#!/usr/bin/env sh

# should work in any POSIX shell on a UNIX-like environment, so pretty much any modern linux/BSD with essential CLI utilities
# note that busybox wget may not support https URLs (the version from arch linux's repos doesn't) and will not be able to download from ContentDB

content_path="${LUANTI_USER_PATH:-$HOME/.minetest}"
mkdir -p "$content_path"

print_message ()
{
   printf '[\033[%sm%s\033[0m] %s\n' "$1" "$2" "$3"
}

dl_cmd=none

wget &>/dev/null
[ $? -ne 127 ] && dl_cmd='wget -qO'

curl &>/dev/null
[ $? -ne 127 ] && dl_cmd='curl -sLo'

if [ "$dl_cmd" = none ]; then
   print_message 31 ERROR 'curl or wget is needed to download packages!'
   exit 1
fi

print_help ()
{
   echo "$0 <action> <package>
Actions:

install - install a package
remove  - remove a package
update  - update a package
help    - show this help"
}

install_package ()
{
   local tmp_dir="$(mktemp -d)"
   local pkg_name="${1##*/}"

   print_message 34 INFO "Downloading package info for '${pkg_name}'"
   $dl_cmd "${tmp_dir}/${pkg_name}" "https://content.luanti.org/api/packages/${1}"

   # this could in theory fail (especially if changes are made to the JSON structure), though i doubt it would happen by accident
   local pkg_type="$(grep -oE '"type":"(game|mod|txp)"' "${tmp_dir}/${pkg_name}" | grep -oE '(game|mod|txp)' | tail -n1)"

   case "$pkg_type" in
      game)
         : "games"
      ;;
      
      mod)
         : "mods"
      ;;

      txp)
         : "textures"
      ;;

      '')
         print_message 31 ERROR "No such package '$pkg_name'"
         return 1
      ;;

      *)
         print_message 31 ERROR "Unknown package type '$pkg_type'"
         return 1
      ;;
   esac

   local pkg_dir="${content_path}/${_}/"
   mkdir -p "$pkg_dir"

   if [ -d "${pkg_dir}/${pkg_name}" ]; then
      print_message 34 INFO "Package '${pkg_name}' is already installed, not installing."
      return 0
   fi

   print_message 34 INFO "Downloading package '$pkg_name'"
   $dl_cmd "${tmp_dir}/${pkg_name}.zip" "https://content.luanti.org/packages/${1}/download"

   print_message 34 INFO "Installing package '$pkg_name'"
   unzip -q -d "$pkg_dir" "${tmp_dir}/${pkg_name}.zip"

   rm -r "$tmp_dir"

   return 0
}

remove_package ()
{
   local tmp_dir="$(mktemp -d)"
   local pkg_name="${1##*/}"

   print_message 34 INFO "Downloading package info for '${pkg_name}'"
   $dl_cmd "${tmp_dir}/${pkg_name}" "https://content.luanti.org/api/packages/${1}"

   local pkg_type="$(grep -oE '"type":"(game|mod|txp)"' "${tmp_dir}/${pkg_name}" | grep -oE '(game|mod|txp)' | tail -n1)"

   rm -r "$tmp_dir"

   case "$pkg_type" in
      game)
         : "games"
      ;;
      
      mod)
         : "mods"
      ;;

      txp)
         : "textures"
      ;;

      '')
         print_message 31 ERROR "No such package '$pkg_name'"
         return 1
      ;;

      *)
         print_message 31 ERROR "Unknown package type '$pkg_type'"
         return 1
      ;;
   esac

   local pkg_dir="${content_path}/${_}/${pkg_name}"

   if [ -d "$pkg_dir" ]; then
      print_message 34 INFO "Removing package '$pkg_name'"
      rm -r "$pkg_dir"
      return 0
   fi

   print_message 34 INFO "Package '$pkg_name' not installed, not removing."
   return 0
}

# this is just a wrapper to call remove_package and install_package on a package..
update_package ()
{
   local pkg_name="${1##*/}"
   print_message 34 INFO "[1/2] Removing package '$pkg_name'"
   remove_package $1
   print_message 34 INFO "[2/2] Installing package '$pkg_name'"
   install_package $1
}

case $1 in
   install)
      case $2 in
         */*)
            install_package $2
            print_message 32 OK 'Operation complete.'
         ;;

         *)
            print_message 31 ERROR "Invalid syntax for 'install'. Correct syntax: '$0 install <author>/<package>'"
         ;;
      esac
   ;;

   remove)
      case $2 in
         */*)
            remove_package $2
            print_message 32 OK 'Operation complete.'
         ;;

         *)
            print_message 31 ERROR "Invalid syntax for 'remove'. Correct syntax: '$0 remove <author>/package>'"
         ;;
      esac
   ;;

   update)
      case $2 in
         */*)
            update_package $2
            print_message 32 OK 'Operation complete.'
         ;;

         *)
            print_message 31 ERROR "Invalid syntax for 'update'. Correct syntax: '$0 update <author>/package>'"
         ;;
      esac
   ;;

   help)
      print_help
   ;;

   *)
      print_message 31 ERROR 'Invalid usage. Usage:'
      print_help
   ;;
esac