
            status: Vec::new(),
            artifacts: Vec::new(),
        }
    }
}

/// Simple in-memory task storage for testing and example purposes
pub struct InMemoryTaskStorage {
    /// Tasks stored by ID
    pub(crate) tasks: Arc<Mutex<HashMap<String, Task>>>,
    /// Subscribers for task updates
    pub(crate) subscribers: Arc<Mutex<HashMap<String, TaskSubscribers>>>,
    /// Push notification registry
    pub(crate) push_notification_registry: Arc<PushNotificationRegistry>,
}

impl InMemoryTaskStorage {
    /// Create a new empty task storage
    pub fn new() -> Self {
        // Use the appropriate push notification sender based on available features
        #[cfg(feature = "http-client")]
        let push_sender = HttpPushNotificationSender::new();
        #[cfg(not(feature = "http-client"))]
        let push_sender = NoopPushNotificationSender;

        let push_registry = PushNotificationRegistry::new(push_sender);

        Self {
            tasks: Arc::new(Mutex::new(HashMap::new())),
            subscribers: Arc::new(Mutex::new(HashMap::new())),
            push_notification_registry: Arc::new(push_registry),
        }
    }

    /// Create a new task storage with a custom push notification sender
    pub fn with_push_sender(push_sender: impl PushNotificationSender + 'static) -> Self {
        let push_registry = PushNotificationRegistry::new(push_sender);

        Self {
            tasks: Arc::new(Mutex::new(HashMap::new())),
            subscribers: Arc::new(Mutex::new(HashMap::new())),
            push_notification_registry: Arc::new(push_registry),
        }
    }

    /// Add a status update subscriber for streaming (convenience method)
    pub async fn add_status_subscriber_legacy(
        &self,
        task_id: &str,
        subscriber: Box<dyn Subscriber<TaskStatusUpdateEvent> + Send + Sync>,
    ) -> Result<(), A2AError> {
        self.add_status_subscriber(task_id, subscriber)
            .await
            .map(|_| ())
    }

    /// Add an artifact update subscriber for streaming (convenience method)
    pub async fn add_artifact_subscriber_legacy(
        &self,
        task_id: &str,
        subscriber: Box<dyn Subscriber<TaskArtifactUpdateEvent> + Send + Sync>,
    ) -> Result<(), A2AError> {
        self.add_artifact_subscriber(task_id, subscriber)
            .await
            .map(|_| ())
    }
}

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

impl InMemoryTaskStorage {
    /// Look up the context_id for a task
    async fn get_task_context_id(&self, task_id: &str) -> String {
        let tasks_guard = self.tasks.lock().await;
        tasks_guard
            .get(task_id)
            .map(|t| t.context_id.clone())
            .unwrap_or_else(|| "default".to_string())
    }

    /// Send a status update to all subscribers for a task
    pub(crate) async fn broadcast_status_update(
        &self,
        task_id: &str,
        status: TaskStatus,
    ) -> Result<(), A2AError> {
        let context_id = self.get_task_context_id(task_id).await;

        // Create the update event
        let event = TaskStatusUpdateEvent {
            task_id: task_id.to_string(),
            context_id,
            kind: "status-update".to_string(),
            status: status.clone(),
            metadata: None,
        };

        #[cfg(feature = "tracing")]
        tracing::debug!(
            task_id = %task_id,
            state = ?status.state,
            "📡 Broadcasting status update to subscribers"
        );

        // Get all subscribers for this task and notify them
        let subscriber_count = {
            let subscribers_guard = self.subscribers.lock().await;

            if let Some(task_subscribers) = subscribers_guard.get(task_id) {
                let count = task_subscribers.status.len();
                #[cfg(feature = "tracing")]
                tracing::info!(
                    task_id = %task_id,
                    subscriber_count = count,
                    state = ?status.state,
                    "📡 Notifying WebSocket subscribers of status update"
                );

