#!/bin/bash

# We check for the existance of needed commands

usage() {
  echo "

Usage :

  add-ftp-account [ --help ] [ --target /some/path ] [ --password some-password ] username

  This little script help you to add a user to your FTP server.
  Available options are:

  -h
  --help
    Display this little help.

  -p some-password
  --password some-password
    By default, a password is automatically created for the user you are
    adding. This option allow you to choose a custom password for you user.

  -t /some/path
  --target  /some/path
    By default, a directory for the user is created in the default FTP
    server root. This option allow you to set a different path for the user.
"
  exit 0
}

if [ ! -x /usr/bin/mysql ]; then
  echo "Unable to find 'mysql' on your system. Please install the package 'mysql'."
  exit 1
fi

if [ ! -x /usr/bin/apg ]; then
  echo "Unable to find 'apg' on your system. Please install the package 'apg'."
  exit 1
fi


# We fetch MySQL configuration from PAM.
MYSQL_USERNAME=$(cat /etc/pam.d/vsftpd \
                    | grep "user=" | head -n 1 \
                    | sed -e 's/.*user=\([^ \t]*\).*/\1/')
MYSQL_USERPWD=$(cat /etc/pam.d/vsftpd \
                    | grep "passwd=" | head -n 1 \
                    | sed -e 's/.*passwd=\([^ \t]*\).*/\1/')
MYSQL_HOST=$(cat /etc/pam.d/vsftpd \
                    | grep "host=" | head -n 1 \
                    | sed -e 's/.*host=\([^ \t]*\).*/\1/')
MYSQL_DB=$(cat /etc/pam.d/vsftpd \
                    | grep "db=" | head -n 1 \
                    | sed -e 's/.*db=\([^ \t]*\).*/\1/')

# We fetch default USER home directory from VSFTPD configuration.
LOCAL_ROOT=$(cat /etc/vsftpd.conf \
                    | grep -e "^local_root=" | head -n 1 \
                    | sed -e 's/^local_root=\([^ \t]*\).*$/\1/')

# We fetch local user from VSFTPD configuration.
LOCAL_USER=$(cat /etc/vsftpd.conf \
                    | grep -e "^guest_username=" | head -n 1 \
                    | sed -e 's/^guest_username=\([^ \t]*\).*$/\1/')

#
# We create a random default password:
#
FTP_PASSWORD=$(apg -q -a  0 -n 1 -M NCL)
FTP_PATH=""
FTP_USERNAME=""

# Parse the command line 
while [ $# -ge 1 ]; do
  case $1 in
    -h|--help)
      usage
    ;;
   -p|--password)
      # in this case, $2 should be the conffile !
      if [ -n "$2" ]; then
        FTP_PASSWORD=$2
      else
        echo "The -p (--password) option must be followed by a password."
        usage
      fi
      # we shift here to avoid processing the file path 
      shift
    ;;
    -t|--target)
      # in this case, $2 should be the conffile !
      if [ -n "$2" ]; then
        FTP_PATH=$2
      else
        echo "The -t (--target) option must be followed by a path."
        usage
      fi
      # we shift here to avoid processing the file path 
      shift
    ;;
    *)
      if [ -n "$FTP_USERNAME" ]; then
        echo "Unknown option $1"
        usage
      fi

      FTP_USERNAME=$1
    ;;
  esac
  shift
done

if [ -z "$FTP_USERNAME" ]; then
  echo "You must specify a username."
  usage
fi

if [ -z "$FTP_PATH" ]; then
  # We compute default user FTP path:
  FTP_PATH=$(/bin/echo ${LOCAL_ROOT} | /bin/sed -e "s/\$USER/${FTP_USERNAME}/")
else
  # We use a custom user path. We need to configure vsftpd for it:
  echo "# Custom user path.
local_root=$FTP_PATH" | /usr/bin/tee /etc/vsftpd.d/$FTP_USERNAME
fi

/bin/echo "INSERT INTO accounts (username, pass) VALUES('$FTP_USERNAME', PASSWORD('$FTP_PASSWORD'));" \
    | /usr/bin/mysql --user=$MYSQL_USERNAME --password=$MYSQL_USERPWD --host=$MYSQL_HOST $MYSQL_DB

if [ ! -e "${FTP_PATH}" ]; then
  command mkdir --parent "${FTP_PATH}"
  command chown -R ${LOCAL_USER}:nogroup "${FTP_PATH}"
else
  command echo "Do you really want to change owner of '${FTP_PATH}' to ${LOCAL_USER}:nogroup (y/n) ?"
  command read CHANGE_PERM

  if [ "${CHANGE_PERM}" = "y" ]; then
    command chown -R ${LOCAL_USER}:nogroup "${FTP_PATH}"
  fi
fi

echo "
A new user has been created for your FTP server:
  * username : $FTP_USERNAME
  * password : $FTP_PASSWORD
  * path : $FTP_PATH
"