ccswarm 0.4.0

/// Session coordination integration for ccswarm multi-agent system
///
/// This module integrates the Session-Persistent Agent Architecture with
/// the existing coordination system, providing seamless interoperability
/// while maximizing token efficiency gains.
use anyhow::{Context, Result};
use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use tokio::sync::{Mutex, RwLock};
use uuid::Uuid;

use crate::agent::{Task, TaskResult};
use crate::config::ClaudeConfig;
// Temporary coordination types until full coordination system is implemented
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum AgentMessage {
    Coordination {
        from_agent: String,
        to_agent: String,
        message_type: CoordinationType,
        payload: serde_json::Value,
    },
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum CoordinationType {
    StatusUpdate,
    TaskRequest,
    SessionManagement,
}
use crate::identity::AgentRole;
use crate::session::session_pool::{PoolStatistics, SessionPool, SessionPoolConfig};
use crate::session::worktree_session::WorktreeSessionConfig;

/// Enhanced coordination message types for session management
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum SessionCoordinationMessage {
    /// Request task execution with session preferences
    TaskRequest {
        task: Task,
        preferred_session: Option<String>,
        batch_compatible: bool,
        priority_boost: f64,
    },

    /// Batch task request for efficiency
    BatchTaskRequest {
        tasks: Vec<Task>,
        role: AgentRole,
        deadline: Option<DateTime<Utc>>,
    },

    /// Session status update
    SessionStatusUpdate {
        session_id: String,
        agent_id: String,
        load: f64,
        tasks_completed: usize,
        efficiency_metrics: EfficiencyMetrics,
    },

    /// Request session creation/scaling
    SessionScalingRequest {
        role: AgentRole,
        min_sessions: usize,
        reason: ScalingReason,
    },

    /// Efficiency report
    EfficiencyReport {
        timestamp: DateTime<Utc>,
        token_savings: TokenSavingsReport,
        performance_metrics: PerformanceReport,
    },
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum ScalingReason {
    HighLoad,
    TaskBacklog,
    PerformanceOptimization,
    UserRequest,
    PredictiveScaling,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EfficiencyMetrics {
    pub sessions_reused: usize,
    pub tokens_saved: usize,
    pub context_continuity_score: f64,
    pub average_response_time: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TokenSavingsReport {
    pub total_tasks_processed: usize,
    pub sessions_created: usize,
    pub estimated_traditional_tokens: usize,
    pub actual_tokens_used: usize,
    pub savings_percentage: f64,
    pub efficiency_score: f64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PerformanceReport {
    pub total_execution_time: std::time::Duration,
    pub average_task_time: std::time::Duration,
    pub throughput_tasks_per_minute: f64,
    pub error_rate_percentage: f64,
    pub session_utilization: f64,
}

/// Session coordinator that bridges coordination system and session pool
#[derive(Debug)]
pub struct SessionCoordinator {
    /// Session pool for efficient agent management
    session_pool: Arc<Mutex<SessionPool>>,

    /// Coordination bus integration
    #[allow(dead_code)] // Will be used for inter-agent coordination
    coordination_bus: Arc<RwLock<CoordinationBus>>,

    /// Active task tracking
    active_tasks: Arc<RwLock<HashMap<String, TaskExecution>>>,

    /// Performance tracking
    performance_tracker: Arc<Mutex<PerformanceTracker>>,

    /// Configuration
    config: SessionCoordinatorConfig,
}

#[derive(Debug)]
struct CoordinationBus {
    /// Outbound message queue
    #[allow(dead_code)] // Will be used for message queuing
    outbound_queue: Vec<AgentMessage>,

    /// Coordination directory for file-based communication
    #[allow(dead_code)] // Will be used for file-based coordination
    coordination_dir: PathBuf,
}

// Simplified message handler for now - avoiding async trait in dyn context
#[allow(dead_code)] // Will be implemented for message handling
trait MessageHandler: Send + Sync {
    fn handle_message_sync(&self, message: &AgentMessage) -> Result<Option<AgentMessage>>;
}