                // Clone the subscribers so we don't hold the lock during notification
                for (i, subscriber) in task_subscribers.status.iter().enumerate() {
                    if let Err(e) = subscriber.on_update(event.clone()).await {
                        #[cfg(feature = "tracing")]
                        tracing::error!(
                            task_id = %task_id,
                            subscriber_index = i,
                            error = %e,
                            "❌ Failed to notify subscriber"
                        );
                        eprintln!("Failed to notify subscriber: {}", e);
                    } else {
                        #[cfg(feature = "tracing")]
                        tracing::debug!(
                            task_id = %task_id,
                            subscriber_index = i,
                            "✅ Successfully notified subscriber"
                        );
                    }
                }
                count
            } else {
                // No subscribers is the steady-state for tasks created via
                // message/send (no streaming requested). Only worth tracing
                // at DEBUG — WARN here floods logs in normal operation.
                #[cfg(feature = "tracing")]
                tracing::debug!(
                    task_id = %task_id,
                    "no WebSocket subscribers for task; status broadcast skipped"
                );
                0
            }
        }; // Lock is dropped here

        #[cfg(feature = "tracing")]
        tracing::debug!(
            task_id = %task_id,
            notified_count = subscriber_count,
            "📡 Finished broadcasting to WebSocket subscribers"
        );

        // Send push notification if configured
        if let Err(e) = self
            .push_notification_registry
            .send_status_update(task_id, &event)
            .await
        {
            eprintln!("Failed to send push notification: {}", e);
        }

        Ok(())
    }

    /// Send an artifact update to all subscribers for a task
    pub(crate) async fn broadcast_artifact_update(
        &self,
        task_id: &str,
        artifact: Artifact,
        _index: Option<u32>,
        _final: bool,
    ) -> Result<(), A2AError> {
        let context_id = self.get_task_context_id(task_id).await;

        // Create the update event
        let event = TaskArtifactUpdateEvent {
            task_id: task_id.to_string(),
            context_id,
            kind: "artifact-update".to_string(),
            artifact,
            append: None,
            last_chunk: None,
            metadata: None,
        };

        // Get all subscribers for this task
        {
            let subscribers_guard = self.subscribers.lock().await;

            if let Some(task_subscribers) = subscribers_guard.get(task_id) {
                // Clone the subscribers so we don't hold the lock during notification
                for subscriber in task_subscribers.artifacts.iter() {
                    if let Err(e) = subscriber.on_update(event.clone()).await {
                        eprintln!("Failed to notify subscriber: {}", e);
                    }
                }
            }
        }; // Lock is dropped here

        // Send push notification if configured
        if let Err(e) = self
            .push_notification_registry
            .send_artifact_update(task_id, &event)
            .await
        {
            eprintln!("Failed to send push notification: {}", e);
        }

        Ok(())
    }
}

#[async_trait]
impl AsyncTaskManager for InMemoryTaskStorage {
    async fn create_task(&self, task_id: &str, context_id: &str) -> Result<Task, A2AError> {
        let mut tasks_guard = self.tasks.lock().await;

        if tasks_guard.contains_key(task_id) {
            return Err(A2AError::TaskNotFound(format!(
                "Task {} already exists",
                task_id
            )));
        }

        let task = Task::new(task_id.to_string(), context_id.to_string());
        tasks_guard.insert(task_id.to_string(), task.clone());

        Ok(task)
    }

    async fn update_task_status(
        &self,
        task_id: &str,
        state: TaskState,
        message: Option<Message>,
    ) -> Result<Task, A2AError> {
        let mut tasks_guard = self.tasks.lock().await;

        let task = tasks_guard
            .get_mut(task_id)
            .ok_or_else(|| A2AError::TaskNotFound(task_id.to_string()))?;

        // Update the task status with the optional message
        task.update_status(state, message);

        // Clone status before cloning the entire task to avoid double clone
        let status_for_broadcast = task.status.clone().into_option().unwrap_or_default();
        let updated_task = task.clone();

        // Release the lock before broadcasting
        drop(tasks_guard);

        // Broadcast status update
        self.broadcast_status_update(task_id, status_for_broadcast)
            .await?;

        Ok(updated_task)
    }

    async fn task_exists(&self, task_id: &str) -> Result<bool, A2AError> {
        let tasks_guard = self.tasks.lock().await;
        Ok(tasks_guard.contains_key(task_id))
    }

    async fn get_task(&self, task_id: &str, history_length: Option<u32>) -> Result<Task, A2AError> {
        // Get the task
        let task = {
            let tasks_guard = self.tasks.lock().await;

            let Some(task) = tasks_guard.get(task_id) else {
                return Err(A2AError::TaskNotFound(task_id.to_string()));
            };

