#include <jni.h>
#include <string>
#include <vector>
#include <ctime>
#include <android/log.h>
#include <unordered_map>

typedef struct record {
    int year;
    int month;
    int day;
    double temperature;
} Record;

inline void group(std::vector<Record> &records, std::unordered_map<std::string, std::vector<Record>> &map) {
    for (const auto &record : records) {
        map[std::to_string(record.year) + " " + std::to_string(record.month)].push_back(record);
    }
}

inline int64_t nanoTime() {
    struct timespec now{};
    clock_gettime(CLOCK_MONOTONIC, &now);
    return (int64_t) now.tv_sec * 1000000000LL + now.tv_nsec;
}

inline int64_t measureNanoTime(const std::function<void()> &body) {
    int64_t start = nanoTime();
    body();
    int64_t end = nanoTime();
    return end - start;
}

extern "C" JNIEXPORT void JNICALL
Java_eu_lepicekmichal_android_1sdk_1ndk_MainActivity_dataProcessingTest(
        JNIEnv *env,
        jobject,
) {
    std::vector<Record> records;
    std::unordered_map<std::string, std::vector<Record>> map;

    std::ios::sync_with_stdio(false);

    int64_t groupTime = measureNanoTime([&]() -> void { group(records, map); });

    __android_log_print(ANDROID_LOG_DEBUG, __FUNCTION__, "GROUP: %li", groupTime);
}