'use strict';
// CNN v3 WGSL shaders — matches cnn_v3/shaders/*.wgsl exactly.
// Weight offsets (f16 index): enc0=0, enc1=724, bn=1020, dec1=1092, dec0=1672, total=1964

const ENC0_OFF=0, ENC1_OFF=724, BN_OFF=1020, DEC1_OFF=1092, DEC0_OFF=1672;
const TOTAL_F16=1964, TOTAL_U32=982;

// Inlined helpers — prepended to shaders that need them.
const H = `
fn get_w(base:u32,idx:u32)->f32{
  let i=base+idx; let v=unpack2x16float(weights[i>>1u]);
  return select(v.y,v.x,(i&1u)==0u);
}
fn unpack8(tex:texture_2d<u32>,c:vec2i)->array<f32,8>{
  let t=textureLoad(tex,c,0);
  let a=unpack2x16float(t.x);let b=unpack2x16float(t.y);
  let d=unpack2x16float(t.z);let e=unpack2x16float(t.w);
  return array<f32,8>(a.x,a.y,b.x,b.y,d.x,d.y,e.x,e.y);
}`;

// Pack simple image (albedo+mips+alpha) into feat_tex0/1
const PACK_SHADER=`
@group(0) @binding(0) var inp:texture_2d<f32>;
@group(0) @binding(1) var smp:sampler;
@group(0) @binding(2) var f0:texture_storage_2d<rgba32uint,write>;
@group(0) @binding(3) var f1:texture_storage_2d<rgba32uint,write>;
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let c=vec2i(id.xy); let d=vec2i(textureDimensions(inp));
  if(c.x>=d.x||c.y>=d.y){return;}
  let uv=(vec2f(c)+.5)/vec2f(d);
  let px=textureLoad(inp,c,0);
  let alb=px.rgb; let tr=1.-px.a;
  let m1=textureSampleLevel(inp,smp,uv,1.).rgb;
  let m2=textureSampleLevel(inp,smp,uv,2.).rgb;
  textureStore(f0,c,vec4u(pack2x16float(alb.rg),pack2x16float(vec2f(alb.b,0.)),
                           pack2x16float(vec2f(0.,0.)),pack2x16float(vec2f(0.,0.))));
  textureStore(f1,c,vec4u(pack4x8unorm(vec4f(0.,0.,0.,0.)),
                           pack4x8unorm(vec4f(m1.r,m1.g,m1.b,m2.r)),
                           pack4x8unorm(vec4f(m2.g,m2.b,1.,tr)),0u));
}`;

// Enc0: Conv(20→4, 3×3, zero-pad) + FiLM + ReLU → rgba16float
// Params (48 bytes): weight_offset u32 _pad×3 gamma vec4f beta vec4f
const ENC0_SHADER=H+`
struct P{wo:u32,_a:u32,_b:u32,_c:u32,g:vec4f,b:vec4f}
@group(0) @binding(0) var t0:texture_2d<u32>;
@group(0) @binding(1) var t1:texture_2d<u32>;
@group(0) @binding(2) var<storage,read> weights:array<u32>;
@group(0) @binding(3) var<uniform> p:P;
@group(0) @binding(4) var out:texture_storage_2d<rgba16float,write>;
fn feat(c:vec2i,d:vec2i)->array<f32,20>{
  if(c.x<0||c.y<0||c.x>=d.x||c.y>=d.y){return array<f32,20>(0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.);}
  let a=unpack2x16float(textureLoad(t0,c,0).x); let b=unpack2x16float(textureLoad(t0,c,0).y);
  let cc=unpack2x16float(textureLoad(t0,c,0).z);let dd=unpack2x16float(textureLoad(t0,c,0).w);
  let e=unpack4x8unorm(textureLoad(t1,c,0).x);  let f=unpack4x8unorm(textureLoad(t1,c,0).y);
  let g=unpack4x8unorm(textureLoad(t1,c,0).z);
  return array<f32,20>(a.x,a.y,b.x,b.y,cc.x,cc.y,dd.x,dd.y,e.x,e.y,e.z,e.w,f.x,f.y,f.z,f.w,g.x,g.y,g.z,g.w);
}
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let c=vec2i(id.xy); let d=vec2i(textureDimensions(t0));
  if(c.x>=d.x||c.y>=d.y){return;}
  const IN:u32=20u; const OUT:u32=4u;
  var o:array<f32,4>;
  for(var oc:u32=0u;oc<OUT;oc++){
    var s=get_w(p.wo,OUT*IN*9u+oc);
    for(var ky:i32=-1;ky<=1;ky++){for(var kx:i32=-1;kx<=1;kx++){
      let ft=feat(c+vec2i(kx,ky),d); let ki=u32(ky+1)*3u+u32(kx+1);
      for(var i:u32=0u;i<IN;i++){s+=get_w(p.wo,oc*IN*9u+i*9u+ki)*ft[i];}
    }}
    o[oc]=max(0.,p.g[oc]*s+p.b[oc]);
  }
  textureStore(out,c,vec4f(o[0],o[1],o[2],o[3]));
}`;

