//! Normalization operations using Metal Performance Shaders

use metal::foreign_types::ForeignType;
use metal::{CommandBuffer, Device};
use objc2::msg_send;
use objc2::runtime::AnyObject;

use crate::metal::{buffer::MetalBuffer, error::Result};

/// Batch normalization using MPS
#[allow(dead_code)]
pub struct MPSBatchNorm {
    batch_norm: *mut AnyObject,
}

impl MPSBatchNorm {
    /// Create a new batch normalization operation
    pub fn new(
        device: &Device,
        _num_features: usize,
        _epsilon: f32,
        _momentum: f32,
    ) -> Result<Self> {
        unsafe {
            let class = objc2::class!(MPSCNNBatchNormalization);
            let batch_norm: *mut AnyObject = msg_send![class, alloc];

            // Note: This is a simplified version. Real implementation would need
            // to properly initialize with gamma, beta, moving mean, and moving variance
            let batch_norm: *mut AnyObject = msg_send![batch_norm,
                initWithDevice: device.as_ptr() as *mut AnyObject,
                dataSource: std::ptr::null::<AnyObject>() // Would need proper data source
            ];

            Ok(Self { batch_norm })
        }
    }

    /// Apply batch normalization
    pub fn apply(
        &self,
        _command_buffer: &CommandBuffer,
        _input: &MetalBuffer,
        _output: &MetalBuffer,
        _training: bool,
    ) -> Result<()> {
        // Implementation would encode the batch norm operation
        Ok(())
    }
}

impl Drop for MPSBatchNorm {
    fn drop(&mut self) {
        unsafe {
            let _: () = msg_send![self.batch_norm, release];
        }
    }
}

/// Layer normalization using custom kernel
#[allow(dead_code)]
pub struct MPSLayerNorm {
    kernel_manager: crate::metal::kernels::KernelManager,
    normalized_shape: Vec<usize>,
    epsilon: f32,
}

#[allow(dead_code)]
impl MPSLayerNorm {
    /// Create a new layer normalization operation
    pub fn new(device: &Device, normalized_shape: Vec<usize>, epsilon: f32) -> Result<Self> {
        let kernel_manager = crate::metal::kernels::KernelManager::new(device)?;

        Ok(Self {
            kernel_manager,
            normalized_shape,
            epsilon,
        })
    }

    /// Apply layer normalization
    pub fn apply(
        &self,
        _command_buffer: &CommandBuffer,
        _input: &MetalBuffer,
        _output: &MetalBuffer,
        _gamma: Option<&MetalBuffer>,
        _beta: Option<&MetalBuffer>,
    ) -> Result<()> {
        // Would use custom Metal kernel for layer norm
        // This is a placeholder implementation
        Ok(())
    }
}
