#!/bin/bash

SAVEIFS=$IFS
IFS="$(printf '\n\t')"
DEFAULT_FNAME=compressed_output
DEFAULT_FORMAT=tar.gz
SCRIPT="$(basename $0)"

function help {
  printf "Usage: %s [-o|--output FNAME] [-f|--format FORMAT] <file1> [file2] ... [-- [OPTS_TO_PASSTHROUGH]]\n" "$SCRIPT"
  printf "Usage: %s <file1>\n" "$SCRIPT"
  printf "\n"
  printf "Use corresponding compression software based on output filename\n"
  printf "If only one input is given, .%s format is assumed, and named as file1.%s\n" "$DEFAULT_FORMAT" "$DEFAULT_FORMAT"
  exit
}

function get_ext {
  _f="$(basename "$1")"
  echo "${_f##*.}"
}

function get_fname {
  _f="$(basename "$1")"
  echo "${_f%.*}"
}

function is_supported_format {
  case "$1" in
    *.cbt|*.tar.bz2|*.tar.gz|*.tar.xz|*.tbz2|*.tgz|*.txz|*.tar) return 0 ;;
    *.7z) return 0 ;;
    *.zip) return 0 ;;
    *.rar) return 0 ;;
  esac
  return 1
}


if test $# -eq 0; then
  help
fi

IFS=$SAVEIFS


function compress {
  filelist=()

  output_format="$DEFAULT_FORMAT"
  while test $# -gt 0; do
      case "$1" in
        -o|--output)
          shift
          output_fname="$1"
          ;;
        -f|--format)
          shift
          output_format="$1"
          ;;
        -h|--help)
          help
          ;;
        --verbose)
          export VERBOSE="true"
          ;;
        --)
          # the rest will be passed to ffmpeg
          breaknow=true
          ;;
        *)
          # set to file list
          filelist+=("$1")
          #set -- "$filelist" "$arg"
      esac
      shift
      if [ -n "$breaknow" ]; then
        break
      fi
  done

  if [ -z "$output_fname" ]; then
    # fallback to first file's name
    output_fname="$(get_fname ${filelist[0]})"

    # fallback to default
    [ -z "$output_fname" ] && "$DEFAULT_FNAME"
  fi

  # see if output filename has extension, and file format is supported
  if [ -n "$(get_ext "$output_fname")" ] && is_supported_format "$output_fname"; then
    target="$output_fname"
  else
    target="$output_fname.$output_format"
  fi
  case "${target%,}" in
    *.cbt|*.tar.bz2|*.tar.gz|*.tar.xz|*.tbz2|*.tgz|*.txz|*.tar)
                  tar cavf "$target" $@ ${filelist[@]}
                  ;;
#      *.lzma)      unlzma ./"$target"      ;;
#      *.bz2)       bunzip2 ./"$target"     ;;
#      *.cbr|*.rar) unrar x -ad ./"$target" ;;
#      *.gz)        gunzip ./"$target"      ;;
#      *.cbz|*.epub|*.zip)
#                   unzip ./"$target" $unzip_args
#                   ;;
#      *.z)         uncompress ./"$target"  ;;
    *.7z)
                  7z a "$target" $@ ${filelist[@]}
                  ;;
    *.zip)
                  zip -r "$target" $@ ${filelist[@]}
                  ;;
    *.rar)
                  rar a "$target" $@ ${filelist[@]}
                  ;;
#      *.7z|*.apk|*.arj|*.cab|*.cb7|*.chm|*.deb|*.dmg|*.iso|*.lzh|*.msi|*.pkg|*.rpm|*.udf|*.wim|*.xar)
#                   7z x ./"$target"        ;;
#      *.xz)        unxz ./"$target"        ;;
#      *.exe)       cabextract ./"$target"  ;;
#      *.cpio)      cpio -id < ./"$target"  ;;
#      *.cba|*.ace) unace x ./"$target"     ;;
#      *.zpaq)      zpaq x ./"$target"      ;;
#      *.arc)       arc e ./"$target"       ;;
#      *.cso)       ciso 0 ./"$target" ./"$target.iso" && \
#                        extract $target.iso && \rm -f $target ;;
    *)
                  echo "$SCRIPT: '$target' - unknown archive method"
                  return 1
                  ;;
  esac
}


compress $@