#!/bin/bash -eu

REPO=${REPO:-cimryan}
BRANCH=${BRANCH:-master}
HEADLESS_SETUP=${HEADLESS_SETUP:-false}
USE_LED_FOR_SETUP_PROGRESS=true
CONFIGURE_ARCHIVING=${CONFIGURE_ARCHIVING:-true}
UPGRADE_PACKAGES=${UPGRADE_PACKAGES:-true}
export campercent=${campercent:-90}

function setup_progress () {
  local setup_logfile=/boot/teslausb-headless-setup.log
  if [ $HEADLESS_SETUP = "true" ]
  then
    echo "$( date ) : $1" >> "$setup_logfile"
  fi
    echo $1
}

if ! [ $(id -u) = 0 ]
then
  setup_progress "STOP: Run sudo -i."
  exit 1
fi

function headless_setup_populate_variables () {
  # Pull in the conf file variables to make avail to this script and subscripts
  if [ -e /boot/teslausb_setup_variables.conf ] && [ $HEADLESS_SETUP = "true" ]
  then
    source /boot/teslausb_setup_variables.conf
  fi
}


function headless_setup_mark_setup_failed () {
  if [ $HEADLESS_SETUP = "true" ]
  then
    setup_progress "ERROR: Setup Failed."
    touch /boot/TESLAUSB_SETUP_FAILED
  fi
}

function headless_setup_mark_setup_success () {
  if [ $HEADLESS_SETUP = "true" ]
  then

    if [ -e /boot/TESLAUSB_SETUP_FAILED ]
    then
      rm /boot/TESLAUSB_SETUP_FAILED
    fi

    rm /boot/TESLAUSB_SETUP_STARTED
    touch /boot/TESLAUSB_SETUP_FINISHED
    # This sed shouldn't be needed, but double checking just to be sure. 
    sed -i'.bak' -e "s/TEMPARCHIVESERVER/$archiveserver/g" /etc/rc.local
    setup_progress "Main setup completed. Remounting file systems read only."
  fi
}

function headless_setup_progress_flash () {
  if [ $USE_LED_FOR_SETUP_PROGRESS = "true" ] && [ $HEADLESS_SETUP = "true" ]
  then
    /etc/stage_flash $1
  fi
}

function setup_led_off () {

  if [ $USE_LED_FOR_SETUP_PROGRESS = "true" ] && [ $HEADLESS_SETUP = "true" ]
  then
    echo "none" | sudo tee /sys/class/leds/led0/trigger > /dev/null
    echo 1 | sudo tee /sys/class/leds/led0/brightness > /dev/null
  fi
}

function setup_led_on () {

  if [ $USE_LED_FOR_SETUP_PROGRESS = "true" ] && [ $HEADLESS_SETUP = "true" ]
  then
    echo 0 | sudo tee /sys/class/leds/led0/brightness > /dev/null
  fi
}

function check_variable () {
  local var_name="$1"
  if [ -z "${!var_name+x}" ]
  then
    setup_progress "STOP: Define the variable $var_name like this: export $var_name=value"
    exit 1
  fi
}

function check_available_space () {
  setup_progress "Verifying that there is sufficient space available on the MicroSD card..."

  local available_space="$( parted -m /dev/mmcblk0 u b print free | tail -1 | cut -d ":" -f 4 | sed 's/B//g' )"

  if [ "$available_space" -lt  4294967296 ]
  then
    setup_progress "STOP: The MicroSD card is too small."
    exit 1
  fi

  setup_progress "There is sufficient space available."
}

function verify_configuration () {
  get_script /tmp verify-configuration.sh setup/pi
  
