HomeEnergyMeter/main/http_client.c

#include <string.h>
#include <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_system.h"
#include "esp_event.h"

#include "wifi.h"
#include "config.h"

#ifdef HTTP_ENABLED

#include "nvs_flash.h"
#include "esp_netif.h"
#include "esp_tls.h"
#include "esp_http_client.h"

#define MAX_HTTP_RECV_BUFFER 512
static const char *TAG = "HTTP_CLIENT";

esp_err_t _http_event_handler(esp_http_client_event_t *evt)
{
    static char *output_buffer;  // Buffer to store response of http request from event handler
    static int output_len;       // Stores number of bytes read
    switch(evt->event_id) {
        case HTTP_EVENT_ERROR:
            ESP_LOGD(TAG, "HTTP_EVENT_ERROR");
            break;
        case HTTP_EVENT_ON_CONNECTED:
            ESP_LOGD(TAG, "HTTP_EVENT_ON_CONNECTED");
            break;
        case HTTP_EVENT_HEADER_SENT:
            ESP_LOGD(TAG, "HTTP_EVENT_HEADER_SENT");
            break;
        case HTTP_EVENT_ON_HEADER:
            ESP_LOGD(TAG, "HTTP_EVENT_ON_HEADER, key=%s, value=%s", evt->header_key, evt->header_value);
            break;
        case HTTP_EVENT_ON_DATA:
            ESP_LOGD(TAG, "HTTP_EVENT_ON_DATA, len=%d", evt->data_len);
            /*
             *  Check for chunked encoding is added as the URL for chunked encoding used in this example returns binary data.
             *  However, event handler can also be used in case chunked encoding is used.
             */
            if (!esp_http_client_is_chunked_response(evt->client)) {
                // If user_data buffer is configured, copy the response into the buffer
                if (evt->user_data) {
                    memcpy(evt->user_data + output_len, evt->data, evt->data_len);
                } else {
                    if (output_buffer == NULL) {
                        output_buffer = (char *) malloc(esp_http_client_get_content_length(evt->client));
                        output_len = 0;
                        if (output_buffer == NULL) {
                            ESP_LOGE(TAG, "Failed to allocate memory for output buffer");
                            return ESP_FAIL;
                        }
                    }
                    memcpy(output_buffer + output_len, evt->data, evt->data_len);
                }
                output_len += evt->data_len;
            }

            break;
        case HTTP_EVENT_ON_FINISH:
            ESP_LOGD(TAG, "HTTP_EVENT_ON_FINISH");
            if (output_buffer != NULL) {
                // Response is accumulated in output_buffer. Uncomment the below line to print the accumulated response
                //ESP_LOG_BUFFER_HEX(TAG, output_buffer, output_len);
                free(output_buffer);
                output_buffer = NULL;
            }
            output_len = 0;
            break;
        case HTTP_EVENT_DISCONNECTED:
            ESP_LOGD(TAG, "HTTP_EVENT_DISCONNECTED");
            int mbedtls_err = 0;
            esp_err_t err = esp_tls_get_and_clear_last_error(evt->data, &mbedtls_err, NULL);
            if (err != 0) {
                ESP_LOGI(TAG, "Last esp error code: 0x%x", err);
                ESP_LOGI(TAG, "Last mbedtls failure: 0x%x", mbedtls_err);
            }
            if (output_buffer != NULL) {
                free(output_buffer);
                output_buffer = NULL;
            }
            output_len = 0;
            break;
    }
    return ESP_OK;
}

void http_rest_with_url()
{
    char local_response_buffer[MAX_HTTP_RECV_BUFFER] = {0};

    uint32_t kontaktor = 1;     // The default state is always ON

    esp_http_client_config_t config = {
        .url = "http://192.168.1.110/electrical/system/isBoilerOn.php",
        .event_handler = _http_event_handler,
        .user_data = local_response_buffer,        // Pass address of local buffer to get response
    };
    esp_http_client_handle_t client = esp_http_client_init(&config);

    esp_http_client_set_method(client, HTTP_METHOD_GET);
    esp_err_t err = esp_http_client_perform(client);
    if (err == ESP_OK) {

        const int status = esp_http_client_get_status_code(client);
        const int dLen = esp_http_client_get_content_length(client);
        ESP_LOGI(TAG, "HTTP GET Status = %d, content_length = %d",status,dLen );
        //ESP_LOG_BUFFER_HEX(TAG,local_response_buffer,dLen);
        
        if( status == 200 && dLen >= 6 ) {
            local_response_buffer[6] = '\0';
            if( strstr(local_response_buffer,"Ok") != NULL ) {
                ESP_LOGI(TAG, "HTTP Received: Ok" );
                if( strstr(local_response_buffer,"OFF") != NULL ) {
                    ESP_LOGI(TAG, "HTTP Received: OFF" );
                    kontaktor = 0;
                }
                else if( strstr(local_response_buffer,"ON") != NULL ) {
                    ESP_LOGI(TAG, "HTTP Received: ON" );
                }
            }
        }

    } else {
        ESP_LOGE(TAG, "HTTP GET request failed: %s", esp_err_to_name(err));
    }
    
    esp_http_client_cleanup(client);

    ESP_LOGI(TAG, "Change relay state: %u",kontaktor);
    gpio_set_level(VVB_RELAY_OUTPUT_IO, kontaktor);
}



#endif