/*
 * Copyright (c) 2023 North River Systems Ltd
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/emul.h>
#include <zephyr/drivers/i2c_emul.h>
#include <zephyr/drivers/sensor.h>
#include <zephyr/dt-bindings/sensor/ina230.h>
#include <zephyr/ztest.h>

#include <ina230_emul.h>
#include <ina230.h>

struct ina230_fixture {
	const struct device *dev;
	const struct emul *mock;
	const uint16_t current_lsb_uA;
	const uint16_t rshunt_uOhms;
	const uint16_t config;
};

/**
 * @brief Verify devicetree default configuration is correct.
 */
ZTEST(ina230_0, test_default_config)
{
	const struct ina230_config *config;
	const struct device *dev = DEVICE_DT_GET(DT_NODELABEL(ina230_default_test));

	zassert_not_null(dev);
	config = dev->config;
	zassert_not_null(config);

	/* confirm default DT configuration */
	uint16_t expected = 0x0127;

	zexpect_equal(expected, config->config, "0x%x != config (0x%x)",
		expected, config->config);
}

static void test_datasheet_example(struct ina230_fixture *fixture)
{
	struct sensor_value sensor_val;
	double actual;

	/* only run test for datasheet example of 1mA current LSB and 2 mOhm shunt */
	if (fixture->current_lsb_uA != 1000 || fixture->rshunt_uOhms != 2000) {
		ztest_test_skip();
	}

	ina230_mock_set_register(fixture->mock->data, INA230_REG_BUS_VOLT, 9584);
	ina230_mock_set_register(fixture->mock->data, INA230_REG_CURRENT, 10000);
	ina230_mock_set_register(fixture->mock->data, INA230_REG_POWER, 4792);
	zassert_ok(sensor_sample_fetch(fixture->dev));

	zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_VOLTAGE, &sensor_val));
	actual = sensor_value_to_double(&sensor_val);
	zexpect_within(11.98, actual, 1.25e-3, "Expected 11.98 V, got %.6f V", actual);

	zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_CURRENT, &sensor_val));
	actual = sensor_value_to_double(&sensor_val);
	zexpect_within(10.0, actual, 1e-3, "Expected 10 A, got %.6f V", actual);

	zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_POWER, &sensor_val));
	actual = sensor_value_to_double(&sensor_val);
	zexpect_within(119.82, actual, 25e-3, "Expected 119.82 W, got %.6f W", actual);
}

/**
 * @brief Verify bus voltages for all ina230 nodes in DT
 *
 * @param fixture
 */
static void test_shunt_cal(struct ina230_fixture *fixture)
{
	/* Confirm SHUNT_CAL register which is 5120e-6 / Current_LSB * Rshunt */
	double shunt_cal = 5120e-6 / (fixture->current_lsb_uA * 1e-6 *
		fixture->rshunt_uOhms * 1e-6);

	uint32_t shunt_register_actual;
	uint16_t shunt_register_expected = (uint16_t)shunt_cal;

	zassert_ok(ina230_mock_get_register(fixture->mock->data, INA230_REG_CALIB,
		&shunt_register_actual));
	zexpect_within(shunt_register_expected, shunt_register_actual, 1,
		"Expected %d, got %d", shunt_register_expected, shunt_register_actual);
}

static void test_current(struct ina230_fixture *fixture)
{
	/* 16-bit signed value for current register */
	const int16_t current_reg_vectors[] = {
		32767,
		1000,
		100,
		1,
		0,
		-1,
		-100,
		-1000,
		-32768,
	};

	for (int idx = 0; idx < ARRAY_SIZE(current_reg_vectors); idx++) {
		struct sensor_value sensor_val;
		int16_t current_register = current_reg_vectors[idx];
		double current_expected_A = fixture->current_lsb_uA * 1e-6 * current_register;

		/* set current reading */
		ina230_mock_set_register(fixture->mock->data, INA230_REG_CURRENT, current_register);

