optirs-tpu 0.3.1

use std::fmt::Debug;
// Memory planning and layout optimization for XLA computations
//
// This module implements memory layout optimization, buffer allocation strategies,
// memory bandwidth optimization, and memory hierarchy utilization for TPU execution.

use scirs2_core::numeric::Float;
use std::cmp::Ordering;
use std::collections::{BTreeMap, HashMap, HashSet, VecDeque};

use super::super::frontend::{
    DataType, Layout, MemorySpace, OperandId, OperationId, OperationType, TensorShape, Tile,
    XLAComputation, XLAOperation,
};
use super::super::TPUConfig;
use super::HardwareTarget;
use crate::error::{OptimError, Result};

/// Memory planner for XLA computations
pub struct MemoryPlanner<T: Float + Debug + Send + Sync + 'static> {
    /// Target hardware configuration
    target_hardware: TPUConfig,

    /// Memory allocation strategy
    allocation_strategy: AllocationStrategy,

    /// Layout optimizer
    layout_optimizer: LayoutOptimizer<T>,

    /// Buffer manager
    buffer_manager: BufferManager<T>,

    /// Memory bandwidth optimizer
    bandwidth_optimizer: BandwidthOptimizer<T>,

    /// Memory hierarchy manager
    hierarchy_manager: MemoryHierarchyManager<T>,

    /// Memory planning statistics
    planning_stats: MemoryPlanningStats,
}

/// Memory allocation strategy
#[derive(Debug, Clone)]
pub enum AllocationStrategy {
    /// First-fit allocation
    FirstFit,

    /// Best-fit allocation
    BestFit,

    /// Worst-fit allocation
    WorstFit,

    /// Buddy system allocation
    BuddySystem,

    /// Pool-based allocation
    PoolBased,

    /// Linear allocation
    Linear,
}

/// Layout optimizer for memory access patterns
pub struct LayoutOptimizer<T: Float + Debug + Send + Sync + 'static> {
    /// Supported layout formats
    supported_layouts: Vec<LayoutFormat>,

    /// Access pattern analyzer
    access_analyzer: AccessPatternAnalyzer,

    /// Layout transformation rules
    transformation_rules: Vec<LayoutTransformationRule>,

    _phantom: std::marker::PhantomData<T>,
}

/// Memory buffer manager
pub struct BufferManager<T: Float + Debug + Send + Sync + 'static> {
    /// Active buffers
    active_buffers: HashMap<OperandId, BufferInfo>,

    /// Buffer pool
    buffer_pool: Vec<PooledBuffer>,

    /// Memory allocator
    allocator: MemoryAllocator,

    /// Buffer reuse tracker
    reuse_tracker: BufferReuseTracker,

    _phantom: std::marker::PhantomData<T>,
}

/// Memory bandwidth optimizer
pub struct BandwidthOptimizer<T: Float + Debug + Send + Sync + 'static> {
    /// Memory access schedule
    access_schedule: MemoryAccessSchedule,

    /// Prefetch strategies
    prefetch_strategies: Vec<PrefetchStrategy>,

    /// Cache management
    cache_manager: CacheManager,

    _phantom: std::marker::PhantomData<T>,
}

/// Memory hierarchy manager
pub struct MemoryHierarchyManager<T: Float + Debug + Send + Sync + 'static> {
    /// Memory levels (L1, L2, HBM, etc.)
    memory_levels: Vec<MemoryLevel>,

    /// Data placement strategy
    placement_strategy: PlacementStrategy,

    /// Migration policies
    migration_policies: Vec<MigrationPolicy>,

    _phantom: std::marker::PhantomData<T>,
}

/// Memory planning statistics
#[derive(Debug, Default)]
pub struct MemoryPlanningStats {
    /// Total memory allocated
    pub total_memory_allocated: usize,

