optirs-tpu 0.3.1

use std::fmt::Debug;
// XLA (Accelerated Linear Algebra) Compilation for TPU Optimization
//
// This module implements comprehensive XLA compilation capabilities for TPU-optimized
// optimization algorithms. It provides high-level abstractions for building, optimizing,
// and executing XLA computations on TPU hardware.

pub mod backend;
pub mod frontend;
pub mod optimization;

use scirs2_core::ndarray::{Array1, Array2};
use scirs2_core::numeric::Float;
use std::collections::{BTreeMap, HashMap, HashSet, VecDeque};
use std::sync::{Arc, RwLock};
use std::time::{Duration, Instant};

use super::{PodTopology, TPUConfig, TPUVersion, XLAOptimizationLevel};
use crate::error::{OptimError, Result};

// Note: Submodules have conflicting type names (ExecutionScheduler, ResourceManager, MemorySpace)
// Users should access types via full module paths (e.g., backend::ExecutionScheduler)

// Selective re-exports of non-conflicting types used in this module
use backend::{RuntimeIntegration, TPUCodeGenerator};
use frontend::{ComputationGraphBuilder, OperationLowering, ShapeInference};
use optimization::{MemoryPlanner, OptimizationPipeline, PerformanceAnalyzer};

// Re-export for public API
pub use frontend::XLAComputation;

/// XLA Compiler for TPU optimization
pub struct XLACompiler<T: Float + Debug + Send + Sync + 'static> {
    /// Compiler configuration
    config: XLACompilerConfig,

    /// Computation graph builder
    graph_builder: ComputationGraphBuilder<T>,

    /// Optimization pipeline
    optimization_pipeline: OptimizationPipeline<T>,

    /// Code generator
    code_generator: TPUCodeGenerator<T>,

    /// Compilation cache
    compilation_cache: Arc<RwLock<CompilationCache>>,

    /// Performance analyzer
    performance_analyzer: PerformanceAnalyzer<T>,

    /// Memory planner
    memory_planner: MemoryPlanner<T>,

    /// Parallel compilation manager
    parallel_compiler: ParallelCompilationManager<T>,

    /// Profiling data
    profiling_data: ProfilingData,
}

/// XLA compiler configuration
#[derive(Debug, Clone)]
pub struct XLACompilerConfig {
    /// Target TPU configuration
    pub target_tpu: TPUConfig,

    /// Optimization level
    pub optimization_level: XLAOptimizationLevel,

    /// Enable auto-tuning
    pub enable_auto_tuning: bool,

    /// Compilation timeout (seconds)
    pub compilation_timeout: u64,

    /// Maximum cache size (MB)
    pub max_cache_size_mb: usize,

    /// Enable parallel compilation
    pub parallel_compilation: bool,

    /// Number of compilation threads
    pub compilation_threads: usize,

    /// Enable fusion optimization
    pub enable_fusion: bool,

    /// Enable layout optimization
    pub enable_layout_optimization: bool,

    /// Enable memory optimization
    pub enable_memory_optimization: bool,

    /// Enable pipeline optimization
    pub enable_pipeline_optimization: bool,

    /// Debug mode
    pub debug_mode: bool,

    /// Profile compilation
    pub profile_compilation: bool,

    /// Custom optimization passes
    pub custom_passes: Vec<String>,

    /// Enable advanced tensor core optimizations
    pub enable_tensor_core_optimization: bool,

    /// Enable sparsity-aware optimizations
    pub enable_sparsity_optimization: bool,
}

/// Compilation cache for reusing compiled computations
#[derive(Debug)]
pub struct CompilationCache {
    /// Cached compiled computations
    pub cache: HashMap<String, CachedComputation>,

    /// Cache statistics
    pub stats: CacheStatistics,

    /// Maximum cache size
    pub max_size: usize,

    /// Current cache size
    pub current_size: usize,
}

/// Cached compilation result
#[derive(Debug, Clone)]
pub struct CachedComputation {
    /// Computation identifier
    pub id: String,

