import bpy
import sys
import os
import argparse

glb_input = "trellis_out/sample.ply"
obj_output = "obj_output/sample.obj"


def parse_args():
    argv = sys.argv
    argv = argv[argv.index("--") + 1:] if "--" in argv else []
    p = argparse.ArgumentParser()
    p.add_argument("-i", "--input", default=True)
    p.add_argument("-o", "--output", required=True)
    return p.parse_args(argv)


def clean():
    bpy.ops.object.select_all(action='SELECT')
    bpy.ops.object.delete(use_global=False)


def main():
    args = parse_args()
    clean()

    bpy.ops.import_scene.gltf(filepath=args.input)  # 支持 .glb/.gltf

    # 只保留 mesh，并合并成一个（符合你“单资产”假设）
    meshes = [o for o in bpy.context.scene.objects if o.type == "MESH"]
    if not meshes:
        raise RuntimeError("No mesh objects found in GLB/GLTF.")
    bpy.ops.object.select_all(action='DESELECT')
    for o in meshes:
        o.select_set(True)
    bpy.context.view_layer.objects.active = meshes[0]
    if len(meshes) > 1:
        bpy.ops.object.join()

    obj = bpy.context.view_layer.objects.active
    obj.select_set(True)

    out_dir = os.path.dirname(args.output)
    if out_dir:
        os.makedirs(out_dir, exist_ok=True)

    # bpy.ops.wm.obj_export(
    #     filepath=args.output,
    #     export_selected_objects=True,
    #     export_normals=True,
    #     export_uv=True,
    # )

    bpy.ops.export_scene.obj(
        filepath=args.output,
        use_selection=True,  # 只导出选中的对象
        use_normals=True,
        use_uvs=True,
        use_materials=True,  # 根据需要改（你原来没导出材质）
        axis_forward='-Z',  # glTF 通常是 -Z forward，Y up，可根据需要调整
        axis_up='Y',
        # keep_vertex_order=True,    # 可选：保持顶点顺序
    )


if __name__ == "__main__":
    main()