		/* Verify sensor value is correct */
		zassert_ok(sensor_sample_fetch(fixture->dev));
		zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_CURRENT, &sensor_val));
		double current_actual_A = sensor_value_to_double(&sensor_val);

		zexpect_within(current_expected_A, current_actual_A, fixture->current_lsb_uA*1e-6,
			"Expected %.6f A, got %.6f A", current_expected_A, current_actual_A);
	}
}

static void test_bus_voltage(struct ina230_fixture *fixture)
{
	zassert_not_null(fixture->mock);

	/* 16-bit signed value for voltage register (but always positive) 1.25 mV/bit */
	const int16_t voltage_reg_vectors[] = {
		32767,
		28800,	/* 36V maximum voltage */
		1000,
		100,
		1,
		0,
	};

	for (int idx = 0; idx < ARRAY_SIZE(voltage_reg_vectors); idx++) {
		struct sensor_value sensor_val;

		ina230_mock_set_register(fixture->mock->data, INA230_REG_BUS_VOLT,
			voltage_reg_vectors[idx]);

		/* Verify sensor value is correct */
		zassert_ok(sensor_sample_fetch(fixture->dev));
		zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_VOLTAGE, &sensor_val));

		double voltage_actual_V = sensor_value_to_double(&sensor_val);
		double voltage_expected_V = voltage_reg_vectors[idx] * 1.25e-3;

		zexpect_within(voltage_expected_V, voltage_actual_V, 1e-6,
			"Expected %.6f A, got %.6f A", voltage_expected_V, voltage_actual_V);
	}
}

static void test_power(struct ina230_fixture *fixture)
{
	/* 16-bit unsigned value for power register */
	const uint16_t power_reg_vectors[] = {
		65535,
		32767,
		10000,
		1000,
		100,
		1,
		0,
	};

	for (int idx = 0; idx < ARRAY_SIZE(power_reg_vectors); idx++) {
		struct sensor_value sensor_val;
		uint32_t power_register = power_reg_vectors[idx];

		/* power is power_register * 25 * current_lsb */
		double power_expected_W = power_register * 25 * fixture->current_lsb_uA * 1e-6;

		/* set current reading */
		ina230_mock_set_register(fixture->mock->data, INA230_REG_POWER, power_register);

		/* Verify sensor value is correct */
		zassert_ok(sensor_sample_fetch(fixture->dev));
		zassert_ok(sensor_channel_get(fixture->dev, SENSOR_CHAN_POWER, &sensor_val));
		double power_actual_W = sensor_value_to_double(&sensor_val);

		zexpect_within(power_expected_W, power_actual_W, 1e-6,
			"Expected %.6f W, got %.6f W for %d",
			power_expected_W, power_actual_W, power_register);
	}
}

/* Create a test fixture for each enabled ina230 device node */
#define DT_DRV_COMPAT ti_ina230
#define INA230_FIXTURE_ENTRY(inst) \
	{ \
		.dev = DEVICE_DT_INST_GET(inst), \
		.mock = EMUL_DT_GET(DT_DRV_INST(inst)), \
		.current_lsb_uA = DT_INST_PROP(inst, current_lsb_microamps), \
		.rshunt_uOhms = DT_INST_PROP(inst, rshunt_micro_ohms), \
		.config = DT_INST_PROP(inst, config), \
	},

static struct ina230_fixture fixtures[] = {
	DT_INST_FOREACH_STATUS_OKAY(INA230_FIXTURE_ENTRY)
};

/* Create a test suite for each enabled ina230 device node */
#define INA230_TESTS(inst) \
	ZTEST(ina230_##inst, test_datasheet_example) { test_datasheet_example(&fixtures[inst]); } \
	ZTEST(ina230_##inst, test_shunt_cal) { test_shunt_cal(&fixtures[inst]); } \
	ZTEST(ina230_##inst, test_current) { test_current(&fixtures[inst]); } \
	ZTEST(ina230_##inst, test_bus_voltage) { test_bus_voltage(&fixtures[inst]); } \
	ZTEST(ina230_##inst, test_power) { test_power(&fixtures[inst]); } \
	ZTEST_SUITE(ina230_##inst, NULL, NULL, NULL, NULL, NULL);

DT_INST_FOREACH_STATUS_OKAY(INA230_TESTS)