install

#!/bin/bash

set -euo pipefail

usage() {
	cat <<EOF
Usage: sudo ./install [OPTIONS]

Installs the backUP tool and optional Bash auto-completion.

Options:
  -u <user>		  User to install auto-completion for (default: \$SUDO_USER)
  -d <dir>		  Destination directory for bash completions (default: ~<user>/.bash_completion.d)
  -n			  Do NOT install bash completion
  -h			  Show this help message
EOF
	exit 0
}

# Default values
user="${SUDO_USER:-}"
completion_dir=""
install_completion=true

# Parse options
while getopts ":u:d:nh" opt; do
	case "$opt" in
		u) user="$OPTARG" ;;
		d) completion_dir="$OPTARG" ;;
		n) install_completion=false ;;
		h) usage ;;
		:) echo "Missing argument for -$OPTARG" >&2; exit 1 ;;
		\?) echo "Unknown option: -$OPTARG" >&2; usage ;;
	esac
done

# Confirm user is root
if [[ $EUID -ne 0 ]]; then
	echo "This script must be run as root (e.g., with sudo)" >&2
	exit 1
fi

# Determine user home
if [[ -z "$user" ]]; then
	echo "No user provided; attempting to use SUDO_USER..."
	[[ -n "${SUDO_USER:-}" ]] || { echo "Error: -u required when SUDO_USER is not set." >&2; exit 1; }
	user="$SUDO_USER"
fi

user_home=$(eval echo "~$user")
[[ -d "$user_home" ]] || { echo "Error: Home directory for $user not found." >&2; exit 1; }

if [[ -z "$completion_dir" ]]; then
	completion_dir="$user_home/.bash_completion.d"
fi

# Install binary and library files
echo "Installing backUP and support files..."
declare -A FILES=(
	[backUP]="/usr/local/bin/backUP"
	[args2array]="/usr/local/lib/backUP/args2array"
	[logging]="/usr/local/lib/backUP/logging"
)

mkdir -p /usr/local/lib/backUP /usr/local/etc/backUP

for src in "${!FILES[@]}"; do
	dst="${FILES[$src]}"
	if [[ -e "$dst" ]]; then
		if cmp -s "$src" "$dst"; then
			echo "✓ $dst is up to date, skipping"
			continue
		else
			read -p "⚠ $dst differs from source. Overwrite? [y/N] " ans
			[[ "$ans" =~ ^[Yy]$ ]] || { echo "Skipping $dst"; continue; }
		fi
	else
		echo "→ Installing $dst"
	fi
	install -o root -g root -m 755 "$src" "$dst"
done

for cfg in /usr/local/etc/backUP/backUP.conf /usr/local/etc/backUP/backup.txt; do
	[[ -e "$cfg" ]] || touch "$cfg"
	chmod 660 "$cfg"
	chown root:root "$cfg"
done

# Install bash completion if enabled
if $install_completion; then
	echo "Setting up Bash completion..."

	mkdir -p "$completion_dir"
	chown "$user":"$user" "$completion_dir"

	completion_src=".bash_completion.d/backUP"
	completion_dst="$completion_dir/backUP"

	if [[ -e "$completion_dst" ]]; then
		if cmp -s "$completion_src" "$completion_dst"; then
			echo "✓ Bash completion is up to date, skipping"
		else
			read -p "⚠ Bash completion differs. Overwrite $completion_dst? [y/N] " ans
			[[ "$ans" =~ ^[Yy]$ ]] && cp "$completion_src" "$completion_dst"
		fi
	else
		cp "$completion_src" "$completion_dst"
		echo "→ Installed bash completion to $completion_dst"
	fi

	chown "$user":"$user" "$completion_dst"

	# Add sourcing line to .bashrc if needed
	bashrc="$user_home/.bashrc"
	source_line="[[ -f \"$completion_dst\" ]] && source \"$completion_dst\""

	if ! grep -Fxq "$source_line" "$bashrc"; then
		read -p "→ Would you like to add sourcing to $bashrc? [y/N] " ans
		if [[ "$ans" =~ ^[Yy]$ ]]; then
			echo "$source_line" >> "$bashrc"
			echo "✓ Added to $bashrc"
		else
			echo "Skipping .bashrc modification"
		fi
	else
		echo "✓ .bashrc already sources the completion"
	fi
else
	echo "Skipping bash completion setup (-n was passed)"
fi