#!/bin/bash

if [[ $EUID > 0 ]]
    then echo "Please run as root"
    exit
fi

prime_select="/usr/bin/prime-select.sh"
r3_execute=$(sed -n '1p' /etc/prime/config)
boot_default=$(sed -n '2p' /etc/prime/config)
last_session=$(sed -n '3p' /etc/prime/config)

if [ $r3_execute = "1" ]; then
    while [ `lsmod | grep -o ^nouveau` ]; do
        rmmod nouveau
        sleep 1
    done
    sed -i '1 c0' /etc/prime/config
    sed -i '3 cD' /etc/prime/config
    modprobe nvidia &&  modprobe nvidia_drm &&  modprobe nvidia_modeset &&  modprobe nvidia_uvm
    bash $prime_select nvidia
    init 4

elif [ $r3_execute = "2" ]; then 
    bash $prime_select intel
    sed -i '1 c0' /etc/prime/config
    sed -i '3 cI' /etc/prime/config
    while [ `lsmod | grep -o ^'nvidia '` ]; do
        rmmod nvidia_uvm
        rmmod nvidia_drm
        rmmod nvidia_modeset
        rmmod nvidia
        sleep 1
    done
    modprobe nouveau 
    init 4

elif [ $r3_execute = "0" ]; then
    if [ $boot_default = "I" ]; then
        modprobe nouveau
        bash $prime_select intel
        sed -i '3 cI' /etc/prime/config

    elif [ $boot_default = "D" ]; then
        sed -i '3 cD' /etc/prime/config
        modprobe nvidia &&  modprobe nvidia_drm &&  modprobe nvidia_modeset &&  modprobe nvidia_uvm
        bash $prime_select nvidia
    
    elif [ $boot_default = "L" ]; then
        if [ $last_session = "I" ]; then
            modprobe nouveau
            bash $prime_select intel

        elif [ $last_session = "D" ]; then
            modprobe nvidia &&  modprobe nvidia_drm &&  modprobe nvidia_modeset &&  modprobe nvidia_uvm
            bash $prime_select nvidia
        fi
    fi
    sed -i '1 c0' /etc/prime/config
    #nothing_to_do
fi