#!/bin/bash

# Exit immediately if a command exits with a non-zero status
set -e

# Define variables
WORK_DIR="/root/build-alpine"
INPUT_DIR="$WORK_DIR/input"  # Directory containing files to be included in the image
OUTPUT_DIR="$WORK_DIR/output"
SCRIPT_NAME="alpine-make-vm-image"
SCRIPT_URL="https://raw.githubusercontent.com/alpinelinux/alpine-make-vm-image/v0.13.0/$SCRIPT_NAME"
SCRIPT_SHA1="0fe2deca927bc91eb8ab32584574eee72a23d033"
ALPINE_IMAGE_NAME="alpine-custom.raw"
SETUP_SCRIPT="$INPUT_DIR/vm-setup.sh"  # Correct path to vm-setup.sh

# Ensure a custom TMPDIR is used to avoid filling up /tmp
export TMPDIR="$WORK_DIR/tmp"
mkdir -p "$TMPDIR"

# Create working, input, and output directories
mkdir -p "$INPUT_DIR"
mkdir -p "$OUTPUT_DIR"
cd "$WORK_DIR"

# Install necessary dependencies
sudo apt-get update
sudo apt-get install -y qemu-utils qemu-system-x86 rsync util-linux e2fsprogs dosfstools

# Check available disk space before proceeding
REQUIRED_SPACE_MB=2048 # Minimum required space in MB
AVAILABLE_SPACE_MB=$(df --output=avail -m "$OUTPUT_DIR" | tail -n 1)

if [ "$AVAILABLE_SPACE_MB" -lt "$REQUIRED_SPACE_MB" ]; then
    echo "Error: Not enough space in $OUTPUT_DIR. Required: ${REQUIRED_SPACE_MB}MB, Available: ${AVAILABLE_SPACE_MB}MB."
    exit 1
fi

# Download the alpine-make-vm-image script
wget "$SCRIPT_URL" -O "$SCRIPT_NAME"

# Verify the script SHA1 hash
echo "$SCRIPT_SHA1  $SCRIPT_NAME" | sha1sum -c || exit 1

# Make the alpine-make-vm-image script executable
chmod +x "$SCRIPT_NAME"

# Ensure vm-setup.sh is executable
chmod +x "$SETUP_SCRIPT"

# Run the alpine-make-vm-image script to create the VM image
./"$SCRIPT_NAME" \
  -f raw \
  -s 2G \
  -a x86_64 \
  -B BIOS \
  -b latest-stable \
  -p "openssh-server htop curl nano zsh" \
  -S "$INPUT_DIR" \
  --fs-skel-chown=root:root \
  --script-chroot \
  "$OUTPUT_DIR/$ALPINE_IMAGE_NAME" \
  "$SETUP_SCRIPT"  # Use the correct path for the setup script

# Check if the image creation was successful
if [ -f "$OUTPUT_DIR/$ALPINE_IMAGE_NAME" ]; then
    echo "Alpine Linux VM image created successfully at: $OUTPUT_DIR/$ALPINE_IMAGE_NAME"
else
    echo "Error: Image creation failed."
    exit 1
fi