#!/usr/bin/env bash
###             _   _     _      _
###  __ _  ___ | |_| |__ | | ___| |_ _   _
### / _` |/ _ \| __| '_ \| |/ _ \ __| | | |
###| (_| | (_) | |_| |_) | |  __/ |_| |_| |
### \__, |\___/ \__|_.__/|_|\___|\__|\__,_|
### |___/
###       https://www.youtube.com/user/gotbletu
###       https://twitter.com/gotbletu
###       https://github.com/gotbletu
###       gotbletu@gmail.com
###
### Name            : 404urlcleaner
### Version         : 0.3
### Date            : 20190508
### Description     : Remove all dead urls with HTTP status code 404 (mainly use with newsboat/newsbeuter)
### Depends On      : bash  curl  coreutils  grep  moreutils
### Video Demo      : https://youtu.be/dTpEuQZRRDM

# Reset
Color_Off='\e[0m'       # Text Reset
# Regular Colors
Black='\e[0;30m'        # Black
Red='\e[0;31m'          # Red
Green='\e[0;32m'        # Green
Yellow='\e[0;33m'       # Yellow
Blue='\e[0;34m'         # Blue
Purple='\e[0;35m'       # Purple
Cyan='\e[0;36m'         # Cyan
White='\e[0;37m'        # White

display_usage() {
  echo "Remove all dead urls with HTTP status code 404 (mainly use with newsboat/newsbeuter)"
  echo -e "\n  Usage:\n  $0 [file]"
  echo -e "\n  Example:\n  $0 ~/.newsboat/urls"
}
  # if less than one argument supplied, display usage
  if [  $# -lt 1 ]
  then
    display_usage
    exit 1
  fi
  # check whether user had supplied -h or --help . If yes display usage
  if [[ ( $@ == "--help") ||  $@ == "-h" ]]
  then
    display_usage
    exit 0
  fi

# all url status code
TMPFILE1=/tmp/urlstatus.txt
# only 404 status code
TMPFILE2=/tmp/urlstatus2nd.txt

# create backup file
echo -e "${Green}>>>Creating Backup File${Color_Off}"
cp -aiv "$1" "$1_`date +'%F_%Hh%Ms%S'`"

# check all links and print http code
echo -e "${Green}>>>Checking HTTP Status Code${Color_Off}"
grep '^http' -i "$1" | awk '{print $1}' | while read url
do
    urlstatus=$(curl -o /dev/null --silent --head --write-out '%{http_code}' "$url")
    echo "$url  C0DE-$urlstatus" | tee -a "$TMPFILE1"
done

# double check 404 links again (sometime the first check is not acurrate)
echo -e "${Blue}>>>Double Checking ONLY DEAD HTTP Status Code${Color_Off}"
grep 'C0DE-404' -i "$TMPFILE1" | awk '{print $1}' | while read url
do
    urlstatus=$(curl -o /dev/null --silent --head --write-out '%{http_code}' "$url")
    echo "$url  C0DE-$urlstatus" | tee -a "$TMPFILE2"
done

# remove all 404
grep 'C0DE-404' -s -i "$TMPFILE2" | awk '{print $1}' | while read url
do
    grep -F -v "$url" "$1" | sponge "$1"
    echo -e "${Red}>>>REMOVING $url ${Color_Off}"
done

# remove temp files if it exist
if [ -f "$TMPFILE1" ] ; then
  rm "$TMPFILE1"
fi
if [ -f "$TMPFILE2" ] ; then
  rm "$TMPFILE2"
fi

echo -e "${Green}>>>Scan Completed${Color_Off}"