#!/bin/bash -eu

USER_ENABLED_PUSHOVER=false

REPO=${REPO:-cimryan}

BRANCH=${BRANCH:-master}

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

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

function check_pushover_enabled () {
  if [ ! -z "${pushover_enabled+x}" ]
  then
    if [ ! -n "${pushover_user_key+x}" ] || [ ! -n "${pushover_app_key+x}"  ]
    then
      echo "STOP: You're trying to setup Pushover but didn't provide your User and/or App key."
      echo "Define the variables like this:"
      echo "export pushover_user_key=put_your_userkey_here"
      echo "export pushover_app_key=put_your_appkey_here"
      exit 1
    elif [ "${pushover_user_key}" = "put_your_userkey_here" ] || [  "${pushover_app_key}" = "put_your_appkey_here" ]
    then
      echo "STOP: You're trying to setup Pushover, but didn't replace the default User and App key values."
      exit 1
    else
      USER_ENABLED_PUSHOVER=true
      echo "export pushover_enabled=true" > /root/.teslaCamPushoverCredentials
      echo "export pushover_user_key=$pushover_user_key" >> /root/.teslaCamPushoverCredentials
      echo "export pushover_app_key=$pushover_app_key" >> /root/.teslaCamPushoverCredentials
    fi
  fi
}

function check_archive_server_reachable () {
  echo "Verifying that the archive server $archiveserver is reachable..."
  local serverunreachable=false
  ping -c 1 -w 1 "$archiveserver" 1>/dev/null 2>&1 || serverunreachable=true

  if [ "$serverunreachable" = true ]
  then
    echo "STOP: The archive server $archiveserver is unreachable. Try specifying its IP address instead."
    exit 1
  fi

  echo "The archive server is reachable."
}

function write_archive_credentials_to () {
  local file_path="$1"
  
  echo "username=$shareuser" > "$file_path"
  echo "password=$sharepassword" >> "$file_path"

}

function check_archive_mountable () {
  local archive_server_ip_address="$1"
  
  local test_mount_location="/tmp/archivetestmount"
  
  if [ ! -e "$test_mount_location" ]
  then
    mkdir "$test_mount_location"
  fi
  
  local tmp_credentials_file_path="/tmp/teslaCamArchiveCredentials"
  
  write_archive_credentials_to "$tmp_credentials_file_path"
  
  local mount_failed=false
  mount -t cifs "//$archive_server_ip_address/$sharename" "$test_mount_location" -o "vers=${cifs_version},credentials=${tmp_credentials_file_path},iocharset=utf8,file_mode=0777,dir_mode=0777" || mount_failed=true

  if [ "$mount_failed" = true ]
  then
    echo "STOP: The archive couldn't be mounted with CIFS version ${cifs_version}. Try specifying a lower number for the CIFS version like this: export cifs_version=2"
    exit 1
  fi
  
  umount "$test_mount_location"
}

function check_available_space () {
  echo "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
    echo "STOP: The MicroSD card is too small."
    exit 1
  fi

  echo "There is sufficient space available."
}

function get_ancillary_setup_scripts () {
  pushd /tmp
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/create-backingfiles-partition.sh
  chmod +x ./create-backingfiles-partition.sh
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/create-backingfiles.sh
  chmod +x ./create-backingfiles.sh
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/make-root-fs-readonly.sh
  chmod +x ./make-root-fs-readonly.sh
  popd
}

function fix_cmdline_txt_modules_load ()
{
  echo "Fixing the modules-load parameter in /boot/cmdline.txt..."
  cp /boot/cmdline.txt ~
  cat ~/cmdline.txt | sed 's/[[:space:]]\+modules-load=[^ [:space:]]\+//' | sed 's/rootwait/rootwait modules-load=dwc2/' > /boot/cmdline.txt
  rm ~/cmdline.txt
  echo "Fixed cmdline.txt."
}

BACKINGFILES_MOUNTPOINT=/backingfiles

function create_usb_drive_backing_files () {
  mkdir "$BACKINGFILES_MOUNTPOINT"
  /tmp/create-backingfiles-partition.sh "$BACKINGFILES_MOUNTPOINT"

  echo "Mounting the partition for the backing files..."
  mount /backingfiles
  echo "Mounted the partition for the backing files."

