#!/bin/bash
# Copyright (C) 2014 Ian Kelling
# This program is under GPL v. 3 or later, see <http://www.gnu.org/licenses/>

lnf() {
    local help="lnf [--help] LN_ARGUMENTS...
Create symlinks conveniently and forcefully.
Remove existing file/links using trash-put or rm -rf if it is not available.
Create directory if needed. Small change to ln argument semantics: for 2 arguments,
the second is the link, never a directory to put the link in.
LN_ARGUMENTS are passed to ln -s --, meaning no ln option arguments are supported."
    if [[ $1 == --help ]]; then
        echo "$help"
        return 0
    fi
    
    local remove x
    if type -P dircolors >/dev/null; then
        remove=trash-put
    else
        remove="rm -rf"
    fi
    
    if [[ $# -ge 3 ]]; then
        if [[ -d ${!#} ]]; then
            local oldcwd=$PWD
            cd ${!#} # last arg
            for x in "${@:1:$(($#-1))}"; do # all but last arg
                # remove any trailing slashes
                x="${x%%+(/)}"
                # remove any leading directory components
                x="${x##*/}"
                [[ -e "$x" || -L "$x" ]] && $remove "$x"
            done
            cd "$oldcwd"
        else
            mkdir -p "${!#}"
        fi
    elif [[ $# -eq 2 ]]; then
        if [[ -e "$2" || -L "$2" ]]; then
            $remove "$2"
        elif [[ ! -d "$2/.." ]]; then
            mkdir -p "$2/.."
        fi
    elif  [[ $# -eq 1 ]]; then
        [[ -e "${1##*/}" || -L "${1##*/}" ]] && $remove "${1##*/}"
    fi
    ln -s -- "$@"
}
lnf "$@"