// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif

#include <util/time.h>

#include <atomic>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <ctime>
#include <thread>

#include <tinyformat.h>

void UninterruptibleSleep(const std::chrono::microseconds& n) { std::this_thread::sleep_for(n); }

static std::atomic<int64_t> nMockTime(0); //!< For unit testing

int64_t GetTime()
{
    int64_t mocktime = nMockTime.load(std::memory_order_relaxed);
    if (mocktime) return mocktime;

    time_t now = time(nullptr);
    assert(now > 0);
    return now;
}

template <typename T>
T GetTime()
{
    const std::chrono::seconds mocktime{nMockTime.load(std::memory_order_relaxed)};

    return std::chrono::duration_cast<T>(
        mocktime.count() ?
            mocktime :
            std::chrono::microseconds{GetTimeMicros()});
}
template std::chrono::seconds GetTime();
template std::chrono::milliseconds GetTime();
template std::chrono::microseconds GetTime();

void SetMockTime(int64_t nMockTimeIn)
{
    nMockTime.store(nMockTimeIn, std::memory_order_relaxed);
}

int64_t GetMockTime()
{
    return nMockTime.load(std::memory_order_relaxed);
}

int64_t GetTimeMillis()
{
    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_milliseconds();
    assert(now > 0);
    return now;
}

int64_t GetTimeMicros()
{
    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_microseconds();
    assert(now > 0);
    return now;
}

int64_t GetSystemTimeInSeconds()
{
    return GetTimeMicros()/1000000;
}

std::string FormatISO8601DateTime(int64_t nTime) {
    struct tm ts;
    time_t time_val = nTime;
#ifdef HAVE_GMTIME_R
    if (gmtime_r(&time_val, &ts) == nullptr) {
#else
    if (gmtime_s(&ts, &time_val) != 0) {
#endif
        return {};
    }
    return strprintf("%04i-%02i-%02iT%02i:%02i:%02iZ", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday, ts.tm_hour, ts.tm_min, ts.tm_sec);
}

std::string FormatISO8601Date(int64_t nTime) {
    struct tm ts;
    time_t time_val = nTime;
#ifdef HAVE_GMTIME_R
    if (gmtime_r(&time_val, &ts) == nullptr) {
#else
    if (gmtime_s(&ts, &time_val) != 0) {
#endif
        return {};
    }
    return strprintf("%04i-%02i-%02i", ts.tm_year + 1900, ts.tm_mon + 1, ts.tm_mday);
}

int64_t ParseISO8601DateTime(const std::string& str)
{
    static const boost::posix_time::ptime epoch = boost::posix_time::from_time_t(0);
    static const std::locale loc(std::locale::classic(),
        new boost::posix_time::time_input_facet("%Y-%m-%dT%H:%M:%SZ"));
    std::istringstream iss(str);
    iss.imbue(loc);
    boost::posix_time::ptime ptime(boost::date_time::not_a_date_time);
    iss >> ptime;
    if (ptime.is_not_a_date_time() || epoch > ptime)
        return 0;
    return (ptime - epoch).total_seconds();
}