#!/usr/bin/env bash
# ─────────────────────────────────────────────────────────────
# Cezen AI Suite — Custom ISO Builder
# Runs on macOS using Docker. Produces a bootable USB image.
#
# Usage: bash autoinstall/build-iso.sh
# Output: autoinstall/cezen-ai-ubuntu2204.iso
#
# Requirements:
#   - Docker Desktop running on your MacBook
#   - ~6 GB free disk space (ISO download + work)
# ─────────────────────────────────────────────────────────────
set -e

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
OUTPUT_ISO="$SCRIPT_DIR/cezen-ai-ubuntu2204.iso"
UBUNTU_ISO_URL="https://releases.ubuntu.com/22.04.5/ubuntu-22.04.5-live-server-amd64.iso"

echo "╔══════════════════════════════════════════╗"
echo "║   Cezen AI — ISO Builder                 ║"
echo "╚══════════════════════════════════════════╝"
echo ""

# Check Docker is running
if ! docker info &>/dev/null; then
  echo "ERROR: Docker is not running. Start Docker Desktop and try again."
  exit 1
fi
echo "✓ Docker is running"

# Check autoinstall files exist
if [ ! -f "$SCRIPT_DIR/user-data" ] || [ ! -f "$SCRIPT_DIR/meta-data" ]; then
  echo "ERROR: user-data or meta-data not found in $SCRIPT_DIR"
  exit 1
fi
echo "✓ Autoinstall files found"

echo ""
echo "→ Building ISO inside Docker container (Ubuntu 22.04)..."
echo "  This will take 5–15 minutes depending on internet speed."
echo ""

docker run --rm \
  -v "$SCRIPT_DIR:/autoinstall" \
  -v "$REPO_ROOT:/repo" \
  ubuntu:22.04 \
  bash -c '
set -e

# Install tools
export DEBIAN_FRONTEND=noninteractive
apt-get update -qq
apt-get install -y -qq xorriso wget isolinux rsync

WORK_DIR="/tmp/iso-work"
ORIGINAL_ISO="/tmp/ubuntu-22.04.5-live-server-amd64.iso"
UBUNTU_URL="https://releases.ubuntu.com/22.04.5/ubuntu-22.04.5-live-server-amd64.iso"

# Download Ubuntu ISO if not already cached
if [ ! -f "$ORIGINAL_ISO" ]; then
  echo "→ Downloading Ubuntu 22.04.5 Server ISO (~1.8 GB)..."
  wget -q --show-progress -O "$ORIGINAL_ISO" "$UBUNTU_URL"
fi
echo "✓ Ubuntu ISO ready"

# Extract ISO contents
echo "→ Extracting ISO..."
rm -rf "$WORK_DIR"
mkdir -p "$WORK_DIR"
xorriso -osirrox on \
  -indev "$ORIGINAL_ISO" \
  -extract / "$WORK_DIR" 2>/dev/null
chmod -R u+w "$WORK_DIR"
echo "✓ ISO extracted"

# Inject autoinstall files
echo "→ Injecting autoinstall config..."
mkdir -p "$WORK_DIR/nocloud"
cp /autoinstall/user-data "$WORK_DIR/nocloud/user-data"
cp /autoinstall/meta-data "$WORK_DIR/nocloud/meta-data"

# Modify GRUB to auto-select install with autoinstall
GRUB_CFG="$WORK_DIR/boot/grub/grub.cfg"

# Backup original
cp "$GRUB_CFG" "$GRUB_CFG.orig"

# Set default to first entry and zero timeout
sed -i "s/set timeout=.*/set timeout=5/" "$GRUB_CFG"
sed -i "s/set timeout_style=.*/set timeout_style=countdown/" "$GRUB_CFG"

# Add autoinstall + nocloud parameters to the first linux line
# This patches the "Install Ubuntu Server" entry
sed -i "/^\s*linux.*vmlinuz/s/$/ autoinstall quiet ds=nocloud;s=\/cdrom\/nocloud\//" "$GRUB_CFG"

echo "✓ GRUB config patched"

# Get original ISO metadata for repacking
MBR_TEMPLATE=$(mktemp)
dd if="$ORIGINAL_ISO" bs=1 count=432 of="$MBR_TEMPLATE" 2>/dev/null

# Get EFI partition info
EFI_START=$(fdisk -l "$ORIGINAL_ISO" 2>/dev/null | grep "EFI" | awk "{print \$2}")
EFI_SIZE=$(fdisk -l "$ORIGINAL_ISO" 2>/dev/null | grep "EFI" | awk "{print \$4}")

echo "→ Repacking ISO..."
xorriso -as mkisofs \
  -r \
  -V "Cezen_AI_Ubuntu2204" \
  -o /autoinstall/cezen-ai-ubuntu2204.iso \
  --grub2-mbr "$MBR_TEMPLATE" \
  -partition_offset 16 \
  --mbr-force-bootable \
  -append_partition 2 28732ac11ff8d211ba4b00a0c93ec93b "$WORK_DIR/boot/grub/efi.img" \
  -appended_part_as_gpt \
  -iso_mbr_part_type a2a0d0ebe5b9334487c068b6b72699c7 \
  -c "/boot.catalog" \
  -b "/boot/grub/i386-pc/eltorito.img" \
  -no-emul-boot \
  -boot-load-size 4 \
  -boot-info-table \
  --grub2-boot-info \
  -eltorito-alt-boot \
  -e "--interval:appended_partition_2_start_${EFI_START}s_size_${EFI_SIZE}s:all::" \
  -no-emul-boot \
  -boot-load-size 4 \
  "$WORK_DIR" 2>/dev/null

echo "✓ ISO built successfully"
ls -lh /autoinstall/cezen-ai-ubuntu2204.iso
'

echo ""
echo "╔══════════════════════════════════════════════════════╗"
echo "║   ISO built: autoinstall/cezen-ai-ubuntu2204.iso    ║"
echo "║                                                      ║"
echo "║   Flash to USB:                                      ║"
echo "║   sudo dd if=autoinstall/cezen-ai-ubuntu2204.iso \  ║"
echo "║        of=/dev/diskX bs=4m status=progress           ║"
echo "║   (replace /dev/diskX with your USB drive)           ║"
echo "╚══════════════════════════════════════════════════════╝"
echo ""
echo "→ To find your USB drive: diskutil list"