#!/usr/bin/env bash

# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.


# Check if we're root, if not show a warning
if [[ $UID -ne 0 ]]; then
  case $1 in
    ""|help) # You should be allowed to check the help without being root
      ;;
    *)
      echo "Sorry, but Dazzle needs to be run as root."
      exit 1
      ;;
  esac
fi

GIT=$( which git ) > /dev/null

# Define text styles
BOLD=$( tput bold )
NORMAL=$( tput sgr0 )

# Nice defaults
DAZZLE_USER="${DAZZLE_USER:-storage}"
DAZZLE_GROUP="${DAZZLE_GROUP:-$DAZZLE_USER}"
DAZZLE_HOME="${DAZZLE_HOME:-/home/$DAZZLE_USER}"

show_help () {
    echo "${BOLD}Dazzle, SparkleShare host setup script${NORMAL}"
    echo "This script needs to be run as root"
    echo
    echo "Usage: dazzle [COMMAND]"
    echo
    echo "  setup                            configures this machine to serve as a SparkleShare host"
    echo "  create PROJECT_NAME              creates a SparkleShare project called PROJECT_NAME"
    echo "  create-encrypted PROJECT_NAME    creates an encrypted SparkleShare project"
    echo "  link                             links a SparkleShare client to this host by entering a link code"
    echo
}

create_account () {
  STORAGE=$( grep "^$DAZZLE_USER:" /etc/passwd | cut -d : -f 1 )

  # Create user
  if [ "$STORAGE" = "$DAZZLE_USER" ]; then
    echo "  -> Account already exists."
  else
    STORAGE=$( grep "^$DAZZLE_GROUP:" /etc/group | cut -d : -f 1 )
    GIT_SHELL=$( which git-shell )

    if [ "$STORAGE" = "$DAZZLE_GROUP" ]; then
      echo "  -> useradd $DAZZLE_USER --create-home --home $DAZZLE_HOME --system --shell $GIT_SHELL --password \"*\" --gid $DAZZLE_GROUP"
      useradd $DAZZLE_USER --create-home --home $DAZZLE_HOME --system --shell $GIT_SHELL --password "*" --gid $DAZZLE_GROUP

    else
      echo "  -> useradd $DAZZLE_USER --create-home --home $DAZZLE_HOME --system --shell $GIT_SHELL --password \"*\" --user-group"
      useradd $DAZZLE_USER --create-home --home $DAZZLE_HOME --system --shell $GIT_SHELL --password "*" --user-group
    fi
  fi

  # Create base directory
  if [ ! -d "$DAZZLE_HOME" ]; then
    echo "  -> mkdir --parents $DAZZLE_HOME"
    mkdir -p "$DAZZLE_HOME"
  fi

  sleep 0.5
}

configure_ssh () {
  echo "  -> mkdir --parents $DAZZLE_HOME/.ssh"
  mkdir -p "$DAZZLE_HOME/.ssh"

  echo "  -> touch $DAZZLE_HOME/.ssh/authorized_keys"
  touch "$DAZZLE_HOME/.ssh/authorized_keys"

  echo "  -> chmod 700 $DAZZLE_HOME/.ssh"
  chmod 700 "$DAZZLE_HOME/.ssh"

  echo "  -> chmod 600 $DAZZLE_HOME/.ssh/authorized_keys"
  chmod 600 "$DAZZLE_HOME/.ssh/authorized_keys"

  # Disable the password for the "storage" user to force authentication using a key
  CONFIG_CHECK=$( grep "^# SparkleShare$" /etc/ssh/sshd_config )
  if ! [ "$CONFIG_CHECK" = "# SparkleShare" ]; then
      {
          echo ""
          echo "# SparkleShare"
          echo "# Please do not edit the above comment as it's used as a check by Dazzle"
          echo "Match User $DAZZLE_USER"
          echo "    PasswordAuthentication no"
          echo "    PubkeyAuthentication yes"
          echo "# End of SparkleShare configuration"
      } >> /etc/ssh/sshd_config
  fi

  sleep 0.5
}

reload_ssh_config () {
  if [ -f "/etc/init.d/sshd" ]; then
    echo "  -> /etc/init.d/sshd reload"
    /etc/init.d/sshd reload >/dev/null

  elif [ -f "/etc/rc.d/sshd" ]; then
    echo "  -> /etc/rc.d/sshd reload"
    /etc/rc.d/sshd reload >/dev/null

  elif [ -f "/etc/init.d/ssh" ]; then
    echo "  -> /etc/init.d/ssh reload"
    /etc/init.d/ssh reload >/dev/null

  else
    echo "  -> systemctl reload sshd"
    systemctl reload sshd
  fi
}

install_git_failed () {
  echo "${BOLD}Could not install Git... Please install it manually before continuing.${NORMAL}"
  echo
  exit 1
}

install_git () {
  if [ -n "$GIT" ]; then
    GIT_VERSION=$( $GIT --version | cut -b 13- )
    echo "  -> The Git package has already been installed (version $GIT_VERSION)."

