#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_log.h"
#include "driver/uart.h"
#include "string.h"
#include "driver/gpio.h"
#include "meter_zigbee.h"
#include <math.h>

#define TAG "meter_zigbee"

#define TXD_PIN (GPIO_NUM_17)
#define RXD_PIN (GPIO_NUM_16)
#define BUF_SIZE 128
#define RX_BUF_SIZE 14

#define VOLTAGE_CURRENT1_ATTR 0x0006
#define VOLTAGE_CURRENT2_ATTR 0x0007
#define VOLTAGE_CURRENT3_ATTR 0x0008

static TaskHandle_t meter_zigbee_task = NULL;
static float l1_current = 0, l2_current = 0, l3_current = 0;

static float decode_current(const uint8_t *buf) {
    return (buf[9] + (buf[8] << 8) + (buf[7] << 16)) / 100.0f;
}

static void decode_frame(const uint8_t *buf) {
    uint16_t attr_code = buf[1] | (buf[2] << 8);
    uint8_t size = buf[4];

    if (size != 8) {
        ESP_LOGW(TAG, "Unexpected data size: %d", size);
        return;
    }

    float current = decode_current(buf);
    ESP_LOGI(TAG, "Attr 0x%04X - Current: %.2f A", attr_code, current);

    switch (attr_code) {
        case VOLTAGE_CURRENT1_ATTR: l1_current = current; break;
        case VOLTAGE_CURRENT2_ATTR: l2_current = current; break;
        case VOLTAGE_CURRENT3_ATTR: l3_current = current; break;
        default:
            ESP_LOGW(TAG, "Unknown attribute code: 0x%04X", attr_code);
            return;
    }

    float max_current = fmaxf(fmaxf(l1_current, l2_current), l3_current);
    ESP_LOGI(TAG, "Max current: %.2f A", max_current);
}

static void meter_zigbee_task_func(void *param) {
    ESP_LOGI(TAG, "Zigbee meter task started");
    uint8_t *buf = malloc(RX_BUF_SIZE);
    if (!buf) {
        ESP_LOGE(TAG, "Memory allocation failed");
        vTaskDelete(NULL);
        return;
    }

    while (1) {
        int len = uart_read_bytes(UART_NUM_1, buf, RX_BUF_SIZE, pdMS_TO_TICKS(1000));
        if (len >= 10) {
            decode_frame(buf);
        }
    }

    free(buf);
    vTaskDelete(NULL);
}

int meter_zigbee_send_data(const char *data) {
    int len = strlen(data);
    int sent = uart_write_bytes(UART_NUM_1, data, len);
    ESP_LOGI(TAG, "Sent %d bytes", sent);
    return sent;
}

void meter_zigbee_start(void) {
    ESP_LOGI(TAG, "Starting Zigbee UART");

    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
        .source_clk = UART_SCLK_DEFAULT
    };

    ESP_ERROR_CHECK(uart_param_config(UART_NUM_1, &uart_config));
    ESP_ERROR_CHECK(uart_set_pin(UART_NUM_1, TXD_PIN, RXD_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
    ESP_ERROR_CHECK(uart_driver_install(UART_NUM_1, BUF_SIZE * 2, 0, 0, NULL,0));

    xTaskCreate(meter_zigbee_task_func, "meter_zigbee_task", 4096, NULL, 5, &meter_zigbee_task);
}

void meter_zigbee_stop(void) {
    ESP_LOGI(TAG, "Stopping Zigbee UART");

    if (meter_zigbee_task) {
        vTaskDelete(meter_zigbee_task);
        meter_zigbee_task = NULL;
    }

    uart_driver_delete(UART_NUM_1);
}