"""Default container command: print usage and refuse to start a silent toy run."""

from __future__ import annotations

HELP = """kda image: one GPU runtime for train / monitor / eval.

Do not docker run without a command — toy overfit is not the default.

Volumes (host → container):
  ./ckpts            → /workspace/kda/ckpts
  pretrain corpus    → /data/pretrain   (ro)
  SFT bitext         → /data/sft        (ro)
  frozen eval        → /data/eval       (ro)
  HF tokenizer cache → /cache/huggingface
  SWANLAB_API_KEY    via -e  (never COPY into the image)

Examples:
  docker run --rm --gpus all kda:<tag> python train.py
  docker run --rm --gpus all -e SWANLAB_API_KEY \\
    -v "$PWD/ckpts:/workspace/kda/ckpts" \\
    kda:<tag> python train_k3.py --preset toy --attnres off
  docker run --rm --gpus all kda:<tag> swanlab ping
  docker run --rm --gpus all \\
    -v "$PWD/ckpts:/workspace/kda/ckpts" -v "$PWD/data/eval:/data/eval:ro" \\
    kda:<tag> python -m kda.training.eval_mt \\
      --ckpt /workspace/kda/ckpts/k3_wiki.pt \\
      --src /data/eval/zh2en.src.txt --ref /data/eval/zh2en.ref.txt \\
      --target-lang en
  docker run --rm --gpus all \\
    -v "$PWD/ckpts:/workspace/kda/ckpts" -v "$PWD/data/sft:/data/sft:ro" \\
    kda:<tag> python train_sft.py --ckpt /workspace/kda/ckpts/k3_wiki.pt \\
      --data /data/sft/toy.jsonl
  docker run --rm --gpus all kda:<tag> python -m pytest -q
"""


def main() -> None:
    print(HELP)
    raise SystemExit(2)


if __name__ == "__main__":
    main()