//! Dynamic Partial Reconfiguration for FPGAs
//!
//! This module provides support for dynamic partial reconfiguration (DPR) on FPGAs,
//! allowing runtime reconfiguration of parts of the FPGA fabric without stopping
//! the entire system.

use crate::error::Result;
use crate::hardware::fpga::{FPGADevice, FPGAKernel, ResourceAllocation};
use std::collections::HashMap;
use std::sync::{Arc, Mutex};
/// Partial reconfiguration region on FPGA
#[derive(Debug, Clone)]
pub struct PartialRegion {
    /// Region ID
    pub id: usize,
    /// Region name
    pub name: String,
    /// Starting coordinates (x, y)
    pub start_coords: (u32, u32),
    /// Ending coordinates (x, y)
    pub end_coords: (u32, u32),
    /// Available resources in this region
    pub available_resources: ResourceAllocation,
    /// Currently loaded module
    pub current_module: Option<String>,
    /// Reconfiguration state
    pub state: ReconfigurationState,
}
/// Reconfiguration state
#[derive(Debug, Clone, PartialEq)]
pub enum ReconfigurationState {
    /// Region is idle and ready for reconfiguration
    Idle,
    /// Region is being reconfigured
    Reconfiguring,
    /// Region is active and running
    Active,
    /// Region has an error
    Error(String),
/// Partial bitstream for dynamic reconfiguration
pub struct PartialBitstream {
    /// Module name
    pub module_name: String,
    /// Target region ID
    pub target_region: usize,
    /// Bitstream data
    pub bitstream_data: Vec<u8>,
    /// Resource requirements
    pub resource_requirements: ResourceAllocation,
    /// Configuration metadata
    pub metadata: ReconfigurationMetadata,
/// Reconfiguration metadata
pub struct ReconfigurationMetadata {
    /// Reconfiguration time estimate in microseconds
    pub reconfig_time_us: u64,
    /// Power consumption estimate in Watts
    pub power_estimate: f32,
    /// Interface compatibility requirements
    pub interface_requirements: Vec<InterfaceRequirement>,
    /// Clock domain requirements
    pub clock_domains: Vec<ClockDomain>,
/// Interface requirement for partial modules
pub struct InterfaceRequirement {
    /// Interface name
    /// Interface type
    pub interface_type: InterfaceType,
    /// Data width in bits
    pub data_width: u32,
    /// Clock frequency in MHz
    pub clock_freq: u32,
/// Interface types for partial modules
pub enum InterfaceType {
    /// AXI4 Stream
    AXI4Stream,
    /// AXI4 Memory Mapped
    AXI4MM,
    /// Custom interface
    Custom(String),
/// Clock domain specification
pub struct ClockDomain {
    /// Clock name
    /// Frequency in MHz
    pub frequency: u32,
    /// Phase offset in degrees
    pub phase_offset: f32,
/// Dynamic Partial Reconfiguration Manager
pub struct DPRManager {
    /// FPGA device
    device: Arc<Mutex<FPGADevice>>,
    /// Partial regions
    regions: Arc<Mutex<HashMap<usize, PartialRegion>>>,
    /// Available partial bitstreams
    bitstreams: Arc<Mutex<HashMap<String, PartialBitstream>>>,
    /// Reconfiguration history
    reconfig_history: Arc<Mutex<Vec<ReconfigurationEvent>>>,
    /// Performance metrics
    metrics: Arc<Mutex<DPRMetrics>>,
impl DPRManager {
    /// Create a new DPR manager
    pub fn new(device: FPGADevice) -> Self {
        Self {
            _device: Arc::new(Mutex::new(_device)),
            regions: Arc::new(Mutex::new(HashMap::new())),
            bitstreams: Arc::new(Mutex::new(HashMap::new())),
            reconfig_history: Arc::new(Mutex::new(Vec::new())),
            metrics: Arc::new(Mutex::new(DPRMetrics::default())),
        }
    }
    /// Define a partial reconfiguration region
    pub fn define_region(&self, region: PartialRegion) -> Result<()> {
        let mut regions = self.regions.lock().expect("Operation failed");
        // Validate region coordinates and resources
        self.validate_region(&region)?;
        regions.insert(region.id, region);
        Ok(())
    /// Load a partial bitstream into the registry
    pub fn load_bitstream(&self, bitstream: PartialBitstream) -> Result<()> {
        let mut bitstreams = self.bitstreams.lock().expect("Operation failed");
        // Validate bitstream compatibility
        self.validate_bitstream(&bitstream)?;
        bitstreams.insert(bitstream.module_name.clone(), bitstream);
    /// Reconfigure a region with a specific module
