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

#include "sound.h"

#include "console.h"

#include "driver/dac.h"
#include "esp_log.h"
#include "esp_timer.h"
#include <string.h>

#define TAG "Sound"

#define CHANNEL DAC_CHANNEL_1
#define SIGNAL_FREQ CONFIG_ALERT_FREQ
#define SIGNAL_AMPLITUDE CONFIG_ALERT_AMPLITUDE
#define TOGGLE_PERIOD_US (1000 * CONFIG_ALERT_TOGGLE_PERIOD_MS)

static esp_timer_handle_t timer;
static bool signal_active;

static void toggle_signal(void *arg)
{
	(void)arg;
	if (signal_active) {
		const esp_err_t error = dac_cw_generator_enable();
		if (error != ESP_OK)
			ESP_LOGE(TAG, "Error enabling signal: %04x", error);
		else
			signal_active = false;
	} else {
		const esp_err_t error = dac_cw_generator_disable();
		if (error != ESP_OK)
			ESP_LOGE(TAG, "Error disabling signal: %04x", error);
		else
			signal_active = true;
	}
}

static int alert_command_func(int argc, char **argv)
{
	if (argc != 2) {
		printf("Invalid number of arguments\n");
		return 1;
	} else if (strcmp(argv[1], "on") == 0) {
		sound_alert_on();
		return 0;
	} else if (strcmp(argv[1], "off") == 0) {
		sound_alert_off();
		return 0;
	} else {
		printf("Invalid state %s\n", argv[1]);
		return 1;
	}
}

void sound_init()
{
	esp_err_t error;

	dac_cw_config_t wave_gen_config = {
		.en_ch = CHANNEL,
		.scale = SIGNAL_AMPLITUDE,
		.freq = SIGNAL_FREQ,
	};
	error = dac_cw_generator_config(&wave_gen_config);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error configuring wave generator: %04x", error);
		return;
	}

	const esp_timer_create_args_t timer_config = {
		.callback = &toggle_signal,
		.arg = NULL,
		.name = "signal toggle task",
	};
	error = esp_timer_create(&timer_config, &timer);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error creating toggle timer: %04x", error);
		return;
	}

	console_register(
	    "alert", "Set alert sound on and off", "alert <on|off>",
	    alert_command_func);
}

void sound_alert_on()
{
	esp_err_t error;

	error = dac_output_enable(CHANNEL);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error enabling DAC output: %04x", error);
		return;
	}

	signal_active = false;
	toggle_signal(NULL);

	error = esp_timer_start_periodic(timer, TOGGLE_PERIOD_US);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error starting toggle timer: %04x", error);
		return;
	}
}

void sound_alert_off()
{
	esp_err_t error;

	error = esp_timer_stop(timer);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error stopping toggle timer: %04x", error);
		return;
	}

	if (signal_active)
		toggle_signal(NULL);

	error = dac_output_disable(CHANNEL);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error disabling DAC output: %04x", error);
		return;
	}
}