    /// Compiled binary
    pub binary: Vec<u8>,

    /// Compilation metadata
    pub metadata: CompilationMetadata,

    /// Last access time
    pub last_accessed: Instant,

    /// Access count
    pub access_count: u64,

    /// Size in bytes
    pub size: usize,
}

/// Compilation metadata
#[derive(Debug, Clone)]
pub struct CompilationMetadata {
    /// Source computation hash
    pub computation_hash: String,

    /// Compiler version
    pub compiler_version: String,

    /// Target TPU configuration
    pub target_config: TPUConfig,

    /// Compilation time
    pub compilation_time: Duration,

    /// Optimization passes applied
    pub optimization_passes: Vec<String>,

    /// Performance characteristics
    pub performance_info: PerformanceInfo,
}

/// Performance information
#[derive(Debug, Clone, Default)]
pub struct PerformanceInfo {
    /// Estimated execution time (microseconds)
    pub estimated_execution_time: u64,

    /// Memory usage (bytes)
    pub memory_usage: usize,

    /// Flop count
    pub flop_count: u64,

    /// Memory bandwidth utilization
    pub memory_bandwidth_util: f64,

    /// Compute utilization
    pub compute_utilization: f64,
}

/// Cache statistics
#[derive(Debug, Clone, Default)]
pub struct CacheStatistics {
    /// Total cache hits
    pub hits: u64,

    /// Total cache misses
    pub misses: u64,

    /// Total evictions
    pub evictions: u64,

    /// Hit rate
    pub hit_rate: f64,
}

/// Profiling data for compilation analysis
#[derive(Debug, Default)]
pub struct ProfilingData {
    /// Pass execution times
    pub pass_times: HashMap<String, Duration>,

    /// Memory usage per pass
    pub pass_memory_usage: HashMap<String, usize>,

    /// Total compilation time
    pub total_compilation_time: Duration,

    /// Peak memory usage
    pub peak_memory_usage: usize,

    /// Number of operations processed
    pub operations_processed: usize,
}

/// Parallel compilation manager
#[derive(Debug)]
pub struct ParallelCompilationManager<T: Float + Debug + Send + Sync + 'static> {
    /// Number of compilation threads
    pub num_threads: usize,

    /// Compilation queue
    pub compilation_queue: VecDeque<CompilationTask<T>>,

    /// Active compilations
    pub active_compilations: HashMap<String, CompilationProgress>,

    /// Thread pool
    pub thread_pool: Option<std::thread::JoinHandle<()>>,
}

/// Compilation task
#[derive(Debug)]
pub struct CompilationTask<T: Float + Debug + Send + Sync + 'static> {
    /// Task identifier
    pub id: String,

    /// Computation to compile
    pub computation: XLAComputation<T>,

    /// Compilation configuration
    pub config: XLACompilerConfig,

    /// Priority level
    pub priority: u8,

    /// Creation time
    pub created_at: Instant,
}

/// Compilation progress tracking
#[derive(Debug)]
pub struct CompilationProgress {
    /// Current phase
    pub current_phase: CompilationPhase,

    /// Progress percentage (0.0-1.0)
    pub progress: f64,

    /// Start time
    pub started_at: Instant,

    /// Estimated completion time
    pub estimated_completion: Option<Instant>,
}

/// Compilation phases
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum CompilationPhase {
    GraphCapture,
    ShapeInference,
    OperationLowering,
    GraphOptimization,
    KernelFusion,
    MemoryPlanning,
    Scheduling,
    CodeGeneration,
    RuntimeIntegration,
    Finalization,
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> XLACompiler<T> {
    /// Create new XLA compiler
    pub fn new(config: XLACompilerConfig) -> Result<Self> {
        let graph_builder = ComputationGraphBuilder::new();
        let optimization_pipeline = OptimizationPipeline::new(&config);
        let code_generator = TPUCodeGenerator::new(config.target_tpu.clone());
        let compilation_cache =
            Arc::new(RwLock::new(CompilationCache::new(config.max_cache_size_mb)));
        let performance_analyzer = PerformanceAnalyzer::new();
        let memory_planner = MemoryPlanner::new(config.target_tpu.clone());
        let parallel_compiler = ParallelCompilationManager::new(config.compilation_threads);