    /// Peak memory usage
    pub peak_memory_usage: usize,

    /// Memory fragmentation ratio
    pub fragmentation_ratio: f64,

    /// Buffer reuse ratio
    pub buffer_reuse_ratio: f64,

    /// Memory bandwidth utilization
    pub bandwidth_utilization: f64,

    /// Layout transformations performed
    pub layout_transformations: usize,

    /// Memory level utilization
    pub level_utilization: HashMap<String, f64>,
}

/// Memory plan for computation
#[derive(Debug)]
pub struct MemoryPlan<T: Float + Debug + Send + Sync + 'static> {
    /// Buffer allocations
    pub buffer_allocations: HashMap<OperandId, BufferAllocation>,

    /// Layout assignments
    pub layout_assignments: HashMap<OperandId, Layout>,

    /// Memory level assignments
    pub memory_assignments: HashMap<OperandId, MemorySpace>,

    /// Execution order for memory operations
    pub execution_order: Vec<MemoryOperation>,

    /// Total memory requirements
    pub total_memory: usize,

    /// Performance characteristics
    pub performance_info: MemoryPerformanceInfo,

    /// Phantom data for type parameter
    _phantom: std::marker::PhantomData<T>,
}

/// Buffer allocation information
#[derive(Debug, Clone)]
pub struct BufferAllocation {
    /// Buffer identifier
    pub buffer_id: String,

    /// Memory address (virtual)
    pub address: usize,

    /// Buffer size in bytes
    pub size: usize,

    /// Alignment requirements
    pub alignment: usize,

    /// Lifetime information
    pub lifetime: BufferLifetime,

    /// Access pattern
    pub access_pattern: AccessPattern,
}

/// Buffer lifetime tracking
#[derive(Debug, Clone)]
pub struct BufferLifetime {
    /// First use operation
    pub first_use: OperationId,

    /// Last use operation
    pub last_use: OperationId,

    /// Live range
    pub live_range: (usize, usize),

    /// Reuse opportunities
    pub reuse_opportunities: Vec<OperandId>,
}

/// Memory access pattern
#[derive(Debug, Clone)]
pub enum AccessPattern {
    /// Sequential access
    Sequential,

    /// Random access
    Random,

    /// Strided access
    Strided { stride: usize },

    /// Block access
    Block { block_size: usize },

    /// Broadcast access
    Broadcast,
}

/// Layout format specification
#[derive(Debug, Clone)]
pub struct LayoutFormat {
    /// Format name
    pub name: String,

    /// Dimension ordering (minor to major)
    pub dimension_order: Vec<usize>,

    /// Memory layout type
    pub layout_type: LayoutType,

    /// Tiling specification
    pub tiling: Option<TilingSpec>,

    /// Alignment requirements
    pub alignment: usize,
}

/// Memory layout types
#[derive(Debug, Clone)]
pub enum LayoutType {
    /// Row-major (C-style)
    RowMajor,

    /// Column-major (Fortran-style)
    ColumnMajor,

    /// Blocked layout
    Blocked,

    /// Compressed layout
    Compressed,

    /// Custom layout
    Custom(String),
}

/// Tiling specification
#[derive(Debug, Clone)]
pub struct TilingSpec {
    /// Tile dimensions
    pub tile_dims: Vec<usize>,

    /// Tile order
    pub tile_order: Vec<usize>,

    /// Padding strategy
    pub padding: PaddingStrategy,
}

/// Padding strategies for tiling
#[derive(Debug, Clone)]
pub enum PaddingStrategy {
    /// No padding
    None,

    /// Zero padding
    Zero,

    /// Edge replication
    EdgeReplicate,

    /// Mirror padding
    Mirror,
}

/// Access pattern analyzer
pub struct AccessPatternAnalyzer {
    /// Detected patterns
    patterns: HashMap<OperandId, AccessPattern>,

    /// Pattern confidence scores
    confidence_scores: HashMap<OperandId, f64>,

    /// Stride analysis results
    stride_analysis: HashMap<OperandId, StrideAnalysis>,
}

/// Stride analysis information
#[derive(Debug)]
pub struct StrideAnalysis {
    /// Detected strides per dimension
    pub strides: Vec<i64>,

