#!/bin/sh

: ${RCM_LIB:=`dirname $0`/../share/rcm}
. $RCM_LIB/rcm.sh

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 exclude_file_globs="$5"
  local include_file_globs="$6"
  local dest_path=`build_path $dest_dir $dir $dotted`

  $DEBUG "link_dir $1 $2 $3 $4 $5 $6"

  $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 "$exclude_file_globs" "$include_file_globs"
  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
  local exclude_file_globs="$5"
  local include_file_globs="$6"

  $DEBUG "handle_file $1 $2 $3 $4 $5 $6"

  if [ ! -e $file ]; then
    $VERBOSE "skipping non-existent file $file"
  elif is_excluded $file "$exclude_file_globs" "$include_file_globs"; then
    $VERBOSE "skipping excluded file $file"
  elif [ -d $file ]; then
    link_dir $file $dest_dir $dotfiles_dir $dotted "$exclude_file_globs" "$include_file_globs"
  else
    link_file $file $dest_dir $dotfiles_dir $dotted
  fi
}

is_metafile() {
  host_portion=`echo $1 | sed -e 's/host-.*/host-/'`
  tag_portion=`echo $1 | sed -e 's/tag-.*/tag-/'`

  [ x$host_portion = 'xhost-' -o x$tag_portion = 'xtag-' ]
}

dotfiles_dir_excludes() {
  local dotfiles_dir=$1
  local excludes="$2"

  $DEBUG "dotfiles_dir_excludes $dotfiles_dir"
  $DEBUG "  with excludes: $excludes"

  for exclude in $excludes; do
    if echo $exclude | grep -q :; then
      dotfiles_dir_pat=`echo $exclude | sed 's/:.*//'`
      file_glob=`echo $exclude | sed 's/.*://'`

      if [ "x$dotfiles_dir_pat" != "x*" ] && is_relative $dotfiles_dir_pat; then
        dotfiles_dir_pat=$PWD/$dotfiles_dir_pat
      fi

      if [ "x$dotfiles_dir_pat" = "x*" -o "x$dotfiles_dir_pat" = "x$dotfiles_dir" ]; then
        echo $file_glob
      fi
    else
      echo $exclude
    fi
  done
}

is_excluded() {
  local file=$1
  local exclude_file_globs="$2"
  local include_file_globs="$3"

  $DEBUG "is_excluded $file $exclude_file_globs $include_file_globs"

  for exclude_file_glob in $exclude_file_globs; do
    $DEBUG "file: $file"
    $DEBUG "exclude_file_glob: $exclude_file_glob"

    case $file in
      $exclude_file_glob)
        for include_file_glob in $include_file_globs; do
          case $file in
            $include_file_glob) return 1;;
          esac
        done

        return 0
        ;;
    esac
  done

  return 1
}

handle_command_line() {
  local arg_tags=
  local verbosity=0
  local version=0
  local dotfiles_dirs=
  local excludes=
  local includes=

  while getopts VqvI:x:t:d: opt; do
    case "$opt" in
      I) includes="$includes $OPTARG";;
      t) arg_tags="$arg_tags $OPTARG";;
      v) verbosity=$(($verbosity + 1));;
      q) verbosity=$(($verbosity - 1));;
      d) dotfiles_dirs="$dotfiles_dirs $OPTARG";;
      V) version=1;;
      x) excludes="$excludes $OPTARG";;
    esac
  done
  shift $(($OPTIND-1))

  handle_common_flags lsrc $version $verbosity
  TAGS=${arg_tags:-$TAGS}
  DOTFILES_DIRS=${dotfiles_dirs:-$DOTFILES_DIRS}
  EXCLUDES=${excludes:-$EXCLUDES}
  INCLUDES=${includes:-$INCLUDES}
  FILES=$@

  $DEBUG "TAGS: $TAGS"
  $DEBUG "DOTFILES_DIRS: $DOTFILES_DIRS"
}

DEST_STACK=

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

handle_command_line $*

: ${DOTFILES_DIRS:=$DOTFILES_DIRS $DEFAULT_DOTFILES_DIR}
$DEBUG "DOTFILES_DIRS: $DOTFILES_DIRS"

for DOTFILES_DIR in $DOTFILES_DIRS; do
  if is_relative $DOTFILES_DIR; then
    DOTFILES_DIR=$PWD/$DOTFILES_DIR
  fi

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

  exclude_file_globs=`dotfiles_dir_excludes $DOTFILES_DIR "$EXCLUDES"`
  $DEBUG "exclude_file_globs: $exclude_file_globs"
  include_file_globs=`dotfiles_dir_excludes $DOTFILES_DIR "$INCLUDES"`

  cd $DOTFILES_DIR
  DIR_STACK=":$DOTFILES_DIR"

  for file in ${FILES:-*}; do
    if is_metafile $file; then
      continue
    fi

    handle_file $file $DEST_DIR $DOTFILES_DIR 0 "$exclude_file_globs" "$include_file_globs"
  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 $host_files 0 "$exclude_file_globs" "$include_file_globs"
    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
        $DEBUG "TAG: $tag, exclude_file_globs: $exclude_file_globs"
        handle_file $file $DEST_DIR $DOTFILES_DIR/tag-$tag 0 "$exclude_file_globs" "$include_file_globs"
      done
      popdir
    fi
  done

done