#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "${ROOT_DIR}"

export http_proxy="${http_proxy:-http://100.72.0.101:8888}"
export https_proxy="${https_proxy:-http://100.72.0.101:8888}"
export HTTP_PROXY="${HTTP_PROXY:-${http_proxy}}"
export HTTPS_PROXY="${HTTPS_PROXY:-${https_proxy}}"
export HF_ENDPOINT="${HF_ENDPOINT:-https://hf-mirror.com}"
export TOKENIZERS_PARALLELISM="${TOKENIZERS_PARALLELISM:-false}"

if [[ -f .venv/bin/activate ]]; then
  source .venv/bin/activate
elif [[ "${DRY_RUN:-0}" != "1" ]]; then
  echo "Missing .venv. Run ./scripts/setup_env.sh first." >&2
  exit 2
fi
mkdir -p outputs runs logs

TRAIN_JSONL="${TRAIN_JSONL:-data/processed/training_probe/train.jsonl}"
VAL_JSONL="${VAL_JSONL:-data/processed/training_probe/validation.jsonl}"
MAX_LENGTH="${MAX_LENGTH:-262144}"
SAVE_STEPS="${SAVE_STEPS:-1000}"
EVAL_STEPS="${EVAL_STEPS:-1000}"
LOGGING_STEPS="${LOGGING_STEPS:-1}"
GRAD_ACCUM_STEPS="${GRAD_ACCUM_STEPS:-1}"
PER_DEVICE_BATCH_SIZE="${PER_DEVICE_BATCH_SIZE:-1}"
NUM_EPOCHS="${NUM_EPOCHS:-1}"
LEARNING_RATE="${LEARNING_RATE:-1e-5}"
WARMUP_RATIO="${WARMUP_RATIO:-0.1}"
LORA_RANK="${LORA_RANK:-32}"

require_file() {
  if [[ ! -f "$1" ]]; then
    echo "Missing required file: $1" >&2
    exit 2
  fi
}

run_swift_train() {
  local model_path="$1"
  local train_type="$2"
  local run_name="$3"
  local output_dir="outputs/${run_name}"
  local tb_dir="runs/${run_name}"
  local log_file="logs/${run_name}.log"

  require_file "${TRAIN_JSONL}"
  require_file "${VAL_JSONL}"
  mkdir -p "${output_dir}" "${tb_dir}" logs

  local cmd=(
    swift sft
    --model "${model_path}"
    --dataset "${TRAIN_JSONL}"
    --val_dataset "${VAL_JSONL}"
    --train_type "${train_type}"
    --torch_dtype bfloat16
    --num_train_epochs "${NUM_EPOCHS}"
    --per_device_train_batch_size "${PER_DEVICE_BATCH_SIZE}"
    --per_device_eval_batch_size 1
    --gradient_accumulation_steps "${GRAD_ACCUM_STEPS}"
    --learning_rate "${LEARNING_RATE}"
    --warmup_ratio "${WARMUP_RATIO}"
    --max_length "${MAX_LENGTH}"
    --save_steps "${SAVE_STEPS}"
    --eval_steps "${EVAL_STEPS}"
    --logging_steps "${LOGGING_STEPS}"
    --report_to tensorboard
    --logging_dir "${tb_dir}"
    --output_dir "${output_dir}"
    --save_total_limit "${SAVE_TOTAL_LIMIT:-3}"
    --dataloader_num_workers "${DATALOADER_NUM_WORKERS:-4}"
  )

  if [[ "${train_type}" == "lora" ]]; then
    cmd+=(--lora_rank "${LORA_RANK}")
  fi

  printf '%q ' "${cmd[@]}" | tee "${log_file}.cmd"
  echo
  if [[ "${DRY_RUN:-0}" == "1" ]]; then
    return 0
  fi
  "${cmd[@]}" 2>&1 | tee "${log_file}"
}