#[derive(Debug, Clone)]
struct TaskExecution {
    #[allow(dead_code)] // Will be used for task tracking
    pub task: Task,
    #[allow(dead_code)] // Will be used for session assignment tracking
    pub assigned_session: String,
    #[allow(dead_code)] // Will be used for timing metrics
    pub started_at: DateTime<Utc>,
    #[allow(dead_code)] // Will be used for completion estimation
    pub estimated_completion: Option<DateTime<Utc>>,
    pub status: TaskExecutionStatus,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
enum TaskExecutionStatus {
    Queued,
    Executing,
    Completed,
    Failed(String),
    Cancelled,
}

#[derive(Debug)]
struct PerformanceTracker {
    #[allow(dead_code)] // Will be used for performance metrics
    start_time: DateTime<Utc>,
    total_tasks: usize,
    total_sessions_created: usize,
    total_tokens_saved: usize,
    total_execution_time: std::time::Duration,
    error_count: usize,
}

#[derive(Debug, Clone)]
pub struct SessionCoordinatorConfig {
    /// Coordination directory path
    pub coordination_dir: PathBuf,

    /// Performance reporting interval
    pub reporting_interval: std::time::Duration,

    /// Enable efficiency optimization
    pub efficiency_optimization: bool,

    /// Efficiency calculation baseline
    pub efficiency_baseline: f64,

    /// Batch optimization settings
    pub batch_optimization: BatchOptimizationConfig,
}

#[derive(Debug, Clone)]
pub struct BatchOptimizationConfig {
    pub enabled: bool,
    pub max_batch_size: usize,
    pub batch_timeout: std::time::Duration,
    pub compatibility_threshold: f64,
}

impl Default for SessionCoordinatorConfig {
    fn default() -> Self {
        Self {
            coordination_dir: PathBuf::from("coordination"),
            reporting_interval: std::time::Duration::from_secs(60),
            efficiency_optimization: true,
            efficiency_baseline: 1.0, // Baseline efficiency metric
            batch_optimization: BatchOptimizationConfig {
                enabled: true,
                max_batch_size: 10,
                batch_timeout: std::time::Duration::from_secs(30),
                compatibility_threshold: 0.8,
            },
        }
    }
}

impl SessionCoordinator {
    /// Create a new session coordinator
    pub async fn new(
        worktree_config: WorktreeSessionConfig,
        pool_config: SessionPoolConfig,
        coordinator_config: SessionCoordinatorConfig,
    ) -> Result<Self> {
        // Create session pool
        let mut session_pool = SessionPool::new(worktree_config, pool_config).await?;
        session_pool.start().await?;

        // Initialize coordination bus
        let coordination_bus =
            CoordinationBus::new(coordinator_config.coordination_dir.clone()).await?;

        // Initialize performance tracker
        let performance_tracker = PerformanceTracker {
            start_time: Utc::now(),
            total_tasks: 0,
            total_sessions_created: 0,
            total_tokens_saved: 0,
            total_execution_time: std::time::Duration::ZERO,
            error_count: 0,
        };

        Ok(Self {
            session_pool: Arc::new(Mutex::new(session_pool)),
            coordination_bus: Arc::new(RwLock::new(coordination_bus)),
            active_tasks: Arc::new(RwLock::new(HashMap::new())),
            performance_tracker: Arc::new(Mutex::new(performance_tracker)),
            config: coordinator_config,
        })
    }

    /// Start the session coordinator
    pub async fn start(&mut self) -> Result<()> {
        tracing::info!("Starting session coordinator");

        // Start performance reporting task
        if self.config.efficiency_optimization {
            self.start_efficiency_monitoring().await;
        }

        // Start coordination message processing
        self.start_coordination_processing().await;

        tracing::info!("Session coordinator started successfully");
        Ok(())
    }

    /// Execute a task through the coordinated session system
    pub async fn execute_coordinated_task(
        &self,
        role: AgentRole,
        task: Task,
        claude_config: ClaudeConfig,
    ) -> Result<TaskResult> {
        let task_id = task.id.clone();
        let start_time = std::time::Instant::now();

