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

#include "display.h"

#include "display_driver.h"
#include "fatal.h"
#include "time.h"

#include "esp_log.h"
#include "esp_timer.h"
#include <string.h>

#define TAG "Display"

#define DRIVER_TASK_PERIOD_US 4000UL
#define TIME_UPDATE_PERIOD_US 1000000UL

#define CLAMP(x, lim) ((x) > (lim) ? (lim) : (x))

const DisplayDigitState digit_encodings[10] = {
	[0] = { true, true, true, true, true, true, false, false },
	[1] = { false, true, true, false, false, false, false, false },
	[2] = { true, true, false, true, true, false, true, false },
	[3] = { true, true, true, true, false, false, true, false },
	[4] = { false, true, true, false, false, true, true, false },
	[5] = { true, false, true, true, false, true, true, false },
	[6] = { true, false, true, true, true, true, true, false },
	[7] = { true, true, true, false, false, false, false, false },
	[8] = { true, true, true, true, true, true, true, false },
	[9] = { true, true, true, false, false, true, true, false },
};

static void show_digit(DisplayDigit digit, unsigned value)
{
	memcpy(
	    &display_state[digit], digit_encodings[value],
	    sizeof(DisplayDigitState));
}

static void show_time(unsigned hour, unsigned minute)
{
	if (hour > 99 || minute > 99)
		ESP_LOGW(TAG, "Un-displayable time: %02u:%02u", hour, minute);

	show_digit(DISPLAY_DIGIT_1, (hour / 10) % 10);
	show_digit(DISPLAY_DIGIT_2, hour % 10);

	display_state[DISPLAY_DIGIT_2][DISPLAY_SEGMENT_DP] = true;

	show_digit(DISPLAY_DIGIT_3, (minute / 10) % 10);
	show_digit(DISPLAY_DIGIT_4, minute % 10);
}

static void update_time(void *arg)
{
	(void)arg;
	const Time time = time_get();
	show_time(time.hour, time.minute);
}

void display_init()
{
	esp_err_t error;

	display_driver_init();

	esp_timer_handle_t driver_timer;
	const esp_timer_create_args_t driver_timer_config = {
		.callback = &display_driver_task,
		.arg = NULL,
		.name = "display driver task",
	};
	error = esp_timer_create(&driver_timer_config, &driver_timer);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error creating timer for driver task: %04x", error);
		FATAL();
	}

	error = esp_timer_start_periodic(driver_timer, DRIVER_TASK_PERIOD_US);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error starting timer for driver task: %04x", error);
		FATAL();
	}

	esp_timer_handle_t update_timer;
	const esp_timer_create_args_t update_timer_config = {
		.callback = &update_time,
		.arg = NULL,
		.name = "display driver task",
	};
	error = esp_timer_create(&update_timer_config, &update_timer);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error creating timer for driver task: %04x", error);
		FATAL();
	}

	error = esp_timer_start_periodic(update_timer, TIME_UPDATE_PERIOD_US);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error starting timer for driver task: %04x", error);
		FATAL();
	}

	update_time(NULL);
}