#!/bin/bash

# Check the amount of available RAM
#
# usage: ynh_check_ram [--required=RAM required in Mb] [--no_swap|--only_swap] [--free_ram]
# | arg: -r, --required= - Amount of RAM required in Mb. The helper will return 0 is there's enough RAM, or 1 otherwise.
# If --required isn't set, the helper will print the amount of RAM, in Mb.
# | arg: -s, --no_swap   - Ignore swap
# | arg: -o, --only_swap - Ignore real RAM, consider only swap.
# | arg: -f, --free_ram  - Count only free RAM, not the total amount of RAM available.
ynh_check_ram () {
	# Declare an array to define the options of this helper.
	declare -Ar args_array=( [r]=required= [s]=no_swap [o]=only_swap [f]=free_ram )
	local required
	local no_swap
	local only_swap
	# Manage arguments with getopts
	ynh_handle_getopts_args "$@"
	required=${required:-}
	no_swap=${no_swap:-0}
	only_swap=${only_swap:-0}

	local total_ram=$(vmstat --stats --unit M | grep "total memory" | awk '{print $1}')
	local total_swap=$(vmstat --stats --unit M | grep "total swap" | awk '{print $1}')
	local total_ram_swap=$(( total_ram + total_swap ))

	local free_ram=$(vmstat --stats --unit M | grep "free memory" | awk '{print $1}')
	local free_swap=$(vmstat --stats --unit M | grep "free swap" | awk '{print $1}')
	local free_ram_swap=$(( free_ram + free_swap ))

	# Use the total amount of ram
	local ram=$total_ram_swap
	if [ $free_ram -eq 1 ]
	then
		# Use the total amount of free ram
		ram=$free_ram_swap
		if [ $no_swap -eq 1 ]
		then
			# Use only the amount of free ram
			ram=$free_ram
		elif [ $only_swap -eq 1 ]
		then
			# Use only the amount of free swap
			ram=$free_swap
		fi
	else
		if [ $no_swap -eq 1 ]
		then
			# Use only the amount of free ram
			ram=$total_ram
		elif [ $only_swap -eq 1 ]
		then
			# Use only the amount of free swap
			ram=$total_swap
		fi
	fi

	if [ -n "$required" ]
	then
		# Return 1 if the amount of ram isn't enough.
		if [ $ram -lt $required ]
		then
			return 1
		else
			return 0
		fi

	# If no RAM is required, return the amount of available ram.
	else
		echo $ram
	fi
}