//! Convolution operator code generation.

use proc_macro2::TokenStream;
use quote::quote;

use super::sanitize_name;
use crate::error::Result;
use crate::ir::{Node, OnnxGraph};

/// Default strides for 2D convolution.
const DEFAULT_STRIDES: &[i64] = &[1, 1];
/// Default padding for 2D convolution.
const DEFAULT_PADS: &[i64] = &[0, 0, 0, 0];
/// Default dilations for 2D convolution.
const DEFAULT_DILATIONS: &[i64] = &[1, 1];
/// Default output padding for transposed convolution.
const DEFAULT_OUTPUT_PADDING: &[i64] = &[0, 0];

/// Generate Conv operation.
pub fn generate_conv(node: &Node, _graph: &OnnxGraph) -> Result<TokenStream> {
    let input = &node.inputs[0];
    let weight = &node.inputs[1];
    let output = &node.outputs[0];

    let in_ident = quote::format_ident!("{}", sanitize_name(input));
    let weight_ident = quote::format_ident!("{}", sanitize_name(weight));
    let out_ident = quote::format_ident!("{}", sanitize_name(output));

    // Get attributes
    let strides = node.get_ints("strides").unwrap_or(DEFAULT_STRIDES);
    let pads = node.get_ints("pads").unwrap_or(DEFAULT_PADS);
    let dilations = node.get_ints("dilations").unwrap_or(DEFAULT_DILATIONS);
    let group = node.get_int("group").unwrap_or(1) as usize;

    // Handle optional bias
    let has_bias = node.inputs.len() > 2 && !node.inputs[2].is_empty();

    // Convert pads to padding tuple (assuming symmetric padding)
    let pad_h = pads.first().copied().unwrap_or(0) as usize;
    let pad_w = pads.get(1).copied().unwrap_or(0) as usize;

    let stride_h = strides.first().copied().unwrap_or(1) as usize;
    let stride_w = strides.get(1).copied().unwrap_or(1) as usize;

    let dilation_h = dilations.first().copied().unwrap_or(1) as usize;
    let dilation_w = dilations.get(1).copied().unwrap_or(1) as usize;

    let bias_arg = if has_bias {
        let bias_ident = quote::format_ident!("{}", sanitize_name(&node.inputs[2]));
        quote! { Some(&self.#bias_ident) }
    } else {
        quote! { None }
    };

    Ok(quote! {
        let #out_ident = rtx_nn::functional::conv2d(
            &#in_ident,
            &self.#weight_ident,
            #bias_arg,
            (#stride_h, #stride_w),
            (#pad_h, #pad_w),
            (#dilation_h, #dilation_w),
            #group,
        )?;
    })
}

/// Generate ConvTranspose operation.
pub fn generate_conv_transpose(node: &Node, _graph: &OnnxGraph) -> Result<TokenStream> {
    let input = &node.inputs[0];
    let weight = &node.inputs[1];
    let output = &node.outputs[0];

    let in_ident = quote::format_ident!("{}", sanitize_name(input));
    let weight_ident = quote::format_ident!("{}", sanitize_name(weight));
    let out_ident = quote::format_ident!("{}", sanitize_name(output));

    // Get attributes
    let strides = node.get_ints("strides").unwrap_or(DEFAULT_STRIDES);
    let pads = node.get_ints("pads").unwrap_or(DEFAULT_PADS);
    let output_padding = node
        .get_ints("output_padding")
        .unwrap_or(DEFAULT_OUTPUT_PADDING);
    let dilations = node.get_ints("dilations").unwrap_or(DEFAULT_DILATIONS);
    let group = node.get_int("group").unwrap_or(1) as usize;

    // Handle optional bias
    let has_bias = node.inputs.len() > 2 && !node.inputs[2].is_empty();

    let pad_h = pads.first().copied().unwrap_or(0) as usize;
    let pad_w = pads.get(1).copied().unwrap_or(0) as usize;

    let stride_h = strides.first().copied().unwrap_or(1) as usize;
    let stride_w = strides.get(1).copied().unwrap_or(1) as usize;

    let out_pad_h = output_padding.first().copied().unwrap_or(0) as usize;
    let out_pad_w = output_padding.get(1).copied().unwrap_or(0) as usize;

    let dilation_h = dilations.first().copied().unwrap_or(1) as usize;
    let dilation_w = dilations.get(1).copied().unwrap_or(1) as usize;

    let bias_arg = if has_bias {
        let bias_ident = quote::format_ident!("{}", sanitize_name(&node.inputs[2]));
        quote! { Some(&self.#bias_ident) }
    } else {
        quote! { None }
    };

    Ok(quote! {
        let #out_ident = rtx_nn::functional::conv_transpose2d(
            &#in_ident,
            &self.#weight_ident,
            #bias_arg,
            (#stride_h, #stride_w),
            (#pad_h, #pad_w),
            (#out_pad_h, #out_pad_w),
            (#dilation_h, #dilation_w),
            #group,
        )?;
    })
}