#include "http_get.h"

// Callback for libcurl to write response into our struct
static size_t write_callback(void *data, size_t size, size_t nmemb, void *userp) {
    size_t realsize = size * nmemb;
    struct Memory *mem = (struct Memory *)userp;

    char *ptr = realloc(mem->response, mem->size + realsize + 1);
    if(ptr == NULL) {
        // Out of memory!
        fprintf(stderr, "realloc() failed\n");
        return 0;
    }

    mem->response = ptr;
    memcpy(&(mem->response[mem->size]), data, realsize);
    mem->size += realsize;
    mem->response[mem->size] = '\0';
    return realsize;
}

// Function: GET request, returns heap string (caller must free)
char *http_get(const char *url) {
    CURL *curl;
    CURLcode res;
    struct Memory chunk;

    chunk.response = malloc(1);  // start with empty buffer
    chunk.size = 0;

    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();

    if(curl) {
        curl_easy_setopt(curl, CURLOPT_URL, url);
        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L); // follow redirects
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);

        res = curl_easy_perform(curl);

        if(res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
            free(chunk.response);
            chunk.response = NULL;
        }

        curl_easy_cleanup(curl);
    }

    curl_global_cleanup();
    return chunk.response;
}