#!/bin/bash -eu

LOG_FILE=/tmp/archive-teslacam-clips.log
CAM_MOUNT=/mnt/cam
ARCHIVE_MOUNT=/mnt/archive

function log () {
  echo "$( date )" >> "$LOG_FILE"
  echo "$1" >> "$LOG_FILE"
}

function retry () {
  local attempts=0
  while [ true ]
  do
    if eval "$@"
    then
      true
      return
    fi
    if [ "$attempts" -ge 10 ]
    then
      log "Attempts exhausted."
      false
      return
    fi
    log "Sleeping before retry..."
    /bin/sleep 1
    attempts=$((attempts + 1))
    log "Retrying..."
  done
  false
  return
}

function mount_mountpoint () {
  local mount_point="$1"
  log "Mounting $mount_point..."

  local mounted=true
  mount "$mount_point" >> "$LOG_FILE" 2>&1 || mounted=false
  if [ "$mounted" = true ]
  then
    log "Mounted $mount_point."
    true
    return
  else
    log "Failed to mount $mount_point."
    false
    return
  fi
}

function ensure_mountpoint_is_mounted () {
  local mount_point="$1"
  local mount_exists=true

  findmnt --mountpoint "$mount_point" > /dev/null || mount_exists=false

  if [ "$mount_exists" = true ]
  then
    log "$mount_point is already mounted."
  else
    mount_mountpoint "$mount_point"
  fi
}

function ensure_mountpoint_is_mounted_with_retry () {
  retry ensure_mountpoint_is_mounted "$1"
}

function move_clips_to_archive () {
  log "Moving clips to archive..."
  for file_name in "$CAM_MOUNT"/TeslaCam/saved*; do
    [ -e "$file_name" ] || continue
    log "Moving $file_name ..."
    mv -- "$file_name" "$ARCHIVE_MOUNT" >> "$LOG_FILE" 2>&1 || echo ""
    log "Moved $file_name."
  done
  log "Finished moving clips to archive."
}

function disconnect_usb_drives_from_host () {
  log "Disconnecting usb from host..."
  modprobe -r g_mass_storage
  log "Disconnected usb from host."
}

function fix_errors_on_cam_drive () {
  log "Running fsck..."
  /sbin/fsck "$CAM_MOUNT" -- -a >> "$LOG_FILE" 2>&1 || echo ""
  log "Finished running fsck."
}

function ensure_archive_is_mounted () {
  log "Ensuring cam archive is mounted..."
  ensure_mountpoint_is_mounted_with_retry "$ARCHIVE_MOUNT"
  log "Ensured cam archive is mounted."
}

function ensure_cam_drive_is_mounted () {
  log "Ensuring cam drive is mounted..."
  ensure_mountpoint_is_mounted_with_retry "$CAM_MOUNT"
  log "Ensured cam drive is mounted."
}

function unmount_cam_drive () {
  log "Unmounting cam drive..."
  umount "$CAM_MOUNT"
  log "Unmounted cam drive."
}

log "Starting..."

ensure_archive_is_mounted

disconnect_usb_drives_from_host

fix_errors_on_cam_drive

ensure_cam_drive_is_mounted

move_clips_to_archive

unmount_cam_drive

connect_usb_drives_to_host