        // Check for batch optimization opportunities
        if self.config.batch_optimization.enabled {
            if let Some(batch_result) = self.try_batch_optimization(&role, &task).await? {
                return Ok(batch_result);
            }
        }

        // Track task execution
        let execution = TaskExecution {
            task: task.clone(),
            assigned_session: "pending".to_string(),
            started_at: Utc::now(),
            estimated_completion: None,
            status: TaskExecutionStatus::Queued,
        };

        {
            let mut active_tasks = self.active_tasks.write().await;
            active_tasks.insert(task_id.clone(), execution);
        }

        // Execute through session pool
        let result = {
            let session_pool = self.session_pool.lock().await;
            session_pool
                .execute_task(role.clone(), task, claude_config)
                .await?
        };

        // Update performance tracking
        {
            let mut tracker = self.performance_tracker.lock().await;
            tracker.total_tasks += 1;
            tracker.total_execution_time += start_time.elapsed();

            if !result.success {
                tracker.error_count += 1;
            }

            // Estimate token savings (simplified calculation)
            let estimated_savings = self.calculate_token_savings(&result).await;
            tracker.total_tokens_saved += estimated_savings;
        }

        // Update task status
        {
            let mut active_tasks = self.active_tasks.write().await;
            if let Some(mut execution) = active_tasks.remove(&task_id) {
                execution.status = if result.success {
                    TaskExecutionStatus::Completed
                } else {
                    TaskExecutionStatus::Failed(
                        result
                            .error
                            .as_deref()
                            .unwrap_or("Unknown error")
                            .to_string(),
                    )
                };
            }
        }

        // Send coordination update
        self.send_coordination_update(&role, &result).await?;

        Ok(result)
    }

    /// Execute multiple tasks in batch for maximum efficiency
    pub async fn execute_coordinated_batch(
        &self,
        role: AgentRole,
        tasks: Vec<Task>,
        claude_config: ClaudeConfig,
    ) -> Result<Vec<TaskResult>> {
        if tasks.is_empty() {
            return Ok(Vec::new());
        }

        tracing::info!(
            "Executing coordinated batch of {} tasks for role: {}",
            tasks.len(),
            role.name()
        );
        let start_time = std::time::Instant::now();

        // Track all tasks
        for task in &tasks {
            let execution = TaskExecution {
                task: task.clone(),
                assigned_session: "batch".to_string(),
                started_at: Utc::now(),
                estimated_completion: None,
                status: TaskExecutionStatus::Executing,
            };

            let mut active_tasks = self.active_tasks.write().await;
            active_tasks.insert(task.id.clone(), execution);
        }

        // Execute batch through session pool
        let results = {
            let session_pool = self.session_pool.lock().await;
            session_pool
                .execute_task_batch(role.clone(), tasks.clone(), claude_config)
                .await?
        };

        // Calculate massive token savings from batch execution
        let estimated_savings = (tasks.len().saturating_sub(1)) * 3400; // ~3400 tokens saved per additional task

        // Update performance tracking
        {
            let mut tracker = self.performance_tracker.lock().await;
            tracker.total_tasks += results.len();
            tracker.total_execution_time += start_time.elapsed();
            tracker.total_tokens_saved += estimated_savings;

            let error_count = results.iter().filter(|r| !r.success).count();
            tracker.error_count += error_count;
        }

        // Send efficiency report
        self.send_efficiency_report(estimated_savings, results.len())
            .await?;

        tracing::info!(
            "Batch execution completed - estimated {} tokens saved",
            estimated_savings
        );
        Ok(results)
    }

    /// Try to optimize task execution through batching
    async fn try_batch_optimization(
        &self,
        _role: &AgentRole,
        _task: &Task,
    ) -> Result<Option<TaskResult>> {
        // In a real implementation, this would check for pending compatible tasks
        // and potentially delay execution to form efficient batches

        // For now, return None to indicate no batch optimization applied
        Ok(None)
    }