            // Apply history length limitation if specified
            task.with_limited_history(history_length)
        }; // Lock is dropped here

        Ok(task)
    }

    async fn cancel_task(&self, task_id: &str) -> Result<Task, A2AError> {
        // Get and update the task
        let (task, status_for_broadcast) = {
            let mut tasks_guard = self.tasks.lock().await;

            let Some(task) = tasks_guard.get(task_id) else {
                return Err(A2AError::TaskNotFound(task_id.to_string()));
            };

            let mut updated_task = task.clone();

            // Only working tasks can be canceled
            if updated_task.status.state != TaskState::Working {
                return Err(A2AError::TaskNotCancelable(format!(
                    "Task {} is in state {:?} and cannot be canceled",
                    task_id, updated_task.status.state
                )));
            }

            // Create a cancellation message to add to history
            let cancel_message = Message {
                role: ::buffa::EnumValue::from(crate::domain::Role::Agent),
                parts: vec![crate::domain::Part::text(format!(
                    "Task {} canceled.",
                    task_id
                ))],
                message_id: uuid::Uuid::new_v4().to_string(),
                task_id: task_id.to_string(),
                context_id: updated_task.context_id.clone(),
                ..Default::default()
            };

            // Update the status with the cancellation message to track in history
            updated_task.update_status(TaskState::Canceled, Some(cancel_message));

            // Clone status before updating storage to avoid cloning task twice
            let status_for_broadcast = updated_task
                .status
                .clone()
                .into_option()
                .unwrap_or_default();
            tasks_guard.insert(task_id.to_string(), updated_task.clone());

            // Drop guard early and return status for use after broadcasting
            drop(tasks_guard);
            (updated_task, status_for_broadcast)
        }; // Lock is dropped here

        // Broadcast status update (with final flag set to true)
        self.broadcast_status_update(task_id, status_for_broadcast)
            .await?;

        Ok(task)
    }

    // ===== v1.0.0 New Methods =====

    async fn list_tasks_v3(
        &self,
        params: &crate::domain::ListTasksParams,
    ) -> Result<crate::domain::ListTasksResult, A2AError> {
        use crate::domain::ListTasksResult;

        let tasks_guard = self.tasks.lock().await;

        // Filter tasks based on parameters
        let mut filtered_tasks: Vec<_> = tasks_guard
            .values()
            .filter(|task| {
                // Filter by context_id if provided
                if let Some(ref context_id) = params.context_id {
                    if &task.context_id != context_id {
                        return false;
                    }
                }

                // Filter by status if provided
                if let Some(ref status) = params.status {
                    if &task.status.state != status {
                        return false;
                    }
                }

                // Filter by status_timestamp_after if provided
                if let Some(status_timestamp_after) = &params.status_timestamp_after {
                    if let Ok(after_dt) =
                        chrono::DateTime::parse_from_rfc3339(status_timestamp_after)
                    {
                        let after_utc = after_dt.with_timezone(&chrono::Utc);
                        if let Some(timestamp) = task.status.timestamp_utc() {
                            if timestamp <= after_utc {
                                return false;
                            }
                        }
                    }
                }

                true
            })
            .cloned()
            .collect();

        // Sort by timestamp (most recent first)
        filtered_tasks.sort_by(|a, b| {
            let a_time = a
                .status
                .timestamp_utc()
                .map(|t| t.timestamp_millis())
                .unwrap_or(0);
            let b_time = b
                .status
                .timestamp_utc()
                .map(|t| t.timestamp_millis())
                .unwrap_or(0);
            b_time.cmp(&a_time)
        });

        let total_size = filtered_tasks.len() as i32;

        // Handle pagination
        let page_size = params.page_size.unwrap_or(50).clamp(1, 100) as usize;
        let page_start = if let Some(ref token) = params.page_token {
            // Parse page token as a number (simple implementation)
            token.parse::<usize>().unwrap_or(0)
        } else {
            0
        };

        let page_end = (page_start + page_size).min(filtered_tasks.len());
        let has_more = page_end < filtered_tasks.len();

        // Get the page of tasks
        let mut page_tasks: Vec<_> = filtered_tasks[page_start..page_end].to_vec();

