flash.cpp

#include <iostream>
#include <string>
#include <curl/curl.h>
#include <jsoncpp/json/json.h>

/**
    flash.cpp: a c++ program to run Gemini Flash in a flash
    $ sudo apt-get update
    $ sudo apt-get install libcurl4-openssl-dev libjsoncpp-dev -y
    $ g++ flash.cpp -o flash -lcurl -ljsoncpp
    $ ./flash "capital of france"
**/

// Function to write the response data to a string
static size_t WriteCallback(void* contents, size_t size, size_t nmemb, void* userp) {
    ((std::string*)userp)->append((char*)contents, size * nmemb);
    return size * nmemb;
}

int main(int argc, char* argv[]) {
    if (argc != 2) {
        std::cerr << "Usage: " << argv[0] << " <prompt>" << std::endl;
        return 1;
    }

    std::string prompt = argv[1];
    CURL* curl;
    CURLcode res;
    std::string readBuffer;

    // Initialize a CURL session
    curl = curl_easy_init();
    if (curl) {
        // Set the URL for the POST request
        std::string url = "https://generativelanguage.googleapis.com/v1/models/gemini-1.5-flash:generateContent?key=" + std::string(getenv("GEMINI_API_KEY"));
        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());

        // Set the Content-Type header
        struct curl_slist* headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: application/json");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

        // Set the POST data
        std::string postData = R"({"contents":[{"parts":[{"text":")" + prompt + R"("}]}]})";
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postData.c_str());

        // Set the callback function to capture the response
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);

        // Perform the request, res will get the return code
        res = curl_easy_perform(curl);

        // Check for errors
        if (res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        } else {
            // Parse the JSON response
            Json::CharReaderBuilder readerBuilder;
            Json::Value root;
            std::string errs;

            std::istringstream s(readBuffer);
            if (Json::parseFromStream(readerBuilder, s, &root, &errs)) {
                // Print the desired part of the JSON response
                std::cout << root["candidates"][0]["content"]["parts"][0]["text"].asString() << std::endl;
            } else {
                std::cerr << "Failed to parse JSON: " << errs << std::endl;
            }
        }

        // Clean up
        curl_slist_free_all(headers);
        curl_easy_cleanup(curl);
    }
    return 0;
}