#!/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
}

file_join() {
  local result=

  for file; do
    if [ "x$file" != "x." ]; then
      if [ "x$result" = "x" ]; then
        result="$file"
      else
        result="$result/$file"
      fi
    fi
  done

  echo "$result"
}

show_dir() {
  local dir="$1"
  local dest_dir="$2"
  local dotfiles_dir="$3"
  local dotfiles_subdir="$4"
  local dotted=$5
  local exclude_file_globs="$6"
  local include_file_globs="$7"
  local symlink_dirs_file_globs="$8"
  local mk_dirs_file_globs="$9"
  local dest_path="$(build_path "$dest_dir" "$dir" $dotted)"

  $DEBUG "show_dir $1 $2 $3 $4 $5 $6 $7 $8 $9"

  $VERBOSE "recurring on $dest_path"

  pushdir "$dir"
  for f in *; do
    $DEBUG "handling the file $f"
    next_dir="$(file_join "$dotfiles_subdir" "$dir")"
    handle_file "$f" "$dest_path" "$dotfiles_dir" "$next_dir" 1 "$exclude_file_globs" "$include_file_globs" "$symlink_dirs_file_globs" "$mk_dirs_file_globs"
  done
  popdir
}

sigil_for() {
  local file="$1"
  local symlink_dirs_file_globs="$2"
  local copy_always=0
  local symlink_dirs=0

  for copy_file in $COPY_ALWAYS; do
    $DEBUG "copy_file: $copy_file"
    $DEBUG "file: $file"

    case "$file" in
      $copy_file)
        copy_always=1
        break
        ;;
    esac
  done

  if [ -n "$symlink_dirs_file_globs" ]; then
    symlink_dirs=1
  fi

  if [ $copy_always -eq 1 ]; then
    echo 'X'
  elif [ $symlink_dirs -eq 1 ]; then
    echo '$'
  else
    echo '@'
  fi
}

show_file() {
  local file="$1"
  local dest_dir="$2"
  local dotfiles_dir="$3"
  local dotfiles_subdir="$4"
  local dotted=$5
  local symlink_dirs_file_globs="$6"
  local dest_file="$(build_path "$dest_dir" "$file" $dotted)"
  local src_file="$(file_join "$dotfiles_subdir" "$file")"
  local abs_src_file="$(file_join "$dotfiles_dir" "$src_file")"
  local output="$dest_file:$abs_src_file"

  if [ $SHOW_SIGILS -eq 1 ]; then
    sigil="$(sigil_for "$src_file" "$symlink_dirs_file_globs")"
    output="$output:$sigil"
  fi

  if echo "$DEST_STACK:" | grep -v ":$dest_file:" >/dev/null; then
    DEST_STACK="$DEST_STACK:$dest_file"
    $PRINT "$output"
  else
    $VERBOSE "skipping hidden file $output"
  fi
}

handle_file() {
  local file="$1"
  local dest_dir="$2"
  local dotfiles_dir="$3"
  local dotfiles_subdir="$4"
  local dotted=$5
  local exclude_file_globs="$6"
  local include_file_globs="$7"
  local symlink_dirs_file_globs="$8"
  local mk_dirs_file_globs="$9"

  $DEBUG "handle_file $1 $2 $3 $4 $5 $6 $7 $8" "$9"

  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" ] && is_excluded "$file" "$symlink_dirs_file_globs" "$mk_dirs_file_globs"; then
    show_file "$file" "$dest_dir" "$dotfiles_dir" "$dotfiles_subdir" $dotted
  elif [ -d "$file" ]; then
    show_dir "$file" "$dest_dir" "$dotfiles_dir" "$dotfiles_subdir" $dotted "$exclude_file_globs" "$include_file_globs" "$symlink_dirs_file_globs" "$mk_dirs_file_globs"
  else
    show_file "$file" "$dest_dir" "$dotfiles_dir" "$dotfiles_subdir" $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-' -o "x$1" = "xhooks" ]
}

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 ':' >/dev/null; 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
}

show_help() {
  local exit_code=${1:-0}

  $PRINT "Usage: lsrc [-FhqVv] [-B HOSTNAME] [-d DOT_DIR] [-I EXCL_PAT] [-S EXCL_PAT] [-s EXCL_PAT] [-t TAG] [-U EXCL_PAT] [-u EXCL_PAT] [-x EXCL_PAT]"
  $PRINT "see lsrc(1) and rcm(7) for more details"

  exit $exit_code
}

handle_command_line() {
  local arg_tags=
  local verbosity=0
  local version=0
  local show_sigils=0
  local dotfiles_dirs=
  local excludes=
  local includes=
  local symlink_dirs=
  local never_symlink_dirs=
  local hostname=
  local undotted=
  local never_undotted=