    pub fn reconfigure_region(&self, region_id: usize, modulename: &str) -> Result<()> {
        let start_time = std::time::Instant::now();
        // Get region and bitstream
        let bitstreams = self.bitstreams.lock().expect("Operation failed");
        let region = regions.get_mut(&region_id).ok_or_else(|| {
            crate::error::NeuralError::InvalidArgument(format!("Region {} not found", region_id))
        })?;
        let bitstream = bitstreams.get(module_name).ok_or_else(|| {
            crate::error::NeuralError::InvalidArgument(format!(
                "Bitstream {} not found",
                module_name
            ))
        // Check if region is available for reconfiguration
        if region.state != ReconfigurationState::Idle {
            return Err(crate::error::NeuralError::InvalidState(format!(
                "Region {} is not available for reconfiguration",
                region_id
            )));
        // Validate resource requirements
        if !self.check_resource_fit(
            &region.available_resources,
            &bitstream.resource_requirements,
        ) {
            return Err(crate::error::NeuralError::ResourceExhausted(
                "Insufficient resources in target region".to_string(),
            ));
        // Start reconfiguration
        region.state = ReconfigurationState::Reconfiguring;
        drop(regions);
        drop(bitstreams);
        // Perform actual reconfiguration
        let result = self.perform_reconfiguration(region_id, bitstream);
        // Update region state
        let region = regions.get_mut(&region_id).expect("Operation failed");
        match result {
            Ok(_) => {
                region.state = ReconfigurationState::Active;
                region.current_module = Some(module_name.to_string());
                // Record successful reconfiguration
                let event = ReconfigurationEvent {
                    timestamp: chrono::Utc::now(),
                    region_id,
                    module_name: module_name.to_string(),
                    operation: ReconfigurationOperation::Load,
                    duration_us: start_time.elapsed().as_micros() as u64,
                    success: true,
                    error_message: None,
                };
                let mut history = self.reconfig_history.lock().expect("Operation failed");
                history.push(event);
                // Update metrics
                let mut metrics = self.metrics.lock().expect("Operation failed");
                metrics.total_reconfigurations += 1;
                metrics.successful_reconfigurations += 1;
                metrics.total_reconfig_time_us += start_time.elapsed().as_micros() as u64;
                Ok(())
            }
            Err(e) => {
                region.state = ReconfigurationState::Error(e.to_string());
                // Record failed reconfiguration
                    success: false,
                    error_message: Some(e.to_string()),
                metrics.failed_reconfigurations += 1;
                Err(e)
    /// Unload a module from a region
    pub fn unload_region(&self, regionid: usize) -> Result<()> {
        if region.state != ReconfigurationState::Active {
            return Err(crate::error::NeuralError::InvalidState(
                "Region is not active".to_string(),
        // Perform unload operation
        region.state = ReconfigurationState::Idle;
        let module_name = region.current_module.take();
        // Record unload event
        if let Some(module) = module_name {
            let event = ReconfigurationEvent {
                timestamp: chrono::Utc::now(),
                region_id,
                module_name: module,
                operation: ReconfigurationOperation::Unload,
                duration_us: 0, // Instant operation
                success: true,
                error_message: None,
            };
            let mut history = self.reconfig_history.lock().expect("Operation failed");
            history.push(event);
    /// Get optimal module placement for a set of kernels
    pub fn get_optimal_placement(&self, kernels: &[FPGAKernel]) -> Result<Vec<PlacementDecision>> {
        let regions = self.regions.lock().expect("Operation failed");
        let mut placements = Vec::new();
