#!/usr/bin/env bash
# https://github.com/junegunn/myvim

set -u
set -e

EDIT=0
COMPRESS=-z
OUTPUT=vim.$(whoami)
GREPV="cat"
VIMRC=.vimrc
if [ ! -e ~/$VIMRC ]; then
  if [ -e ~/.vim/vimrc ]; then
    VIMRC=.vim/vimrc
  else
    >&2 echo "~/.vimrc (or ~/.vim/vimrc) not found"
    exit 1
  fi
fi

usage() {
  echo "usage: $0 [-e|--edit] [--exclude PATTERN] [-j] [output]"
}

while [ $# -gt 0 ]; do
  case $1 in
    -e|--edit) EDIT=1 ;;
    -z|-j)     COMPRESS=$1 ;;
    --exclude) shift; GREPV="grep -v $(printf %q "$1")" ;;
    -h|--help) usage; exit 0 ;;
    -*)        echo "$0: Unrecognized option $1"; exit 1 ;;
    *)         OUTPUT=$1 ;;
  esac
  shift
done

get_md5() {
  if which md5sum > /dev/null 2>&1; then
    md5sum "$1" | awk '{print $1}'
  else
    md5 -q "$1"
  fi
}

list() {
  (cd ~ &&
   find -L .vim $VIMRC \
   \( -name .git -o -name .hg -o -name .svn \) -prune \
   -o ! -type d -print) | eval "$GREPV"
}

gitenv() {
  local NAME EMAIL
  if which git > /dev/null 2>&1 && NAME=$(git config user.name 2> /dev/null) &&
     EMAIL=$(git config user.email 2> /dev/null); then
    echo "export GIT_AUTHOR_NAME=\"$NAME\""
    echo "export GIT_AUTHOR_EMAIL=\"$EMAIL\""
    echo 'export GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"'
    echo 'export GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"'
  fi
}

generate() {
  if [ $EDIT -eq 1 ]; then
    CONF="$OUTPUT.conf.sh"
    echo "# EDIT: environment variables" > "$CONF"
    gitenv >> "$CONF"
    echo >> "$CONF"

    echo "# EDIT: the list of files to be archived" >> "$CONF"
    list >> "$CONF"

    ${EDITOR:-vim} "$CONF"
    ENV_VARS=$(sed -n '1,/^# EDIT/{/^# EDIT/d; p;}' "$CONF")
    FILES=$(sed '1,/^# EDIT/d' "$CONF")
    rm -f "$CONF"
  else
    ENV_VARS=""
    FILES=$(list)
  fi

  TEMP=/tmp/myvim-$(whoami).tar.compressed
  tar -C ~ -h $COMPRESS -cf $TEMP -T <(echo "$FILES")

  MD5=$(get_md5 "$TEMP")
  MD5=${MD5:0:8}
  echo '#!/usr/bin/env bash
# Created at: '$(date)'
'"$ENV_VARS"'
if [ "$1" == --hard ]; then
  HARD=1
  BASE=~
  echo "** Overwriting ~/.vim and ~/'"$VIMRC"' **"
  for e in ~/.vim ~/'"$VIMRC"'; do
    rm -rf ${e}.bak
    [ -e $e ] && mv ${e} ${e}.bak
  done
  shift
else
  HARD=""
  BASE=/tmp/myvim-$(whoami)/'$MD5'
fi

set -eu

if [ ! -d $BASE/.vim ]; then
  >&2 echo "Extracting Vim environment to $BASE"
  mkdir -p $BASE
  sed "1,/^# EOF #$/d" "$0" | tar -C $BASE -x '$COMPRESS'
  [ -z "$HARD" ] && (cd $BASE
   mv -f '"$VIMRC"' '"$VIMRC"'.org
   echo "let [s:home_org, \$HOME] = [\$HOME, \"$BASE\"]" > '"$VIMRC"'
   echo "set rtp^=$BASE/.vim" >> '"$VIMRC"'
   echo "autocmd VimEnter * let \$HOME = s:home_org" >> '"$VIMRC"'
   cat '"$VIMRC"'.org >> '"$VIMRC"'
   echo "let \$HOME = s:home_org" >> '"$VIMRC"'
   rm -f '"$VIMRC"'.org)
fi

\vim -Nu $BASE/'"$VIMRC"' "$@"
exit $?
# EOF #' > "$OUTPUT"
  cat "$TEMP" >> "$OUTPUT"
  chmod +x "$OUTPUT"
  echo "Created $OUTPUT executable"
  rm -f "$TEMP"
}

if [ ! -e ~/.vim ]; then
  mkdir -p ~/.vim
fi

generate