/*
 * SPDX-License-Identifier: AGPL-3.0-only
 * Copyright (c) Camden Dixie O'Brien
 */

#include "display_driver.h"

#include "fatal.h"

#include "driver/gpio.h"
#include "esp_log.h"
#include <string.h>

#define TAG "Display driver"

#define PIN_BITMASK(n) ((uint64_t)1 << n)

#define DIGIT_1_SELECT_PIN GPIO_NUM_15
#define DIGIT_2_SELECT_PIN GPIO_NUM_2
#define DIGIT_3_SELECT_PIN GPIO_NUM_0
#define DIGIT_4_SELECT_PIN GPIO_NUM_4

#define SEGMENT_A_PIN GPIO_NUM_16
#define SEGMENT_B_PIN GPIO_NUM_23
#define SEGMENT_C_PIN GPIO_NUM_19
#define SEGMENT_D_PIN GPIO_NUM_5
#define SEGMENT_E_PIN GPIO_NUM_17
#define SEGMENT_F_PIN GPIO_NUM_22
#define SEGMENT_G_PIN GPIO_NUM_21
#define SEGMENT_DP_PIN GPIO_NUM_18

static const gpio_num_t digit_select_pins[DISPLAY_DIGIT_COUNT] = {
	[DISPLAY_DIGIT_1] = DIGIT_1_SELECT_PIN,
	[DISPLAY_DIGIT_2] = DIGIT_2_SELECT_PIN,
	[DISPLAY_DIGIT_3] = DIGIT_3_SELECT_PIN,
	[DISPLAY_DIGIT_4] = DIGIT_4_SELECT_PIN,
};

static const gpio_num_t segment_pins[DISPLAY_SEGMENT_COUNT] = {
	[DISPLAY_SEGMENT_A] = SEGMENT_A_PIN,
	[DISPLAY_SEGMENT_B] = SEGMENT_B_PIN,
	[DISPLAY_SEGMENT_C] = SEGMENT_C_PIN,
	[DISPLAY_SEGMENT_D] = SEGMENT_D_PIN,
	[DISPLAY_SEGMENT_E] = SEGMENT_E_PIN,
	[DISPLAY_SEGMENT_F] = SEGMENT_F_PIN,
	[DISPLAY_SEGMENT_G] = SEGMENT_G_PIN,
	[DISPLAY_SEGMENT_DP] = SEGMENT_DP_PIN,
};

static DisplayDigit active_digit;

DisplayState display_state;

void display_driver_init()
{
	esp_err_t error;

	memset(&display_state, 0, sizeof(DisplayState));

	active_digit = DISPLAY_DIGIT_1;

	uint64_t digit_select_pin_bitmask = 0;
	for (unsigned i = 0; i < DISPLAY_DIGIT_COUNT; ++i)
		digit_select_pin_bitmask |= PIN_BITMASK(digit_select_pins[i]);
	const gpio_config_t digit_select_gpio_config = {
		.pin_bit_mask = digit_select_pin_bitmask,
		.mode = GPIO_MODE_OUTPUT,
	};
	error = gpio_config(&digit_select_gpio_config);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error configuring digit select pins: %04x", error);
		FATAL();
	}

	uint64_t segment_pin_bitmask = 0;
	for (unsigned i = 0; i < DISPLAY_SEGMENT_COUNT; ++i)
		segment_pin_bitmask |= PIN_BITMASK(segment_pins[i]);
	const gpio_config_t segment_gpio_config = {
		.pin_bit_mask = segment_pin_bitmask,
		.mode = GPIO_MODE_OUTPUT_OD,
		.pull_down_en = GPIO_PULLDOWN_ENABLE,
	};
	error = gpio_config(&segment_gpio_config);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error configuring segment pins: %04x", error);
		FATAL();
	}
}

void display_driver_task(void *arg)
{
	(void)gpio_set_level(digit_select_pins[active_digit], 0);
	active_digit = (active_digit + 1) % DISPLAY_DIGIT_COUNT;
	(void)gpio_set_level(digit_select_pins[active_digit], 1);

	for (unsigned i = 0; i < DISPLAY_SEGMENT_COUNT; ++i) {
		(void)gpio_set_level(
		    segment_pins[i], display_state[active_digit][i] ? 0 : 1);
	}
}