#!/bin/bash

set -e

if [ "$UID" -ne 0 ]; then
    >&2 echo 'Must be run as root'
    exit 1
fi

# Get the current kernel version
current_kernel=$(uname -r)

echo "Current kernel: $current_kernel"
echo "Searching for old kernel files in /boot..."

# Extract base kernel version (without possible suffixes)
current_base=$(echo "$current_kernel" | sed 's/-.*//')

cd /boot || { echo "/boot directory not found!"; exit 1; }

for file in vmlinuz-* initrd.img-* System.map-* config-*; do
    # Extract version from filename
    version=$(echo "$file" | sed -E 's/^[^0-9]*([0-9][^ ]*).*/\1/')
    # Skip if file matches current kernel version
    if [[ "$file" == *"$current_kernel"* ]]; then
        continue
    fi
    # Compare versions, delete if less than current
    if dpkg --compare-versions "$version" lt "$current_kernel"; then
        echo "Deleting $file (version $version is older than $current_kernel)"
        sudo rm -f "$file"
    fi
done

echo "Old kernel files deleted."