#!/bin/bash

#=================================================
#
# Redis HELPERS
#
# Point of contact : Jean-Baptiste Holcroft <jean-baptiste@holcroft.fr>
#=================================================

# get the first available redis database
#
# usage: ynh_redis_get_free_db
# | returns: the database number to use
ynh_redis_get_free_db() {
	local result max db
	result=$(redis-cli INFO keyspace)

	# get the num
	max=$(cat /etc/redis/redis.conf | grep ^databases | grep -Eow "[0-9]+")

	db=0
	# default Debian setting is 15 databases
	for i in $(seq 0 "$max")
	do
	 	if ! echo "$result" | grep -q "db$i"
	 	then
			db=$i
	 		break 1
 		fi
 		db=-1
	done

	test "$db" -eq -1 && ynh_die "No available Redis databases..."

	echo "$db"
}

# Create a master password and set up global settings
# Please always call this script in install and restore scripts
#
# usage: ynh_redis_remove_db database
# | arg: database - the database to erase
ynh_redis_remove_db() {
	local db=$1
	redis-cli -n "$db" flushall
}

#=================================================
#
# POSTGRES HELPERS
#
# Point of contact : Jean-Baptiste Holcroft <jean-baptiste@holcroft.fr>
#=================================================

# Create a master password and set up global settings
# Please always call this script in install and restore scripts
#
# usage: ynh_psql_test_if_first_run

ynh_psql_test_if_first_run() {
	if [ -f /etc/yunohost/psql ];
	then
		echo "PostgreSQL is already installed, no need to create master password"
	else
		pgsql=$(ynh_string_random)
		pg_hba=""
		echo "$pgsql" >> /etc/yunohost/psql

		if [ -e /etc/postgresql/9.4/ ]
		then
			pg_hba=/etc/postgresql/9.4/main/pg_hba.conf
		elif [ -e /etc/postgresql/9.6/ ]
		then
			pg_hba=/etc/postgresql/9.6/main/pg_hba.conf
		else
			ynh_die "postgresql shoud be 9.4 or 9.6"
		fi

		systemctl start postgresql
		sudo --login --user=postgres psql -c"ALTER user postgres WITH PASSWORD '$pgsql'" postgres

		# force all user to connect to local database using passwords
		# https://www.postgresql.org/docs/current/static/auth-pg-hba-conf.html#EXAMPLE-PG-HBA.CONF
		# Note: we can't use peer since YunoHost create users with nologin
		#  See: https://github.com/YunoHost/yunohost/blob/unstable/data/helpers.d/user
		sed -i '/local\s*all\s*all\s*peer/i \
		local all all password' "$pg_hba"
		systemctl enable postgresql
		systemctl reload postgresql
	fi
}

# Open a connection as a user
#
# example: ynh_psql_connect_as 'user' 'pass' <<< "UPDATE ...;"
# example: ynh_psql_connect_as 'user' 'pass' < /path/to/file.sql
#
# usage: ynh_psql_connect_as user pwd [db]
# | arg: user - the user name to connect as
# | arg: pwd - the user password
# | arg: db - the database to connect to
ynh_psql_connect_as() {
	user="$1"
	pwd="$2"
	db="$3"
	sudo --login --user=postgres PGUSER="$user" PGPASSWORD="$pwd" psql "$db"
}

# # Execute a command as root user
#
# usage: ynh_psql_execute_as_root sql [db]
# | arg: sql - the SQL command to execute
# | arg: db - the database to connect to
ynh_psql_execute_as_root () {
	sql="$1"
	sudo --login --user=postgres psql <<< "$sql"
}

# Execute a command from a file as root user
#
# usage: ynh_psql_execute_file_as_root file [db]
# | arg: file - the file containing SQL commands
# | arg: db - the database to connect to
ynh_psql_execute_file_as_root() {
	file="$1"
	db="$2"
	sudo --login --user=postgres psql "$db" < "$file"
}

# Create a database, an user and its password. Then store the password in the app's config
#
# After executing this helper, the password of the created database will be available in $db_pwd
# It will also be stored as "psqlpwd" into the app settings.
#
# usage: ynh_psql_setup_db user name [pwd]
# | arg: user - Owner of the database
# | arg: name - Name of the database
# | arg: pwd - Password of the database. If not given, a password will be generated
ynh_psql_setup_db () {
	db_user="$1"
	db_name="$2"
	new_db_pwd=$(ynh_string_random)	# Generate a random password
	# If $3 is not given, use new_db_pwd instead for db_pwd.
	db_pwd="${3:-$new_db_pwd}"
	ynh_psql_create_db "$db_name" "$db_user" "$db_pwd"	# Create the database
	ynh_app_setting_set "$app" psqlpwd "$db_pwd"	# Store the password in the app's config
}

# Create a database and grant privilegies to a user
#
# usage: ynh_psql_create_db db [user [pwd]]
# | arg: db - the database name to create
# | arg: user - the user to grant privilegies
# | arg: pwd  - the user password
ynh_psql_create_db() {
	db="$1"
	user="$2"
	pwd="$3"
	ynh_psql_create_user "$user" "$pwd"
	sudo --login --user=postgres createdb --owner="$user" "$db"
}

# Drop a database
#
# usage: ynh_psql_drop_db db
# | arg: db - the database name to drop
# | arg: user - the user to drop
ynh_psql_remove_db() {
	db="$1"
	user="$2"
	sudo --login --user=postgres dropdb "$db"
	ynh_psql_drop_user "$user"
}

# Dump a database
#
# example: ynh_psql_dump_db 'roundcube' > ./dump.sql
#
# usage: ynh_psql_dump_db db
# | arg: db - the database name to dump
# | ret: the psqldump output
ynh_psql_dump_db() {
	db="$1"
	sudo --login --user=postgres pg_dump "$db"
}


# Create a user
#
# usage: ynh_psql_create_user user pwd [host]
# | arg: user - the user name to create
ynh_psql_create_user() {
	user="$1"
	pwd="$2"
        sudo --login --user=postgres psql -c"CREATE USER $user WITH PASSWORD '$pwd'" postgres
}

# Drop a user
#
# usage: ynh_psql_drop_user user
# | arg: user - the user name to drop
ynh_psql_drop_user() {
	user="$1"
	sudo --login --user=postgres dropuser "$user"
}

# 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="${1:-...No specific informations...}"
	local recipients="${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 informations 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"
}