/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <gtest/gtest.h>
#include <iostream>
#include <thread>
#include <vector>
#include <chrono>

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wwrite-strings"
#pragma GCC diagnostic ignored "-Wunused-function"
#pragma GCC diagnostic ignored "-Wunused-variable"
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wformat"
#pragma GCC diagnostic ignored "-Wint-to-pointer-cast"
#pragma GCC diagnostic ignored "-Wpointer-arith"

#include "os.h"
#include "tlog.h"

TEST(osTimeTests, taosLocalTime) {
  // Test 1: Test when both timep and result are not NULL
  time_t     timep = 1617531000;  // 2021-04-04 18:10:00
  struct tm  result;
  struct tm *local_time = taosLocalTime(&timep, &result, NULL, 0, NULL);
  ASSERT_NE(local_time, nullptr);
  ASSERT_EQ(local_time->tm_year, 121);
  ASSERT_EQ(local_time->tm_mon, 3);
  ASSERT_EQ(local_time->tm_mday, 4);
  ASSERT_EQ(local_time->tm_hour, 18);
  ASSERT_EQ(local_time->tm_min, 10);
  ASSERT_EQ(local_time->tm_sec, 00);

  // Test 2: Test when timep is NULL
  local_time = taosLocalTime(NULL, &result, NULL, 0, NULL);
  ASSERT_EQ(local_time, nullptr);

  // Test 4: Test when timep is negative on Windows
#ifdef WINDOWS
  time_t pos_timep = 1609459200;  // 2021-01-01 08:00:00
  local_time = taosLocalTime(&pos_timep, &result, NULL, 0, NULL);
  ASSERT_NE(local_time, nullptr);
  ASSERT_EQ(local_time->tm_year, 121);
  ASSERT_EQ(local_time->tm_mon, 0);
  ASSERT_EQ(local_time->tm_mday, 1);
  ASSERT_EQ(local_time->tm_hour, 8);
  ASSERT_EQ(local_time->tm_min, 0);
  ASSERT_EQ(local_time->tm_sec, 0);

  time_t neg_timep = -1617531000;  // 1918-09-29 21:50:00
  local_time = taosLocalTime(&neg_timep, &result, NULL, 0, NULL);
  ASSERT_NE(local_time, nullptr);
  ASSERT_EQ(local_time->tm_year, 18);
  ASSERT_EQ(local_time->tm_mon, 8);
  ASSERT_EQ(local_time->tm_mday, 29);
  ASSERT_EQ(local_time->tm_hour, 21);
  ASSERT_EQ(local_time->tm_min, 50);
  ASSERT_EQ(local_time->tm_sec, 0);

  time_t neg_timep2 = -315619200;  // 1960-01-01 08:00:00
  local_time = taosLocalTime(&neg_timep2, &result, NULL, 0, NULL);
  ASSERT_NE(local_time, nullptr);
  ASSERT_EQ(local_time->tm_year, 60);
  ASSERT_EQ(local_time->tm_mon, 0);
  ASSERT_EQ(local_time->tm_mday, 1);
  ASSERT_EQ(local_time->tm_hour, 8);
  ASSERT_EQ(local_time->tm_min, 0);
  ASSERT_EQ(local_time->tm_sec, 0);

  time_t zero_timep = 0;  // 1970-01-01 08:00:00
  local_time = taosLocalTime(&zero_timep, &result, NULL, 0, NULL);
  ASSERT_NE(local_time, nullptr);
  ASSERT_EQ(local_time->tm_year, 70);
  ASSERT_EQ(local_time->tm_mon, 0);
  ASSERT_EQ(local_time->tm_mday, 1);
  ASSERT_EQ(local_time->tm_hour, 8);
  ASSERT_EQ(local_time->tm_min, 0);
  ASSERT_EQ(local_time->tm_sec, 0);

  time_t neg_timep3 = -78115158887;
  local_time = taosLocalTime(&neg_timep3, &result, NULL, 0, NULL);
  ASSERT_EQ(local_time, nullptr);
#endif
}

TEST(osTimeTests, taosGmTimeR) {
  // Test 1: Test when both timep and result are not NULL
  time_t     timep = 1617531000;  // 2021-04-04 18:10:00
  struct tm  tmInfo;
  ASSERT_NE(taosGmTimeR(&timep, &tmInfo), nullptr);

  char buf[128];
  taosStrfTime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", &tmInfo);
  ASSERT_STREQ(buf, "2021-04-04T10:10:00");
}

TEST(osTimeTests, taosTimeGm) {
  char *timestr= "2021-04-04T18:10:00";
  struct tm tm = {0};

  taosStrpTime(timestr, "%Y-%m-%dT%H:%M:%S", &tm);
  int64_t seconds = taosTimeGm(&tm);
  ASSERT_EQ(seconds, 1617559800);
}

