#!/usr/bin/env bash
# ─────────────────────────────────────────────────────────────
# Cezen AI Suite — Custom ISO Builder
# Runs directly on Ubuntu 22.04 (run on the server)
#
# Usage:
#   cd ~/aipackage
#   bash autoinstall/build-iso.sh
#
# Output: ~/aipackage/autoinstall/cezen-ai-ubuntu2204.iso
# Then copy the ISO to a USB stick or burn it.
# ─────────────────────────────────────────────────────────────
set -e

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

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

# ── Install build tools ────────────────────────
echo "→ Installing build tools..."
apt-get update -qq
apt-get install -y -qq xorriso wget isolinux
echo "✓ Tools ready"

# ── Download Ubuntu ISO ────────────────────────
if [ -f "$ORIGINAL_ISO" ]; then
  echo "✓ Ubuntu ISO already downloaded"
else
  echo "→ Downloading Ubuntu 22.04.5 Server ISO (~1.8 GB)..."
  wget --show-progress -O "$ORIGINAL_ISO" "$UBUNTU_URL"
  echo "✓ Downloaded"
fi

# ── Extract ISO ────────────────────────────────
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 "✓ Extracted"

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

# ── Patch GRUB ────────────────────────────────
echo "→ Patching GRUB config..."
GRUB_CFG="$WORK_DIR/boot/grub/grub.cfg"
cp "$GRUB_CFG" "$GRUB_CFG.orig"

# Set 5 second countdown then auto-install
sed -i "s/set timeout=.*/set timeout=5/" "$GRUB_CFG"
sed -i "s/set timeout_style=.*/set timeout_style=countdown/" "$GRUB_CFG"

# Add autoinstall params to the first linux kernel line
sed -i "/^\s*linux.*vmlinuz/s/$/ autoinstall quiet ds=nocloud;s=\/cdrom\/nocloud\//" "$GRUB_CFG"
echo "✓ GRUB patched"

# ── Get EFI partition info for repacking ───────
MBR_TEMPLATE=$(mktemp)
dd if="$ORIGINAL_ISO" bs=1 count=432 of="$MBR_TEMPLATE" 2>/dev/null

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}')

# ── Repack ISO ─────────────────────────────────
echo "→ Repacking ISO (this takes ~2 minutes)..."
xorriso -as mkisofs \
  -r \
  -V "Cezen_AI_Ubuntu2204" \
  -o "$OUTPUT_ISO" \
  --grub2-mbr "$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 ""
echo "╔══════════════════════════════════════════════════════╗"
echo "║   Done!                                              ║"
echo "╚══════════════════════════════════════════════════════╝"
echo ""
ls -lh "$OUTPUT_ISO"
echo ""
echo "→ Copy to your MacBook:"
echo "   scp user@172.16.10.180:~/aipackage/autoinstall/cezen-ai-ubuntu2204.iso ."
echo ""
echo "→ Flash to USB on MacBook:"
echo "   diskutil list                        # find USB e.g. /dev/disk4"
echo "   diskutil unmountDisk /dev/disk4"
echo "   sudo dd if=cezen-ai-ubuntu2204.iso of=/dev/disk4 bs=4m status=progress"