/*
 * Copyright 2021 The Chromium OS Authors
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/ztest.h>
#include <zephyr/smf.h>

/*
 * Hierarchical Test Transition:
 *
 *	PARENT_AB_ENTRY --> A_ENTRY --> A_RUN --> PARENT_AB_RUN ---|
 *	                                                           |
 *	|----------------------------------------------------------|
 *	|
 *	|--> B_ENTRY --> B_RUN --> B_EXIT --> PARENT_AB_EXIT ------|
 *	                                                           |
 *	|----------------------------------------------------------|
 *	|
 *	|--> PARENT_C_ENTRY --> C_ENTRY --> C_RUN --> C_EXIT ------|
 *	                                                           |
 *      |----------------------------------------------------------|
 *      |
 *	|--> PARENT_C_EXIT
 */

/*
 * Hierarchical 10 Ancestor State Test Transition:
 *
 *	P10_ENTRY --> P09_ENTRY --> ... -- P02_ENTRY --> P01_ENTRY --|
 *                                                                   |
 *      |------------------------------------------------------------|
 *      |
 *      |--> A_ENTRY --> A_RUN --> P01_RUN --> P02_RUN --> P03_RUN --|
 *                                                                   |
 *      |------------------------------------------------------------|
 *      |
 *      |--> ... --> P09_RUN --> P10_RUN --> B_ENTRY -->
 */

#define TEST_OBJECT(o) ((struct test_object *)o)

#define SMF_RUN                         3

#define PARENT_AB_ENTRY_BIT     (1 << 0)
#define STATE_A_ENTRY_BIT       (1 << 1)
#define STATE_A_RUN_BIT         (1 << 2)
#define PARENT_AB_RUN_BIT       (1 << 3)
#define STATE_A_EXIT_BIT        (1 << 4)

#define STATE_B_ENTRY_BIT       (1 << 5)
#define STATE_B_RUN_BIT         (1 << 6)
#define STATE_B_EXIT_BIT        (1 << 7)
#define PARENT_AB_EXIT_BIT      (1 << 8)

#define PARENT_C_ENTRY_BIT      (1 << 9)
#define STATE_C_ENTRY_BIT       (1 << 10)
#define STATE_C_RUN_BIT         (1 << 11)
#define STATE_C_EXIT_BIT        (1 << 12)
#define PARENT_C_EXIT_BIT       (1 << 13)

#define TEST_PARENT_ENTRY_VALUE_NUM 0
#define TEST_PARENT_RUN_VALUE_NUM   3
#define TEST_PARENT_EXIT_VALUE_NUM  8
#define TEST_ENTRY_VALUE_NUM        1
#define TEST_RUN_VALUE_NUM          6
#define TEST_EXIT_VALUE_NUM         12
#define TEST_VALUE_NUM              14
static uint32_t test_value[] = {
	0x00,   /* PARENT_AB_ENTRY */
	0x01,   /* STATE_A_ENTRY */
	0x03,   /* STATE_A_RUN */
	0x07,   /* PARENT_AB_RUN */
	0x0f,   /* STATE_A_EXIT */
	0x1f,   /* STATE_B_ENTRY */
	0x3f,   /* STATE_B_RUN */
	0x7f,   /* STATE_B_EXIT */
	0xff,   /* STATE_AB_EXIT */
	0x1ff,  /* PARENT_C_ENTRY */
	0x3ff,  /* STATE_C_ENTRY */
	0x7ff,  /* STATE_C_RUN */
	0xfff,  /* STATE_C_EXIT */
	0x1fff, /* PARENT_C_EXIT */
	0x3fff, /* FINAL VALUE */
};

/* Forward declaration of test_states */
static const struct smf_state test_states[];

/* List of all TypeC-level states */
enum test_state {
	PARENT_AB,
	PARENT_C,
	STATE_A,
	STATE_B,
	STATE_C,
	STATE_D
};

enum terminate_action {
	NONE,
	PARENT_ENTRY,
	PARENT_RUN,
	PARENT_EXIT,
	ENTRY,
	RUN,
	EXIT
};

static struct test_object {
	struct smf_ctx ctx;
	uint32_t transition_bits;
	uint32_t tv_idx;
	enum terminate_action terminate;
} test_obj;

static void parent_ab_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx = 0;
	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test Parent AB entry failed");

	if (o->terminate == PARENT_ENTRY) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= PARENT_AB_ENTRY_BIT;
}

static void parent_ab_run(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test Parent AB run failed");

	if (o->terminate == PARENT_RUN) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= PARENT_AB_RUN_BIT;

	smf_set_state(SMF_CTX(obj), &test_states[STATE_B]);
}

static void parent_ab_exit(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test Parent AB exit failed");

	if (o->terminate == PARENT_EXIT) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= PARENT_AB_EXIT_BIT;
}

static void parent_c_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test Parent C entry failed");
	o->transition_bits |= PARENT_C_ENTRY_BIT;
}

static void parent_c_run(void *obj)
{
	/* This state should not be reached */
	zassert_true(0, "Test Parent C run failed");
}

static void parent_c_exit(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test Parent C exit failed");
	o->transition_bits |= PARENT_C_EXIT_BIT;
}

static void state_a_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State A entry failed");

	if (o->terminate == ENTRY) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= STATE_A_ENTRY_BIT;
}

static void state_a_run(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State A run failed");

	o->transition_bits |= STATE_A_RUN_BIT;