  /tmp/verify-configuration.sh
}

function get_script () {
  local local_path="$1"
  local name="$2"
  local remote_path="${3:-}"
  
  curl --fail -o "$local_path/$name" https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/"$remote_path"/"$name"
  # wget -O "$local_path/$name" https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/"$remote_path"/"$name"
  chmod +x "$local_path/$name"
  setup_progress "Downloaded $local_path/$name ..."
}

function get_ancillary_setup_scripts () {
  get_script /tmp create-backingfiles-partition.sh setup/pi
  get_script /tmp create-backingfiles.sh setup/pi
  get_script /tmp make-root-fs-readonly.sh setup/pi
  get_script /root configure.sh setup/pi
}

function fix_cmdline_txt_modules_load ()
{
  setup_progress "Fixing the modules-load parameter in /boot/cmdline.txt..."
  cp /boot/cmdline.txt ~
  cat ~/cmdline.txt | sed 's/ modules-load=dwc2,g_ether/ modules-load=dwc2/' > /boot/cmdline.txt
  rm ~/cmdline.txt
  setup_progress "Fixed cmdline.txt."
}

BACKINGFILES_MOUNTPOINT=/backingfiles
MUTABLE_MOUNTPOINT=/mutable

function create_usb_drive_backing_files () {
  if [ ! -e "$BACKINGFILES_MOUNTPOINT" ]
  then
    mkdir "$BACKINGFILES_MOUNTPOINT"
  fi

  if [ ! -e "$MUTABLE_MOUNTPOINT" ]
  then
    mkdir "$MUTABLE_MOUNTPOINT"
  fi
  
  if [ ! -e /dev/mmcblk0p3 ]
  then
    setup_progress "Starting to create backing files partition..."
    /tmp/create-backingfiles-partition.sh "$BACKINGFILES_MOUNTPOINT" "$MUTABLE_MOUNTPOINT"
  fi
  
  if ! findmnt --mountpoint $BACKINGFILES_MOUNTPOINT
  then
    setup_progress "Mounting the partition for the backing files..."
    mount $BACKINGFILES_MOUNTPOINT
    setup_progress "Mounted the partition for the backing files."
  fi

  if [ ! -e $BACKINGFILES_MOUNTPOINT/*.bin ]
  then
    setup_progress "Creating backing disk files."
    /tmp/create-backingfiles.sh "$campercent" "$BACKINGFILES_MOUNTPOINT"
  fi
}

function configure_hostname () {
  # Headless image already has hostname set
  if [ ! $HEADLESS_SETUP = "true" ]
  then
    setup_progress "Configuring the hostname..."

    local new_host_name="teslausb"
    cp /etc/hosts ~
    sed "s/raspberrypi/$new_host_name/g" ~/hosts > /etc/hosts
    rm ~/hosts

    cp /etc/hostname ~
    sed "s/raspberrypi/$new_host_name/g" ~/hostname > /etc/hostname
    setup_progress "Configured the hostname."
    rm ~/hostname
  fi
}

function make_root_fs_readonly () {
  /tmp/make-root-fs-readonly.sh
}

function update_package_index () {
  setup_progress "Updating package index files..."
  apt-get update
}

function upgrade_packages () {
  if [ "$UPGRADE_PACKAGES" = true ]
  then
    setup_progress "Upgrading installed packages..."
    apt-get --assume-yes upgrade
  else
    setup_progress "Skipping package upgrade."
  fi
}

export -f setup_progress
export HEADLESS_SETUP

update_package_index

headless_setup_populate_variables

# If USE_LED_FOR_SETUP_PROGRESS = true. 
setup_led_off

# Flash for stage 2 headless (verify requested configuration)
headless_setup_progress_flash 1

setup_progress "Verifying that the requested configuration is valid..."

verify_configuration

# Flash for Stage 3 headless (grab scripts)
headless_setup_progress_flash 2

setup_progress "Downloading additional setup scripts."

get_ancillary_setup_scripts

pushd ~

fix_cmdline_txt_modules_load

echo "" >> /etc/fstab

# Flash for stage 4 headless (Create backing files)
headless_setup_progress_flash 3

create_usb_drive_backing_files

configure_hostname

# Flash for stage 5 headless (Mark success, FS readonly)
headless_setup_progress_flash 4

headless_setup_mark_setup_success

if [ "$CONFIGURE_ARCHIVING" = true ]
then
  /root/configure.sh
fi

make_root_fs_readonly

upgrade_packages

# If USE_LED_FOR_SETUP_PROGRESS = true. 
setup_led_on

setup_progress "All done."