AI-on-the-edge-device/code/src/server_main.cpp

#include "server_main.h"

#include <string>

#include "server_help.h"

#include "time_sntp.h"


httpd_handle_t server = NULL;   


std::string starttime = "";


/* An HTTP GET handler */
esp_err_t hello_get_handler(httpd_req_t *req)
{
    char*  buf;
    size_t buf_len;
    printf("req uri:\n");
    printf(req->uri);
    printf("\n");

    /* Get header value string length and allocate memory for length + 1,
     * extra byte for null termination */
    buf_len = httpd_req_get_hdr_value_len(req, "Host") + 1;
    if (buf_len > 1) {
        buf = (char*) malloc(buf_len);
        /* Copy null terminated value string into buffer */
        if (httpd_req_get_hdr_value_str(req, "Host", buf, buf_len) == ESP_OK) {
            ESP_LOGI(TAG, "Found header => Host: %s", buf);
        }
        free(buf);
    }

    buf_len = httpd_req_get_hdr_value_len(req, "Test-Header-2") + 1;
    if (buf_len > 1) {
        buf = (char*) malloc(buf_len);
        if (httpd_req_get_hdr_value_str(req, "Test-Header-2", buf, buf_len) == ESP_OK) {
            ESP_LOGI(TAG, "Found header => Test-Header-2: %s", buf);
        }
        free(buf);
    }

    buf_len = httpd_req_get_hdr_value_len(req, "Test-Header-1") + 1;
    if (buf_len > 1) {
        buf = (char*) malloc(buf_len);
        if (httpd_req_get_hdr_value_str(req, "Test-Header-1", buf, buf_len) == ESP_OK) {
            ESP_LOGI(TAG, "Found header => Test-Header-1: %s", buf);
        }
        free(buf);
    }

    /* Read URL query string length and allocate memory for length + 1,
     * extra byte for null termination */
    buf_len = httpd_req_get_url_query_len(req) + 1;
    if (buf_len > 1) {
        buf = (char*) malloc(buf_len);
        if (httpd_req_get_url_query_str(req, buf, buf_len) == ESP_OK) {
            ESP_LOGI(TAG, "Found URL query => %s", buf);
            char param[32];
            /* Get value of expected key from query string */
            if (httpd_query_key_value(buf, "query1", param, sizeof(param)) == ESP_OK) {
                ESP_LOGI(TAG, "Found URL query parameter => query1=%s", param);
            }
            if (httpd_query_key_value(buf, "query3", param, sizeof(param)) == ESP_OK) {
                ESP_LOGI(TAG, "Found URL query parameter => query3=%s", param);
            }
            if (httpd_query_key_value(buf, "query2", param, sizeof(param)) == ESP_OK) {
                ESP_LOGI(TAG, "Found URL query parameter => query2=%s", param);
            }
        }
        free(buf);
    }

    /* Set some custom headers */
    httpd_resp_set_hdr(req, "Custom-Header-1", "Custom-Value-1");
    httpd_resp_set_hdr(req, "Custom-Header-2", "Custom-Value-2");

    /* Send response with custom headers and body set as the
     * string passed in user context*/
    const char* resp_str = (const char*) req->user_ctx;
    httpd_resp_send(req, resp_str, strlen(resp_str));

    /* After sending the HTTP response the old HTTP request
     * headers are lost. Check if HTTP request headers can be read now. */
    if (httpd_req_get_hdr_value_len(req, "Host") == 0) {
        ESP_LOGI(TAG, "Request headers lost");
    }
    return ESP_OK;
}

esp_err_t starttime_get_handler(httpd_req_t *req)
{
    httpd_resp_send(req, starttime.c_str(), strlen(starttime.c_str())); 
    /* Respond with an empty chunk to signal HTTP response completion */
    httpd_resp_send_chunk(req, NULL, 0);     

    return ESP_OK;
}

esp_err_t hello_main_handler(httpd_req_t *req)
{
    char filepath[50];
    struct stat file_stat;
    printf("uri: %s\n", req->uri);

    char *base_path = (char*) req->user_ctx;
    std::string filetosend(base_path);

    const char *filename = get_path_from_uri(filepath, base_path,
                                             req->uri - 1, sizeof(filepath));    
    printf("1 uri: %s, filename: %s, filepath: %s\n", req->uri, filename, filepath);

    if ((strcmp(req->uri, "/") == 0))
    {
        filetosend = filetosend + "/html/index.html";
    }
    else
    {
        filetosend = filetosend + "/html" + std::string(req->uri);
    }
    
    printf("File to upload: %s\n", filetosend.c_str());    

    if (!filename) {
        ESP_LOGE(TAG, "Filename is too long");
        /* Respond with 500 Internal Server Error */
        httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "Filename too long");
        return ESP_FAIL;
    }
    if (stat(filetosend.c_str(), &file_stat) == -1) {
        /* If file not present on SPIFFS check if URI
         * corresponds to one of the hardcoded paths */
        ESP_LOGE(TAG, "Failed to stat file : %s", filetosend.c_str());
        /* Respond with 404 Not Found */
        httpd_resp_send_err(req, HTTPD_404_NOT_FOUND, "File does not exist");
        return ESP_FAIL;
    }
    esp_err_t res;
    res = httpd_resp_set_hdr(req, "Access-Control-Allow-Origin", "*");
    if (res != ESP_OK)
        return res;

    res = send_file(req, filetosend, &file_stat);
    if (res != ESP_OK)
        return res;