    /// Regularity score
    pub regularity: f64,

    /// Memory locality score
    pub locality: f64,
}

/// Layout transformation rule
#[derive(Debug)]
pub struct LayoutTransformationRule {
    /// Rule name
    pub name: String,

    /// Source layout pattern
    pub source_pattern: LayoutPattern,

    /// Target layout pattern
    pub target_pattern: LayoutPattern,

    /// Applicability conditions
    pub conditions: Vec<String>,

    /// Expected benefit
    pub benefit: f64,
}

/// Layout pattern for matching
#[derive(Debug)]
pub struct LayoutPattern {
    /// Tensor rank constraints
    pub rank_constraints: Vec<RankConstraint>,

    /// Dimension constraints
    pub dimension_constraints: Vec<DimensionConstraint>,

    /// Access pattern requirements
    pub access_requirements: Vec<AccessPattern>,
}

/// Rank constraint for layout patterns
#[derive(Debug)]
pub enum RankConstraint {
    /// Exact rank
    Exact(usize),

    /// Minimum rank
    Minimum(usize),

    /// Maximum rank
    Maximum(usize),

    /// Range of ranks
    Range(usize, usize),
}

/// Dimension constraint for layout patterns
#[derive(Debug)]
pub struct DimensionConstraint {
    /// Dimension index
    pub dimension: usize,

    /// Size constraint
    pub size_constraint: SizeConstraint,

    /// Alignment constraint
    pub alignment_constraint: Option<usize>,
}

/// Size constraint for dimensions
#[derive(Debug)]
pub enum SizeConstraint {
    /// Exact size
    Exact(usize),

    /// Multiple of value
    MultipleOf(usize),

    /// Range of sizes
    Range(usize, usize),

    /// Any size
    Any,
}

/// Buffer information
#[derive(Debug)]
pub struct BufferInfo {
    /// Buffer size
    pub size: usize,

    /// Current allocation
    pub allocation: Option<BufferAllocation>,

    /// Reference count
    pub ref_count: usize,

    /// Access statistics
    pub access_stats: AccessStatistics,
}

/// Pooled buffer for reuse
#[derive(Debug)]
pub struct PooledBuffer {
    /// Buffer identifier
    pub id: String,

    /// Buffer size
    pub size: usize,

    /// Is available for reuse
    pub available: bool,

    /// Last used timestamp
    pub last_used: u64,
}

/// Memory allocator
pub struct MemoryAllocator {
    /// Allocation strategy
    strategy: AllocationStrategy,

    /// Free memory regions
    free_regions: BTreeMap<usize, usize>, // address -> size

    /// Allocated regions
    allocated_regions: HashMap<usize, usize>, // address -> size

    /// Total memory capacity
    total_capacity: usize,

    /// Current usage
    current_usage: usize,
}

/// Buffer reuse tracker
pub struct BufferReuseTracker {
    /// Reuse candidates
    candidates: Vec<ReuseCandidate>,

    /// Reuse statistics
    stats: ReuseStatistics,
}

/// Buffer reuse candidate
#[derive(Debug)]
pub struct ReuseCandidate {
    /// Source buffer
    pub source_buffer: OperandId,

    /// Target buffer
    pub target_buffer: OperandId,

    /// Reuse score
    pub score: f64,

    /// Size compatibility
    pub size_compatible: bool,
}

/// Reuse statistics
#[derive(Debug, Default)]
pub struct ReuseStatistics {
    /// Total reuse opportunities
    pub total_opportunities: usize,

    /// Successful reuses
    pub successful_reuses: usize,

    /// Memory saved
    pub memory_saved: usize,
}

/// Access statistics for buffers
#[derive(Debug, Default)]
pub struct AccessStatistics {
    /// Number of reads
    pub read_count: usize,

    /// Number of writes
    pub write_count: usize,

    /// Access pattern
    pub pattern: Option<AccessPattern>,

    /// Average access size
    pub avg_access_size: usize,
}

/// Memory access schedule
pub struct MemoryAccessSchedule {
    /// Scheduled accesses
    accesses: Vec<ScheduledAccess>,