// Enc1: AvgPool(enc0) + Conv(4→8, 3×3) + FiLM + ReLU → rgba32uint half-res
// Params (80 bytes): wo u32 _pad×3 glo ghi blo bhi vec4f×4
const ENC1_SHADER=H+`
struct P{wo:u32,_a:u32,_b:u32,_c:u32,gl:vec4f,gh:vec4f,bl:vec4f,bh:vec4f}
@group(0) @binding(0) var e0:texture_2d<f32>;
@group(0) @binding(1) var<storage,read> weights:array<u32>;
@group(0) @binding(2) var<uniform> p:P;
@group(0) @binding(3) var out:texture_storage_2d<rgba32uint,write>;
fn fg(o:u32)->f32{if(o<4u){return p.gl[o];}return p.gh[o-4u];}
fn fb(o:u32)->f32{if(o<4u){return p.bl[o];}return p.bh[o-4u];}
fn avg(hc:vec2i,fd:vec2i)->array<f32,4>{
  let hd=fd/2; if(hc.x<0||hc.y<0||hc.x>=hd.x||hc.y>=hd.y){return array<f32,4>(0.,0.,0.,0.);}
  var s=vec4f(0.);
  for(var y:i32=0;y<2;y++){for(var x:i32=0;x<2;x++){s+=textureLoad(e0,clamp(hc*2+vec2i(x,y),vec2i(0),fd-vec2i(1)),0);}}
  let a=s*.25; return array<f32,4>(a.x,a.y,a.z,a.w);
}
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let fd=vec2i(textureDimensions(e0)); let hd=fd/2; let c=vec2i(id.xy);
  if(c.x>=hd.x||c.y>=hd.y){return;}
  const IN:u32=4u; const OUT:u32=8u;
  var o:array<f32,8>;
  for(var oc:u32=0u;oc<OUT;oc++){
    var s=get_w(p.wo,OUT*IN*9u+oc);
    for(var ky:i32=-1;ky<=1;ky++){for(var kx:i32=-1;kx<=1;kx++){
      let ft=avg(c+vec2i(kx,ky),fd); let ki=u32(ky+1)*3u+u32(kx+1);
      for(var i:u32=0u;i<IN;i++){s+=get_w(p.wo,oc*IN*9u+i*9u+ki)*ft[i];}
    }}
    o[oc]=max(0.,fg(oc)*s+fb(oc));
  }
  textureStore(out,c,vec4u(pack2x16float(vec2f(o[0],o[1])),pack2x16float(vec2f(o[2],o[3])),
                            pack2x16float(vec2f(o[4],o[5])),pack2x16float(vec2f(o[6],o[7]))));
}`;

// Bottleneck: AvgPool(enc1) + Conv(8→8, 1×1) + ReLU → rgba32uint quarter-res (no FiLM)
// Params (16 bytes): wo u32 _pad×3
const BN_SHADER=H+`
struct P{wo:u32,_a:u32,_b:u32,_c:u32}
@group(0) @binding(0) var e1:texture_2d<u32>;
@group(0) @binding(1) var<storage,read> weights:array<u32>;
@group(0) @binding(2) var<uniform> p:P;
@group(0) @binding(3) var out:texture_storage_2d<rgba32uint,write>;
fn avg(qc:vec2i,hd:vec2i)->array<f32,8>{
  let qd=hd/2; if(qc.x<0||qc.y<0||qc.x>=qd.x||qc.y>=qd.y){return array<f32,8>(0.,0.,0.,0.,0.,0.,0.,0.);}
  var s:array<f32,8>;
  for(var y:i32=0;y<2;y++){for(var x:i32=0;x<2;x++){
    let f=unpack8(e1,clamp(qc*2+vec2i(x,y),vec2i(0),hd-vec2i(1)));
    for(var i:u32=0u;i<8u;i++){s[i]+=f[i];}
  }}
  for(var i:u32=0u;i<8u;i++){s[i]*=.25;} return s;
}
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let hd=vec2i(textureDimensions(e1)); let qd=hd/2; let c=vec2i(id.xy);
  if(c.x>=qd.x||c.y>=qd.y){return;}
  let ft=avg(c,hd); var o:array<f32,8>;
  for(var oc:u32=0u;oc<8u;oc++){
    var s=get_w(p.wo,64u+oc);
    for(var i:u32=0u;i<8u;i++){s+=get_w(p.wo,oc*8u+i)*ft[i];}
    o[oc]=max(0.,s);
  }
  textureStore(out,c,vec4u(pack2x16float(vec2f(o[0],o[1])),pack2x16float(vec2f(o[2],o[3])),
                            pack2x16float(vec2f(o[4],o[5])),pack2x16float(vec2f(o[6],o[7]))));
}`;

