#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>

#include <osmocom/core/utils.h>
#include <osmocom/core/select.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/fsm.h>

enum {
	DMAIN,
};

static void *g_ctx;


enum test_fsm_states {
	ST_NULL = 0,
	ST_ONE,
	ST_TWO,
};

enum test_fsm_evt {
	EV_A,
	EV_B,
};

static void test_fsm_null(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	switch (event) {
	case EV_A:
		OSMO_ASSERT(data == (void *) 23);
		osmo_fsm_inst_state_chg(fi, ST_ONE, 0, 0);
		break;
	default:
		OSMO_ASSERT(0);
		break;
	}
}

static void test_fsm_one(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	switch (event) {
	case EV_B:
		OSMO_ASSERT(data == (void *) 42);
		osmo_fsm_inst_state_chg(fi,ST_TWO, 1, 2342);
		break;
	default:
		OSMO_ASSERT(0);
		break;
	}
}

static void test_fsm_tmr_cb(struct osmo_fsm_inst *fi)
{
	OSMO_ASSERT(fi->T == 2342);
	OSMO_ASSERT(fi->state == ST_TWO);
	LOGP(DMAIN, LOGL_INFO, "Timer\n");

	exit(0);
}

static struct osmo_fsm_state test_fsm_states[] = {
	[ST_NULL] = {
		.in_event_mask = (1 << EV_A),
		.out_state_mask = (1 << ST_ONE),
		.name = "NULL",
		.action = test_fsm_null,
	},
	[ST_ONE]= {
		.in_event_mask = (1 << EV_B),
		.out_state_mask = (1 << ST_TWO),
		.name = "ONE",
		.action= test_fsm_one,
	},
	[ST_TWO]= {
		.in_event_mask = 0,
		.name = "TWO",
		.action = NULL,
	},
};

static struct osmo_fsm fsm = {
	.name = "Test FSM",
	.states = test_fsm_states,
	.num_states = ARRAY_SIZE(test_fsm_states),
	.log_subsys = DMAIN,
};

static struct osmo_fsm_inst *foo(void)
{
	struct osmo_fsm_inst *fi;

	LOGP(DMAIN, LOGL_INFO, "Checking FSM allocation\n");
	fi = osmo_fsm_inst_alloc(&fsm, g_ctx, NULL, LOGL_DEBUG, NULL);
	OSMO_ASSERT(fi);
	OSMO_ASSERT(fi->fsm == &fsm);
	OSMO_ASSERT(!strncmp(osmo_fsm_inst_name(fi), fsm.name, strlen(fsm.name)));
	OSMO_ASSERT(fi->state == ST_NULL);
	OSMO_ASSERT(fi->log_level == LOGL_DEBUG);

	/* Try invalid state transition */
	osmo_fsm_inst_dispatch(fi, EV_B, (void *) 42);
	OSMO_ASSERT(fi->state == ST_NULL);

	/* Legitimate state transition */
	osmo_fsm_inst_dispatch(fi, EV_A, (void *) 23);
	OSMO_ASSERT(fi->state == ST_ONE);

	/* Legitimate transition with timer */
	fsm.timer_cb = test_fsm_tmr_cb;
	osmo_fsm_inst_dispatch(fi, EV_B, (void *) 42);
	OSMO_ASSERT(fi->state == ST_TWO);


	return fi;
}

static const struct log_info_cat default_categories[] = {
	[DMAIN] = {
		.name = "DMAIN",
		.description = "Main",
		.enabled = 1, .loglevel = LOGL_DEBUG,
	},
};

static const struct log_info log_info = {
	.cat = default_categories,
	.num_cat = ARRAY_SIZE(default_categories),
};

int main(int argc, char **argv)
{
	struct log_target *stderr_target;
	struct osmo_fsm_inst *finst;

	osmo_fsm_log_addr(false);

	log_init(&log_info, NULL);
	stderr_target = log_target_create_stderr();
	log_add_target(stderr_target);
	log_set_print_filename(stderr_target, 0);

	g_ctx = NULL;
	osmo_fsm_register(&fsm);

	finst = foo();

	while (1) {
		osmo_select_main(0);
	}
	osmo_fsm_inst_free(finst);
	osmo_fsm_unregister(&fsm);
	exit(0);
}