MYSQL_ROOT_PWD_FILE=/etc/yunohost/mysql

# Open a connection as a user
#
# example: ynh_mysql_connect_as 'user' 'pass' <<< "UPDATE ...;"
# example: ynh_mysql_connect_as 'user' 'pass' < /path/to/file.sql
#
# usage: ynh_mysql_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_mysql_connect_as() {
    mysql -u "$1" --password="$2" -B "${3:-}"
}

# Execute a command as root user
#
# usage: ynh_mysql_execute_as_root sql [db]
# | arg: sql - the SQL command to execute
# | arg: db - the database to connect to
ynh_mysql_execute_as_root() {
    ynh_mysql_connect_as "root" "$(sudo cat $MYSQL_ROOT_PWD_FILE)" \
        "${2:-}" <<< "$1"
}

# Execute a command from a file as root user
#
# usage: ynh_mysql_execute_file_as_root file [db]
# | arg: file - the file containing SQL commands
# | arg: db - the database to connect to
ynh_mysql_execute_file_as_root() {
    ynh_mysql_connect_as "root" "$(sudo cat $MYSQL_ROOT_PWD_FILE)" \
        "${2:-}" < "$1"
}

# Create a database and grant optionnaly privilegies to a user
#
# usage: ynh_mysql_create_db db [user [pwd]]
# | arg: db - the database name to create
# | arg: user - the user to grant privilegies
# | arg: pwd - the password to identify user by
ynh_mysql_create_db() {
    db=$1

    sql="CREATE DATABASE ${db};"

    # grant all privilegies to user
    if [[ $# -gt 1 ]]; then
        sql+=" GRANT ALL PRIVILEGES ON ${db}.* TO '${2}'@'localhost'"
        [[ -n ${3:-} ]] && sql+=" IDENTIFIED BY '${3}'"
        sql+=" WITH GRANT OPTION;"
    fi

    ynh_mysql_execute_as_root "$sql"
}

# Drop a database
#
# If you intend to drop the database *and* the associated user,
# consider using ynh_mysql_remove_db instead.
#
# usage: ynh_mysql_drop_db db
# | arg: db - the database name to drop
ynh_mysql_drop_db() {
    ynh_mysql_execute_as_root "DROP DATABASE ${1};"
}

# Dump a database
#
# example: ynh_mysql_dump_db 'roundcube' > ./dump.sql
#
# usage: ynh_mysql_dump_db db
# | arg: db - the database name to dump
# | ret: the mysqldump output
ynh_mysql_dump_db() {
    mysqldump -u "root" -p"$(sudo cat $MYSQL_ROOT_PWD_FILE)" --skip-dump-date "$1"
}

# Create a user
#
# usage: ynh_mysql_create_user user pwd [host]
# | arg: user - the user name to create
# | arg: pwd - the password to identify user by
ynh_mysql_create_user() {
    ynh_mysql_execute_as_root \
        "CREATE USER '${1}'@'localhost' IDENTIFIED BY '${2}';"
}

# Check if a mysql user exists
#
# usage: ynh_mysql_user_exists user
# | arg: user - the user for which to check existence
function ynh_mysql_user_exists()
{
   local user=$1
   if [[ -z $(ynh_mysql_execute_as_root "SELECT User from mysql.user WHERE User = '$user';") ]]
   then
      return 1
   else
      return 0
   fi
}

# Drop a user
#
# usage: ynh_mysql_drop_user user
# | arg: user - the user name to drop
ynh_mysql_drop_user() {
    ynh_mysql_execute_as_root "DROP USER '${1}'@'localhost';"
}

# 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 "mysqlpwd" into the app settings.
#
# usage: ynh_mysql_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_mysql_setup_db () {
	local db_user="$1"
	local db_name="$2"
	local new_db_pwd=$(ynh_string_random)	# Generate a random password
	# If $3 is not given, use new_db_pwd instead for db_pwd.
	db_pwd="${3:-$new_db_pwd}"
	ynh_mysql_create_db "$db_name" "$db_user" "$db_pwd"	# Create the database
	ynh_app_setting_set $app mysqlpwd $db_pwd	# Store the password in the app's config
}

# Remove a database if it exists, and the associated user
#
# usage: ynh_mysql_remove_db user name
# | arg: user - Owner of the database
# | arg: name - Name of the database
ynh_mysql_remove_db () {
	local db_user="$1"
	local db_name="$2"
	local mysql_root_password=$(sudo cat $MYSQL_ROOT_PWD_FILE)
	if mysqlshow -u root -p$mysql_root_password | grep -q "^| $db_name"; then	# Check if the database exists
		echo "Removing database $db_name" >&2
		ynh_mysql_drop_db $db_name	# Remove the database	
	else
		echo "Database $db_name not found" >&2
	fi

	# Remove mysql user if it exists
        if $(ynh_mysql_user_exists $db_user); then
		ynh_mysql_drop_user $db_user
	fi
}

# Sanitize a string intended to be the name of a database
# (More specifically : replace - and . by _)
#
# Exemple: dbname=$(ynh_sanitize_dbid $app)
#
# usage: ynh_sanitize_dbid name
# | arg: name - name to correct/sanitize
# | ret: the corrected name
ynh_sanitize_dbid () {
	dbid=${1//[-.]/_}	# We should avoid having - and . in the name of databases. They are replaced by _
	echo $dbid
}