#!/bin/bash

# Get currently running kernel version
current_kernel=$(uname -r)
echo "Currently running kernel: $current_kernel"

# Get all installed kernels
installed_kernels=$(dpkg --list | grep linux-image | awk '{print $2}')

# Determine the latest kernel version installed
kernel_versions=$(echo "$installed_kernels" | grep -Eo '6.1.0-[0-9]+-cloud-amd64' | sort -V)

latest_kernel=$(echo "$kernel_versions" | tail -n 1)
second_latest=$(echo "$kernel_versions" | tail -n 2 | head -n 1)
third_latest=$(echo "$kernel_versions" | tail -n 3 | head -n 1)

echo -e "\nKernels that will be KEPT:"
echo "$current_kernel (currently running)"
echo "$latest_kernel (latest installed)"
echo "$second_latest (second latest)"
echo "$third_latest (third latest)"

# Prepare a list of kernels to remove
echo -e "\nKernels that will be REMOVED:"
kernels_to_remove=()
for kernel in $installed_kernels; do
    if [[ "$kernel" != *"$current_kernel"* ]] && \
       [[ "$kernel" != *"$latest_kernel"* ]] && \
       [[ "$kernel" != *"$second_latest"* ]] && \
       [[ "$kernel" != *"$third_latest"* ]]; then
        echo "$kernel"
        kernels_to_remove+=("$kernel")
    fi
done

# Confirm before removing
echo -e "\nDo you want to proceed with the removal? (y/N): "
read -r confirm
if [[ "$confirm" != "y" && "$confirm" != "Y" ]]; then
    echo "Aborted."
    exit 0
fi

# Remove old kernels
if [ ${#kernels_to_remove[@]} -eq 0 ]; then
    echo "No old kernels to remove."
else
    echo "Removing old kernels..."
    sudo apt-get purge -y "${kernels_to_remove[@]}"
    sudo apt-get autoremove --purge -y
    sudo apt-get clean
fi

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

# Display remaining disk space
echo -e "\nDisk space after cleanup:"
df -h /

echo "Cleanup completed!"