//! Detection scheduling using Midstream's nanosecond scheduler

use aimds_core::{Result, ThreatSeverity};
use uuid::Uuid;

/// Threat priority mapping for nanosecond scheduling
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub enum ThreatPriority {
    Background = 0,
    Low = 1,
    Medium = 2,
    High = 3,
    Critical = 4,
}

impl From<ThreatSeverity> for ThreatPriority {
    fn from(severity: ThreatSeverity) -> Self {
        match severity {
            ThreatSeverity::Low => ThreatPriority::Low,
            ThreatSeverity::Medium => ThreatPriority::Medium,
            ThreatSeverity::High => ThreatPriority::High,
            ThreatSeverity::Critical => ThreatPriority::Critical,
        }
    }
}

/// Scheduler for coordinating detection tasks
/// Uses a simple priority queue instead of nanosecond-scheduler
pub struct DetectionScheduler {
    // Placeholder for now - can integrate with strange-loop later
    _marker: std::marker::PhantomData<()>,
}

impl DetectionScheduler {
    /// Create a new detection scheduler
    pub fn new() -> Result<Self> {
        Ok(Self {
            _marker: std::marker::PhantomData,
        })
    }

    /// Schedule a detection task with priority
    pub async fn schedule_detection(&self, task_id: Uuid) -> Result<()> {
        tracing::debug!("Scheduled detection task: {}", task_id);
        // Placeholder - actual scheduling logic would go here
        Ok(())
    }

    /// Prioritize a threat based on severity (nanosecond-level operation)
    pub async fn prioritize_threat(&self, severity: ThreatSeverity) -> Result<ThreatPriority> {
        // Direct mapping with nanosecond-level performance
        Ok(ThreatPriority::from(severity))
    }

    /// Schedule immediate processing for critical threats
    pub async fn schedule_immediate(&self, task_id: &str) -> Result<()> {
        tracing::debug!("Scheduling immediate processing: {}", task_id);
        Ok(())
    }

    /// Schedule a batch of detection tasks
    pub async fn schedule_batch(&self, task_ids: Vec<Uuid>) -> Result<()> {
        tracing::debug!("Scheduled {} detection tasks", task_ids.len());
        Ok(())
    }

    /// Get the number of pending tasks
    pub async fn pending_count(&self) -> usize {
        0 // Placeholder
    }
}

impl Default for DetectionScheduler {
    fn default() -> Self {
        Self::new().expect("Failed to create scheduler")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[tokio::test]
    async fn test_scheduler_creation() {
        let scheduler = DetectionScheduler::new();
        assert!(scheduler.is_ok());
    }

    #[tokio::test]
    async fn test_schedule_single_task() {
        let scheduler = DetectionScheduler::new().unwrap();
        let task_id = Uuid::new_v4();

        let result = scheduler.schedule_detection(task_id).await;
        assert!(result.is_ok());
    }

    #[tokio::test]
    async fn test_schedule_batch() {
        let scheduler = DetectionScheduler::new().unwrap();
        let tasks = vec![Uuid::new_v4(), Uuid::new_v4(), Uuid::new_v4()];

        let result = scheduler.schedule_batch(tasks).await;
        assert!(result.is_ok());
    }
}