#########################################################################
#
#			COMMON HELPER FUNCTIONS
#

#########################################################################
#
# Function to drop a debug shell with an error message.
#
# Usage:
#	drop_shell "This is your error message."
#
drop_shell() {
	if [ -n "$MUTED_OUTPUT" ]; then
		exec 1>&4 2>&5
		reset
	fi
	[ $# -gt 0 ] && echo $@
	echo "CTRL + D will continue booting."
	setsid sh -c 'exec sh </dev/tty1 >/dev/tty1 2>&1'
}

#########################################################################
#
# Helper function to download given FILE_URL from servers in 'slxsrv'
# as given through the kernel command line. File will be saved under TARGET_PATH
#
# Usage:
#       download FILE_URL TARGET_PATH
#
# Example:
#	download "config" "/opt/openslx/config"
#
# Note:
#	FILE_URL can have subpath, e.g. "ubuntu-13.04-x64/config"
#
download() {
	[ $# -ne 2 ] && echo "Error - 'download' requires 2 arguments, $# given." && return 1
	
	if [ -z "$SLX_KCL_SERVERS" ]; then
		. "/opt/openslx/config" || echo "Error - could not source '/opt/openslx/config'"
	fi
	
	local FILE_URL="$1"
	local TARGET_PATH="$2"
	
	# Shuffle server list
	local SERVERS=$(for SERVER in $SLX_CONFIG_SERVERS $SLX_KCL_SERVERS; do echo "$RANDOM $SERVER"; done | sort -u | sed -r 's/^[0-9]+ //')
	
	for TIMEOUT in 1 1 2; do
		for SERVER in $SERVERS; do
			rm -f "$TARGET_PATH"
			wget -T 5 -q -O "$TARGET_PATH" "http://${SERVER}/${FILE_URL}"
			RET=$?
			if [ "x$RET" != "x0" -o ! -e "$TARGET_PATH" ]; then
				echo "Error - downloading 'http://$SERVER/$FILE_URL' via wget failed. Exit Code: $RET"
				usleep 50000 # 50ms
			else
				echo "Successfully downloaded 'http://${SERVER}/$FILE_URL'."
				return 0
			fi
		done
		echo "Trying again in $(($TIMEOUT * 250)) ms..."
		usleep $(($TIMEOUT * 250000))
	done
	# Max retries reached, no success :-(
	return 1
}

# Add benchmark event to var, including uptime as prefix
bench_event() {
	bench_result="${bench_result}$(cut -f 1 -d ' ' "/proc/uptime") $@
"
}