#include <inttypes.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/uart.h"
#include "driver/gpio.h"
#include "esp_log.h"

/**
 * This is an example which echos any data it receives on configured UART back to the sender,
 * with hardware flow control turned off. It does not use UART driver event queue.
 *
 * - Port: configured UART
 * - Receive (Rx) buffer: on
 * - Transmit (Tx) buffer: off
 * - Flow control: off
 * - Event queue: off
 */

static const char *TAG = "UART TEST";

#define UART_PORT UART_NUM_0
#define BUF_SIZE (1024)

void setup_uart(void);
void echo_task(void*);

void app_main(void)
{
    xTaskCreate(echo_task, "uart_echo_task", 1024, NULL, 10, NULL);
}


void echo_task(void *arg)
{
  const uint8_t uart_num = UART_PORT;

  setup_uart();

  // Configure a temporary buffer for the incoming data
  uint8_t *data = (uint8_t *) malloc(BUF_SIZE);
  int len;
  while (1) {
      // Read data from the UART
      len = uart_read_bytes(uart_num, data, (BUF_SIZE - 1), 20 / portTICK_PERIOD_MS);
      if (len > 0) {
        // Write data back to the UART
        uart_write_bytes(uart_num, data, len);
        //data[len] = '\0';
        //ESP_LOGI(TAG, "Recv str: %s", (char *) data);
      }
  }
}

void setup_uart(void)
{
  /* Configure parameters of an UART driver,
    * communication pins and install the driver */
  const uint8_t uart_num = UART_PORT;
  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,
  };
  int intr_alloc_flags = 0;

#if CONFIG_UART_ISR_IN_IRAM
    intr_alloc_flags = ESP_INTR_FLAG_IRAM;
#endif

  ESP_ERROR_CHECK(uart_param_config(uart_num, &uart_config));
  ESP_ERROR_CHECK(uart_set_pin(uart_num, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
  ESP_ERROR_CHECK(uart_driver_install(uart_num, BUF_SIZE * 2, 0, 0, NULL, intr_alloc_flags));
}