// Dec1: NearestUp(bn)+cat(enc1_skip) → Conv(16→4,3×3) + FiLM + ReLU → rgba16float half-res
// Params (48 bytes): same layout as enc0
const DEC1_SHADER=H+`
struct P{wo:u32,_a:u32,_b:u32,_c:u32,g:vec4f,b:vec4f}
@group(0) @binding(0) var bn:texture_2d<u32>;
@group(0) @binding(1) var e1:texture_2d<u32>;
@group(0) @binding(2) var<storage,read> weights:array<u32>;
@group(0) @binding(3) var<uniform> p:P;
@group(0) @binding(4) var out:texture_storage_2d<rgba16float,write>;
fn cat(hc:vec2i,hd:vec2i)->array<f32,16>{
  if(hc.x<0||hc.y<0||hc.x>=hd.x||hc.y>=hd.y){return array<f32,16>(0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.);}
  let qd=hd/2; let b=unpack8(bn,clamp(hc/2,vec2i(0),qd-vec2i(1)));
  let s=unpack8(e1,hc);
  return array<f32,16>(b[0],b[1],b[2],b[3],b[4],b[5],b[6],b[7],s[0],s[1],s[2],s[3],s[4],s[5],s[6],s[7]);
}
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let hd=vec2i(textureDimensions(e1)); let c=vec2i(id.xy);
  if(c.x>=hd.x||c.y>=hd.y){return;}
  const IN:u32=16u; const OUT:u32=4u;
  var o:array<f32,4>;
  for(var oc:u32=0u;oc<OUT;oc++){
    var s=get_w(p.wo,OUT*IN*9u+oc);
    for(var ky:i32=-1;ky<=1;ky++){for(var kx:i32=-1;kx<=1;kx++){
      let ft=cat(c+vec2i(kx,ky),hd); let ki=u32(ky+1)*3u+u32(kx+1);
      for(var i:u32=0u;i<IN;i++){s+=get_w(p.wo,oc*IN*9u+i*9u+ki)*ft[i];}
    }}
    o[oc]=max(0.,p.g[oc]*s+p.b[oc]);
  }
  textureStore(out,c,vec4f(o[0],o[1],o[2],o[3]));
}`;

// Dec0: NearestUp(dec1)+cat(enc0_skip) → Conv(8→4,3×3) + FiLM + ReLU + Sigmoid → rgba16float
// Params (48 bytes): same layout as enc0
const DEC0_SHADER=H+`
struct P{wo:u32,_a:u32,_b:u32,_c:u32,g:vec4f,b:vec4f}
@group(0) @binding(0) var d1:texture_2d<f32>;
@group(0) @binding(1) var e0:texture_2d<f32>;
@group(0) @binding(2) var<storage,read> weights:array<u32>;
@group(0) @binding(3) var<uniform> p:P;
@group(0) @binding(4) var out:texture_storage_2d<rgba16float,write>;
fn cat(c:vec2i,fd:vec2i)->array<f32,8>{
  if(c.x<0||c.y<0||c.x>=fd.x||c.y>=fd.y){return array<f32,8>(0.,0.,0.,0.,0.,0.,0.,0.);}
  let hd=vec2i(textureDimensions(d1));
  let a=textureLoad(d1,clamp(c/2,vec2i(0),hd-vec2i(1)),0);
  let b=textureLoad(e0,c,0);
  return array<f32,8>(a.x,a.y,a.z,a.w,b.x,b.y,b.z,b.w);
}
@compute @workgroup_size(8,8)
fn main(@builtin(global_invocation_id) id:vec3u){
  let fd=vec2i(textureDimensions(e0)); let c=vec2i(id.xy);
  if(c.x>=fd.x||c.y>=fd.y){return;}
  const IN:u32=8u; const OUT:u32=4u;
  var o:array<f32,4>;
  for(var oc:u32=0u;oc<OUT;oc++){
    var s=get_w(p.wo,OUT*IN*9u+oc);
    for(var ky:i32=-1;ky<=1;ky++){for(var kx:i32=-1;kx<=1;kx++){
      let ft=cat(c+vec2i(kx,ky),fd); let ki=u32(ky+1)*3u+u32(kx+1);
      for(var i:u32=0u;i<IN;i++){s+=get_w(p.wo,oc*IN*9u+i*9u+ki)*ft[i];}
    }}
    let v=max(0.,p.g[oc]*s+p.b[oc]);
    o[oc]=1./(1.+exp(-v));
  }
  textureStore(out,c,vec4f(o[0],o[1],o[2],o[3]));
}`;

