#!/usr/bin/env bash
set -e

REPO_DIR="$(cd "$(dirname "$0")" && pwd)"
BASH_SRC="$REPO_DIR/.bashrc"

install_user() {
    local target="$1"
    if [ -z "$target" ]; then
        target="~"
    fi
    if [ -f "$target/.bashrc" ] && [ ! -f "$target/.bashrc.bak" ]; then
        cp "$target/.bashrc" "$target/.bashrc.bak"
        echo "backup: $target/.bashrc -> $target/.bashrc.bak"
    fi
    cp "$BASH_SRC" "$target/.bashrc"
    echo "installed: $target/.bashrc"

    if command -v chsh >/dev/null 2>&1; then
        local shell_path
        shell_path="$(command -v bash)"
        if [ "$SHELL" != "$shell_path" ]; then
            echo "change default shell to $shell_path? [y/N]"
            read -r ans
            if [ "$ans" = "y" ] || [ "$ans" = "Y" ]; then
                chsh -s "$shell_path"
                echo "default shell changed to bash"
            fi
        fi
    fi
}

install_system() {
    if [ ! -f /etc/skel/.bashrc.bak ] && [ -f /etc/skel/.bashrc ]; then
        cp /etc/skel/.bashrc /etc/skel/.bashrc.bak
        echo "backup: /etc/skel/.bashrc -> /etc/skel/.bashrc.bak"
    fi
    cp "$BASH_SRC" /etc/skel/.bashrc
    echo "installed: /etc/skel/.bashrc"
}

case "${1:-user}" in
    user)
        install_user "${2:-$HOME}"
        ;;
    system)
        install_system
        ;;
    *)
        echo "usage: $0 [user|system] [target_dir]"
        exit 1
        ;;
esac