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

BINARY="${BINARY:-/opt/lingniu-go-native/current/stats-backfill}"
DATE_FROM="${DATE_FROM:-}"
DATE_TO="${DATE_TO:-}"
PARALLEL="${PARALLEL:-4}"
APPLY=false
WORK_DIR=""

usage() {
  cat <<'USAGE'
Usage: replay-pure-hydrogen-mileage.sh --date-from YYYY-MM-DD --date-to YYYY-MM-DD [options]

Options:
  --apply             Write the rebuilt daily mileage rows. Default is dry-run.
  --parallel N        Concurrent VIN workers. Default: 4.
  --binary PATH       stats-backfill binary path.
  --work-dir PATH     Keep VIN lists and per-VIN logs in this directory.
USAGE
}

if [[ "${1:-}" == "--worker" ]]; then
  vin="$2"
  dry_run="$3"
  log_dir="$4"
  env \
    BACKFILL_METHOD=scan \
    BACKFILL_DRY_RUN="$dry_run" \
    BACKFILL_DATE_FROM="$DATE_FROM" \
    BACKFILL_DATE_TO="$DATE_TO" \
    BACKFILL_PROTOCOLS=GB32960 \
    BACKFILL_VINS="$vin" \
    BACKFILL_PROGRESS_EVERY=100000 \
    "$BINARY" >"$log_dir/$vin.log" 2>&1
  printf 'completed vin=%s\n' "$vin"
  exit 0
fi

while (($#)); do
  case "$1" in
    --date-from) DATE_FROM="$2"; shift 2 ;;
    --date-to) DATE_TO="$2"; shift 2 ;;
    --parallel) PARALLEL="$2"; shift 2 ;;
    --binary) BINARY="$2"; shift 2 ;;
    --work-dir) WORK_DIR="$2"; shift 2 ;;
    --apply) APPLY=true; shift ;;
    -h|--help) usage; exit 0 ;;
    *) echo "unknown argument: $1" >&2; usage >&2; exit 2 ;;
  esac
done

if [[ ! "$DATE_FROM" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ || ! "$DATE_TO" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
  echo "--date-from and --date-to are required" >&2
  exit 2
fi
if [[ ! "$PARALLEL" =~ ^[1-9][0-9]*$ ]]; then
  echo "--parallel must be a positive integer" >&2
  exit 2
fi
if [[ ! -x "$BINARY" ]]; then
  echo "stats-backfill is not executable: $BINARY" >&2
  exit 2
fi

if [[ -z "$WORK_DIR" ]]; then
  WORK_DIR="$(mktemp -d /tmp/pure-hydrogen-replay.XXXXXX)"
else
  mkdir -p "$WORK_DIR"
fi
LOG_DIR="$WORK_DIR/logs"
mkdir -p "$LOG_DIR"

hydrogen_vins="$WORK_DIR/hydrogen-vins.txt"
active_vins="$WORK_DIR/active-gb32960-vins.txt"
target_vins="$WORK_DIR/target-vins.txt"
pending_vins="$WORK_DIR/pending-vins.txt"

BACKFILL_LIST_HYDROGEN_VINS=true "$BINARY" | LC_ALL=C sort -u >"$hydrogen_vins"
env \
  BACKFILL_LIST_ACTIVE_VINS=true \
  BACKFILL_DATE_FROM="$DATE_FROM" \
  BACKFILL_DATE_TO="$DATE_TO" \
  BACKFILL_PROTOCOLS=GB32960 \
  "$BINARY" | LC_ALL=C sort -u >"$active_vins"
comm -12 "$hydrogen_vins" "$active_vins" >"$target_vins"

target_count="$(wc -l <"$target_vins" | tr -d ' ')"
: >"$pending_vins"
while IFS= read -r vin; do
  if [[ -f "$LOG_DIR/$vin.log" ]] && grep -q 'stats backfill complete' "$LOG_DIR/$vin.log"; then
    continue
  fi
  echo "$vin" >>"$pending_vins"
done <"$target_vins"
pending_count="$(wc -l <"$pending_vins" | tr -d ' ')"
dry_run=true
if [[ "$APPLY" == true ]]; then
  dry_run=false
fi
printf 'pure-hydrogen replay: date=%s..%s vins=%s pending=%s parallel=%s dry_run=%s work_dir=%s\n' \
  "$DATE_FROM" "$DATE_TO" "$target_count" "$pending_count" "$PARALLEL" "$dry_run" "$WORK_DIR"

if [[ "$pending_count" == "0" ]]; then
  printf 'pure-hydrogen replay complete: vins=%s logs=%s\n' "$target_count" "$LOG_DIR"
  exit 0
fi

export BINARY DATE_FROM DATE_TO
set +e
xargs -I '{}' -P "$PARALLEL" "$0" --worker '{}' "$dry_run" "$LOG_DIR" <"$pending_vins"
xargs_status=$?
set -e

failed_vins="$WORK_DIR/failed-vins.txt"
: >"$failed_vins"
while IFS= read -r vin; do
  if [[ ! -f "$LOG_DIR/$vin.log" ]] || ! grep -q 'stats backfill complete' "$LOG_DIR/$vin.log"; then
    echo "$vin" >>"$failed_vins"
  fi
done <"$target_vins"
if [[ "$xargs_status" != "0" || -s "$failed_vins" ]]; then
  echo "replay incomplete; inspect $failed_vins and $LOG_DIR" >&2
  exit 1
fi
printf 'pure-hydrogen replay complete: vins=%s logs=%s\n' "$target_count" "$LOG_DIR"