#!/bin/sh

#set -x

REPLACE_ALL=0

DEST_DIR=$HOME
DEBUG=:
PRINT=echo
PROMPT=echo_n
VERBOSE=:
MKDIR=mkdir
LN=ln
RM=rm

echo_n() {
  printf "%s " "$*"
}

link_file() {
  local src=$1
  local dest=$2

  $PRINT "linking $dest"
  if [ -h $dest ]; then
    rm -f $dest
  fi

  $LN -s $src $dest
}

replace_file() {
  local src=$1
  local dest=$2

  $DEBUG replace_file $1 $2
  
  $RM -rf $dest
  link_file $src $dest
}

is_nested() {
  echo $1 | sed "s:$DEST_DIR/::" | grep -q /
  return $?
}

is_identical() {
  diff -q -s $1 $2 > /dev/null
}

handle_dir() {
  local dest=$1

  $DEBUG handle_dir $1

  dirname $dest | xargs $MKDIR -p
}

handle_file() {
  local src=$1
  local dest=$2

  $DEBUG handle_file $1 $2

  if [ -e "$dest" ]; then
    if is_identical $src $dest; then
      $VERBOSE "identical $dest"
    elif [ $REPLACE_ALL -eq 1 ]; then
      replace_file $src $dest
    else
      $PROMPT "overwrite ${dest}? [ynaq]"
      read overwrite
      case $overwrite in
        a) REPLACE_ALL=1
           replace_file $src $dest
           ;;
        y) replace_file $src $dest ;;
        q) exit 1 ;;
        *) $VERBOSE "skipping $dest" ;;
      esac
    fi
  else
    link_file $src $dest
  fi
}

handle_command_line() {
  arg_tags=""
  verbosity=0
  version=0
  dotfiles_dirs=
  LS_ARGS=
  while getopts Vqvt:d: opt; do
    case "$opt" in
      t)
        arg_tags="$arg_tags $OPTARG"
        LS_ARGS="$LS_ARGS -t $OPTARG"
        ;;
      v) verbosity=$(($verbosity + 1));;
      q) verbosity=$(($verbosity - 1));;
      d)
        dotfiles_dirs="$dotfiles_dirs $OPTARG"
        LS_ARGS="$LS_ARGS -d $OPTARG"
        ;;
      V) version=1
    esac
  done
  shift $(($OPTIND-1))

  if [ $version -eq 1 ]; then
    version rcup
    exit 0
  elif [ $verbosity -ge 2 ]; then
    DEBUG=echo
    VERBOSE=echo
    PRINT=echo
  elif [ $verbosity -eq 1 ]; then
    DEBUG=:
    VERBOSE=echo
    PRINT=echo
  elif [ $verbosity -eq 0 ]; then
    DEBUG=:
    VERBOSE=:
    PRINT=echo
  else
    DEBUG=:
    VERBOSE=:
    PRINT=:
  fi

  if [ "x$arg_tags" != "x" ]; then
    TAGS=$arg_tags
  fi

  if [ "x$dotfiles_dirs" != "x" ]; then
    DOTFILES_DIRS=$dotfiles_dirs
  fi

  FILES=$@
  LS_ARGS="$LS_ARGS $FILES"
}

if [ -e $HOME/.rcrc ]; then
  . $HOME/.rcrc
fi

. `dirname $0`/../share/rcm/rcm.sh
handle_command_line $*

for dest_and_src in `lsrc $LS_ARGS`; do
  dest=`echo $dest_and_src | sed 's/:.*//'`
  src=`echo $dest_and_src | sed 's/.*://'`

  if is_nested $dest; then
    handle_dir $dest
  fi

  handle_file $src $dest
done