        Ok(Self {
            config,
            graph_builder,
            optimization_pipeline,
            code_generator,
            compilation_cache,
            performance_analyzer,
            memory_planner,
            parallel_compiler,
            profiling_data: ProfilingData::default(),
        })
    }

    /// Compile XLA computation
    pub fn compile(&mut self, computation: XLAComputation<T>) -> Result<CompiledComputation> {
        let start_time = Instant::now();

        // Check cache first
        let computation_hash = self.compute_hash(&computation);
        if let Some(cached) = self.get_cached_computation(&computation_hash)? {
            return Ok(CompiledComputation {
                binary: cached.binary,
                metadata: cached.metadata,
                execution_info: ExecutionInfo::default(),
            });
        }

        // Run compilation pipeline
        // Shape inference
        let shaped_computation = self.run_shape_inference(computation)?;

        // Operation lowering
        let lowered_computation = self.run_operation_lowering(shaped_computation)?;

        // Graph optimization
        let optimized_computation = self.optimization_pipeline.optimize(lowered_computation)?;

        // Memory planning
        let memory_plan = self
            .memory_planner
            .create_memory_plan(&optimized_computation)?;

        // Code generation
        let generated_code = self
            .code_generator
            .generate_code(&optimized_computation, &memory_plan)?;

        // Runtime integration
        let binary = self.integrate_runtime(generated_code)?;

        // Cache the result
        let metadata = CompilationMetadata {
            computation_hash: computation_hash.clone(),
            compiler_version: "1.0.0".to_string(),
            target_config: self.config.target_tpu.clone(),
            compilation_time: start_time.elapsed(),
            optimization_passes: self.optimization_pipeline.get_applied_passes(),
            performance_info: PerformanceInfo::default(),
        };

        self.cache_computation(computation_hash, binary.clone(), metadata.clone())?;

        Ok(CompiledComputation {
            binary,
            metadata,
            execution_info: ExecutionInfo::default(),
        })
    }

    /// Run shape inference on computation
    fn run_shape_inference(&self, computation: XLAComputation<T>) -> Result<XLAComputation<T>> {
        // Delegate to frontend shape inference
        ShapeInference::infer_shapes(computation)
    }

    /// Run operation lowering
    fn run_operation_lowering(&self, computation: XLAComputation<T>) -> Result<XLAComputation<T>> {
        // Delegate to frontend operation lowering
        OperationLowering::lower_operations(computation)
    }

    /// Integrate runtime components
    fn integrate_runtime(&self, code: GeneratedCode) -> Result<Vec<u8>> {
        // Delegate to backend runtime integration
        let mut runtime = RuntimeIntegration::new(self.config.target_tpu.clone());
        runtime.integrate(code, &self.config.target_tpu)
    }

    /// Compute hash for computation
    fn compute_hash(&self, computation: &XLAComputation<T>) -> String {
        // Simplified hash computation
        format!("comp_{}", computation.id.0)
    }

    /// Get cached computation
    fn get_cached_computation(&self, hash: &str) -> Result<Option<CachedComputation>> {
        let cache = self.compilation_cache.read().expect("lock poisoned");
        Ok(cache.cache.get(hash).cloned())
    }

    /// Cache compiled computation
    fn cache_computation(
        &self,
        hash: String,
        binary: Vec<u8>,
        metadata: CompilationMetadata,
    ) -> Result<()> {
        let mut cache = self.compilation_cache.write().expect("lock poisoned");

        let binary_size = binary.len();
        let cached_comp = CachedComputation {
            id: hash.clone(),
            binary,
            metadata,
            last_accessed: Instant::now(),
            access_count: 0,
            size: binary_size,
        };

        cache.cache.insert(hash, cached_comp);
        Ok(())
    }
}

/// Compiled computation result
#[derive(Debug)]
pub struct CompiledComputation {
    /// Compiled binary
    pub binary: Vec<u8>,

    /// Compilation metadata
    pub metadata: CompilationMetadata,

    /// Execution information
    pub execution_info: ExecutionInfo,
}

/// Execution information
#[derive(Debug, Default)]
pub struct ExecutionInfo {
    /// Estimated execution time
    pub estimated_time: Duration,