    /// Memory pressure timeline
    pressure_timeline: Vec<MemoryPressurePoint>,
}

/// Scheduled memory access
#[derive(Debug)]
pub struct ScheduledAccess {
    /// Operation ID
    pub operation_id: OperationId,

    /// Access type
    pub access_type: MemoryAccessType,

    /// Buffer ID
    pub buffer_id: OperandId,

    /// Scheduled time
    pub scheduled_time: u64,

    /// Access size
    pub size: usize,
}

/// Memory access types
#[derive(Debug)]
pub enum MemoryAccessType {
    /// Read access
    Read,

    /// Write access
    Write,

    /// Read-modify-write
    ReadModifyWrite,

    /// Prefetch
    Prefetch,
}

/// Memory pressure point in timeline
#[derive(Debug)]
pub struct MemoryPressurePoint {
    /// Time point
    pub time: u64,

    /// Memory usage
    pub memory_usage: usize,

    /// Bandwidth usage
    pub bandwidth_usage: f64,
}

/// Prefetch strategy
#[derive(Debug)]
pub struct PrefetchStrategy {
    /// Strategy name
    pub name: String,

    /// Prefetch distance
    pub distance: usize,

    /// Confidence threshold
    pub confidence_threshold: f64,

    /// Memory level
    pub target_level: MemorySpace,
}

/// Cache manager for memory hierarchy
pub struct CacheManager {
    /// Cache levels
    cache_levels: Vec<CacheLevel>,

    /// Cache policies
    policies: HashMap<MemorySpace, CachePolicy>,
}

/// Cache level information
#[derive(Debug)]
pub struct CacheLevel {
    /// Cache identifier
    pub id: String,

    /// Cache size
    pub size: usize,

    /// Line size
    pub line_size: usize,

    /// Associativity
    pub associativity: usize,

    /// Access latency
    pub latency: u32,
}

/// Cache replacement policy
#[derive(Debug)]
pub enum CachePolicy {
    /// Least Recently Used
    LRU,

    /// Least Frequently Used
    LFU,

    /// First In First Out
    FIFO,

    /// Random replacement
    Random,

    /// Optimal (theoretical)
    Optimal,
}

/// Memory level in hierarchy
#[derive(Debug)]
pub struct MemoryLevel {
    /// Level identifier
    pub id: String,

    /// Memory space type
    pub memory_space: MemorySpace,

    /// Capacity (bytes)
    pub capacity: usize,

    /// Bandwidth (bytes/second)
    pub bandwidth: f64,

    /// Access latency (nanoseconds)
    pub latency: u32,

    /// Power consumption (watts)
    pub power: f64,
}

/// Data placement strategy
#[derive(Debug)]
pub enum PlacementStrategy {
    /// Place in fastest available memory
    FastestAvailable,

    /// Place based on access frequency
    AccessFrequency,

    /// Place based on data size
    SizeBased,

    /// Manual placement
    Manual,

    /// Machine learning guided
    MLGuided,
}

/// Migration policy for moving data between levels
#[derive(Debug)]
pub struct MigrationPolicy {
    /// Policy name
    pub name: String,

    /// Migration trigger
    pub trigger: MigrationTrigger,

    /// Source memory level
    pub source_level: MemorySpace,

    /// Target memory level
    pub target_level: MemorySpace,

    /// Migration cost model
    pub cost_model: CostModel,
}

/// Migration triggers
#[derive(Debug)]
pub enum MigrationTrigger {
    /// Access frequency threshold
    AccessFrequency(f64),

    /// Memory pressure threshold
    MemoryPressure(f64),

    /// Time-based
    TimeBased(u64),

    /// Predictive
    Predictive,
}

/// Cost model for migration decisions
#[derive(Debug)]
pub struct CostModel {
    /// Migration cost (time)
    pub migration_cost: f64,

    /// Access cost difference
    pub access_cost_diff: f64,

    /// Energy cost difference
    pub energy_cost_diff: f64,
}

/// Memory operation for execution ordering
#[derive(Debug)]
pub enum MemoryOperation {
    /// Allocate buffer
    Allocate {
        buffer_id: OperandId,
        size: usize,
        alignment: usize,
    },

