"""FBX 减面 CLI：减到指定三角面数并 Smart UV 重展，输出 <名>_low.fbx。
用法：python model_decimate.py src/well1500.fbx --tris 5000 [-o dir] [--blender exe]"""
import argparse
import os

from mt_run import find_blender, run_blender_script


def main():
    ap = argparse.ArgumentParser(description=__doc__)
    ap.add_argument("input", help="FBX 文件")
    ap.add_argument("--tris", type=int, required=True, help="目标三角面数")
    ap.add_argument("-o", "--out", default=None, help="输出目录（默认源文件同目录）")
    ap.add_argument("--blender", default=None)
    args = ap.parse_args()

    blender = find_blender(args.blender)
    name = os.path.splitext(os.path.basename(args.input))[0]
    outdir = args.out or os.path.dirname(os.path.abspath(args.input))
    out_fbx = os.path.join(outdir, name + "_low.fbx")
    s = run_blender_script(blender, "bl_decimate.py",
                           [args.input, out_fbx, str(args.tris)])
    print("== %s: %d -> %d 面（目标 %d）-> %s" %
          (s["src"], s["tris_before"], s["tris_after"], s["target"], out_fbx))
    for w in s["warnings"]:
        print("  [警告] %s" % w)


if __name__ == "__main__":
    main()