    /// Memory requirements
    pub memory_requirements: usize,

    /// Resource utilization
    pub resource_utilization: ResourceUtilization,
}

/// Resource utilization information
#[derive(Debug, Default)]
pub struct ResourceUtilization {
    /// Compute utilization
    pub compute: f64,

    /// Memory bandwidth utilization
    pub memory_bandwidth: f64,

    /// Interconnect utilization
    pub interconnect: f64,
}

/// Generated code structure
#[derive(Debug)]
pub struct GeneratedCode {
    /// Main computation kernel
    pub kernel_code: String,

    /// Initialization code
    pub init_code: String,

    /// Cleanup code
    pub cleanup_code: String,

    /// Memory management code
    pub memory_code: String,
}

impl CompilationCache {
    /// Create new compilation cache
    pub fn new(max_size_mb: usize) -> Self {
        Self {
            cache: HashMap::new(),
            stats: CacheStatistics::default(),
            max_size: max_size_mb * 1024 * 1024, // Convert to bytes
            current_size: 0,
        }
    }

    /// Check if cache needs eviction
    pub fn needs_eviction(&self, new_size: usize) -> bool {
        self.current_size + new_size > self.max_size
    }

    /// Evict least recently used items
    pub fn evict_lru(&mut self, target_size: usize) {
        let mut items: Vec<_> = self.cache.iter().collect();
        items.sort_by_key(|(_, cached)| cached.last_accessed);

        let mut freed_size = 0;
        let mut to_remove = Vec::new();

        for (key, cached) in items {
            if freed_size >= target_size {
                break;
            }
            freed_size += cached.size;
            to_remove.push(key.clone());
        }

        for key in to_remove {
            if let Some(cached) = self.cache.remove(&key) {
                self.current_size -= cached.size;
                self.stats.evictions += 1;
            }
        }
    }
}

impl<T: Float + Debug + Default + std::fmt::Debug + Send + Sync> ParallelCompilationManager<T> {
    /// Create new parallel compilation manager
    pub fn new(num_threads: usize) -> Self {
        Self {
            num_threads,
            compilation_queue: VecDeque::new(),
            active_compilations: HashMap::new(),
            thread_pool: None,
        }
    }

    /// Submit compilation task
    pub fn submit_task(&mut self, task: CompilationTask<T>) {
        self.compilation_queue.push_back(task);
    }

    /// Get compilation status
    pub fn get_status(&self, task_id: &str) -> Option<&CompilationProgress> {
        self.active_compilations.get(task_id)
    }
}

impl Default for XLACompilerConfig {
    fn default() -> Self {
        Self {
            target_tpu: TPUConfig::default(),
            optimization_level: XLAOptimizationLevel::Standard,
            enable_auto_tuning: true,
            compilation_timeout: 300, // 5 minutes
            max_cache_size_mb: 1024,  // 1 GB
            parallel_compilation: true,
            compilation_threads: num_cpus::get(),
            enable_fusion: true,
            enable_layout_optimization: true,
            enable_memory_optimization: true,
            enable_pipeline_optimization: true,
            debug_mode: false,
            profile_compilation: false,
            custom_passes: Vec::new(),
            enable_tensor_core_optimization: true,
            enable_sparsity_optimization: true,
        }
    }
}

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

    #[test]
    fn test_xla_compiler_creation() {
        let config = XLACompilerConfig::default();
        let compiler: Result<XLACompiler<f32>> = XLACompiler::new(config);
        assert!(compiler.is_ok());
    }

    #[test]
    fn test_compilation_cache() {
        let cache = CompilationCache::new(10); // 10 MB
        assert_eq!(cache.current_size, 0);
        assert!(!cache.needs_eviction(100));
    }

    #[test]
    fn test_parallel_compilation_manager() {
        let manager: ParallelCompilationManager<f32> = ParallelCompilationManager::new(4);
        assert_eq!(manager.num_threads, 4);
        assert!(manager.compilation_queue.is_empty());
    }
}