#!/bin/sh
# rfs mount modules flist over /lib/modules/$(uname -r) (plain S3 route embedded in the .fl)
# Looks for modules-$(uname -r).fl in known locations; can be overridden via MODULES_FLIST env.

set -eu

log() { echo "[rfs-modules] $*"; }

RFS_BIN="${RFS_BIN:-rfs}"
KVER="$(uname -r)"
TARGET="/lib/modules/${KVER}"
# Accept both FLISTS_BASE_URL and FLIST_BASE_URL (alias); prefer FLISTS_BASE_URL
if [ -n "${FLISTS_BASE_URL:-}" ]; then
  BASE_URL="${FLISTS_BASE_URL}"
elif [ -n "${FLIST_BASE_URL:-}" ]; then
  BASE_URL="${FLIST_BASE_URL}"
else
  BASE_URL="https://zos.grid.tf/store/flists"
fi

# HTTP readiness helper: wait until BASE_URL responds to HTTP(S)
wait_for_http() {
  url="$1"
  tries="${2:-60}"
  delay="${3:-2}"
  i=0
  while [ "$i" -lt "$tries" ]; do
    if command -v wget >/dev/null 2>&1; then
      if wget -q --spider "$url"; then
        return 0
      fi
    elif command -v busybox >/dev/null 2>&1; then
      if busybox wget -q --spider "$url"; then
        return 0
      fi
    fi
    i=$((i+1))
    log "waiting for $url (attempt $i/$tries)"
    sleep "$delay"
  done
  return 1
}

# Allow override via env
if [ -n "${MODULES_FLIST:-}" ] && [ -f "${MODULES_FLIST}" ]; then
  FL="${MODULES_FLIST}"
else
  # Candidate paths for the flist manifest
  for p in \
    "/etc/rfs/modules-${KVER}.fl" \
    "/var/lib/rfs/modules-${KVER}.fl" \
    "/root/modules-${KVER}.fl" \
    "/modules-${KVER}.fl" \
    ; do
    if [ -f "$p" ]; then
      FL="$p"
      break
    fi
  done
fi

if [ -z "${FL:-}" ]; then
  # Try remote fetch as a fallback (modules-<uname -r>-Zero-OS.fl)
  mkdir -p /etc/rfs
  FL="/etc/rfs/modules-${KVER}.fl"
  URL="${BASE_URL%/}/modules-${KVER}-Zero-OS.fl"
  log "modules-${KVER}.fl not found locally; will fetch ${URL}"

  # Probe BASE_URL root so DNS/HTTP are ready before fetch
  ROOT_URL="${BASE_URL%/}/"
  if ! wait_for_http "$ROOT_URL" 60 2; then
    log "BASE_URL not reachable yet: ${ROOT_URL}; continuing to attempt fetch anyway"
  fi
  log "fetching ${URL}"

  if command -v wget >/dev/null 2>&1; then
    wget -q -O "${FL}" "${URL}" || true
  elif command -v busybox >/dev/null 2>&1; then
    busybox wget -q -O "${FL}" "${URL}" || true
  else
    log "no wget available to fetch ${URL}"
  fi

  if [ ! -s "${FL}" ]; then
    log "failed to fetch ${URL}; skipping mount"
    exit 0
  fi
fi

# Ensure target directory exists
mkdir -p "$TARGET"

# Skip if already mounted
if mountpoint -q "$TARGET" 2>/dev/null; then
  log "already mounted: $TARGET"
  exit 0
fi

# Perform the mount
log "mounting ${FL} -> ${TARGET}"
exec "$RFS_BIN" mount -m "$FL" "$TARGET"