  /tmp/create-backingfiles.sh "$campercent" "$BACKINGFILES_MOUNTPOINT"
}

function configure_archive () {
  local archive_server_ip_address="$1"

  echo "Configuring the archive..."
  
  if [ $RSYNC_ENABLE = true ]
  then
    echo "Configuring for Rsync..."
    echo "user=$RSYNC_USER" > /root/.teslaCamRsyncConfig
    echo "server=$RSYNC_SERVER" >> /root/.teslaCamRsyncConfig
    echo "path=$RSYNC_PATH" >> /root/.teslaCamRsyncConfig
  else
    local archive_path="/mnt/archive"
  
    if [ ! -e "$archive_path" ]
    then
      mkdir "$archive_path"  
    fi
  
    local credentials_file_path="/root/.teslaCamArchiveCredentials"

    write_archive_credentials_to "$credentials_file_path"

    echo "//$archive_server_ip_address/$sharename $archive_path cifs vers=${cifs_version},credentials=${credentials_file_path},iocharset=utf8,file_mode=0777,dir_mode=0777 0" >> /etc/fstab
  
    echo "Configured the archive."
  fi
}

function configure_archive_scripts () {
  echo "Configuring the archive scripts..."
  mkdir /root/bin

  pushd ~
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/archiveloop
  sed s/ARCHIVE_HOST_NAME=archiveserver/ARCHIVE_HOST_NAME=$archiveserver/ ~/archiveloop > /root/bin/archiveloop
  rm ~/archiveloop
  chmod +x /root/bin/archiveloop
  popd

  pushd /root/bin
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/archive-teslacam-clips
  chmod +x archive-teslacam-clips

  if [ $RSYNC_ENABLE = true ]
  then
    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/rsync_archive/archive-clips.sh
    
    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/rsync_archive/connect-archive.sh

    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/rsync_archive/disconnect-archive.sh
  else
    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/archive-clips.sh
    
    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/connect-archive.sh

    wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/disconnect-archive.sh
  fi 

  chmod +x archive-clips.sh
  chmod +x connect-archive.sh
  chmod +x disconnect-archive.sh

  popd
  echo "Configured the archive scripts."

  pushd /root
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/remountfs_rw
  chmod +x remountfs_rw
  popd
  echo "Downloaded script to remount filesystems read/write if needed (/root/remountfs_rw)."
}

function configure_pushover_scripts() {
  pushd /root/bin
  wget https://raw.githubusercontent.com/"$REPO"/teslausb/"$BRANCH"/windows_archive/send-pushover
  chmod +x send-pushover
  popd
}

function configure_rc_local () {
  echo "Configuring /etc/rc.local to run the archive scripts at startup..."
  echo "#!/bin/bash -eu" > ~/rc.local
  tail -n +2 /etc/rc.local | sed '$d' >> ~/rc.local
cat << 'EOF' >> ~/rc.local
LOGFILE=/tmp/rc.local.log

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

log "Launching archival script..."
/root/bin/archiveloop &
log "All done"
exit 0
EOF

  cat ~/rc.local > /etc/rc.local
  rm ~/rc.local
  echo "Configured rc.local."
}

function configure_hostname () {
  echo "Configuring the hostname..."

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

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

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

echo "Verifying environment variables..."

if [ ! -n "${cifs_version+x}" ]
then
  cifs_version=3
fi

if [ $RSYNC_ENABLE = true ]
then
    check_variable "RSYNC_USER"
    check_variable "RSYNC_SERVER"
    export archiveserver=$RSYNC_SERVER
    check_variable "RSYNC_PATH"
else # Else for now, TODO allow both for more redundancy?
    check_variable "sharename"
    check_variable "shareuser"
    check_variable "sharepassword"
fi
check_variable "archiveserver"
check_variable "campercent"

check_pushover_enabled

check_archive_server_reachable

ARCHIVE_SERVER_IP_ADDRESS="$(ping -c 1 -w 1 $archiveserver 2>/dev/null | head -n 1 | grep -o -e "(\([[:digit:]]\{1,3\}\.\)\{3\}[[:digit:]]\{1,3\})" | tr -d '()')"

check_archive_mountable "$ARCHIVE_SERVER_IP_ADDRESS"

check_available_space

get_ancillary_setup_scripts

pushd ~

configure_archive_scripts

configure_pushover_scripts

fix_cmdline_txt_modules_load

echo "" >> /etc/fstab

create_usb_drive_backing_files

configure_archive "$ARCHIVE_SERVER_IP_ADDRESS"

configure_rc_local

configure_hostname

make_root_fs_readonly

echo "All done."