/*
 * MTG RFID Companion - Piezo buzzer driver (LEDC PWM)
 */

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "driver/ledc.h"
#include "hw_pins.h"
#include "buzzer.h"

static const char *TAG = "buzzer";

#define BUZZER_SPEED_MODE LEDC_LOW_SPEED_MODE
#define BUZZER_TIMER_NUM  LEDC_TIMER_0
#define BUZZER_CHANNEL    LEDC_CHANNEL_0

esp_err_t buzzer_init(void)
{
    ledc_timer_config_t timer_cfg = {
        .speed_mode = BUZZER_SPEED_MODE,
        .timer_num = BUZZER_TIMER_NUM,
        .duty_resolution = LEDC_TIMER_13_BIT,
        .freq_hz = 2000,
        .clk_cfg = LEDC_AUTO_CLK,
    };
    esp_err_t ret = ledc_timer_config(&timer_cfg);
    if (ret != ESP_OK) {
        return ret;
    }

    ledc_channel_config_t chan_cfg = {
        .gpio_num = HW_BUZZER_GPIO,
        .speed_mode = BUZZER_SPEED_MODE,
        .channel = BUZZER_CHANNEL,
        .timer_sel = BUZZER_TIMER_NUM,
        .duty = 0,
        .hpoint = 0,
    };
    ret = ledc_channel_config(&chan_cfg);
    if (ret != ESP_OK) {
        return ret;
    }

    ESP_LOGI(TAG, "buzzer ready on GPIO %d", HW_BUZZER_GPIO);
    return ESP_OK;
}

esp_err_t buzzer_start(uint32_t freq_hz, uint32_t duty_percent)
{
    if (freq_hz == 0) {
        return buzzer_stop();
    }
    uint32_t duty = ((uint32_t)1 << 13) * duty_percent / 100u;
    if (duty_percent >= 100) {
        duty = ((uint32_t)1 << 13);
    }

    esp_err_t ret = ledc_set_freq(BUZZER_SPEED_MODE, BUZZER_TIMER_NUM, freq_hz);
    if (ret != ESP_OK) {
        return ret;
    }
    ret = ledc_set_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL, duty);
    if (ret != ESP_OK) {
        return ret;
    }
    return ledc_update_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL);
}

esp_err_t buzzer_stop(void)
{
    ledc_set_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL, 0);
    return ledc_update_duty(BUZZER_SPEED_MODE, BUZZER_CHANNEL);
}

esp_err_t buzzer_chirp(uint32_t freq_hz, uint32_t duration_ms)
{
    esp_err_t ret = buzzer_start(freq_hz, 30);
    if (ret != ESP_OK) {
        return ret;
    }
    vTaskDelay(pdMS_TO_TICKS(duration_ms));
    return buzzer_stop();
}