#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_adc/adc_oneshot.h"
#include "driver/ledc.h"

#define CONFIG_LOG_MAXIMUM_LEVEL          5

static const char *TAG = "ADC_LED";

// 硬體配置 (不變)
#define ADC_CHAN          ADC_CHANNEL_6 
#define LED_PIN           GPIO_NUM_41   
#define LEDC_TIMER        LEDC_TIMER_0
#define LEDC_MODE         LEDC_LOW_SPEED_MODE
#define LEDC_CHANNEL      LEDC_CHANNEL_0
#define LEDC_DUTY_RES     LEDC_TIMER_12_BIT 
#define LEDC_FREQUENCY    5000              

// 宣告 Task Handle，用於指向接收通知的任務
static TaskHandle_t led_task_handle = NULL;

void ledc_init() {
    ledc_timer_config_t ledc_timer = {
        .speed_mode       = LEDC_MODE,
        .timer_num        = LEDC_TIMER,
        .duty_resolution  = LEDC_DUTY_RES,
        .freq_hz          = LEDC_FREQUENCY,
        .clk_cfg          = LEDC_AUTO_CLK
    };
    ESP_ERROR_CHECK(ledc_timer_config(&ledc_timer));

    ledc_channel_config_t ledc_channel = {
        .speed_mode     = LEDC_MODE,
        .channel        = LEDC_CHANNEL,
        .timer_sel      = LEDC_TIMER,
        .intr_type      = LEDC_INTR_DISABLE,
        .gpio_num       = LED_PIN,
        .duty           = 0,
        .hpoint         = 0
    };
    ESP_ERROR_CHECK(ledc_channel_config(&ledc_channel));
}

// ADC 讀取任務 (發送者)
void adc_task(void *arg) {
    adc_oneshot_unit_handle_t adc_handle;
    adc_oneshot_unit_init_cfg_t unit_cfg = { .unit_id = ADC_UNIT_1 };
    ESP_ERROR_CHECK(adc_oneshot_new_unit(&unit_cfg, &adc_handle));

    adc_oneshot_chan_cfg_t chan_cfg = {
        .bitwidth = ADC_BITWIDTH_DEFAULT,
        .atten    = ADC_ATTEN_DB_12,
    };
    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc_handle, ADC_CHAN, &chan_cfg));

    int raw_val = 0;
    int last_val = -1;

    while (1) {
        ESP_ERROR_CHECK(adc_oneshot_read(adc_handle, ADC_CHAN, &raw_val));

        // 如果變化大於 10 且接收任務已就緒
        if (abs(raw_val - last_val) >= 10 && led_task_handle != NULL) {
            // 發送通知：更新 led_task 的通知值
            // eSetValueWithOverwrite 確保任務收到的永遠是最新的 ADC 值
            xTaskNotify(led_task_handle, (uint32_t)raw_val, eSetValueWithOverwrite);
            last_val = raw_val;
        }
        vTaskDelay(pdMS_TO_TICKS(20));
    }
}

// LED 控制任務 (接收者)
void led_task(void *arg) {
    uint32_t received_adc_val = 0;

    while (1) {
        // 等待通知
        // 第一個 0: 進入前不清除 bits
        // 第二個 0xFFFFFFFF: 離開後清除所有 bits
        // 第三個 &received_adc_val: 存入收到的數值
        // 第四個 portMAX_DELAY: 無限期等待直到收到通知
        if (xTaskNotifyWait(0, 0xffffffff, &received_adc_val, portMAX_DELAY) == pdTRUE) {
            ledc_set_duty(LEDC_MODE, LEDC_CHANNEL, received_adc_val);
            ledc_update_duty(LEDC_MODE, LEDC_CHANNEL);
            ESP_LOGI(TAG, "PWM 更新完成: %lu", received_adc_val);
        }
    }
}

void app_main(void) {
    esp_log_level_set(TAG, ESP_LOG_VERBOSE);
    ledc_init(); 

    // 建立 LED 任務，並將其 Handle 存起來
    xTaskCreate(led_task, "led_task", 3000, NULL, 4, &led_task_handle);
    
    // 建立 ADC 任務
    xTaskCreate(adc_task, "adc_task", 3000, NULL, 5, NULL);
}