"""Isolated A/B trial of the installed Studio baker; never edits the shared backend.

Blender -- --job DIR --output DIR --ray-mode legacy|adaptive
Uses the same source geometry and Studio UVs, keeping baked/exported normals consistent.
"""
import argparse
import hashlib
import json
import sys
from pathlib import Path

parser = argparse.ArgumentParser()
parser.add_argument('--job', required=True)
parser.add_argument('--output', required=True)
parser.add_argument('--ray-mode', choices=['legacy', 'adaptive'], default='adaptive')
args = parser.parse_args(sys.argv[sys.argv.index('--') + 1:])
job, out = Path(args.job).resolve(), Path(args.output).resolve()
out.mkdir(parents=True, exist_ok=True)
backend = Path('D:/UD/AI/XModel/LLM3DGraphics/backend/blender_lowpoly_bake.py')
source = backend.read_text(encoding='utf-8')
baseline_hash = hashlib.sha256(backend.read_bytes()).hexdigest()
needle = 'outward_faces = bias_normals_outward(low)'
assert source.count(needle) == 1
source = source.replace(needle, 'outward_faces = 0  # Preserve the same tangent basis used by the normal bake')
if args.ray_mode == 'adaptive':
    needle = 'ray = estimate_ray_distance(low)'
    assert source.count(needle) == 1
    source = source.replace(needle, '''
# Trial: surface separation rather than a fixed 4% of the full bounding box.
_bvh = BVHTree.FromObject(high, bpy.context.evaluated_depsgraph_get())
_distances = []
for _poly in low.data.polygons:
    _hit = _bvh.find_nearest(low.matrix_world @ _poly.center)
    if _hit[0] is not None:
        _distances.append(float(_hit[3]))
_diag = float(low.dimensions.length)
_p99 = float(np.percentile(_distances, 99))
ray = min(max(_p99 * 1.5, _diag * .0005), _diag * .01)
print('TRIAL_PROJECTION ' + json.dumps(dict(p99=_p99, bbox_diagonal=_diag,
    cage_extrusion=ray, legacy_cage_extrusion=_diag*.04)))
''')
sys.argv = [str(backend), '--', str(job/'model.glb'), str(out/'model_baked.glb'),
            '1', '1024', str(job/'model_lowpoly_uv.glb')]
(out/'baker_snapshot.py').write_text(source, encoding='utf-8')
(out/'trial_settings.json').write_text(json.dumps(dict(
    source_job=str(job), shared_backend_sha256=baseline_hash,
    ray_mode=args.ray_mode, post_bake_normal_bias=False,
    preserve_studio_uv=True, source_unchanged=True), indent=2), encoding='utf-8')
exec(compile(source, str(out/'baker_snapshot.py'), 'exec'),
     {'__file__': str(backend), '__name__': '__main__'})