    /// Deallocate buffer
    Deallocate { buffer_id: OperandId },

    /// Copy data between buffers
    Copy {
        source: OperandId,
        target: OperandId,
        size: usize,
    },

    /// Prefetch data
    Prefetch {
        buffer_id: OperandId,
        target_level: MemorySpace,
    },
}

/// Memory performance information
#[derive(Debug, Default)]
pub struct MemoryPerformanceInfo {
    /// Estimated memory bandwidth utilization
    pub bandwidth_utilization: f64,

    /// Estimated access latency
    pub avg_access_latency: f64,

    /// Memory efficiency score
    pub efficiency_score: f64,

    /// Cache hit rates by level
    pub cache_hit_rates: HashMap<String, f64>,
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> MemoryPlanner<T> {
    /// Create new memory planner
    pub fn new(target_hardware: TPUConfig) -> Self {
        Self {
            layout_optimizer: LayoutOptimizer::new(&target_hardware),
            buffer_manager: BufferManager::new(),
            bandwidth_optimizer: BandwidthOptimizer::new(&target_hardware),
            hierarchy_manager: MemoryHierarchyManager::new(&target_hardware),
            allocation_strategy: AllocationStrategy::BestFit,
            target_hardware,
            planning_stats: MemoryPlanningStats::default(),
        }
    }

    /// Create memory plan for computation
    pub fn create_memory_plan(&mut self, computation: &XLAComputation<T>) -> Result<MemoryPlan<T>> {
        // Analyze memory requirements
        let memory_analysis = self.analyze_memory_requirements(computation)?;

        // Optimize layouts
        let layout_assignments = self.layout_optimizer.optimize_layouts(computation)?;

        // Allocate buffers
        let buffer_allocations = self.buffer_manager.allocate_buffers(&memory_analysis)?;

        // Assign memory levels
        let memory_assignments = self
            .hierarchy_manager
            .assign_memory_levels(&memory_analysis)?;

        // Schedule memory operations
        let execution_order = self
            .bandwidth_optimizer
            .schedule_memory_operations(computation)?;

        // Calculate performance characteristics
        let performance_info =
            self.calculate_performance_info(&buffer_allocations, &memory_assignments)?;

        let total_memory = buffer_allocations.values().map(|alloc| alloc.size).sum();

        Ok(MemoryPlan {
            buffer_allocations,
            layout_assignments,
            memory_assignments,
            execution_order,
            total_memory,
            performance_info,
            _phantom: std::marker::PhantomData,
        })
    }

    /// Optimize memory layout for computation
    pub fn optimize_memory_layout(
        &mut self,
        computation: XLAComputation<T>,
    ) -> Result<XLAComputation<T>> {
        let memory_plan = self.create_memory_plan(&computation)?;

        // Apply layout optimizations to computation
        let mut optimized_computation = computation;

        // Update operand layouts
        for (operand_id, layout) in memory_plan.layout_assignments {
            if let Some(operand) = optimized_computation.operands.get_mut(&operand_id) {
                operand.layout = layout;
            }
        }

        // Update memory spaces
        for (operand_id, memory_space) in memory_plan.memory_assignments {
            if let Some(operand) = optimized_computation.operands.get_mut(&operand_id) {
                operand.layout.memory_space = memory_space;
            }
        }

        Ok(optimized_computation)
    }

    /// Analyze memory requirements for computation
    fn analyze_memory_requirements(
        &self,
        computation: &XLAComputation<T>,
    ) -> Result<MemoryAnalysis> {
        let mut analysis = MemoryAnalysis::default();

        // Analyze each operand
        for (operand_id, operand) in &computation.operands {
            let size = self.calculate_operand_size(operand)?;
            let lifetime = self.calculate_operand_lifetime(*operand_id, computation)?;
            let access_pattern = self.analyze_access_pattern(*operand_id, computation)?;

            analysis.operand_info.insert(
                *operand_id,
                OperandMemoryInfo {
                    size,
                    lifetime,
                    access_pattern,
                    alignment_requirements: vec![32], // Default 32-byte alignment
                },
            );
        }

        analysis.total_memory = analysis.operand_info.values().map(|info| info.size).sum();

