#!/bin/bash


install_nginx(){
	echo -e "\e[33m>\e[0m nginx installer \e[33m<\e[0m\n"

	CNF_ROOT="/etc/nginx"

	# (1) Check config location #
	errcount="0";
	ls $CNF_ROOT                 >/dev/null 2>&1; errcount="`expr $errcount + $?`";
	ls $CNF_ROOT/sites-available >/dev/null 2>&1; errcount="`expr $errcount + $?`";
	ls $CNF_ROOT/sites-enabled   >/dev/null 2>&1; errcount="`expr $errcount + $?`";

	if [ "$errcount" -gt 0 ]; then
		echo -e "  \e[33m/!\\\\\e[0m Invalid configuration structure in $CNF_ROOT."
		echo -e "      expected \e[33msites-available\e[0m and \e[33msites-enabled\e[0m mechanism."
		exit 1;
	fi

	# (3) Ask server name #
	read -p "[server name] (ptut.example.com): " server_name;
	if [ -z "$server_name" ]; then
		echo -e "  \e[33m/!\\\\\e[0m Invalid server name."
		exit 1;
	fi;


	# (3) Copy config #
	echo "1- build configuration"
	echo """server {
	listen 80;
	server_name $server_name www.$server_name;

	location / {
		proxy_set_header Host \$host;
		proxy_pass http://127.0.0.1:$PORT;
	}
}""" | sudo tee $CNF_ROOT/sites-available/ptut.reverse-proxy > /dev/null

	# manage error
	if [ "$?" -ne 0 ]; then
		echo -e "  \e[33m/!\\\\\e[0m You must have 'sudo' permissions."
		exit 1;
	fi;

	# (4) Setup nginx #
	echo "2- enable configuration"
	sudo ln -fs ../sites-available/ptut.reverse-proxy $CNF_ROOT/sites-enabled/ptut.reverse-proxy;
	sudo systemctl reload nginx;

	echo -e "\e[33m>\e[0m done \e[33m<\e[0m"

}
install_httpd(){
	echo -e "\e[33m>\e[0m httpd installer \e[33m<\e[0m\n"
}
install_apache(){
	echo -e "\e[33m>\e[0m apache installer \e[33m<\e[0m\n"

	CNF_ROOT="/etc/apache2"

	# (1) Check config location #
	errcount="0";
	ls $CNF_ROOT                 >/dev/null 2>&1; errcount="`expr $errcount + $?`";
	ls $CNF_ROOT/sites-available >/dev/null 2>&1; errcount="`expr $errcount + $?`";
	ls $CNF_ROOT/sites-enabled   >/dev/null 2>&1; errcount="`expr $errcount + $?`";

	if [ "$errcount" -gt 0 ]; then
		echo -e "  \e[33m/!\\\\\e[0m Invalid configuration structure in $CNF_ROOT."
		echo -e "      expected \e[33msites-available\e[0m and \e[33msites-enabled\e[0m mechanism."
		exit 1;
	fi

	# (3) Ask server name #
	read -p "[server name] (ptut.example.com): " server_name;
	if [ -z "$server_name" ]; then
		echo -e "  \e[33m/!\\\\\e[0m Invalid server name."
		exit 1;
	fi;


	# (3) Copy config #
	echo "1- build configuration"
	echo """<VirtualHost *:80>
	ServerName $server_name
	ServerAlias www.$server_name

	ProxyPreserveHost On
	ProxyRequests off
	ProxyPass / http://127.0.0.1:$PORT/
	ProxyPassReverse / http://127.0.0.1:$PORT/
</VirtualHost>""" | sudo tee $CNF_ROOT/sites-available/ptut.reverse-proxy > /dev/null

	# manage error
	if [ "$?" -ne 0 ]; then
		echo -e "  \e[33m/!\\\\\e[0m You must have 'sudo' permissions."
		exit 1;
	fi;

	# (4) Setup nginx #
	echo "2- enable configuration"
	sudo ln -fs ../sites-available/ptut.reverse-proxy $CNF_ROOT/sites-enabled/ptut.reverse-proxy;
	sudo systemctl reload apache2;

	echo -e "\e[33m>\e[0m done \e[33m<\e[0m"
}




# (1) Set optional port
#--------------------------------------------------------#
# (1) Default value #
PORT="8080";

# (2) If port given as argument[0] #
if [ "$#" -ge 1 ]; then

	# fail if invalid number
	if [ "`expr $1 + 0 2>/dev/null`" != "$1" ]; then
		echo -e "\e[33m/!\\\\\e[0m Invalid port (expected a number)"
		exit 1
	fi;

	PORT="`expr $1 + 0`"

fi;


# (2) Detect installed/running HTTP server
#--------------------------------------------------------#
# (1) Check for existing services #
is_nginx="$(test `systemctl status nginx 2>/dev/null | wc -l` -gt 1 && echo 1 || echo 0)"
is_httpd="$(test `systemctl status httpd 2>/dev/null | wc -l` -gt 1 && echo 1 || echo 0)"
is_apache2="$(test `systemctl status apache2 2>/dev/null | wc -l` -gt 1 && echo 1 || echo 0)"
candidate_n="`expr $is_nginx + $is_httpd + $is_apache2`"

# (2) No candidate #
if [ "$candidate_n" -lt 1 ]; then
	echo -e "\e[33m/!\\\\\e[0m You have no HTTP server installed.\n"
	echo -e "> install \e[33mnginx\e[0m or \e[33mapache/httpd\e[0m"
	exit 1

# (3) One candidate -> automatic select #
elif [ "$candidate_n" -eq 1 ]; then

	test "$is_nginx"   = "1" && install_nginx;
	test "$is_httpd"   = "1" && install_httpd;
	test "$is_apache2" = "1" && install_apache2;

# (4) Multiple choices #
else

	echo "installation candidate:"
	test "$is_nginx"   = "1" && echo -e "  [\e[33mN\e[0m] nginx"
	test "$is_httpd"   = "1" && echo -e "  [\e[33mH\e[0m] httpd (apache)"
	test "$is_apache2" = "1" && echo -e "  [\e[33mA\e[0m] apache2"
	read -p "> " -n1 candidate; echo

	case $candidate in
		"n"|"N")
			if [ "$is_nginx" != "1" ]; then
				echo -e "\e[33m/!\\\\\e[0m Invalid choice... aborting"; exit 1;
			fi;
			install_nginx
			;;

		"h"|"H")
			if [ "$is_httpd" != "1" ]; then
				echo -e "\e[33m/!\\\\\e[0m Invalid choice... aborting"; exit 1;
			fi;
			install_httpd
			;;

		"a"|"A")
			if [ "$is_apache2" != "1" ]; then
				echo -e "\e[33m/!\\\\\e[0m Invalid choice... aborting"; exit 1;
			fi;
			install_apache
			;;
		*) echo -e "\e[33m/!\\\\\e[0m Invalid choice... aborting"; exit 1;;
	esac;

fi;