#! /bin/bash

declare -A conf
conf[ATEXIT_MAX]=16
conf[RTC_CB_ARRAY_SIZE]=5
conf[EVENTS_QUEUE_SIZE]=64
conf[GINT_NO_SYSCALLS]=
fail=false
output="gcc.cfg"

help()
{
	cat << EOF
Configuration script for the gint library.

Options that affect the behavior of the library:
  --no-syscalls  [default: false]
        Never use syscalls. Expect some trouble with the malloc() function...
	Do not trigger this option unless you know what you are doing.

Options that customize size limits:
  --atexit-max=<integer>  [default: 16]
        Number of exit handlers that can be registered by atexit().
  --rtc-callbacks=<integer>  [default: 5]
        Number of RTC callbacks that can be registered.
  --events-queue-size=<integer>  [default: 64]
        Number of events simultaneously stored in the event queue.
EOF

	exit 0
}

for arg; do case "$arg" in
	-h | --help) help;;
	--no-syscalls) conf[GINT_NO_SYSCALLS]=true;;

	--atexit-max=*)
		size=${arg#*=}
		if [[ $size == +([0-9]) ]]; then
			conf[ATEXIT_MAX]=$size
		else echo "error: --atexit-max expects an integer value"
			fail=true; fi;;
	--rtc-callbacks=*)
		size=${arg#*=}
		if [[ $size == +([0-9]) ]]; then
			conf[RTC_CB_ARRAY_SIZE]=$size
		else echo "error: --rtc-callbacks expects an integer value"
			fail=true; fi;;
	--events-queue-size=*)
		size=${arg#*=}
		if [[ $size == +([0-9]) ]]; then
			conf[EVENTS_QUEUE_SIZE]=$size
		else echo "error: --events-queue-size expects an integer value"
			fail=true; fi;;

	--atexit-max | --rtc-callbacks | --events-queue-size)
		echo "error: syntax for $arg is $arg=<integer-value>";;

	*)
		echo "error: unrecognized argument '$arg'"; fail=true;;
esac; done

output_config()
{
	echo "-D ATEXIT_MAX=${conf[ATEXIT_MAX]}"
	echo "-D RTC_CB_ARRAY_SIZE=${conf[RTC_CB_ARRAY_SIZE]}"
	echo "-D EVENTS_QUEUE_SIZE=${conf[EVENTS_QUEUE_SIZE]}"
	if [ "${conf[GINT_NO_SYSCALLS]}" != "" ]; then
		echo "-D GINT_NO_SYSCALLS"
	fi
}

if $fail; then
	echo "Configuration has not been modified."
else
	output_config > $output
	echo "Configuration details have been output to file $output."
fi