        // Apply history length limit
        let history_length = params.history_length.unwrap_or(0);
        for task in &mut page_tasks {
            *task = task.with_limited_history(Some(history_length as u32));

            // Remove artifacts if not requested
            if !params.include_artifacts.unwrap_or(false) {
                task.artifacts.clear();
            }
        }

        // Generate next page token
        let next_page_token = if has_more {
            page_end.to_string()
        } else {
            String::new()
        };

        Ok(ListTasksResult {
            tasks: page_tasks,
            total_size,
            page_size: page_size as i32,
            next_page_token,
        })
    }

    async fn get_push_notification_config(
        &self,
        params: &crate::domain::GetTaskPushNotificationConfigParams,
    ) -> Result<crate::domain::TaskPushNotificationConfig, A2AError> {
        // For in-memory storage, we don't support multiple configs per task yet
        // Just use the existing get_task_notification method
        self.get_task_notification(&params.id).await
    }

    async fn list_push_notification_configs(
        &self,
        params: &crate::domain::ListTaskPushNotificationConfigsParams,
    ) -> Result<Vec<crate::domain::TaskPushNotificationConfig>, A2AError> {
        // For in-memory storage, we only support one config per task
        // Return it as a single-item vec
        match self
            .push_notification_registry
            .get_config(&params.id)
            .await?
        {
            Some(config) => Ok(vec![config]),
            None => Ok(vec![]),
        }
    }

    async fn delete_push_notification_config(
        &self,
        params: &crate::domain::DeleteTaskPushNotificationConfigParams,
    ) -> Result<(), A2AError> {
        // For in-memory storage, just remove the single config
        // In a full implementation, would need to handle config_id
        self.remove_task_notification(&params.id).await
    }
}

// AsyncNotificationManager implementation
#[async_trait]
impl AsyncNotificationManager for InMemoryTaskStorage {
    async fn set_task_notification(
        &self,
        config: &TaskPushNotificationConfig,
    ) -> Result<TaskPushNotificationConfig, A2AError> {
        #[cfg(feature = "tracing")]
        tracing::info!(
            task_id = %config.task_id,
            url = %config.url,
            "🚀 Registering push notification config for task"
        );

        // Register with the push notification registry
        self.push_notification_registry
            .register(&config.task_id, config.clone())
            .await?;

        #[cfg(feature = "tracing")]
        tracing::info!(
            task_id = %config.task_id,
            "✅ Push notification config registered successfully"
        );

        Ok(config.clone())
    }

    async fn get_task_notification(
        &self,
        task_id: &str,
    ) -> Result<TaskPushNotificationConfig, A2AError> {
        // Get the push notification config from the registry
        match self.push_notification_registry.get_config(task_id).await? {
            Some(config) => Ok(config),
            None => Err(A2AError::PushNotificationNotSupported),
        }
    }

    async fn remove_task_notification(&self, task_id: &str) -> Result<(), A2AError> {
        self.push_notification_registry.unregister(task_id).await?;
        Ok(())
    }
}

// AsyncStreamingHandler implementation
#[async_trait]
impl AsyncStreamingHandler for InMemoryTaskStorage {
    async fn add_status_subscriber(
        &self,
        task_id: &str,
        subscriber: Box<dyn Subscriber<TaskStatusUpdateEvent> + Send + Sync>,
    ) -> Result<String, A2AError> {
        #[cfg(feature = "tracing")]
        tracing::info!(
            task_id = %task_id,
            "✅ Adding WebSocket subscriber for status updates"
        );

        // Add the subscriber
        {
            let mut subscribers_guard = self.subscribers.lock().await;

            let task_subscribers = subscribers_guard
                .entry(task_id.to_string())
                .or_insert_with(TaskSubscribers::new);

            task_subscribers.status.push(subscriber);

            #[cfg(feature = "tracing")]
            tracing::info!(
                task_id = %task_id,
                subscriber_count = task_subscribers.status.len(),
                "✅ WebSocket subscriber added successfully"
            );
        } // Lock is dropped here