  else
    if [ -f "/usr/bin/yum" ]; then
      echo "  -> yum --assumeyes install git"
      if ! yum -y --quiet install git; then
        install_git_failed
      fi

    elif [ -f "/usr/bin/apt-get" ]; then
      echo "  -> apt-get --yes install git"
      if apt-get --yes --quiet install git; then
        echo "  -> apt-get --yes install git-core"
        if ! apt-get --yes --quiet install git-core; then
          install_git_failed
        fi
      else
        install_git_failed
      fi

    elif [ -f "/usr/bin/zypper" ]; then
      echo "  -> zypper --yes install git-core"
      if ! zypper --yes --quiet install git-core; then
        install_git_failed
      fi

    elif [ -f "/usr/bin/emerge" ]; then
      echo "  -> emerge dev-vcs/git"
      if ! emerge --quiet dev-vcs/git; then
        install_git_failed
      fi

    elif [ -f "/usr/bin/pacman" ]; then
      echo "  -> pacman -S git"
      if ! pacman -S git; then
        install_git_failed
      fi

    else
      install_git_failed
    fi
  fi
}

create_project () {
  if [ -f "$DAZZLE_HOME/$1/HEAD" ]; then
    echo "  -> Project \"$1\" already exists."
    echo
  else
    # Sanity check for Git
    if [ -z $GIT ]; then
      echo "Git is currently not installed! Run the \"dazzle setup\" command to fix this problem."
      exit 1
    fi

    # Create the Git repository
    echo "  -> $GIT init --bare $DAZZLE_HOME/$1"
    $GIT init --quiet --bare "$DAZZLE_HOME/$1"

    # Don't allow force-pushing and data to get lost
    echo "  -> $GIT config --file $DAZZLE_HOME/$1/config receive.denyNonFastForwards true"
    $GIT config --file "$DAZZLE_HOME/$1/config" receive.denyNonFastForwards true

    # Add list of files that Git should not compress
    EXTENSIONS="jpg jpeg png tiff gif psd xcf flac mp3 ogg oga avi mov mpg mpeg mkv ogv ogx webm zip gz bz xz bz2 rpm deb tgz rar ace 7z pak msi iso dmg"
    for EXTENSION in $EXTENSIONS; do
      sleep 0.05
      echo -ne "  -> echo \"*.$EXTENSION -delta\" >> $DAZZLE_HOME/$1/info/attributes      \r"
      echo "*.$EXTENSION -delta" >> "$DAZZLE_HOME/$1/info/attributes"
      sleep 0.05
      EXTENSION_UPPERCASE=$( echo "$EXTENSION" | tr '[:lower:]' '[:upper:]' )
      echo -ne "  -> echo \"*.$EXTENSION_UPPERCASE -delta\" >> $DAZZLE_HOME/$1/info/attributes      \r"
      echo "*.$EXTENSION_UPPERCASE -delta" >> "$DAZZLE_HOME/$1/info/attributes"
    done

    echo ""

    # Set the right permissions
    echo "  -> chown --recursive $DAZZLE_USER:$DAZZLE_GROUP $DAZZLE_HOME"
    chown -R "$DAZZLE_USER:$DAZZLE_GROUP" "$DAZZLE_HOME"

    echo "  -> chmod --recursive o-rwx $DAZZLE_HOME/$1"
    chmod -R o-rwx "$DAZZLE_HOME"/"$1"

    sleep 0.5

    echo
    echo "${BOLD}Project \"$1\" was successfully created.${NORMAL}"
  fi

  # Fetch the external IP address
  # 1. fetch all inet addresses (IPv4)
  # 2. select only global scope addresses
  # 3. extract the address
  # 4. limit the list to the first address to get only one IP in case the server has more than one
  IP=$( ip -f inet addr |grep "inet .* scope global" | grep -Po "inet ([\d+\.]+)" | cut -c 6- | head -n1 )
  PORT=$( grep --max-count=1 "^Port " /etc/ssh/sshd_config | cut -b 6- )

  # Display info to link with the created project to the user
  echo "To link up a SparkleShare client, enter the following"
  echo "details into the ${BOLD}\"Add Hosted Project...\"${NORMAL} dialog: "
  echo
  echo "      Address: ${BOLD}ssh://$DAZZLE_USER@$IP:$PORT${NORMAL}"
  echo "  Remote Path: ${BOLD}$DAZZLE_HOME/$1${NORMAL}"
  echo
  echo "To link up (more) computers, use the \"dazzle link\" command."
  echo
}

link_client () {
  # Ask the user for the link code with a prompt
  echo "Paste your Client ID (found in the status icon menu) below and press ${BOLD}<ENTER>${NORMAL}."
  echo
  echo -n " ${BOLD}Client ID: ${NORMAL}"
  read -r LINK_CODE

  if [[ "$LINK_CODE" != ssh-rsa\ * ]]; then
    echo
    echo "${BOLD}The supplied string is not a valid Client ID!${NORMAL}"
    echo "Please try again."
    echo
    exit 1
  fi

  echo "$LINK_CODE" >> "$DAZZLE_HOME/.ssh/authorized_keys"
  echo
  echo "${BOLD}The client with this ID can now access projects.${NORMAL}"
  echo "Repeat this step to give access to more clients."
  echo
}


# Parse the command line arguments
case $1 in
  setup)
    echo "${BOLD} 1/4 | Installing the Git package...${NORMAL}"
    install_git
    echo "${BOLD} 2/4 | Creating account \"$DAZZLE_USER\"...${NORMAL}"
    create_account
    echo "${BOLD} 3/4 | Configuring account \"$DAZZLE_USER\"...${NORMAL}"
    configure_ssh
    echo "${BOLD} 4/4 | Reloading the SSH config...${NORMAL}"
    reload_ssh_config
    echo
    echo "${BOLD}Setup complete!${NORMAL}"
    echo "To create a new project, run \"dazzle create PROJECT_NAME\"."
    echo
    ;;

  create)
    if [ -n "$2" ]; then
      echo "${BOLD}Creating project \"$2\"...${NORMAL}"
      create_project "$2"

    else
      echo "Please provide a project name."
    fi
    ;;

  create-encrypted)
    echo "${BOLD}Creating encrypted project \"$2\"...${NORMAL}"
    create_project "$2-crypto"
    ;;

  link)
    link_client "$2"
    ;;

  *|help)
    show_help
    ;;
esac