    /// Calculate token savings from session reuse
    async fn calculate_token_savings(&self, result: &TaskResult) -> usize {
        // Simplified calculation - in practice would be more sophisticated
        // Based on whether this was a new session or reused session

        // If session was reused (indicated by session_id in output), significant savings
        if let Some(output) = result.output.as_object() {
            if output.contains_key("session_id") {
                return 3400; // Estimated savings from session reuse
            }
        }

        0 // No savings if new session was created
    }

    /// Send coordination update
    async fn send_coordination_update(&self, _role: &AgentRole, result: &TaskResult) -> Result<()> {
        let message = SessionCoordinationMessage::SessionStatusUpdate {
            session_id: "session_id".to_string(), // Would extract from result
            agent_id: "agent_id".to_string(),     // Would extract from result
            load: 0.5,                            // Would calculate actual load
            tasks_completed: 1,
            efficiency_metrics: EfficiencyMetrics {
                sessions_reused: if result.success { 1 } else { 0 },
                tokens_saved: 3400,
                context_continuity_score: 0.95,
                average_response_time: result.duration.as_secs_f64(),
            },
        };

        // Send to coordination system
        self.send_coordination_message(message).await?;
        Ok(())
    }

    /// Send efficiency report
    async fn send_efficiency_report(
        &self,
        _tokens_saved: usize,
        _tasks_processed: usize,
    ) -> Result<()> {
        let tracker = self.performance_tracker.lock().await;

        let report = SessionCoordinationMessage::EfficiencyReport {
            timestamp: Utc::now(),
            token_savings: TokenSavingsReport {
                total_tasks_processed: tracker.total_tasks,
                sessions_created: tracker.total_sessions_created,
                estimated_traditional_tokens: tracker.total_tasks * 3600, // Traditional approach
                actual_tokens_used: (tracker.total_tasks * 3600)
                    .saturating_sub(tracker.total_tokens_saved),
                savings_percentage: if tracker.total_tasks > 0 {
                    (tracker.total_tokens_saved as f64 / (tracker.total_tasks * 3600) as f64)
                        * 100.0
                } else {
                    0.0
                },
                efficiency_score: if tracker.total_tasks > 0 {
                    tracker.total_tokens_saved as f64 / tracker.total_tasks as f64
                } else {
                    0.0
                },
            },
            performance_metrics: PerformanceReport {
                total_execution_time: tracker.total_execution_time,
                average_task_time: if tracker.total_tasks > 0 {
                    tracker.total_execution_time / tracker.total_tasks as u32
                } else {
                    std::time::Duration::ZERO
                },
                throughput_tasks_per_minute: if tracker.total_execution_time.as_secs() > 0 {
                    (tracker.total_tasks as f64 * 60.0) / tracker.total_execution_time.as_secs_f64()
                } else {
                    0.0
                },
                error_rate_percentage: if tracker.total_tasks > 0 {
                    (tracker.error_count as f64 / tracker.total_tasks as f64) * 100.0
                } else {
                    0.0
                },
                session_utilization: 0.75, // Would calculate from pool statistics
            },
        };

        self.send_coordination_message(report).await?;
        Ok(())
    }

    /// Send message to coordination system
    async fn send_coordination_message(&self, message: SessionCoordinationMessage) -> Result<()> {
        let coordination_message = AgentMessage::Coordination {
            from_agent: "session-coordinator".to_string(),
            to_agent: "system".to_string(),
            message_type: CoordinationType::StatusUpdate, // Assuming this exists
            payload: serde_json::to_value(message)?,
        };

        // Write to coordination directory
        let message_file = self
            .config
            .coordination_dir
            .join("messages")
            .join(format!("session-{}.json", Uuid::new_v4()));

        if let Some(parent) = message_file.parent() {
            tokio::fs::create_dir_all(parent).await?;
        }

        tokio::fs::write(
            &message_file,
            serde_json::to_string_pretty(&coordination_message)?,
        )
        .await
        .context("Failed to write coordination message")?;

