dls2

#!/bin/sh

# DEP: (ls, readlink, mkdir, ln, rmdir)
nl='

'
do_link_check() {
        source_path="$1";target_path="$2";top_path="$source_path";
        ls -A1 -R "$source_path" | while read -r entry; do
                [ "$entry" != "${entry%:}" ] && top_path="${entry%:}" && continue
                [ -z "$entry" ] && continue
                entry_source="$top_path/$entry"
                entry_target="$target_path${entry_source#$source_path}"

                # Make sure dir exist or can be created.
                [ -d "$entry_source" ] && [ ! -d "$entry_target" ]  && [ -e "$entry_target" ] && {
                        echo "[ERROR] $entry_source => $entry_target"
                        printf "\t---> %s needed to be a directory! <---\n" "$entry_target"
                        return 1
                }

                [ -f "$entry_source" ] && [ -e "$entry_target" ] && {
                        echo "[ERROR] $entry_source => $entry_target"
                        printf "\t---> %s file exist! <---\n" "$entry_target"
                        return 1
                }
               [ -n "$verbose" ] && echo "[CHECK:OK] $entry_source"
       done
}

do_link() {
        source_path="$1";target_path="$2";top_path="$source_path";
        ls -A1 -R "$source_path" | while read -r entry; do
                [ "$entry" != "${entry%:}" ] && top_path="${entry%:}" && continue
                [ -z "$entry" ] && continue
                entry_source="$top_path/$entry"
                entry_target="$target_path${entry_source#$source_path}"
                [ -d "$entry_source" ] && mkdir -p "$entry_target"
                [ -f "$entry_source" ] && ln -sr "$entry_source" "$entry_target"
                [ -n "$verbose" ] && echo "[LINK] $entry_source => $entry_target"
        done
}

do_unlink() {
        source_path="$1";target_path="$2";top_path="$source_path";
        dirs=""
        ls -A1 -R "$source_path" | {
        while read -r entry; do
                [ "$entry" != "${entry%:}" ] && top_path="${entry%:}" && continue
                [ -z "$entry" ] && continue
                entry_source="$top_path/$entry"
                entry_target="$target_path${entry_source#$source_path}"
                [ -d "$entry_source" ] && dirs="$entry_target$nl$dirs" && continue
                [ -e "$entry_target" ] && [ ! -L "$entry_target" ] && {
                        echo "[WARN] $entry_target is not symbolic in nature."
                        continue
                }
                symbolic_trace="$(readlink -f "$entry_target")"
                [ -L "$entry_target" ] && [ "$symbolic_trace" == "$entry_source" ] && {
                        rm "$entry_target"
                        [ -n "$verbose" ] && echo "[UNLINK] $entry_target is removed."
                }
        done
        for entry_target in $dirs; do
                [ -z "$(ls -A "$entry_target")" ] && rmdir "$entry_target"
                [ -n "$verbose" ] && echo "[UNLINK] $entry_target is removed." || continue
        done
        }
}



TEMP=$(getopt -o 'ht:SDR' --long 'help,target:,link,delete,re-link' -n 'new-dls' -- "$@") || echo "$useage"
eval set -- "${TEMP}"
unset TEMP
TARGET_DIR="${HOME}"

while true; do
    case "$1" in
        '-h'|'--help')
            echo "$useage" && exit 0
            shift; continue;;
        '-t'|'--target')
            TARGET_DIR="$2"
            shift 2; continue;;
        '-S'|'--link')
            action="link"
            shift; break;;
        '-D'|'--delete')
            action="delete"
            shift; break;;
        '-R'|'--re-link')
            action="re-link"
            shift; break;;
         '--')
             shift; break;;
            *)
             echo 'Internal error!' >&2
             echo "$useage" && exit 1;;
     esac
done

export verbose=1
for source_path in "$@"; do
        [ "$source_path" = '--' ] && continue
        source_path="$(readlink -f "$source_path")"
        if [ "$action" = "link" ]; then
                do_link_check "$source_path" "$TARGET_DIR" && do_link "$source_path" "$TARGET_DIR"
        elif [ "$action" = "delete" ]; then
                do_unlink "$source_path" "$TARGET_DIR"
        elif [ "$action" = "re-link" ]; then
                do_unlink "$source_path" "$TARGET_DIR"
                do_link_check "$source_path" "$TARGET_DIR" && do_link "$source_path" "$TARGET_DIR"
        fi
done