cgi.cpp

#include "lwip/apps/httpd.h"
#include "pico/cyw43_arch.h"
#include "lwipopts.h"
#include "cgi.h"


static const tCGI cgi_handlers[] = {
    {
        "/set_text.cgi", cgi_handler_set_text
    },
};


void render_text(const char* text, uint32_t _ms_per_scroll_tick);


void urldecode2(char *dst, const char *src)
{
        char a, b;
        while (*src) {
                if ((*src == '%') &&
                    ((a = src[1]) && (b = src[2])) &&
                    (isxdigit(a) && isxdigit(b))) {
                        if (a >= 'a')
                                a -= 'a'-'A';
                        if (a >= 'A')
                                a -= ('A' - 10);
                        else
                                a -= '0';
                        if (b >= 'a')
                                b -= 'a'-'A';
                        if (b >= 'A')
                                b -= ('A' - 10);
                        else
                                b -= '0';
                        *dst++ = 16*a+b;
                        src+=3;
                } else if (*src == '+') {
                        *dst++ = ' ';
                        src++;
                } else {
                        *dst++ = *src++;
                }
        }
        *dst++ = '\0';
}

const char* cgi_handler_set_text(int iIndex, int iNumParams, char *pcParam[], char *pcValue[])
{
    int i=0;

    /* We use this handler for one page request only: "/set_text.cgi"
     * and it is at position 0 in the tCGI array (see above).
     * So iIndex should be 0.
     */
    printf("cgi_handler_set_text called with index %d\n", iIndex);

    char* text = NULL;
    int interval_ms = 0;

    for (i = 0; i < iNumParams; i++){
        /* check if parameter is "led" */
        if (strcmp(pcParam[i] , "text") == 0) {
            text = (char*) calloc(200+1, sizeof(char));
            urldecode2(text, pcValue[i]);
        } else if (strcmp(pcParam[i], "interval_ms") == 0) {
            interval_ms = atoi(pcValue[i]);
        }
    }
    if (text != NULL && interval_ms >= 0 && interval_ms < 0xFFFF) {
        render_text(text, interval_ms);
        
    }
    free(text);
    return "/set_text.html";
}

/* initialize the CGI handler */
void
cgi_init(void)
{
    http_set_cgi_handlers(cgi_handlers, 1);
}