armchair_fw/main/http.cpp

extern "C"
{
#include <stdio.h>
#include "mdns.h"
#include "cJSON.h"
#include "esp_http_server.h"
#include "esp_spiffs.h"
#include "esp_wifi.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "freertos/queue.h"

}

#include "http.hpp"
#include "joystick.hpp"


//tag for logging
static const char * TAG = "http";
static httpd_handle_t server = NULL;

QueueHandle_t joystickDataQueue = xQueueCreate( 1, sizeof( struct joystickData_t ) );


//joystickData_t http_readFromJoystickQueue


//==============================
//===== start mdns service =====
//==============================
//function that initializes and starts mdns server for host discovery
void start_mdns_service()
{
//init queue for sending joystickdata from http endpoint to control task
  mdns_init();
  mdns_hostname_set("armchair");
  mdns_instance_name_set("electric armchair");
}




//===========================
//======= default url =======
//===========================
//serve requested files from spiffs
static esp_err_t on_default_url(httpd_req_t *req)
{
  ESP_LOGI(TAG, "Opening page for URL: %s", req->uri);

  esp_vfs_spiffs_conf_t esp_vfs_spiffs_conf = {
      .base_path = "/spiffs",
      .partition_label = NULL,
      .max_files = 5,
      .format_if_mount_failed = true};
  esp_vfs_spiffs_register(&esp_vfs_spiffs_conf);

  char path[600];
  if (strcmp(req->uri, "/") == 0)
    strcpy(path, "/spiffs/index.html");
  else
    sprintf(path, "/spiffs%s", req->uri);
  char *ext = strrchr(path, '.');
  if (ext == NULL || strncmp(ext, ".local", strlen(".local")) == 0)
  {
    httpd_resp_set_status(req, "301 Moved Permanently");
    httpd_resp_set_hdr(req, "Location", "/");
    httpd_resp_send(req, NULL, 0);
    return ESP_OK;
  }
  if (strcmp(ext, ".css") == 0)
    httpd_resp_set_type(req, "text/css");
  if (strcmp(ext, ".js") == 0)
    httpd_resp_set_type(req, "text/javascript");
  if (strcmp(ext, ".png") == 0)
    httpd_resp_set_type(req, "image/png");

  FILE *file = fopen(path, "r");
  if (file == NULL)
  {
    httpd_resp_send_404(req);
    esp_vfs_spiffs_unregister(NULL);
    return ESP_OK;
  }

  char lineRead[256];
  while (fgets(lineRead, sizeof(lineRead), file))
  {
    httpd_resp_sendstr_chunk(req, lineRead);
  }
  httpd_resp_sendstr_chunk(req, NULL);

  esp_vfs_spiffs_unregister(NULL);
  return ESP_OK;
}




//===============================
//====== joystick endpoint ======
//===============================
//function that is called when data is received with post request at /api/joystick
esp_err_t on_joystick_url(httpd_req_t *req)
{
    //--- add header ---
    //to allow cross origin (otherwise browser fails when app is running on another host)
    httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");

    //--- get data from http request ---
    char buffer[100];
    memset(&buffer, 0, sizeof(buffer));
    httpd_req_recv(req, buffer, req->content_len);
    ESP_LOGD(TAG, "/api/joystick: received data: %s", buffer);

    //--- parse received json string to json object ---
    cJSON *payload = cJSON_Parse(buffer);
    ESP_LOGV(TAG, "parsed json: \n %s", cJSON_Print(payload));

    //--- extract relevant items from json object ---
    cJSON *x_json = cJSON_GetObjectItem(payload, "x");  
    cJSON *y_json = cJSON_GetObjectItem(payload, "y");  
    cJSON *radius_json = cJSON_GetObjectItem(payload, "radius");  
    cJSON *angle_json = cJSON_GetObjectItem(payload, "angle");  

    //--- save items to struct ---
    joystickData_t data = { };

    //note cjson can only interpret values as numbers when there are no quotes around the values in json (are removed from json on client side)
    //convert json to double to float
    data.x = static_cast<float>(x_json->valuedouble);
    data.y = static_cast<float>(y_json->valuedouble);
    data.radius = static_cast<float>(radius_json->valuedouble);
    data.angle = static_cast<float>(angle_json->valuedouble);

    //--- evaluate joystick position enum ---
    //data.position = joystick_evaluatePosition(data.x, data.y);


    //log received and parsed values
    ESP_LOGI(TAG, "parsed values from received json: \n x=%.3f  y=%.3f  radius=%.3f  angle=%.3f",
            data.x, data.y, data.radius, data.angle);

    //--- free memory ---
    cJSON_Delete(payload);


    //--- send data to control task via queue ---
    //xQueueSend( joystickDataQueue, ( void * )&data, ( TickType_t ) 0 );
    //changed to length = 1  -> overwrite - older values are no longer relevant
    xQueueOverwrite( joystickDataQueue, ( void * )&data );


    //--- return http response ---
    httpd_resp_set_status(req, "204 NO CONTENT");
    httpd_resp_send(req, NULL, 0);
    return ESP_OK;
}




//============================
//===== init http server =====
//============================
//function that initializes http server and configures available urls
void http_init_server()
{




    //configure webserver
  httpd_config_t config = HTTPD_DEFAULT_CONFIG();
  config.uri_match_fn = httpd_uri_match_wildcard;

  //start webserver
  ESP_ERROR_CHECK(httpd_start(&server, &config));


  //---------------------------
  //------- define URLs -------
  //---------------------------
  httpd_uri_t joystick_url = {
      .uri = "/api/joystick",
      .method = HTTP_POST,
      .handler = on_joystick_url,
      };
  httpd_register_uri_handler(server, &joystick_url);

  httpd_uri_t default_url = {
      .uri = "/*",
      .method = HTTP_GET,
      .handler = on_default_url};
  httpd_register_uri_handler(server, &default_url);

//  httpd_uri_t socket_joystick_url = {
//      .uri = "/ws-api/joystick",
//      .method = HTTP_GET,
//      .handler = on_socket_joystick_url,
//      .is_websocket = true};
//  httpd_register_uri_handler(server, &socket_joystick_url);

}



//============================
//===== stop http server =====
//============================
//function that destroys the http server
void http_stop_server()
{
    printf("stopping http\n");
    httpd_stop(server);
}