// Display: rgba16float output → canvas (mode 0=cnn,1=orig,2=diff, blend)
const DISP_SHADER=`
@group(0) @binding(0) var otex:texture_2d<f32>;
@group(0) @binding(1) var itex:texture_2d<f32>;
@group(0) @binding(2) var<uniform> pr:vec4f; // x=mode y=blend
@vertex fn vs(@builtin(vertex_index) i:u32)->@builtin(position) vec4f{
  var p=array<vec2f,6>(vec2f(-1.,-1.),vec2f(1.,-1.),vec2f(-1.,1.),vec2f(-1.,1.),vec2f(1.,-1.),vec2f(1.,1.));
  return vec4f(p[i],0.,1.);
}
@fragment fn fs(@builtin(position) pos:vec4f)->@location(0) vec4f{
  let c=vec2i(pos.xy); let m=u32(pr.x);
  let orig=textureLoad(itex,c,0).rgb; let cnn=textureLoad(otex,c,0).rgb;
  if(m==1u){return vec4f(orig,1.);}
  if(m==2u){return vec4f(abs(cnn-orig)*10.,1.);}
  return vec4f(mix(orig,cnn,pr.y),1.);
}`;

// Viz f32: show one channel of rgba16float layer
const VIZ_F32=`
@group(0) @binding(0) var t:texture_2d<f32>;
@group(0) @binding(1) var<uniform> ch:u32;
@vertex fn vs(@builtin(vertex_index) i:u32)->@builtin(position) vec4f{
  var p=array<vec2f,6>(vec2f(-1.,-1.),vec2f(1.,-1.),vec2f(-1.,1.),vec2f(-1.,1.),vec2f(1.,-1.),vec2f(1.,1.));
  return vec4f(p[i],0.,1.);
}
@fragment fn fs(@builtin(position) pos:vec4f)->@location(0) vec4f{
  let v=textureLoad(t,vec2i(pos.xy),0); var a=array<f32,4>(v.x,v.y,v.z,v.w);
  let x=clamp(a[min(ch,3u)],0.,1.); return vec4f(x,x,x,1.);
}`;

// Viz u32: show one f16 channel of rgba32uint layer (8 channels packed)
const VIZ_U32=`
@group(0) @binding(0) var t:texture_2d<u32>;
@group(0) @binding(1) var<uniform> ch:u32;
@vertex fn vs(@builtin(vertex_index) i:u32)->@builtin(position) vec4f{
  var p=array<vec2f,6>(vec2f(-1.,-1.),vec2f(1.,-1.),vec2f(-1.,1.),vec2f(-1.,1.),vec2f(1.,-1.),vec2f(1.,1.));
  return vec4f(p[i],0.,1.);
}
@fragment fn fs(@builtin(position) pos:vec4f)->@location(0) vec4f{
  let t2=textureLoad(t,vec2i(pos.xy),0);
  let a=unpack2x16float(t2.x);let b=unpack2x16float(t2.y);
  let c=unpack2x16float(t2.z);let d=unpack2x16float(t2.w);
  var v=array<f32,8>(a.x,a.y,b.x,b.y,c.x,c.y,d.x,d.y);
  let x=clamp(v[min(ch,7u)],0.,1.); return vec4f(x,x,x,1.);
}`;