    /* Respond with an empty chunk to signal HTTP response completion */
    httpd_resp_send_chunk(req, NULL, 0);
    return ESP_OK;
}



esp_err_t img_tmp_handler(httpd_req_t *req)
{
    char filepath[50];
    struct stat file_stat;
    printf("uri: %s\n", req->uri);

    char *base_path = (char*) req->user_ctx;
    std::string filetosend(base_path);

    const char *filename = get_path_from_uri(filepath, base_path,
                                             req->uri  + sizeof("/img_tmp") - 1, sizeof(filepath));    
    printf("1 uri: %s, filename: %s, filepath: %s\n", req->uri, filename, filepath);

    filetosend = filetosend + "/img_tmp/" + std::string(filename);
    printf("File to upload: %s\n", filetosend.c_str());    

    if (!filename) {
        ESP_LOGE(TAG, "Filename is too long");
        /* Respond with 500 Internal Server Error */
        httpd_resp_send_err(req, HTTPD_500_INTERNAL_SERVER_ERROR, "Filename too long");
        return ESP_FAIL;
    }
    if (stat(filetosend.c_str(), &file_stat) == -1) {
        /* If file not present on SPIFFS check if URI
         * corresponds to one of the hardcoded paths */
        ESP_LOGE(TAG, "Failed to stat file : %s", filetosend.c_str());
        /* Respond with 404 Not Found */
        httpd_resp_send_err(req, HTTPD_404_NOT_FOUND, "File does not exist");
        return ESP_FAIL;
    }

    esp_err_t res = send_file(req, filetosend, &file_stat);
    if (res != ESP_OK)
        return res;

    /* Respond with an empty chunk to signal HTTP response completion */
    httpd_resp_send_chunk(req, NULL, 0);
    return ESP_OK;
}



void register_server_main_uri(httpd_handle_t server, const char *base_path)
{
    httpd_uri_t starttime_tmp_handle = {
        .uri       = "/starttime",  // Match all URIs of type /path/to/file
        .method    = HTTP_GET,
        .handler   = starttime_get_handler,
        .user_ctx  = NULL    // Pass server data as context
    };
    httpd_register_uri_handler(server, &starttime_tmp_handle);


    httpd_uri_t img_tmp_handle = {
        .uri       = "/img_tmp/*",  // Match all URIs of type /path/to/file
        .method    = HTTP_GET,
        .handler   = img_tmp_handler,
        .user_ctx  = (void*) base_path    // Pass server data as context
    };
    httpd_register_uri_handler(server, &img_tmp_handle);


    httpd_uri_t main_rest_handle = {
        .uri       = "/*",  // Match all URIs of type /path/to/file
        .method    = HTTP_GET,
        .handler   = hello_main_handler,
        .user_ctx  = (void*) base_path    // Pass server data as context
    };
    httpd_register_uri_handler(server, &main_rest_handle);
}



httpd_handle_t start_webserver(void)
{
    httpd_handle_t server = NULL;
    httpd_config_t config = { };

    config.task_priority      = tskIDLE_PRIORITY+5;
    config.stack_size         = 16384;                  // bei 32k stürzt das Programm beim Bilderaufnehmen ab
    config.core_id            = tskNO_AFFINITY;
    config.server_port        = 80;
    config.ctrl_port          = 32768;
    config.max_open_sockets   = 7;      
    config.max_uri_handlers   = 24;                       
    config.max_resp_headers   = 8;                        
    config.backlog_conn       = 5;                        
    config.lru_purge_enable   = false;                    
    config.recv_wait_timeout  = 30;         // default: 5                       
    config.send_wait_timeout  = 30;         // default: 5                        
    config.global_user_ctx = NULL;                        
    config.global_user_ctx_free_fn = NULL;                
    config.global_transport_ctx = NULL;                   
    config.global_transport_ctx_free_fn = NULL;           
    config.open_fn = NULL;                                
    config.close_fn = NULL;                               
//    config.uri_match_fn = NULL;                            
    config.uri_match_fn = httpd_uri_match_wildcard;


    httpd_uri_t hll = {};
    hll.uri       = "/hello";
    hll.method    = HTTP_GET;
    hll.handler   = hello_get_handler;
    hll.user_ctx  = (void*) "Hello World!";


    starttime = gettimestring("%Y%m%d-%H%M%S");

    // Start the httpd server
    ESP_LOGI(TAG, "Starting server on port: '%d'", config.server_port);
    if (httpd_start(&server, &config) == ESP_OK) {
        // Set URI handlers
        ESP_LOGI(TAG, "Registering URI handlers");
        httpd_register_uri_handler(server, &hll);
        return server;
    }

    ESP_LOGI(TAG, "Error starting server!");
    return NULL;
}

void stop_webserver(httpd_handle_t server)
{
    httpd_stop(server);
}


void disconnect_handler(void* arg, esp_event_base_t event_base, 
                               int32_t event_id, void* event_data)
{
    httpd_handle_t* server = (httpd_handle_t*) arg;
    if (*server) {
        ESP_LOGI(TAG, "Stopping webserver");
        stop_webserver(*server);
        *server = NULL;
    }
}

void connect_handler(void* arg, esp_event_base_t event_base, 
                            int32_t event_id, void* event_data)
{
    httpd_handle_t* server = (httpd_handle_t*) arg;
    if (*server == NULL) {
        ESP_LOGI(TAG, "Starting webserver");
        *server = start_webserver();
    }
}