	/* Return to parent run state */
}

static void state_a_exit(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State A exit failed");
	o->transition_bits |= STATE_A_EXIT_BIT;
}

static void state_b_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State B entry failed");
	o->transition_bits |= STATE_B_ENTRY_BIT;
}

static void state_b_run(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State B run failed");

	if (o->terminate == RUN) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= STATE_B_RUN_BIT;

	smf_set_state(SMF_CTX(obj), &test_states[STATE_C]);
}

static void state_b_exit(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State B exit failed");
	o->transition_bits |= STATE_B_EXIT_BIT;
}

static void state_c_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State C entry failed");
	o->transition_bits |= STATE_C_ENTRY_BIT;
}

static void state_c_run(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State C run failed");
	o->transition_bits |= STATE_C_RUN_BIT;

	smf_set_state(SMF_CTX(obj), &test_states[STATE_D]);
}

static void state_c_exit(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;

	zassert_equal(o->transition_bits, test_value[o->tv_idx],
		      "Test State C exit failed");

	if (o->terminate == EXIT) {
		smf_set_terminate(obj, -1);
		return;
	}

	o->transition_bits |= STATE_C_EXIT_BIT;
}

static void state_d_entry(void *obj)
{
	struct test_object *o = TEST_OBJECT(obj);

	o->tv_idx++;
}

static void state_d_run(void *obj)
{
	/* Do nothing */
}

static void state_d_exit(void *obj)
{
	/* Do nothing */
}

static const struct smf_state test_states[] = {
	[PARENT_AB] = SMF_CREATE_STATE(parent_ab_entry, parent_ab_run,
				       parent_ab_exit, NULL, NULL),
	[PARENT_C] = SMF_CREATE_STATE(parent_c_entry, parent_c_run,
				      parent_c_exit, NULL, NULL),
	[STATE_A] = SMF_CREATE_STATE(state_a_entry, state_a_run, state_a_exit,
				     &test_states[PARENT_AB], NULL),
	[STATE_B] = SMF_CREATE_STATE(state_b_entry, state_b_run, state_b_exit,
				     &test_states[PARENT_AB], NULL),
	[STATE_C] = SMF_CREATE_STATE(state_c_entry, state_c_run, state_c_exit,
				     &test_states[PARENT_C], NULL),
	[STATE_D] = SMF_CREATE_STATE(state_d_entry, state_d_run, state_d_exit,
				     NULL, NULL),
};

ZTEST(smf_tests, test_smf_hierarchical)
{
	/* A) Test state transitions */

	test_obj.transition_bits = 0;
	test_obj.terminate = NONE;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final state not reached");

	/* B) Test termination in parent entry action */

	test_obj.transition_bits = 0;
	test_obj.terminate = PARENT_ENTRY;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_PARENT_ENTRY_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for parent entry termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final parent entry termination state not reached");

	/* C) Test termination in parent run action */

	test_obj.transition_bits = 0;
	test_obj.terminate = PARENT_RUN;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_PARENT_RUN_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for parent run termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final parent run termination state not reached");

	/* D) Test termination in parent exit action */

	test_obj.transition_bits = 0;
	test_obj.terminate = PARENT_EXIT;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_PARENT_EXIT_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for parent exit termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final parent exit termination state not reached");

	/* E) Test termination in child entry action */

	test_obj.transition_bits = 0;
	test_obj.terminate = ENTRY;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_ENTRY_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for entry termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final entry termination state not reached");

	/* F) Test termination in child run action */

	test_obj.transition_bits = 0;
	test_obj.terminate = RUN;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_RUN_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for run termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final run termination state not reached");

	/* G) Test termination in child exit action */

	test_obj.transition_bits = 0;
	test_obj.terminate = EXIT;
	smf_set_initial((struct smf_ctx *)&test_obj, &test_states[STATE_A]);

	for (int i = 0; i < SMF_RUN; i++) {
		if (smf_run_state((struct smf_ctx *)&test_obj) < 0) {
			break;
		}
	}

	zassert_equal(TEST_EXIT_VALUE_NUM, test_obj.tv_idx,
		      "Incorrect test value index for exit termination");
	zassert_equal(test_obj.transition_bits, test_value[test_obj.tv_idx],
		      "Final exit termination state not reached");

}