#!/bin/bash +xe

# Enhance performance through prefetching lookup IP in hosts file (MIT License)
# by Lathanao (last update: 24/02/2024)


USER=$(last | grep "login screen" | tail -n 1 | awk '{print $1}')

TMP_DIR="$(mktemp -d)"
PATH_HISTORY="/home/$USER/.config/chromium/Default/History"
STRING_ALERT="# AUTOMATICALY ADDED BY SCRIPT" 
UPDATE_ALERT="# UPDATED ON $(date +'%Y-%m-%d %T')" 


##	REMOVE PREVIOUS RECORDED IPS FROM HOSTS FILE
################################################################################

sudo sed -i "/${STRING_ALERT}/q" /etc/hosts
sudo sed -i "/$STRING_ALERT/d" /etc/hosts
sudo echo $STRING_ALERT >> /etc/hosts
sudo echo $UPDATE_ALERT >> /etc/hosts


##	DUMP IN CSV THE BROWSER HISTORY FROM the SQLITE FILE 
################################################################################

cp $PATH_HISTORY $TMP_DIR
cd $TMP_DIR

sqlite3 $TMP_DIR/History << EOF
.headers on
.mode csv
.output history.csv
SELECT url FROM urls ORDER BY last_visit_time DESC;
.quit
EOF


##	SORT AND LOOKUP ALL TOP 100 DOMAINS FOUND IN THE HISTORY 
################################################################################

TMP_CSV=$TMP_DIR/history.csv

for url in $(awk -F, '{print $1}' $TMP_CSV | tr "/" " " | awk '{print $2}' | sort | uniq -c | sort -nr | awk '{print $2}' | grep -P "^[a-zA-Z0-9][a-zA-Z0-9-]{1,61}[a-zA-Z0-9](?:\.[a-zA-Z]{2,})+$" | head -n 50) ; do
	echo $(dig +short @9.9.9.9 $url | tail -n 1) $url >> /etc/hosts
done


##	LOG
################################################################################

LOG_DIR=/var/log/usercron
LOG_FILE=/var/log/usercron/update-hosts.log


if [[ ! -d "$LOG_DIR" ]];then
    sudo mkdir -p $LOG_DIR
    sudo chmod -R 0700 $LOG_DIR
    sudo chown -R $USER:$USER $LOG_DIR
fi

if [[ ! -f "$LOG_FILE" ]];then
    sudo touch $LOG_FILE
    sudo chmod 0700 $LOG_FILE
    sudo chown $USER:$USER $LOG_FILE
fi

DATE=$(date +"%Y-%m-%d %T")
echo $DATE $(whoami) "updated /etc/host file" >> $LOG_FILE
echo "Log file updated in $LOG_FILE"