        Ok(analysis)
    }

    /// Calculate operand memory size
    fn calculate_operand_size(
        &self,
        operand: &super::super::frontend::graph_capture::Operand<T>,
    ) -> Result<usize> {
        let element_size = match operand.dtype {
            DataType::F16 => 2,
            DataType::BF16 => 2,
            DataType::F32 => 4,
            DataType::F64 => 8,
            DataType::S8 => 1,
            DataType::S16 => 2,
            DataType::S32 => 4,
            DataType::S64 => 8,
            DataType::U8 => 1,
            DataType::U16 => 2,
            DataType::U32 => 4,
            DataType::U64 => 8,
            DataType::Pred => 1,
            DataType::C64 => 8,
            DataType::C128 => 16,
        };

        Ok(operand.shape.element_count * element_size)
    }

    /// Calculate operand lifetime
    fn calculate_operand_lifetime(
        &self,
        operand_id: OperandId,
        computation: &XLAComputation<T>,
    ) -> Result<BufferLifetime> {
        // Find first and last use of operand
        let mut first_use = None;
        let mut last_use = None;

        for operation in &computation.operations {
            if operation.inputs.contains(&operand_id) || operation.output == operand_id {
                if first_use.is_none() {
                    first_use = Some(operation.id);
                }
                last_use = Some(operation.id);
            }
        }

        Ok(BufferLifetime {
            first_use: first_use.unwrap_or(super::super::frontend::graph_capture::OperationId(0)),
            last_use: last_use.unwrap_or(super::super::frontend::graph_capture::OperationId(0)),
            live_range: (0, computation.operations.len()),
            reuse_opportunities: vec![],
        })
    }

    /// Analyze access pattern for operand
    fn analyze_access_pattern(
        &self,
        _operand_id: OperandId,
        _computation: &XLAComputation<T>,
    ) -> Result<AccessPattern> {
        // Simplified access pattern analysis
        Ok(AccessPattern::Sequential)
    }

    /// Calculate performance information
    fn calculate_performance_info(
        &self,
        _buffer_allocations: &HashMap<OperandId, BufferAllocation>,
        _memory_assignments: &HashMap<OperandId, MemorySpace>,
    ) -> Result<MemoryPerformanceInfo> {
        Ok(MemoryPerformanceInfo {
            bandwidth_utilization: 0.8,
            avg_access_latency: 100.0, // nanoseconds
            efficiency_score: 0.85,
            cache_hit_rates: HashMap::new(),
        })
    }
}

/// Memory analysis results
#[derive(Debug, Default)]
pub struct MemoryAnalysis {
    /// Per-operand memory information
    pub operand_info: HashMap<OperandId, OperandMemoryInfo>,

    /// Total memory requirement
    pub total_memory: usize,

    /// Peak memory usage
    pub peak_memory: usize,

    /// Memory access patterns
    pub access_patterns: HashMap<OperandId, AccessPattern>,
}

/// Memory information for operand
#[derive(Debug)]
pub struct OperandMemoryInfo {
    /// Size in bytes
    pub size: usize,

    /// Buffer lifetime
    pub lifetime: BufferLifetime,

    /// Access pattern
    pub access_pattern: AccessPattern,

    /// Alignment requirements
    pub alignment_requirements: Vec<usize>,
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> LayoutOptimizer<T> {
    /// Create new layout optimizer
    pub fn new(_target_hardware: &TPUConfig) -> Self {
        let supported_layouts = vec![
            LayoutFormat {
                name: "row_major".to_string(),
                dimension_order: vec![1, 0], // Row-major for 2D
                layout_type: LayoutType::RowMajor,
                tiling: None,
                alignment: 32,
            },
            LayoutFormat {
                name: "column_major".to_string(),
                dimension_order: vec![0, 1], // Column-major for 2D
                layout_type: LayoutType::ColumnMajor,
                tiling: None,
                alignment: 32,
            },
        ];