TEST(osTimeTests, taosMktime) {
  char *timestr= "2021-04-04T18:10:00";
  struct tm tm = {0};

  taosStrpTime(timestr, "%Y-%m-%dT%H:%M:%S", &tm);
  time_t seconds = taosMktime(&tm, NULL);
  ASSERT_EQ(seconds, 1617531000);
}

#ifdef WINDOWS
TEST(osTimeTests, windowsGlobalTimezoneOffset) {
  ASSERT_EQ(taosSetGlobalTimezone("UTC-8"), 0);
  ASSERT_EQ(getWindowsTimezoneOffset(), -TdEastZone8);
  int32_t code = 0;
  ASSERT_EQ(taosGetLocalTimezoneOffset(&code), TdEastZone8);

  ASSERT_EQ(taosSetGlobalTimezone("UTC"), 0);
  ASSERT_EQ(getWindowsTimezoneOffset(), 0);
  ASSERT_EQ(taosGetLocalTimezoneOffset(&code), 0);

  // Restore the default expected by existing Windows time tests.
  ASSERT_EQ(taosSetGlobalTimezone("UTC-8"), 0);
}

TEST(osTimeTests, windowsInitTimezoneKeepsConfiguredTZ) {
  // Simulate user config timezone = UTC before initTimezoneInfo() runs.
  ASSERT_EQ(taosSetGlobalTimezone("UTC"), 0);
  ASSERT_EQ(getWindowsTimezoneOffset(), 0);

  ASSERT_EQ(initTimezoneInfo(), TSDB_CODE_SUCCESS);
  ASSERT_EQ(getWindowsTimezoneOffset(), 0);
  int32_t code = 0;
  ASSERT_EQ(taosGetLocalTimezoneOffset(&code), 0);

  // 1602172800 is 2020-10-08 16:00:00 UTC.
  time_t ts = 1602172800;
  struct tm tmVal;
  ASSERT_NE(taosLocalTime(&ts, &tmVal, NULL, 0, NULL), nullptr);
  ASSERT_EQ(tmVal.tm_year + 1900, 2020);
  ASSERT_EQ(tmVal.tm_mon + 1, 10);
  ASSERT_EQ(tmVal.tm_mday, 8);
  ASSERT_EQ(tmVal.tm_hour, 16);
  ASSERT_EQ(tmVal.tm_min, 0);
  ASSERT_EQ(tmVal.tm_sec, 0);

  // Restore the default expected by existing Windows time tests.
  ASSERT_EQ(taosSetGlobalTimezone("UTC-8"), 0);
}

TEST(osTimeTests, windowsInitTimezoneFromSystemZone) {
  // Simulate user not configuring timezone: clear TZ env var and call initTimezoneInfo().
  // This tests that initTimezoneInfo correctly reads from Windows system timezone
  // using GetTimeZoneInformation and sets TZ environment variable.
  
  // Clear any pre-existing TZ
  SetEnvironmentVariableA("TZ", NULL);
  
  // Call initTimezoneInfo() - should read system timezone and set TZ env var
  ASSERT_EQ(initTimezoneInfo(), TSDB_CODE_SUCCESS);
  
  // Verify TZ is now set after initTimezoneInfo
  char tzEnv[128] = {0};
  DWORD len = GetEnvironmentVariableA("TZ", tzEnv, sizeof(tzEnv));
  ASSERT_GT(len, 0);  // TZ should be non-empty
  
  // Verify that getWindowsTimezoneOffset returns a valid value
  int64_t offset = getWindowsTimezoneOffset();
  uInfo("[test] System timezone offset = %lld seconds", offset);
  
  // Verify taosGetLocalTimezoneOffset is consistent
  int32_t code = 0;
  int32_t tz_offset = taosGetLocalTimezoneOffset(&code);
  uInfo("[test] taosGetLocalTimezoneOffset = %d seconds, code = %d", tz_offset, code);
  
  // Restore to a known state
  ASSERT_EQ(taosSetGlobalTimezone("UTC-8"), 0);
}

TEST(osTimeTests, windowsOffsetFallbackWhenTZUnset) {
  // Simulate early call path: time conversion happens before explicit init.
  SetEnvironmentVariableA("TZ", NULL);

  TIME_ZONE_INFORMATION tzi = {0};
  DWORD tzType = GetTimeZoneInformation(&tzi);
  ASSERT_NE(tzType, TIME_ZONE_ID_INVALID);

