#include <unistd.h>
#include "ruby.h"

#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
	#pragma GCC optimize ("O3")
	#pragma GCC diagnostic warning "-Wall"
#elif defined(__clang__)
	#pragma clang optimize on
	#pragma clang diagnostic warning "-Wall"
#elif defined(__INTEL_COMPILER)
	#pragma intel optimization_level 3
#endif

static VALUE getTick(VALUE obj) {
	return INT2FIX(sysconf(_SC_CLK_TCK)) ;
}

static VALUE getChildMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_CHILD_MAX)) ;
}

static VALUE getHostnameMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_HOST_NAME_MAX)) ;
}

static VALUE getLoginNameMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_LOGIN_NAME_MAX)) ;
}

static VALUE getOpenMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_OPEN_MAX)) ;
}

static VALUE getPageSize(VALUE obj) {
	return INT2FIX(sysconf(_SC_PAGESIZE)) ;
}

static VALUE getStreamMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_STREAM_MAX)) ;
}

static VALUE getTTYNameMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_TTY_NAME_MAX)) ;
}

static VALUE getPosixVersion(VALUE obj) {
	return INT2FIX(sysconf(_SC_VERSION)) ;
}

static VALUE getLineMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_LINE_MAX)) ;
}

static VALUE getExprNestMax(VALUE obj) {
	return INT2FIX(sysconf(_SC_EXPR_NEST_MAX)) ;
}

static VALUE getProcessorConfigured(VALUE obj) {
	return INT2FIX(sysconf(_SC_NPROCESSORS_CONF)) ;
}

static VALUE getProcessorOnline(VALUE obj) {
	return INT2FIX(sysconf(_SC_NPROCESSORS_ONLN)) ;
}

static VALUE getUser(VALUE obj) {
	char *name = getlogin() ;
	return name ? rb_str_new_cstr(name) : rb_str_new_cstr("") ;
}

static VALUE getUID(VALUE obj) {
	return INT2FIX(getuid()) ;
}

static VALUE getGID(VALUE obj) {
	return INT2FIX(getgid()) ;
}

static VALUE getEUID(VALUE obj) {
	return INT2FIX(geteuid()) ;
}

void Init_sysconf() {
	VALUE _linux_stat = rb_define_module("LinuxStat") ;
	VALUE _sysconf = rb_define_module_under(_linux_stat, "Sysconf") ;

	rb_define_module_function(_sysconf, "sc_clk_tck", getTick, 0) ;
	rb_define_module_function(_sysconf, "child_max", getChildMax, 0) ;
	rb_define_module_function(_sysconf, "hostname_max", getHostnameMax, 0) ;
	rb_define_module_function(_sysconf, "login_name_max", getLoginNameMax, 0) ;
	rb_define_module_function(_sysconf, "open_max", getOpenMax, 0) ;
	rb_define_module_function(_sysconf, "pagesize", getPageSize, 0) ;
	rb_define_module_function(_sysconf, "stream_max", getStreamMax, 0) ;
	rb_define_module_function(_sysconf, "tty_name_max", getTTYNameMax, 0) ;
	rb_define_module_function(_sysconf, "posix_version", getPosixVersion, 0) ;
	rb_define_module_function(_sysconf, "line_max", getLineMax, 0) ;
	rb_define_module_function(_sysconf, "expr_nest_max", getExprNestMax, 0) ;

	rb_define_module_function(_sysconf, "processor_online", getProcessorOnline, 0) ;
	rb_define_module_function(_sysconf, "processor_configured", getProcessorConfigured, 0) ;

	rb_define_module_function(_sysconf, "get_uid", getUID, 0) ;
	rb_define_module_function(_sysconf, "get_gid", getGID, 0) ;
	rb_define_module_function(_sysconf, "get_euid", getEUID, 0) ;

	rb_define_module_function(_sysconf, "get_user", getUser, 0) ;
	rb_define_module_function(_sysconf, "get_login", getUser, 0) ;
}