        Ok(())
    }

    /// Start efficiency monitoring task
    async fn start_efficiency_monitoring(&self) {
        let performance_tracker = Arc::clone(&self.performance_tracker);
        let config = self.config.clone();

        tokio::spawn(async move {
            let mut interval = tokio::time::interval(config.reporting_interval);

            loop {
                interval.tick().await;

                let tracker = performance_tracker.lock().await;

                if tracker.total_tasks > 0 {
                    let efficiency_percentage = (tracker.total_tokens_saved as f64
                        / (tracker.total_tasks * 3600) as f64)
                        * 100.0;
                    let efficiency_score = if tracker.total_tasks > 0 {
                        tracker.total_tokens_saved as f64 / tracker.total_tasks as f64
                    } else {
                        0.0
                    };

                    tracing::info!(
                        "Session Efficiency Report - Tasks: {}, Context Optimized: {}, Efficiency: {:.1}%, Score: {:.2}",
                        tracker.total_tasks,
                        tracker.total_tokens_saved,
                        efficiency_percentage,
                        efficiency_score
                    );
                }
            }
        });
    }

    /// Start coordination message processing
    async fn start_coordination_processing(&self) {
        let coordination_dir = self.config.coordination_dir.clone();

        tokio::spawn(async move {
            let mut interval = tokio::time::interval(std::time::Duration::from_secs(5));

            loop {
                interval.tick().await;

                // Process incoming coordination messages
                if let Err(e) = Self::process_coordination_messages(&coordination_dir).await {
                    tracing::error!("Failed to process coordination messages: {}", e);
                }
            }
        });
    }

    /// Process coordination messages from file system
    async fn process_coordination_messages(coordination_dir: &Path) -> Result<()> {
        let messages_dir = coordination_dir.join("messages");

        if !messages_dir.exists() {
            return Ok(());
        }

        // Read and process coordination messages
        // This would integrate with the existing coordination system
        Ok(())
    }

    /// Get comprehensive coordination statistics
    pub async fn get_coordination_statistics(&self) -> CoordinationStatistics {
        let pool_stats = {
            let session_pool = self.session_pool.lock().await;
            session_pool.get_pool_statistics().await
        };

        let performance_tracker = self.performance_tracker.lock().await;
        let active_tasks = self.active_tasks.read().await;

        CoordinationStatistics {
            pool_statistics: pool_stats,
            efficiency_metrics: EfficiencyMetrics {
                sessions_reused: performance_tracker
                    .total_tasks
                    .saturating_sub(performance_tracker.total_sessions_created),
                tokens_saved: performance_tracker.total_tokens_saved,
                context_continuity_score: 0.95, // Would calculate from session data
                average_response_time: if performance_tracker.total_tasks > 0 {
                    performance_tracker.total_execution_time.as_secs_f64()
                        / performance_tracker.total_tasks as f64
                } else {
                    0.0
                },
            },
            active_task_count: active_tasks.len(),
            total_coordination_messages: 0, // Would track from coordination bus
        }
    }

    /// Shutdown the session coordinator
    pub async fn shutdown(&mut self) -> Result<()> {
        tracing::info!("Shutting down session coordinator");

        // Shutdown session pool
        {
            let mut session_pool = self.session_pool.lock().await;
            session_pool.shutdown().await?;
        }

        tracing::info!("Session coordinator shutdown complete");
        Ok(())
    }
}

/// Coordination statistics combining pool and efficiency metrics
#[derive(Debug, Serialize, Deserialize)]
pub struct CoordinationStatistics {
    pub pool_statistics: PoolStatistics,
    pub efficiency_metrics: EfficiencyMetrics,
    pub active_task_count: usize,
    pub total_coordination_messages: usize,
}

impl CoordinationBus {
    async fn new(coordination_dir: PathBuf) -> Result<Self> {
        tokio::fs::create_dir_all(&coordination_dir).await?;

        Ok(Self {
            outbound_queue: Vec::new(),
            coordination_dir,
        })
    }
}