//! Window Function Utilities for Filtering
//!
//! This module provides utilities for applying functions to sliding windows
//! across arrays with various border handling modes.

use scirs2_core::ndarray::{Array, Dimension};
use scirs2_core::numeric::{Float, FromPrimitive};
use std::fmt::Debug;

use super::super::BorderMode;
use crate::error::{NdimageError, NdimageResult};

/// Apply a function to all windows in an array
///
/// # Arguments
///
/// * `input` - Input array
/// * `window_size` - Size of the window in each dimension
/// * `mode` - Border handling mode
/// * `constant_value` - Value to use for constant mode
/// * `func` - Function to apply to each window
///
/// # Returns
///
/// * `Result<Array<T, D>>` - Result array
#[allow(dead_code)]
pub fn apply_window_function<T, D, F>(
    input: &Array<T, D>,
    window_size: &[usize],
    _mode: &BorderMode,
    value: Option<T>,
    _func: F,
) -> NdimageResult<Array<T, D>>
where
    T: Float + FromPrimitive + Debug + Clone,
    D: Dimension,
    F: Fn(&Array<T, D>) -> T,
{
    // Validate inputs
    if input.ndim() == 0 {
        return Err(NdimageError::InvalidInput(
            "Input array cannot be 0-dimensional".into(),
        ));
    }

    if window_size.len() != input.ndim() {
        return Err(NdimageError::DimensionError(format!(
            "Window size must have same length as input dimensions (got {} expected {})",
            window_size.len(),
            input.ndim()
        )));
    }

    // Placeholder implementation returning a copy of the input
    // This will be implemented with proper window function application
    Ok(input.to_owned())
}
