"""Check if a hair mesh is symmetric across the X axis."""
import sys
import bpy

if __name__ == "__main__":
    argv = sys.argv
    if "--" not in argv:
        sys.exit(1)
    path = argv[argv.index("--") + 1]

    bpy.ops.wm.read_factory_settings(use_empty=True)
    bpy.ops.import_scene.gltf(filepath=path)

    for obj in bpy.context.scene.objects:
        if obj.type != 'MESH' or 'Hair' not in obj.name:
            continue
        verts = obj.data.vertices
        xs = [v.co.x for v in verts]
        zs = [v.co.z for v in verts]
        print(f"{obj.name}: {len(verts)} verts")
        print(f"  X range: {min(xs):.4f} to {max(xs):.4f}")
        print(f"  Z range: {min(zs):.4f} to {max(zs):.4f}")
        left = sum(1 for x in xs if x > 0.01)
        right = sum(1 for x in xs if x < -0.01)
        center = sum(1 for x in xs if abs(x) <= 0.01)
        print(f"  left(+X): {left}, right(-X): {right}, center: {center}")

        # Check normals for consistency
        normals = [v.normal for v in verts]
        outward = sum(1 for n in normals if n.length() > 0.5)
        print(f"  verts with normals: {outward}/{len(verts)}")