// CNN v2 Layer Template (placeholder for generated shaders)
// This file documents the structure - actual layers generated by export script

// Example: Layer 0 (1×1 kernel, 8→16 channels)
// const KERNEL_SIZE: u32 = 1u;
// const IN_CHANNELS: u32 = 8u;  // 7 features + bias
// const OUT_CHANNELS: u32 = 16u;
// const weights: array<f32, 128> = array(...);

@group(0) @binding(0) var static_features: texture_2d<u32>;
@group(0) @binding(1) var layer_input: texture_2d<u32>;  // Previous layer output
@group(0) @binding(2) var output_tex: texture_storage_2d<rgba32uint, write>;

fn unpack_static_features(coord: vec2<i32>) -> array<f32, 8> {
  let packed = textureLoad(static_features, coord, 0);
  let v0 = unpack2x16float(packed.x);
  let v1 = unpack2x16float(packed.y);
  let v2 = unpack2x16float(packed.z);
  let v3 = unpack2x16float(packed.w);
  return array<f32, 8>(v0.x, v0.y, v1.x, v1.y, v2.x, v2.y, v3.x, v3.y);
}

fn unpack_layer_channels(coord: vec2<i32>) -> array<f32, 8> {
  let packed = textureLoad(layer_input, coord, 0);
  let v0 = unpack2x16float(packed.x);
  let v1 = unpack2x16float(packed.y);
  let v2 = unpack2x16float(packed.z);
  let v3 = unpack2x16float(packed.w);
  return array<f32, 8>(v0.x, v0.y, v1.x, v1.y, v2.x, v2.y, v3.x, v3.y);
}

fn pack_channels(values: array<f32, 8>) -> vec4<u32> {
  return vec4<u32>(
    pack2x16float(vec2<f32>(values[0], values[1])),
    pack2x16float(vec2<f32>(values[2], values[3])),
    pack2x16float(vec2<f32>(values[4], values[5])),
    pack2x16float(vec2<f32>(values[6], values[7]))
  );
}

@compute @workgroup_size(8, 8)
fn main(@builtin(global_invocation_id) id: vec3<u32>) {
  let coord = vec2<i32>(id.xy);
  let dims = textureDimensions(static_features);

  if (coord.x >= i32(dims.x) || coord.y >= i32(dims.y)) {
    return;
  }

  // Load static features (always available)
  let static_feat = unpack_static_features(coord);

  // Convolution loop (example for generated code)
  // var output: array<f32, OUT_CHANNELS>;
  // for (var c: u32 = 0u; c < OUT_CHANNELS; c++) {
  //   var sum: f32 = 0.0;
  //   for (var ky: i32 = -radius; ky <= radius; ky++) {
  //     for (var kx: i32 = -radius; kx <= radius; kx++) {
  //       let sample_coord = coord + vec2<i32>(kx, ky);
  //       // Load static + prev layer, multiply weights, accumulate
  //     }
  //   }
  //   output[c] = max(0.0, sum);  // ReLU
  // }

  // Placeholder output
  textureStore(output_tex, coord, vec4<u32>(0u));
}