basic_f1_driver_lookup.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
#include "cJSON.h"

typedef struct {
    char *data;
    size_t size;
} Memory;

size_t write_callback(void *contents, size_t size, size_t nmemb, void *userp) {
    size_t real_size = size * nmemb;
    Memory *mem = (Memory *)userp;

    char *ptr = realloc(mem->data, mem->size + real_size + 1);
    if (ptr == NULL) {
        printf("Memory allocation failed.\n");
        return 0;
    }

    mem->data = ptr;
    memcpy(mem->data + mem->size, contents, real_size);
    mem->size += real_size;
    mem->data[mem->size] = '\0';

    return real_size;
}

int fetch_api(const char *url, Memory *chunk) {
    CURL *curl = curl_easy_init();
    if (!curl) {
        printf("Curl init failed.\n");
        return 0;
    }

    chunk->data = malloc(1);
    chunk->size = 0;

    if (chunk->data == NULL) {
        curl_easy_cleanup(curl);
        return 0;
    }

    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)chunk);

    CURLcode res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);

    if (res != CURLE_OK) {
        printf("Request failed: %s\n", curl_easy_strerror(res));
        free(chunk->data);
        return 0;
    }

    return 1;
}

void print_driver(cJSON *driver) {
    cJSON *num = cJSON_GetObjectItemCaseSensitive(driver, "driver_number");
    cJSON *name = cJSON_GetObjectItemCaseSensitive(driver, "full_name");
    cJSON *team = cJSON_GetObjectItemCaseSensitive(driver, "team_name");
    cJSON *country = cJSON_GetObjectItemCaseSensitive(driver, "country_code");

    if (cJSON_IsNumber(num) && cJSON_IsString(name) && cJSON_IsString(team)) {
        printf("\nDriver Info\n");
        printf("-------------------------\n");
        printf("Number : %d\n", num->valueint);
        printf("Name   : %s\n", name->valuestring);
        printf("Team   : %s\n", team->valuestring);

        if (cJSON_IsString(country)) {
            printf("Country: %s\n", country->valuestring);
        }
    } else {
        printf("Missing expected fields.\n");
    }
}

int main(void) {
    int driver_number;
    char url[256];

    printf("Enter driver number: ");
    scanf("%d", &driver_number);

    snprintf(url, sizeof(url),
             "https://api.openf1.org/v1/drivers?driver_number=%d",
             driver_number);

    Memory chunk;
    if (!fetch_api(url, &chunk)) {
        return 1;
    }

    cJSON *root = cJSON_Parse(chunk.data);
    if (root == NULL) {
        printf("JSON parse error.\n");
        free(chunk.data);
        return 1;
    }

    if (!cJSON_IsArray(root) || cJSON_GetArraySize(root) == 0) {
        printf("No driver found.\n");
        cJSON_Delete(root);
        free(chunk.data);
        return 0;
    }

    cJSON *driver = cJSON_GetArrayItem(root, 0);
    if (cJSON_IsObject(driver)) {
        print_driver(driver);
    }

    cJSON_Delete(root);
    free(chunk.data);
    return 0;
}