#include <stdio.h>
#include "esp_log.h"
#include "driver/i2c_master.h"
#include "bh1750.h"
#include "bh1750_use.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

static const char *TAG = "BH1750_USE";

#define BH1750_READ_RETRY_COUNT        3
#define BH1750_MEASURE_DELAY_MS        200
#define BH1750_RETRY_INTERVAL_MS       30

static i2c_master_bus_handle_t s_i2c_bus_handle = NULL;
static bh1750_handle_t s_bh1750_handle = NULL;

/**
 * @brief 初始化 BH1750 传感器及其所需的 I2C 总线
 */
esp_err_t bh1750_user_init(void)
{
    // 1. 配置并初始化 I2C 总线 (Master Bus)
    i2c_master_bus_config_t bus_config = {
        .clk_source = I2C_CLK_SRC_DEFAULT,
        .i2c_port = I2C_NUM_0,
        .scl_io_num = BH1750_I2C_SCL_IO,
        .sda_io_num = BH1750_I2C_SDA_IO,
        .glitch_ignore_cnt = 7,
    };
    
    esp_err_t ret = i2c_new_master_bus(&bus_config, &s_i2c_bus_handle);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "I2C 总线初始化失败: %s", esp_err_to_name(ret));
        return ret;
    }

    // 2. 创建 BH1750 设备句柄 (使用驱动默认地址 0x23)
    ret = bh1750_create(s_i2c_bus_handle, BH1750_I2C_ADDRESS_DEFAULT, &s_bh1750_handle);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "BH1750 设备创建失败: %s", esp_err_to_name(ret));
        if (s_i2c_bus_handle) {
            i2c_del_master_bus(s_i2c_bus_handle);
            s_i2c_bus_handle = NULL;
        }
        return ret;
    }

    // 3. 初始上电
    ret = bh1750_power_on(s_bh1750_handle);
    if (ret == ESP_OK) {
        ESP_LOGI(TAG, "BH1750 初始化成功");
    }
    
    return ret;
}

/**
 * @brief 读取一次光照强度数据 (Lux)
 */
esp_err_t bh1750_user_read(float *lux)
{
    if (lux == NULL) {
        return ESP_ERR_INVALID_ARG;
    }

    if (s_bh1750_handle == NULL) {
        return ESP_ERR_INVALID_STATE;
    }

    esp_err_t ret = ESP_FAIL;
    for (int attempt = 1; attempt <= BH1750_READ_RETRY_COUNT; ++attempt) {
        // 单次模式每次读取前都先上电，避免传感器处于掉电状态导致返回 0
        ret = bh1750_power_on(s_bh1750_handle);
        if (ret != ESP_OK) {
            ESP_LOGW(TAG, "上电失败(第%d次): %s", attempt, esp_err_to_name(ret));
            vTaskDelay(pdMS_TO_TICKS(BH1750_RETRY_INTERVAL_MS));
            continue;
        }

        // 设置测量模式：单次高分辨率模式 (1lx)
        ret = bh1750_set_measure_mode(s_bh1750_handle, BH1750_ONETIME_1LX_RES);
        if (ret != ESP_OK) {
            ESP_LOGW(TAG, "设置测量模式失败(第%d次): %s", attempt, esp_err_to_name(ret));
            vTaskDelay(pdMS_TO_TICKS(BH1750_RETRY_INTERVAL_MS));
            continue;
        }

        // 根据数据手册，单次高分辨率模式需要约 120ms-180ms 测量时间
        vTaskDelay(pdMS_TO_TICKS(BH1750_MEASURE_DELAY_MS));

        ret = bh1750_get_data(s_bh1750_handle, lux);
        if (ret != ESP_OK) {
            ESP_LOGW(TAG, "数据读取失败(第%d次): %s", attempt, esp_err_to_name(ret));
            vTaskDelay(pdMS_TO_TICKS(BH1750_RETRY_INTERVAL_MS));
            continue;
        }

        // 在强光/室内环境下长期 0 Lux 通常不合理，重试一次可规避偶发总线抖动
        if (*lux <= 0.0f && attempt < BH1750_READ_RETRY_COUNT) {
            ESP_LOGW(TAG, "读取到 0 Lux，准备重试(第%d次)", attempt);
            vTaskDelay(pdMS_TO_TICKS(BH1750_RETRY_INTERVAL_MS));
            continue;
        }

        return ESP_OK;
    }

    if (ret == ESP_OK && *lux <= 0.0f) {
        ESP_LOGW(TAG, "连续读取均为 0 Lux，请优先检查 I2C 上拉电阻和传感器供电");
        return ESP_OK;
    }

    return ret;
}

/**
 * @brief 释放 BH1750 相关资源
 */
void bh1750_user_deinit(void)
{
    if (s_bh1750_handle) {
        bh1750_delete(s_bh1750_handle);
        s_bh1750_handle = NULL;
    }
    if (s_i2c_bus_handle) {
        i2c_del_master_bus(s_i2c_bus_handle);
        s_i2c_bus_handle = NULL;
    }
    ESP_LOGI(TAG, "资源已释放");
}