#!/usr/bin/env bash
set -euo pipefail
# [ "${DEBUG:-0}" = "1" ] && set -x

export NCCL_DEBUG=INFO
# 如走 IB/RoCE，请按实际网卡开启（示例）：
# export NCCL_IB_HCA="mlx5_0,mlx5_1"
# export NCCL_SOCKET_IFNAME="ib0"
# 纯以太：
# export NCCL_SOCKET_IFNAME="eth0"

# 解析脚本目录，避免相对路径问题
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
DS_CONFIG="${DS_CONFIG:-$SCRIPT_DIR/ds_config_zero3.json}"

# ==== 超参数（本地路径；可用 VAR=xxx ./run_ds.sh 覆写）====
MODEL_NAME_OR_PATH="${MODEL_NAME_OR_PATH:-/home/test/Qwen3-1.7B}"

# 明确区分训练/评测文件（可按需改成通配符）
DATA_GLOB="${DATA_GLOB:-$HOME/datasets/my_corpus/train.jsonl}"
EVAL_DATA_GLOB="${EVAL_DATA_GLOB:-$HOME/datasets/my_corpus/test.jsonl}"

OUTDIR="${OUTDIR:-$HOME/checkpoints/run-qwen3-1.7b}"
SEQ_LEN="${SEQ_LEN:-512}"
LR="${LR:-2e-5}"
GAS="${GAS:-1}"
LOG_STEPS="${LOG_STEPS:-10}"
SAVE_STEPS="${SAVE_STEPS:-10}"
MAX_STEPS="${MAX_STEPS:-62}"

# 轻量校验（只在发起节点做；各 rank 在脚本里也会 mkdir）
[ -d "$MODEL_NAME_OR_PATH" ] || { echo "ERR: model not found at $MODEL_NAME_OR_PATH"; exit 1; }
[ -f "$DS_CONFIG" ] || { echo "ERR: deepspeed config not found at $DS_CONFIG"; exit 1; }

# 检查训练集是否能匹配到
shopt -s nullglob
train_matches=( $DATA_GLOB )
if [ ${#train_matches[@]} -eq 0 ]; then
  echo "WARN: no files matched by DATA_GLOB=$DATA_GLOB on this node (确保每台机器该路径下有数据)"
fi

# 检查评测集（可为空；若为空则不传 --eval_data_glob）
eval_matches=()
if [ -n "${EVAL_DATA_GLOB:-}" ]; then
  eval_matches=( $EVAL_DATA_GLOB )
  if [ ${#eval_matches[@]} -eq 0 ]; then
    echo "WARN: no files matched by EVAL_DATA_GLOB=$EVAL_DATA_GLOB on this node (将不进行评测)"
  fi
fi
shopt -u nullglob

mkdir -p "${OUTDIR}"

# 组装参数（只有 eval 有效才加）
args=(
  --model_name_or_path "${MODEL_NAME_OR_PATH}"
  --data_glob "${DATA_GLOB}"
  --output_dir "${OUTDIR}"
  --seq_len "${SEQ_LEN}"
  --learning_rate "${LR}"
  --gradient_accumulation_steps "${GAS}"
  --per_device_train_batch_size 1
  --warmup_ratio 0.02
  --weight_decay 0.1
  --max_steps "${MAX_STEPS}"
  --log_interval "${LOG_STEPS}"
  --save_steps "${SAVE_STEPS}"
  --deepspeed "${DS_CONFIG}"
  --gradient_checkpointing
  --bf16
)
if [ ${#eval_matches[@]} -gt 0 ]; then
  args+=( --eval_data_glob "${EVAL_DATA_GLOB}" )
fi

# ==== 多机 DeepSpeed ====
deepspeed --hostfile "$SCRIPT_DIR/hostfile" "$SCRIPT_DIR/train_sft_ds.py" "${args[@]}"