        Self {
            supported_layouts,
            access_analyzer: AccessPatternAnalyzer::new(),
            transformation_rules: vec![],
            _phantom: std::marker::PhantomData,
        }
    }

    /// Optimize layouts for computation
    pub fn optimize_layouts(
        &mut self,
        computation: &XLAComputation<T>,
    ) -> Result<HashMap<OperandId, Layout>> {
        let mut layout_assignments = HashMap::new();

        // Analyze access patterns
        self.access_analyzer.analyze_computation(computation)?;

        // Assign optimal layouts
        for operand_id in computation.operands.keys() {
            let optimal_layout = self.select_optimal_layout(*operand_id)?;
            layout_assignments.insert(*operand_id, optimal_layout);
        }

        Ok(layout_assignments)
    }

    /// Select optimal layout for operand
    fn select_optimal_layout(&self, operand_id: OperandId) -> Result<Layout> {
        // Simplified layout selection
        Ok(Layout {
            minor_to_major: vec![1, 0], // Default row-major
            tiles: vec![],
            memory_space: MemorySpace::Default,
        })
    }
}

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

impl AccessPatternAnalyzer {
    pub fn new() -> Self {
        Self {
            patterns: HashMap::new(),
            confidence_scores: HashMap::new(),
            stride_analysis: HashMap::new(),
        }
    }

    pub fn analyze_computation<T: Float + Debug + Send + Sync + 'static>(
        &mut self,
        _computation: &XLAComputation<T>,
    ) -> Result<()> {
        // Access pattern analysis implementation
        Ok(())
    }
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> Default
    for BufferManager<T>
{
    fn default() -> Self {
        Self::new()
    }
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> BufferManager<T> {
    pub fn new() -> Self {
        Self {
            active_buffers: HashMap::new(),
            buffer_pool: vec![],
            allocator: MemoryAllocator::new(AllocationStrategy::BestFit, 1024 * 1024 * 1024), // 1GB
            reuse_tracker: BufferReuseTracker::new(),
            _phantom: std::marker::PhantomData,
        }
    }

    pub fn allocate_buffers(
        &mut self,
        analysis: &MemoryAnalysis,
    ) -> Result<HashMap<OperandId, BufferAllocation>> {
        let mut allocations = HashMap::new();

        for (operand_id, operand_info) in &analysis.operand_info {
            let allocation = self.allocator.allocate(operand_info.size, 32)?;
            allocations.insert(*operand_id, allocation);
        }

        Ok(allocations)
    }
}

impl MemoryAllocator {
    pub fn new(strategy: AllocationStrategy, capacity: usize) -> Self {
        let mut free_regions = BTreeMap::new();
        free_regions.insert(0, capacity);

        Self {
            strategy,
            free_regions,
            allocated_regions: HashMap::new(),
            total_capacity: capacity,
            current_usage: 0,
        }
    }

    pub fn allocate(&mut self, size: usize, alignment: usize) -> Result<BufferAllocation> {
        let aligned_size = (size + alignment - 1) & !(alignment - 1);

        // Find suitable free region
        if let Some((&address, &region_size)) = self
            .free_regions
            .iter()
            .find(|(_, &region_size)| region_size >= aligned_size)
        {
            // Remove from free regions
            self.free_regions.remove(&address);

            // Add to allocated regions
            self.allocated_regions.insert(address, aligned_size);
            self.current_usage += aligned_size;

            // Add remainder back to free regions
            if region_size > aligned_size {
                self.free_regions
                    .insert(address + aligned_size, region_size - aligned_size);
            }

            Ok(BufferAllocation {
                buffer_id: format!("buf_{}", address),
                address,
                size: aligned_size,
                alignment,
                lifetime: BufferLifetime {
                    first_use: super::super::frontend::graph_capture::OperationId(0),
                    last_use: super::super::frontend::graph_capture::OperationId(0),
                    live_range: (0, 0),
                    reuse_opportunities: vec![],
                },
                access_pattern: AccessPattern::Sequential,
            })
        } else {
            Err(OptimError::from(format!(
                "Out of memory: Cannot allocate {} bytes",
                aligned_size
            )))
        }
    }
}

