#!/bin/bash

#=================================================
# DISPLAYING
#=================================================

WARNING () {	# Écrit sur le canal d'erreur pour passer en warning.
	$@ >&2
}

ALL_QUIET () {	# Redirige la sortie standard et d'erreur dans /dev/null
	$@ > /dev/null 2>&1
}

#=================================================
# BACKUP
#=================================================

HUMAN_SIZE () {	# Transforme une taille en Ko en une taille lisible pour un humain
	human=$(numfmt --to=iec --from-unit=1K $1)
	echo $human
}

CHECK_SIZE () {	# Vérifie avant chaque backup que l'espace est suffisant
	file_to_analyse=$1
	backup_size=$(du --summarize "$file_to_analyse" | cut -f1)
	free_space=$(df --output=avail "/home/yunohost.backup" | sed 1d)

	if [ $free_space -le $backup_size ]
	then
		WARNING echo "Espace insuffisant pour sauvegarder $file_to_analyse."
		WARNING echo "Espace disponible: $(HUMAN_SIZE $free_space)"
		ynh_die "Espace nécessaire: $(HUMAN_SIZE $backup_size)"
	fi
}


#=================================================
#============= FUTURE YUNOHOST HELPER ============
#=================================================

# Delete a file checksum from the app settings
#
# $app should be defined when calling this helper
#
# usage: ynh_remove_file_checksum file
# | arg: file - The file for which the checksum will be deleted
ynh_delete_file_checksum () {
	local checksum_setting_name=checksum_${1//[\/ ]/_}	# Replace all '/' and ' ' by '_'
	ynh_app_setting_delete $app $checksum_setting_name
}


#=================================================
# EXPERIMENTAL HELPERS
#=================================================

# Create a dedicated fail2ban config (jail and filter conf files)
#
# usage: ynh_add_fail2ban_config log_file filter [max_retry [ports]]
# | arg: log_file - Log file to be checked by fail2ban
# | arg: failregex - Failregex to be looked for by fail2ban
# | arg: max_retry - Maximum number of retries allowed before banning IP address - default: 3
# | arg: ports - Ports blocked for a banned IP address - default: http,https
ynh_add_fail2ban_config () {
   # Process parameters
   logpath=$1
   failregex=$2
   max_retry=${3:-3}
   ports=${4:-http,https}
   
  test -n "$logpath" || ynh_die "ynh_add_fail2ban_config expects a logfile path as first argument and received nothing."
  test -n "$failregex" || ynh_die "ynh_add_fail2ban_config expects a failure regex as second argument and received nothing."
  
  finalfail2banjailconf="/etc/fail2ban/jail.d/$app.conf"
  finalfail2banfilterconf="/etc/fail2ban/filter.d/$app.conf"
  ynh_backup_if_checksum_is_different "$finalfail2banjailconf" 1
  ynh_backup_if_checksum_is_different "$finalfail2banfilterconf" 1
  
  sudo tee $finalfail2banjailconf <<EOF
[$app]
enabled = true
port = $ports
filter = $app
logpath = $logpath
maxretry = $max_retry
EOF

  sudo tee $finalfail2banfilterconf <<EOF
[INCLUDES]
before = common.conf
[Definition]
failregex = $failregex
ignoreregex =
EOF

  ynh_store_file_checksum "$finalfail2banjailconf"
  ynh_store_file_checksum "$finalfail2banfilterconf"
  
  systemctl restart fail2ban
  local fail2ban_error="$(journalctl -u fail2ban | tail -n50 | grep "WARNING.*$app.*")"
  if [ -n "$fail2ban_error" ]
  then
    echo "[ERR] Fail2ban failed to load the jail for $app" >&2
    echo "WARNING${fail2ban_error#*WARNING}" >&2
  fi
}

# Remove the dedicated fail2ban config (jail and filter conf files)
#
# usage: ynh_remove_fail2ban_config
ynh_remove_fail2ban_config () {
  ynh_secure_remove "/etc/fail2ban/jail.d/$app.conf"
  ynh_secure_remove "/etc/fail2ban/filter.d/$app.conf"
  sudo systemctl restart fail2ban
}

#=================================================

# Read the value of a key in a ynh manifest file
#
# usage: ynh_read_manifest manifest key
# | arg: manifest - Path of the manifest to read
# | arg: key - Name of the key to find
ynh_read_manifest () {
	manifest="$1"
	key="$2"
	python3 -c "import sys, json;print(json.load(open('$manifest'))['$key'])"
}

# Exit without error if the package is up to date
#
# This helper should be used to avoid an upgrade of a package
# when it's not needed.
#
# To force an upgrade, even if the package is up to date,
# you have to set the variable YNH_FORCE_UPGRADE before.
# example: sudo YNH_FORCE_UPGRADE=1 yunohost app upgrade MyApp
#
# usage: ynh_abort_if_up_to_date
ynh_abort_if_up_to_date () {
	local force_upgrade=${YNH_FORCE_UPGRADE:-0}
	local package_check=${PACKAGE_CHECK_EXEC:-0}

	local version=$(ynh_read_manifest "/etc/yunohost/apps/$YNH_APP_INSTANCE_NAME/manifest.json" "version" || echo 1.0)
	local last_version=$(ynh_read_manifest "../manifest.json" "version" || echo 1.0)
	if [ "$version" = "$last_version" ]
	then
		if [ "$force_upgrade" != "0" ]
		then
			echo "Upgrade forced by YNH_FORCE_UPGRADE." >&2
			unset YNH_FORCE_UPGRADE
		elif [ "$package_check" != "0" ]
		then
			echo "Upgrade forced for package check." >&2
		else
			ynh_die "Up-to-date, nothing to do" 0
		fi
	fi
}

#=================================================

# Send an email to inform the administrator
#
# usage: ynh_send_readme_to_admin app_message [recipients]
# | arg: app_message - The message to send to the administrator.
# | arg: recipients - The recipients of this email. Use spaces to separate multiples recipients. - default: root
#	example: "root admin@domain"
#	If you give the name of a YunoHost user, ynh_send_readme_to_admin will find its email adress for you
#	example: "root admin@domain user1 user2"
ynh_send_readme_to_admin() {
	local app_message="${1:-...No specific information...}"
	local recipients="${2:-root}"

	# Retrieve the email of users
	find_mails () {
		local list_mails="$1"
		local mail
		local recipients=" "
		# Read each mail in argument
		for mail in $list_mails
		do
			# Keep root or a real email address as it is
			if [ "$mail" = "root" ] || echo "$mail" | grep --quiet "@"
			then
				recipients="$recipients $mail"
			else
				# But replace an user name without a domain after by its email
				if mail=$(ynh_user_get_info "$mail" "mail" 2> /dev/null)
				then
					recipients="$recipients $mail"
				fi
			fi
		done
		echo "$recipients"
	}
	recipients=$(find_mails "$recipients")

	local mail_subject="☁️🆈🅽🅷☁️: \`$app\` was just installed!"

	local mail_message="This is an automated message from your beloved YunoHost server.

Specific information for the application $app.

$app_message

---
Automatic diagnosis data from YunoHost

$(yunohost tools diagnosis | grep -B 100 "services:" | sed '/services:/d')"

	# Send the email to the recipients
	echo "$mail_message" | mail -a "Content-Type: text/plain; charset=UTF-8" -s "$mail_subject" "$recipients"
}