#!/usr/bin/env bash
note() {
    echo -E "$@"
}

die() {
    echo -E "$@">&2
    exit 1
}

dotless() {
    [[ "${1:0:1}" == "." ]] && REPLY="${1:1}" || REPLY="$1"
}

backup() {
    note "backing up $1"
    mkdir -p "${backup_dir:?backup_dir unset}/$(dirname "$1")"
    [ -e "$backup_dir/$1" ] && die "backup already exists"
    mv "$1" "$backup_dir/$1"
}

hardlink() {
    if [ -e "$1" ]; then
        [ "$1" -ef "$2" ] && return
        [ -h "$1" ] && note "removing symbolic link $1" && rm "$1"
        if [ -s "$1" ]; then
            backup "$1" || die "$1 already exists"
        fi
    fi

    ln "$2" "$1" || die "couldn't hardlink $1"
}

softlink() {
    if [ -e "$1" ]; then
        if [ -h "$1" ]; then
            [ "$(readlink "$1")" == "$2" ] && return
            note "removing symbolic link $1"
            rm "$1"
        else
            die "$1 already exists and is not a symbolic link"
        fi
    fi

    ln -s "$2" "$1" || die "couldn't symlink $1"
}

which readlink >/dev/null || exit 1

rc="$(readlink -f "$(dirname "$0")" )"
cd "$HOME"
PATH="${PATH:?No existing PATH}:$rc/sh"

backup_dir="$rc/backup-$(date '+%s')"

for f in .bashrc .zshrc .-shrc .streamcrap .vimrc \
  .inputrc .screenrc .indent.pro .uncrustify.cfg; do
    dotless "$f"
    r="$rc/home/$REPLY"
    hardlink "$f" "$r"
done

for d in sh .vim .mpv; do
    dotless "$d"
    r="$rc/$REPLY"
    softlink "$d" "$r"
done

for d in ssh; do
    mkdir -p ".$d"
    for r in $rc/$d/*; do
        f=".${r#"$rc/"}"
        hardlink "$f" "$r"
    done
done

grep .bashrc .bash_profile >/dev/null 2>&1 \
 || echo -e '\n[[ -f ~/.bashrc ]] && . ~/.bashrc' >> .bash_profile

for d in Desktop Documents Downloads Music Pictures Public Templates Video Videos; do
    [ -d "$d" ] || continue
    is_empty "$d" && rm -r "$d" || note "skipping unempty $d"
done

mkdir -p opt/local/bin src work play