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

impl BufferReuseTracker {
    pub fn new() -> Self {
        Self {
            candidates: vec![],
            stats: ReuseStatistics::default(),
        }
    }
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> BandwidthOptimizer<T> {
    pub fn new(_target_hardware: &TPUConfig) -> Self {
        Self {
            access_schedule: MemoryAccessSchedule::new(),
            prefetch_strategies: vec![],
            cache_manager: CacheManager::new(),
            _phantom: std::marker::PhantomData,
        }
    }

    pub fn schedule_memory_operations(
        &mut self,
        _computation: &XLAComputation<T>,
    ) -> Result<Vec<MemoryOperation>> {
        // Memory operation scheduling implementation
        Ok(vec![])
    }
}

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

impl MemoryAccessSchedule {
    pub fn new() -> Self {
        Self {
            accesses: vec![],
            pressure_timeline: vec![],
        }
    }
}

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

impl CacheManager {
    pub fn new() -> Self {
        Self {
            cache_levels: vec![],
            policies: HashMap::new(),
        }
    }
}

impl<T: Float + Debug + Default + std::fmt::Debug + Clone + Send + Sync> MemoryHierarchyManager<T> {
    pub fn new(_target_hardware: &TPUConfig) -> Self {
        let memory_levels = vec![
            MemoryLevel {
                id: "L1".to_string(),
                memory_space: MemorySpace::Device,
                capacity: 1024 * 1024, // 1 MB
                bandwidth: 1000e9,     // 1 TB/s
                latency: 1,            // 1 ns
                power: 10.0,           // 10W
            },
            MemoryLevel {
                id: "HBM".to_string(),
                memory_space: MemorySpace::Default,
                capacity: 32 * 1024 * 1024 * 1024, // 32 GB
                bandwidth: 1600e9,                 // 1.6 TB/s
                latency: 100,                      // 100 ns
                power: 200.0,                      // 200W
            },
        ];

        Self {
            memory_levels,
            placement_strategy: PlacementStrategy::AccessFrequency,
            migration_policies: vec![],
            _phantom: std::marker::PhantomData,
        }
    }

    pub fn assign_memory_levels(
        &mut self,
        analysis: &MemoryAnalysis,
    ) -> Result<HashMap<OperandId, MemorySpace>> {
        let mut assignments = HashMap::new();

        for operand_id in analysis.operand_info.keys() {
            // Simplified memory level assignment
            assignments.insert(*operand_id, MemorySpace::Default);
        }

        Ok(assignments)
    }
}

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

    #[test]
    fn test_memory_planner_creation() {
        use crate::main_types::{PodTopology, TPUConfig, TPUVersion};

        let tpu_config = TPUConfig {
            tpu_version: TPUVersion::V4,
            num_cores: 8,
            enable_xla: true,
            xla_optimization_level: crate::main_types::XLAOptimizationLevel::Standard,
            mixed_precision: true,
            batch_size_per_core: 32,
            enable_pod_coordination: false,
            pod_topology: PodTopology::Pod2x2,
            memory_optimization: crate::main_types::TPUMemoryOptimization::Balanced,
            gradient_compression: true,
            prefetch_depth: 2,
            experimental_features: false,
        };

        let planner: MemoryPlanner<f32> = MemoryPlanner::new(tpu_config);
        assert_eq!(planner.planning_stats.total_memory_allocated, 0);
    }

    #[test]
    fn test_memory_allocator() {
        let mut allocator = MemoryAllocator::new(AllocationStrategy::BestFit, 1024);

        let allocation = allocator.allocate(256, 32).expect("unwrap failed");
        assert_eq!(allocation.size, 256);
        assert_eq!(allocation.alignment, 32);
        assert!(allocator.current_usage >= 256);
    }
}