"""Independent field checks and mesh-refinement audits; no training-set tuning."""
import json
from pathlib import Path
import numpy as np
import h5py
from generate import ROOT, run, parameters

def metrics(kind,folder,p):
    with h5py.File(folder/"fields.h5") as f:
        coords=f["Mesh/ReferenceGeometry"][:]
        cells=f["Mesh/Topology"][:]
        out={"nodes":len(coords),"cells":len(cells)}
        def finite(name,obj):
            if isinstance(obj,h5py.Dataset): assert np.isfinite(obj[:]).all(),name
        f.visititems(finite)
        if kind=="notch":
            center=coords[cells[:,:3]].mean(1)
            v=f["Frames/0000/Cell/MISES"][:]
            region=(center[:,0]>.3*p[0])&(center[:,0]<.7*p[0])
            out["central_cell_mises_max_pa"]=float(v[region].max())
        elif kind=="heat":
            vals=np.load(folder/"field.npz")["values"][:,0]
            assert vals.min()>299.99
            out["peak_temperature_rise_k"]=float(vals.max()-300)
        else:
            out["radial_displacement_max_m"]=float(f["Frames/0000/Point/U"][:,0].max())
        return out

if __name__=="__main__":
    import argparse
    ap=argparse.ArgumentParser(); ap.add_argument("kind"); ap.add_argument("--refinement",type=int,default=1)
    args=ap.parse_args(); kind=args.kind; ref=args.refinement
    root=ROOT/"generated"/(kind if ref==1 else kind+f"_r{ref}")
    pars=parameters(kind,256)
    indices=[0,31,64,95,128,159,192,255]
    audit=[]
    for i in indices:
        base=root/"samples"/f"{i:05d}"
        if not (base/"sample.json").exists():
            base=root/"mesh_audit_coarse"/f"{i:05d}"
            run(kind,pars[i],base,ref)
        fine=root/"mesh_audit"/f"{i:05d}"
        if not (fine/"sample.json").exists(): run(kind,pars[i],fine,2*ref)
        a=metrics(kind,base,pars[i]); b=metrics(kind,fine,pars[i]); key=list(a)[-1]
        err=abs(a[key]-b[key])/abs(b[key])
        audit.append({"id":f"{i:05d}","coarse":a,"fine":b,"relative_change":err,"quantity":key})
        print(kind,i,"mesh_change",err,flush=True)
    (root/"mesh_audit.json").write_text(json.dumps(audit,indent=2))