#!/bin/sh

#set -x

DEST_DIR=$HOME
DEFAULT_DOTFILES_DIR=$HOME/.dotfiles
HOSTNAME=`hostname -s`
DEBUG=:
PRINT=echo
VERBOSE=:

pushdir() {
  DIR_STACK="$DIR_STACK:$PWD/$1"
  $DEBUG "cd'ing to $1 from `pwd` with stack $DIR_STACK"
  cd $1
}

popdir() {
  current=`echo $DIR_STACK | sed -e 's/.*://g'`
  prior=`echo $DIR_STACK | sed -e "s|:$current$||" | sed -e 's/.*://g'`
  DIR_STACK=`echo $DIR_STACK | sed -e 's/:[^:]*$//'`
  $DEBUG "cd'ing to $prior from `pwd` with stack $DIR_STACK"
  cd $prior
}

build_path() {
  local dest=$1
  local file=$2
  local dotted=$3

  if [ $dotted -eq 1 ]; then
    echo $dest/$file
  else
    echo $dest/.$file
  fi
}

link_dir() {
  local dir=$1
  local dest_dir=$2
  local dotfiles_dir=$3
  local dotted=$4
  local dest_path=`build_path $dest_dir $dir $dotted`

  $VERBOSE "recurring on $dest_path"
  pushdir $dir
  for f in *; do
    $DEBUG "handling the file $f"
    handle_file $f $dest_path $dotfiles_dir/$dir 1
  done
  popdir
}

link_file() {
  local file=$1
  local dest_dir=$2
  local dotfiles_dir=$3
  local dotted=$4
  local dest_file=`build_path $dest_dir $file $dotted`

  if echo $DEST_STACK | grep -vq ":$dest_file"; then
    DEST_STACK="$DEST_STACK:$dest_file"

    $PRINT $dest_file:$dotfiles_dir/$file
  fi
}

handle_file() {
  local file=$1
  local dest_dir=$2
  local dotfiles_dir=$3
  local dotted=$4

  $DEBUG handle_file $1 $2 $3 $4

  if [ ! -e $file ]; then
    $VERBOSE "skipping non-existent file $file"
  elif [ -d $file ]; then
    link_dir $file $dest_dir $dotfiles_dir $dotted
  else
    dest_file=`build_path $dest_dir $file $dotted`
    link_file $file $dest_dir $dotfiles_dir $dotted
  fi
}

metafile() {
  [ x$2 = 'xhost-' -o x$3 = 'xtag-' ]
}

handle_command_line() {
  arg_tags=""
  verbosity=0
  version=0
  dotfiles_dirs=
  while getopts Vqvt:d: opt; do
    case "$opt" in
      t) arg_tags="$arg_tags $OPTARG";;
      v) verbosity=$(($verbosity + 1));;
      q) verbosity=$(($verbosity - 1));;
      d) dotfiles_dirs="$dotfiles_dirs $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=$@
}

DEST_STACK=

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

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

if [ "x$DOTFILES_DIRS" = "x" ]; then
  DOTFILES_DIRS="$DOTFILES_DIRS $DEFAULT_DOTFILES_DIR"
fi

for DOTFILES_DIR in $DOTFILES_DIRS; do

  if echo $DOTFILES_DIR | grep -vq '^/'; then
    DOTFILES_DIR=$PWD/$DOTFILES_DIR
  fi

  if [ ! -d $DOTFILES_DIR ]; then
    $VERBOSE "skipping non-existent directory: $DOTFILES_DIR" 
    continue
  fi

  cd $DOTFILES_DIR
  DIR_STACK=":$DOTFILES_DIR"

  for file in ${FILES:-*}; do
    host_portion=`echo $file | sed -e 's/host-.*/host-/'`
    tag_portion=`echo $file | sed -e 's/tag-.*/tag-/'`
    if ! metafile $file $host_portion $tag_portion; then
      handle_file $file $DEST_DIR $DOTFILES_DIR 0
    fi
  done

  cd $DOTFILES_DIR

  host_files=$DOTFILES_DIR/host-$HOSTNAME
  if [ -d $host_files ]; then
    pushdir `basename $host_files`
    for file in ${FILES:-*}; do
      handle_file $file $DEST_DIR $host_files 0
    done
    popdir
  fi

  cd $DOTFILES_DIR

  for tag in $TAGS; do
    if [ -d tag-$tag ]; then
      pushdir `basename tag-$tag`
      for file in ${FILES:-*}; do
        handle_file $file $DEST_DIR $DOTFILES_DIR/tag-$tag 0
      done
      popdir
    fi
  done

done