#!/bin/bash

set -e
function helpexit() {
    echo Usage: $( basename "$0" ) [--nc] source [source] target
    echo Copy files with a progress bar to a folder.
    echo This command always 
    echo '* recurses to folders!'
    echo '* overwrites existing files'
    echo '--nc  Dont count bytes first'
    exit
}

SRC=( )
for ((i=1; i<=${#@}; i++)) {
    [[ "${!i}" = "-h" ]] && helpexit
    [[ "${!i}" = "--help" ]] && helpexit
    [[ "${!i}" = "--nc" ]] && { NOCOUNT=1; continue; }
#    [[ "${!i}" = "-"* ]] && helpexit
    SRC+=( "${!i%/}" )
}
[[ "${#SRC[@]}" -lt 2 ]] && helpexit
which pv &> /dev/null || { echo No \'pv\' installed; exit 1; }
TGT=${SRC[${#SRC[@]}-1]}
unset 'SRC[${#SRC[@]}-1]'
for path in ${SRC[@]}; do
  [[ -e "$path" ]] || { echo $path missing; exit 1; }
done

getsize() {
  if [[ "$NOCOUNT" -eq 1 ]]; then
    echo 0
  else
    fastdu -s "$@"
  fi
}

copy_file() {
  pv "$1" > "$2"
  chmod --reference="$1" "$2"
  chown --reference="$1" "$2"
}

copy_dir() {
  mkdir -p "$2"
  chmod --reference="$1" "$2"
  chown --reference="$1" "$2"
  mysize=$( getsize "$1" )
  TGT_ABS=$( readlink -f "$2" )
  pushd "$1" &> /dev/null 
  tar -c "." | pv -s $mysize | tar -x --strip-components=1 -C "$TGT_ABS" 
  popd &> /dev/null 
}

copy_to() {
  if [[ -f "$1" ]]; then   # file to folder
    copy_file "$1" "$2"
  else                       # folder to folder
    copy_dir "$1" "$2"
  fi
}

if [[ ${#SRC[@]} -eq 1 ]]; then  # only one input
  if [[ ! -d "$TGT" ]]; then   # target is not a (existing) dir
    copy_to "${SRC[0]}" "$TGT"
    exit $?
  fi
fi

# Otherwise, create folder, and copy in it
[[ -f "$TGT" ]] && { echo Copying multiple sources: Target can only be a folder; exit 1; }
mkdir -p "$TGT"
for SRC_THIS in "${SRC[@]}"; do
  SRC_BASE=$( basename "$SRC_THIS")
  echo "$SRC_THIS"
  copy_to "$SRC_THIS" "$TGT"/"$SRC_BASE" 
done