#!/bin/sh


# Do argument checks
if [ ! "$#" -ge 1 ]; then
    echo "Usage: $0 {size}"
    echo "Example: $0 4G"
    echo "(Default path: /swapfile)"
    echo "Optional path: Usage: $0 {size} {path}"
    exit 1
fi

SUDO=''

# Check if invoking user is root
if [ "$(id -u)" -ne 0 ]; then
    echo "Root access is required, please run as root or enter sudo password if prompted." >&2
    if sudo true; then
        SUDO='sudo'
    else
        echo "Unable to run command as root. Please check your access and try again." >&2
        exit 1
    fi
fi


## Intro
echo "Welcome to Swap setup script! This script will automatically setup a swap file and enable it."
echo "Source is @ https://github.com/Cretezy/Swap"
echo

## Setup variables

# Get size from first argument
SWAP_SIZE=$1

# Get path from second argument (default to /swapfile)
SWAP_PATH="/swapfile"
if [ ! -z "$2" ]; then
    SWAP_PATH=$2
fi


## Run
$SUDO fallocate -l $SWAP_SIZE $SWAP_PATH  # Allocate size
$SUDO chmod 600 $SWAP_PATH                # Set proper permission
$SUDO mkswap $SWAP_PATH                   # Setup swap
$SUDO swapon $SWAP_PATH                   # Enable swap
echo "$SWAP_PATH   none    swap    sw    0   0" | $SUDO tee /etc/fstab -a # Add to fstab

## Outro

echo
echo "Done! You now have a $SWAP_SIZE swap file at $SWAP_PATH"