        // Simple greedy placement algorithm
        for kernel in kernels {
            let requirements = kernel.resource_requirements();
            // Find best fitting region
            let best_region = regions
                .values()
                .filter(|r| r.state == ReconfigurationState::Idle)
                .filter(|r| self.check_resource_fit(&r.available_resources, &requirements))
                .min_by_key(|r| {
                    self.calculate_placement_cost(&r.available_resources, &requirements)
                });
            if let Some(region) = best_region {
                placements.push(PlacementDecision {
                    kernel_name: kernel.name.clone(),
                    target_region: region.id,
                    estimated_performance: self.estimate_performance(kernel, region),
                    resource_utilization: self
                        .calculate_utilization(&region.available_resources, &requirements),
            } else {
                return Err(crate::error::NeuralError::ResourceExhausted(format!(
                    "No suitable region found for kernel {}",
                    kernel.name
                )));
        Ok(placements)
    /// Validate partial region definition
    fn validate_region(&self, region: &PartialRegion) -> Result<()> {
        // Check coordinate bounds
        if region.start_coords.0 >= region.end_coords.0
            || region.start_coords.1 >= region.end_coords.1
        {
            return Err(crate::error::NeuralError::InvalidArgument(
                "Invalid region coordinates".to_string(),
        // Validate resource allocation
        if region.available_resources.dsp_slices == 0 {
                "Region must have at least some DSP slices".to_string(),
    /// Validate bitstream compatibility
    fn validate_bitstream(&self, bitstream: &PartialBitstream) -> Result<()> {
        // Check if target region exists
        if !regions.contains_key(&bitstream.target_region) {
            return Err(crate::error::NeuralError::InvalidArgument(format!(
                "Target region {} does not exist",
                bitstream.target_region
        // Validate bitstream format (simplified)
        if bitstream.bitstream_data.is_empty() {
                "Empty bitstream data".to_string(),
    /// Check if resources fit in a region
    fn check_resource_fit(
        &self,
        available: &ResourceAllocation,
        required: &ResourceAllocation,
    ) -> bool {
        available.dsp_slices >= required.dsp_slices
            && available.bram_blocks >= required.bram_blocks
            && available.luts >= required.luts
            && available.registers >= required.registers
    /// Perform the actual reconfiguration operation
    fn perform_reconfiguration(
        region_id: usize,
        bitstream: &PartialBitstream,
    ) -> Result<()> {
        // Simulate reconfiguration delay
        std::thread::sleep(std::time::Duration::from_micros(
            bitstream.metadata.reconfig_time_us,
        ));
        // In real implementation, this would:
        // 1. Stop any active operations in the region
        // 2. Download the partial bitstream
        // 3. Perform clock domain crossing setup
        // 4. Restart operations with new module
        println!(
            "Reconfiguring region {} with module {}",
            region_id, bitstream.module_name
        );
    /// Calculate placement cost for optimization
    fn calculate_placement_cost(
    ) -> u64 {
        // Simple cost function based on resource waste
        let dsp_waste = available.dsp_slices.saturating_sub(required.dsp_slices);
        let bram_waste = available.bram_blocks.saturating_sub(required.bram_blocks);
        let lut_waste = available.luts.saturating_sub(required.luts);
        (dsp_waste * 1000 + bram_waste * 100 + lut_waste) as u64
    /// Estimate performance for a kernel in a region
    fn estimate_performance(&self, kernel: &FPGAKernel, region: &PartialRegion) -> f32 {
        // Simple performance model based on parallelism and clock frequency
        let base_performance = kernel.parallelism as f32;
        let region_efficiency = 0.8; // Efficiency factor for partial regions
        base_performance * region_efficiency
    /// Calculate resource utilization percentage