  while getopts :FVqvhI:x:B:S:s:U:u:t:d: opt; do
    case "$opt" in
      F) show_sigils=1;;
      h) show_help ;;
      I) includes="$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 $OPTARG";;
      S) symlink_dirs="$symlink_dirs $OPTARG";;
      s) never_symlink_dirs="$never_symlink_dirs $OPTARG";;
      U) undotted="$undotted $OPTARG";;
      u) never_undotted="$never_undotted $OPTARG";;
      B) hostname="$OPTARG";;
      ?) show_help 64 ;;
    esac
  done
  shift $(($OPTIND-1))

  handle_common_flags lsrc $version $verbosity
  HOSTNAME="$(determine_hostname "$hostname")"
  SHOW_SIGILS=$show_sigils
  TAGS="${arg_tags:-$TAGS}"
  DOTFILES_DIRS="${dotfiles_dirs:-$DOTFILES_DIRS}"
  EXCLUDES="${excludes:-$EXCLUDES}"
  INCLUDES="${includes:-$INCLUDES}"
  SYMLINK_DIRS="${symlink_dirs:-$SYMLINK_DIRS}"
  MK_DIRS="${never_symlink_dirs:-$MK_DIRS}"
  UNDOTTED="${undotted:-$UNDOTTED}"
  NEVER_UNDOTTED="${never_undotted:-$NEVER_UNDOTTED}"
  FILES="$@"

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

DEST_STACK=

handle_command_line "$@"

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

: ${COPY_ALWAYS:=""}
$DEBUG "COPY_ALWAYS: $COPY_ALWAYS"

: ${SYMLINK_DIRS:=""}
$DEBUG "SYMLINK_DIRS: $SYMLINK_DIRS"

: ${MK_DIRS:=""}
$DEBUG "MK_DIRS: $MK_DIRS"

: ${UNDOTTED:=""}
$DEBUG "UNDOTTED: $UNDOTTED"

: ${NEVER_UNDOTTED:=""}
$DEBUG "NEVER_UNDOTTED: $NEVER_UNDOTTED"

relative_root_dir="$PWD"

for DOTFILES_DIR in $DOTFILES_DIRS; do
  cd "$relative_root_dir"

  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")"
  symlink_dirs_file_globs="$(dotfiles_dir_excludes "$DOTFILES_DIR" "$SYMLINK_DIRS")"
  $DEBUG "symlink_dirs_file_globs: $symlink_dirs_file_globs"
  mk_dirs_file_globs="$(dotfiles_dir_excludes "$DOTFILES_DIR" "$MK_DIRS")"
  $DEBUG "mk_dirs_file_globs: $mk_dirs_file_globs"
  undotted_file_globs="$(dotfiles_dir_excludes "$DOTFILES_DIR" "$UNDOTTED")"
  $DEBUG "undotted_file_globs: $undotted_file_globs"
  never_undotted_file_globs="$(dotfiles_dir_excludes "$DOTFILES_DIR" "$NEVER_UNDOTTED")"
  $DEBUG "never_undotted_file_globs: $never_undotted_file_globs"

  cd "$DOTFILES_DIR"
  DIR_STACK=":$DOTFILES_DIR"

  host_files="$DOTFILES_DIR/host-$HOSTNAME"
  if [ -d "$host_files" ]; then
    pushdir "$(basename "$host_files")"
    for file in ${FILES:-*}; do
      dotted=0
      if is_excluded "$file" "$undotted_file_globs" "$never_undotted_file_globs"; then
        dotted=1
      fi

      handle_file "$file" "$DEST_DIR" "$host_files" . "$dotted" "$exclude_file_globs" "$include_file_globs" "$symlink_dirs_file_globs" "$mk_dirs_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: $exclude_file_globs"
        dotted=0
        if is_excluded "$file" "$undotted_file_globs" "$never_undotted_file_globs"; then
          dotted=1
        fi
        handle_file "$file" "$DEST_DIR" "$DOTFILES_DIR/tag-$tag" . "$dotted" "$exclude_file_globs" "$include_file_globs" "$symlink_dirs_file_globs" "$mk_dirs_file_globs"
      done
      popdir
    fi
  done

  cd "$DOTFILES_DIR"

  for file in ${FILES:-*}; do
    dotted=0
    if is_metafile "$file"; then
      continue
    fi

    if is_excluded "$file" "$undotted_file_globs" "$never_undotted_file_globs"; then
      dotted=1
    fi

    handle_file "$file" "$DEST_DIR" "$DOTFILES_DIR" . "$dotted" "$exclude_file_globs" "$include_file_globs" "$symlink_dirs_file_globs" "$mk_dirs_file_globs"
  done
done
