#!/bin/bash

# Manual GRUB fix - completely rewrite the GRUB_CMDLINE_LINUX_DEFAULT line

set -e

if [ "$EUID" -ne 0 ]; then 
    echo "Please run as root: sudo $0"
    exit 1
fi

echo "=== Fixing GRUB Configuration (Manual Method) ==="
echo ""

GRUB_FILE="/etc/default/grub"

# Backup
cp "$GRUB_FILE" "$GRUB_FILE.backup.manual.$(date +%Y%m%d-%H%M%S)"
echo "✓ Backup created"

# Replace the entire line with a clean version
sed -i 's|^GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amd_iommu=on iommu=pt vfio-pci.ids=1002:1586,1002:1640 amdgpu.gttsize=131072 ttm.pages_limit=33554432 amdgpu.si_support=1 amdgpu.cik_support=1 radeon.si_support=0 radeon.cik_support=0"|' "$GRUB_FILE"

echo "✓ GRUB configuration updated"
echo ""
echo "New configuration:"
grep "GRUB_CMDLINE_LINUX_DEFAULT" "$GRUB_FILE"
echo ""

# Update GRUB
echo "Updating GRUB..."
update-grub

echo ""
echo "=== Fix Complete ==="
echo ""
echo "Changes made:"
echo "  - Removed: amd_iommu=off"
echo "  - Added: amd_iommu=on iommu=pt"
echo "  - Added: vfio-pci.ids=1002:1586,1002:1640"
echo ""
echo "⚠️  REBOOT REQUIRED: sudo reboot"
echo ""
echo "After reboot, check:"
echo "  cat /proc/cmdline | grep amd_iommu"
echo "  Should show ONLY: amd_iommu=on"