    fn calculate_utilization(
    ) -> f32 {
        let dsp_util = (required.dsp_slices as f32 / available.dsp_slices as f32) * 100.0;
        let bram_util = (required.bram_blocks as f32 / available.bram_blocks as f32) * 100.0;
        let lut_util = (required.luts as f32 / available.luts as f32) * 100.0;
        dsp_util.max(bram_util).max(lut_util)
    /// Get DPR statistics
    pub fn get_statistics(&self) -> DPRMetrics {
        self.metrics.lock().expect("Operation failed").clone()
    /// Get reconfiguration history
    pub fn get_history(&self) -> Vec<ReconfigurationEvent> {
        self.reconfig_history.lock().expect("Operation failed").clone()
/// Reconfiguration event for history tracking
pub struct ReconfigurationEvent {
    /// Event timestamp
    pub timestamp: chrono::DateTime<chrono::Utc>,
    pub region_id: usize,
    /// Operation type
    pub operation: ReconfigurationOperation,
    /// Operation duration in microseconds
    pub duration_us: u64,
    /// Whether operation succeeded
    pub success: bool,
    /// Error message if failed
    pub error_message: Option<String>,
/// Reconfiguration operation types
pub enum ReconfigurationOperation {
    Load,
    Unload,
    Reset,
/// Placement decision for kernel mapping
pub struct PlacementDecision {
    /// Kernel name
    pub kernel_name: String,
    /// Estimated performance
    pub estimated_performance: f32,
    /// Resource utilization percentage
    pub resource_utilization: f32,
/// DPR performance metrics
#[derive(Debug, Clone, Default)]
pub struct DPRMetrics {
    /// Total number of reconfigurations attempted
    pub total_reconfigurations: u64,
    /// Number of successful reconfigurations
    pub successful_reconfigurations: u64,
    /// Number of failed reconfigurations
    pub failed_reconfigurations: u64,
    /// Total reconfiguration time in microseconds
    pub total_reconfig_time_us: u64,
    /// Average reconfiguration time
    pub avg_reconfig_time_us: f64,
impl DPRMetrics {
    /// Update average reconfiguration time
    pub fn update_average(&mut self) {
        if self.successful_reconfigurations > 0 {
            self.avg_reconfig_time_us =
                self.total_reconfig_time_us as f64 / self.successful_reconfigurations as f64;
#[cfg(test)]
mod tests {
    use super::*;
    use crate::hardware::fpga::{FPGAConfig, FPGAVendor};
    fn create_test_fpga() -> FPGADevice {
        let config = FPGAConfig {
            vendor: FPGAVendor::Xilinx,
            model: "xczu9eg".to_string(),
            clock_frequency: 300,
            dsp_slices: 2520,
            bram_size: 32000,
            memory_bandwidth: 76.8,
            power_budget: 20.0,
            bitstream_path: None,
        };
        FPGADevice::new(config).expect("Operation failed")
    #[test]
    fn test_dpr_manager_creation() {
        let fpga = create_test_fpga();
        let dpr_manager = DPRManager::new(fpga);
        let stats = dpr_manager.get_statistics();
        assert_eq!(stats.total_reconfigurations, 0);
    fn test_region_definition() {
        let region = PartialRegion {
            id: 0,
            name: "test_region".to_string(),
            start_coords: (0, 0),
            end_coords: (10, 10),
            available_resources: ResourceAllocation {
                dsp_slices: 100,
                bram_blocks: 50,
                luts: 10000,
                registers: 20000,
            },
            current_module: None,
            state: ReconfigurationState::Idle,
        assert!(dpr_manager.define_region(region).is_ok());
    fn test_bitstream_loading() {
        // First define a region
        dpr_manager.define_region(region).expect("Operation failed");
        let bitstream = PartialBitstream {
            module_name: "test_module".to_string(),
            target_region: 0,
            bitstream_data: vec![0x01, 0x02, 0x03, 0x04],
            resource_requirements: ResourceAllocation {
                dsp_slices: 50,
                bram_blocks: 25,
                luts: 5000,
                registers: 10000,
            metadata: ReconfigurationMetadata {
                reconfig_time_us: 1000,
                power_estimate: 2.5,
                interface_requirements: vec![],
                clock_domains: vec![],
        assert!(dpr_manager.load_bitstream(bitstream).is_ok());
