#!/bin/bash
# UniversalisOS x86_64 — UEFI Bootable ISO Creator
#
# Creates a bootable ISO image with:
#   - GRUB2 UEFI bootloader
#   - Kernel ELF binary
#   - UEFI application (optional)
#
# Prerequisites: grub-mkrescue, xorriso, mtools
#
# Usage: ./make-uefi-iso.sh [kernel.elf] [output.iso]
#
# SPDX-License-Identifier: MIT

set -e

KERNEL="${1:-/home/fabiorafaelcoutada/portugalfuturista/universalisos/kernel/build/uos-x86_64.elf}"
OUTPUT="${2:-/tmp/uos-uefi.iso}"
WORKDIR="/tmp/uos-iso-build"
GRUB_CFG="$(dirname "$0")/src/arch/x86_64/grub-uefi.cfg"
OVMF_PATH="$(dirname "$0")/src/arch/x86_64/ovmf/OVMF.fd"

echo "=== UniversalisOS UEFI ISO Builder ==="
echo "Kernel: $KERNEL"
echo "Output: $OUTPUT"

# Check prerequisites
if ! command -v grub-mkrescue &>/dev/null; then
    echo "ERROR: grub-mkrescue not found. Install grub2-common or grub2-tools."
    echo "  sudo dnf install grub2-tools-extra xorriso mtools"
    exit 1
fi

# Check if kernel exists
if [ ! -f "$KERNEL" ]; then
    echo "ERROR: Kernel not found at $KERNEL"
    echo "Build first: make ARCH=x86_64 PLATFORM=qemu-x86_64-virt"
    exit 1
fi

# Clean work directory
rm -rf "$WORKDIR"
mkdir -p "$WORKDIR/boot/grub"
mkdir -p "$WORKDIR/EFI/UOS"
mkdir -p "$WORKDIR/EFI/BOOT"

# Copy kernel
cp "$KERNEL" "$WORKDIR/boot/uos-x86_64.elf"
cp "$KERNEL" "$WORKDIR/EFI/UOS/kernel.elf"

# Copy GRUB config
if [ -f "$GRUB_CFG" ]; then
    cp "$GRUB_CFG" "$WORKDIR/boot/grub/grub.cfg"
else
    echo "WARNING: grub-uefi.cfg not found, using default"
    cat > "$WORKDIR/boot/grub/grub.cfg" << 'EOF'
set default=0
set timeout=5
menuentry "UniversalisOS" {
    multiboot2 /boot/uos-x86_64.elf
    boot
}
EOF
fi

# Create the ISO
echo "Creating ISO image..."
grub-mkrescue -o "$OUTPUT" "$WORKDIR" 2>/dev/null || {
    echo "grub-mkrescue failed, trying alternative method..."

    # Alternative: create a basic ISO with the kernel
    # Use xorriso directly
    xorriso -as mkisofs \
        -R -J -joliet-long \
        -b boot/grub/i386-pc/eltorito.bin \
        -no-emul-boot \
        -boot-load-size 4 \
        -boot-info-table \
        -eltorito-alt-boot \
        -e EFI/BOOT/BOOTX64.EFI \
        -no-emul-boot \
        -isohybrid-gpt-basdat \
        -o "$OUTPUT" \
        "$WORKDIR" 2>/dev/null || {
        echo "WARNING: ISO creation failed. Use QEMU directly with OVMF."
        echo ""
        echo "Alternative QEMU commands:"
        echo "  # Direct multiboot (no ISO needed):"
        echo "  qemu-system-x86_64 -kernel $KERNEL -m 4096 -enable-kvm -cpu host -serial stdio -display none"
        echo ""
        echo "  # With UEFI firmware (OVMF):"
        echo "  qemu-system-x86_64 -bios $OVMF_PATH -kernel $KERNEL -m 4096 -serial stdio -nographic"
        exit 0
    }
}

echo "ISO created: $OUTPUT"
echo "Size: $(du -h "$OUTPUT" | cut -f1)"
echo ""
echo "Test with:"
echo "  # UEFI boot:"
echo "  qemu-system-x86_64 -bios $OVMF_PATH -cdrom $OUTPUT -m 4096 -serial stdio -nographic"
echo ""
echo "  # Direct kernel boot:"
echo "  qemu-system-x86_64 -kernel $KERNEL -m 4096 -enable-kvm -cpu host -serial stdio -display none"

# Clean up
rm -rf "$WORKDIR"