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

[ -r "./env-vol_prepare" ] && . ./env-vol_prepare

VOL_NAME="${VOL_NAME:?ERROR: VOL_NAME must be set (Hetzner volume name)}"
VOL_MOUNT_PATH="${VOL_MOUNT_PATH:?ERROR: VOL_MOUNT_PATH must be set}"
VOL_FS_TYPE="${VOL_FS_TYPE:-ext4}"
VOL_LABEL_PREFIX="${VOL_LABEL_PREFIX:-scsi-0HC_Volume_}"
VOL_FSTAB_OPTIONS="${VOL_FSTAB_OPTIONS:-defaults,nofail,discard 0 0}"

DEVICE="/dev/disk/by-id/${VOL_LABEL_PREFIX}${VOL_NAME}"

# Hetzner may expose volumes by numeric ID rather than name.
# When the name-based path is absent, find the HC volume device by scanning.
if [ ! -e "${DEVICE}" ]; then
  HC_DEVICE=$(ls /dev/disk/by-id/ 2>/dev/null \
    | grep "^scsi-0HC_Volume_[0-9]" \
    | grep -v "\-part" \
    | head -1)
  if [ -n "${HC_DEVICE}" ]; then
    DEVICE="/dev/disk/by-id/${HC_DEVICE}"
    echo "=== vol-prepare: name-based path not found, resolved device: ${DEVICE} ==="
  fi
fi

echo "=== vol-prepare: volume=${VOL_NAME}, device=${DEVICE}, mount=${VOL_MOUNT_PATH} ==="

if [ ! -e "${DEVICE}" ]; then
  echo "ERROR: device ${DEVICE} not found." >&2
  echo "       Hetzner volume '${VOL_NAME}' must be attached to this server before this taskserv runs." >&2
  echo "       Available block devices by-id:" >&2
  ls /dev/disk/by-id/ 2>/dev/null | grep -i hc || echo "  (none found)" >&2
  exit 1
fi

# Format only if the device has no existing filesystem
EXISTING_FS="$(blkid -o value -s TYPE "${DEVICE}" 2>/dev/null || echo "")"
if [ -z "${EXISTING_FS}" ]; then
  echo "=== vol-prepare: no filesystem detected — formatting as ${VOL_FS_TYPE} ==="
  mkfs."${VOL_FS_TYPE}" -F "${DEVICE}"
  echo "=== vol-prepare: formatted ${DEVICE} as ${VOL_FS_TYPE} ==="
else
  echo "=== vol-prepare: existing filesystem (${EXISTING_FS}) found — skipping format ==="
fi

# Create mount point
mkdir -p "${VOL_MOUNT_PATH}"

# Mount if not already mounted
if ! mountpoint -q "${VOL_MOUNT_PATH}"; then
  echo "=== vol-prepare: mounting ${DEVICE} → ${VOL_MOUNT_PATH} ==="
  mount "${DEVICE}" "${VOL_MOUNT_PATH}"
else
  echo "=== vol-prepare: ${VOL_MOUNT_PATH} already mounted — skipping mount ==="
fi

# Add to /etc/fstab for persistence across reboots (idempotent)
FSTAB_ENTRY="${DEVICE}  ${VOL_MOUNT_PATH}  ${VOL_FS_TYPE}  ${VOL_FSTAB_OPTIONS}"
if ! grep -qF "${DEVICE}" /etc/fstab; then
  echo "=== vol-prepare: adding fstab entry ==="
  echo "${FSTAB_ENTRY}" >> /etc/fstab
else
  echo "=== vol-prepare: fstab entry already present — skipping ==="
fi

echo "=== vol-prepare: ready (device=${DEVICE}, mount=${VOL_MOUNT_PATH}, fs=${VOL_FS_TYPE}) ==="