#!/bin/sh
# script for downloading videos/audios from sites...
#shellcheck disable=SC2317

info() {
	printf "\033[1;36m[ %s ] [ %s ] %s\033[0m\n" "$2" "$3" "$1"
}

error() {
	printf "\033[1;31m[ %s ] [ %s ] %s\033[0m\n" "$2" "$3" "$1"
}

notify_droid() {
	termux-notification -c "$1"
}

notify_linux() {
	notify-send -e "$1" -h "string:x-canonical-private-synchronous:${0##*/}"
}

conv_to_octal(){
	base=$2
	i=0
	res=0
	for key in $(printf "%s" "$1" | rev | sed 's/./&\n/g'); do
		if [ "$key" -ne 0 ];then 
			j=$i
			tmp=1
			while [ "$j" -ne 0 ];do 
				: $((tmp *= base))
				: $((j-=1))
			done
			res=$((res + (key * tmp)))
		fi
		: $((i+=1))
	done
	
	res=$(printf '%03o' "$((res-${3}))")
	#shellcheck disable=SC2059
	printf "\\$res" | sed 's/[\/&]/\\&/g'
}

instagram() {
	info "Using Alternate Site" "Instagram" "$2"
	sed_file="${TMPDIR:-/tmp}/${0##*/}-sed-file"
	response=$(curl -s "https://snapinsta.app" -o /dev/null -c - | curl -s 'https://snapinsta.app/action2.php' -e 'https://snapinsta.app/' -A 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36' -b - -F "url=$1" -F 'action=post' -F 'lang=' --compressed | sed -nE 's|.*\}\(([^\)]*)\).*|\1|p' | tr -d '"' | tr ',' '\n')
	
	n=$(printf "%s" "$response" | sed -n '3p')
	t=$(printf "%s" "$response" | sed -n '4p')
	e=$(printf "%s" "$response" | sed -n '5p')
	printf '%s' "$n" | cut -c-"$e" | sed 's/./&\n/g' | tr -s '\n' | nl -nln -v0 | sed -nE 's|^([0-9]*)[[:space:]]*(.*)|s\/\2\/\1\/g|p' > "$sed_file"
	printf 's/%s/\\n/g' "$(printf "%s" "$n" | cut -c"$((e+1))")" >> "$sed_file"
	
	data=$(printf "%s" "$response" | head -1 | sed -f "$sed_file" | sed -n '1200,$p')
	
	info "Decoding JS" "Instagram" "$2"
	printf "" > "$sed_file"
	for num in $(printf "%s" "$data" | sort -u); do
		printf 's/^%s$/%s/g\n' "$num" "$(conv_to_octal "$num" "$e" "$t")" >> "$sed_file" &
	done
	wait
	
	video_url=$(printf "%s" "$data" | sed -f "$sed_file" -e 's/\\//g' | tr -d '\n' | sed -nE 's|.*a href="([^"]*)".*|\1|p')
}

#main
link="$1"
agent="Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/12$(head /dev/urandom | tr -dc '3-6' | cut -c1).0.0.0 Safari/537.36"

case $(uname -o) in
	*ndroid*)
		download_dir="/sdcard"
		[ -z "$link" ] && link=$(termux-clipboard-get)
		os="droid"
		;;
	*)
		download_dir="$HOME"
		[ -z "$link" ] && link=$(wl-paste)
		os="linux"
		;;
esac

printf "\033[1;34m Video link :\033[0m%s\n" "$link"
case "$link" in
	*instagram*)
		app="Instagram"
		id=$(printf "%s" "$link" | cut -d'/' -f5)
		[ -z "$id" ] && error "Unable to extract ID" "$app" "$id"
		info "Decoding ID" "$app" "$id"
		res=0
		enc_char="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
		table=$(printf "%s" "$enc_char" | sed 's/\(.\)/\1\n/g' | nl -v0 | tr '\t' ':' | tr -d ' ')
		for key in $(printf "%s" "$id" | sed -e 's/\(.\)/\1\n/g');do 
		    value=$(printf "%s" "$table" | sed -nE "s/([^:]*):$key/\1/p")
		    res=$((res*64+value))
		done

		info "Fetching Video URL" "$app" "$id"
		video_url=$(curl -s "https://i.instagram.com/api/v1/web/get_ruling_for_content/?content_type=MEDIA&target_id=$res" -H "x-ig-app-id:936619743392459" -H "x-ig-www-claim:0" -A "$agent" -c - -o /dev/null | curl -A "$agent" -s -G "https://www.instagram.com/graphql/query/" -H "content-type:application/json" --data-urlencode 'query_hash=9f8827793ef34641b2fb195d4d41151c' --data-urlencode 'variables={"shortcode":"'"$id"'","include_reel":false,"include_logged_out":false}' -e "$link" -b - | tr '{}' '\n' | sed -nE 's|.*video_url":"([^"]*)".*|\1|p' | sed 's/\u0026/\&/g;s/\\//g')
		printf "%s" "$video_url" | grep -qE 'instagram.*mp4' || instagram "$link" "$id"
		;;
	*youtu*)
		app="Youtube"
		id=$(printf "%s" "$link" | cut -d"=" -f2 | cut -d"/" -f4)
		[ -z "$id" ] && error "Unable to extract ID" "$app" "$id"
		info "Fetching Video URL" "$app" "$id"
		yt_ver="2.20231219.04.00"
		json="{
		  \"context\": {
		    \"client\": {
		      \"clientName\": \"WEB\",
		      \"clientVersion\": \"$yt_ver\",
		      \"userAgent\": \"$agent\",
		      \"hl\": \"en\",
		      \"timeZone\": \"Asia/Calcutta\",
		      \"utcOffsetMinutes\": 330
		    }
		  },
		  \"videoId\": \"$id\",
		  \"playbackContext\": {
		    \"contentPlaybackContext\": {
		      \"html5Preference\": \"HTML5_PREF_WANTS\"
		    }
		  },
		  \"contentCheckOk\": true,
		  \"racyCheckOk\": true
		}"
		video_url=$(curl -X POST -A "$agent" -s "https://www.youtube.com/youtubei/v1/player?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8&prettyPrint=false" -H "content-type:application/json" -H "X-Youtube-Client-Version: $yt_ver" -d "$json" -e "$link" | tr '{}' '\n' | sed -nE 's|.*,"title":"([^"]*)".*|\tout=\1\.mp4|p;s|.*itag":18,"url":"([^"]*)".*|\1|p;s|.*itag":22,"url":"([^"]*)".*|\1|p' | tail -2)
		printf "%s" "$video_url" | grep -q "googlevideo\.com" || fallback=1
		;;
	*)
		info "Invalid URL" "none" "none"
		exit 0
		;;
esac

if [ -n "$fallback" ]; then
	info "Using fallback" "$app" "$id"
	yt-dlp "$link" -o "$download_dir/%(title)s.%(ext)s"
else
	info "Downloading Video" "$app" "$id"
	printf "%s" "$video_url" | aria2c -x16 -s16 -j10 -k'1M' --user-agent="$agent" -d "$download_dir" -i - --download-result=hide --summary-interval=0 || notify_$os "Unable to Download $app Video"
fi

notify_$os "$app Video Downloaded"
exit 0