        // Try to get the current status to send as an initial update
        // But don't fail if the task doesn't exist yet - the subscriber will get updates when it's created
        if let Ok(task) = self.get_task(task_id, None).await {
            let _ = self
                .broadcast_status_update(
                    task_id,
                    task.status.clone().into_option().unwrap_or_default(),
                )
                .await;
        }

        Ok(format!("status-{}-{}", task_id, uuid::Uuid::new_v4()))
    }

    async fn add_artifact_subscriber(
        &self,
        task_id: &str,
        subscriber: Box<dyn Subscriber<TaskArtifactUpdateEvent> + Send + Sync>,
    ) -> Result<String, A2AError> {
        // Add the subscriber
        {
            let mut subscribers_guard = self.subscribers.lock().await;

            let task_subscribers = subscribers_guard
                .entry(task_id.to_string())
                .or_insert_with(TaskSubscribers::new);

            task_subscribers.artifacts.push(subscriber);
        } // Lock is dropped here

        // If there are existing artifacts, broadcast them
        // But don't fail if the task doesn't exist yet - the subscriber will get updates when it's created
        if let Ok(task) = self.get_task(task_id, None).await {
            for artifact in &task.artifacts {
                let _ = self
                    .broadcast_artifact_update(task_id, artifact.clone(), None, false)
                    .await;
            }
        }

        Ok(format!("artifact-{}-{}", task_id, uuid::Uuid::new_v4()))
    }

    async fn remove_subscription(&self, _subscription_id: &str) -> Result<(), A2AError> {
        Err(A2AError::UnsupportedOperation(
            "Subscription removal by ID requires storage layer refactoring".to_string(),
        ))
    }

    async fn remove_task_subscribers(&self, task_id: &str) -> Result<(), A2AError> {
        // Remove all subscribers
        {
            let mut subscribers_guard = self.subscribers.lock().await;
            subscribers_guard.remove(task_id);
        } // Lock is dropped here

        Ok(())
    }

    async fn get_subscriber_count(&self, task_id: &str) -> Result<usize, A2AError> {
        let subscribers_guard = self.subscribers.lock().await;

        if let Some(task_subscribers) = subscribers_guard.get(task_id) {
            Ok(task_subscribers.status.len() + task_subscribers.artifacts.len())
        } else {
            Ok(0)
        }
    }

    async fn broadcast_status_update(
        &self,
        task_id: &str,
        update: TaskStatusUpdateEvent,
    ) -> Result<(), A2AError> {
        self.broadcast_status_update(task_id, update.status).await
    }

    async fn broadcast_artifact_update(
        &self,
        task_id: &str,
        update: TaskArtifactUpdateEvent,
    ) -> Result<(), A2AError> {
        self.broadcast_artifact_update(
            task_id,
            update.artifact,
            None,
            update.last_chunk.unwrap_or(false),
        )
        .await
    }

    async fn status_update_stream(
        &self,
        _task_id: &str,
    ) -> Result<
        std::pin::Pin<
            Box<dyn futures::Stream<Item = Result<TaskStatusUpdateEvent, A2AError>> + Send>,
        >,
        A2AError,
    > {
        Err(A2AError::UnsupportedOperation(
            "Status update stream requires storage layer refactoring".to_string(),
        ))
    }

    async fn artifact_update_stream(
        &self,
        _task_id: &str,
    ) -> Result<
        std::pin::Pin<
            Box<dyn futures::Stream<Item = Result<TaskArtifactUpdateEvent, A2AError>> + Send>,
        >,
        A2AError,
    > {
        Err(A2AError::UnsupportedOperation(
            "Artifact update stream requires storage layer refactoring".to_string(),
        ))
    }

    async fn combined_update_stream(
        &self,
        _task_id: &str,
    ) -> Result<
        std::pin::Pin<
            Box<
                dyn futures::Stream<
                        Item = Result<crate::port::streaming_handler::UpdateEvent, A2AError>,
                    > + Send,
            >,
        >,
        A2AError,
    > {
        Err(A2AError::UnsupportedOperation(
            "Combined update stream requires storage layer refactoring".to_string(),
        ))
    }
}

impl Clone for InMemoryTaskStorage {
    fn clone(&self) -> Self {
        Self {
            tasks: self.tasks.clone(),
            subscribers: self.subscribers.clone(),
            push_notification_registry: self.push_notification_registry.clone(),
        }
    }
}