  LONG minute_offset = tzi.Bias;
  if (tzType == TIME_ZONE_ID_DAYLIGHT) {
    minute_offset += tzi.DaylightBias;
  } else if (tzType == TIME_ZONE_ID_STANDARD) {
    minute_offset += tzi.StandardBias;
  }

  int64_t expected = (int64_t)minute_offset * 60;
  ASSERT_EQ(getWindowsTimezoneOffset(), expected);
}
#endif

TEST(osTimeTests, invalidParameter) {
  void          *retp = NULL;
  int32_t        reti = 0;
  char           buf[1024] = {0};
  char           fmt[1024] = {0};
  struct tm      tm = {0};
  struct timeval tv = {0};

  retp = taosStrpTime(buf, fmt, NULL);
  EXPECT_EQ(retp, nullptr);
  retp = taosStrpTime(NULL, fmt, &tm);
  EXPECT_EQ(retp, nullptr);
  retp = taosStrpTime(buf, NULL, &tm);
  EXPECT_EQ(retp, nullptr);

  reti = taosGetTimeOfDay(NULL);
  EXPECT_NE(reti, 0);

  reti = taosTime(NULL);
  EXPECT_NE(reti, 0);

  tm.tm_year = 2024;
  tm.tm_mon = 10;
  tm.tm_mday = 23;
  tm.tm_hour = 12;
  tm.tm_min = 1;
  tm.tm_sec = 0;
  tm.tm_isdst = -1;
  time_t rett = taosMktime(&tm, NULL);
  EXPECT_NE(rett, 0);

  retp = taosLocalTime(NULL, &tm, NULL, 0, NULL);
  EXPECT_EQ(retp, nullptr);

  retp = taosLocalTime(&rett, NULL, NULL, 0, NULL);
  EXPECT_EQ(retp, nullptr);

  reti = taosSetGlobalTimezone(NULL);
  EXPECT_NE(reti, 0);
}

#ifndef WINDOWS
TEST(osTimeTests, truncateTimezoneStringRemovesLeadingSlash) {
  char tz[TD_TIMEZONE_LEN] = "/UTC";

  truncateTimezoneString(tz);

  EXPECT_STREQ(tz, "UTC");
}
#endif

TEST(osTimeTests, user_mktime64) {
  int64_t reti = 0;

  reti = user_mktime64(2024, 10, 23, 12, 3, 2, 1);
  EXPECT_NE(reti, 0);

  reti = user_mktime64(2024, 1, 23, 12, 3, 2, 1);
  EXPECT_NE(reti, 0);
}

TEST(osTimeTests, taosLocalTimeBenchmark) {
  const int threads = 400;
  const int iters = 1000000;

  std::atomic<uint64_t> ok{0}, err{0};
  std::vector<std::thread> ths;

  char tsTimezoneStr[TD_TIMEZONE_LEN] = {0};
  (void)initTimezoneInfo();

  // Use a fixed timestamp to avoid extra syscalls in the hot loop
  time_t tp = taosGetTimestampSec();

  auto start = std::chrono::steady_clock::now();
  ths.reserve(threads);
  for (int i = 0; i < threads; ++i) {
    ths.emplace_back([&]() {
      struct tm tm1;
      for (int j = 0; j < iters; ++j) {
        if (taosLocalTime(&tp, &tm1, NULL, 0, NULL) != nullptr) {
          ok.fetch_add(1, std::memory_order_relaxed);
        } else {
          err.fetch_add(1, std::memory_order_relaxed);
        }
      }
    });
  }
  for (auto &t : ths) t.join();
  auto end = std::chrono::steady_clock::now();

  auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
  const uint64_t total = static_cast<uint64_t>(threads) * static_cast<uint64_t>(iters);
  double qps = ms > 0 ? (double)total / ((double)ms / 1000.0) : 0.0;

  std::cout << "[taosLocalTime bench] threads=" << threads
            << " iters=" << iters
            << " total_calls=" << total
            << " ok=" << ok.load()
            << " err=" << err.load()
            << " elapsed_ms=" << ms
            << " throughput_calls_per_sec=" << qps
            << std::endl;

  // Ensure correctness: all calls should succeed
  EXPECT_EQ(ok.load(), total);
  EXPECT_EQ(err.load(), 0u);
}

#ifdef WINDOWS
#else
TEST(osTimeTests, tzConcurrencyBreakTest) {
  constexpr int kReaderThreads = 16;
  constexpr int kDurationSec = 3;

  ASSERT_EQ(initTimezoneInfo(), TSDB_CODE_SUCCESS);

  std::atomic<bool> stop{false};
  std::atomic<uint64_t> errors{0};
  std::vector<std::thread> threads;

  time_t tp = taosGetTimestampSec();

  threads.emplace_back([&]() {
    const char* tzs[] = {
      "UTC",
      "Asia/Shanghai",
      "America/New_York",
      "Europe/Berlin"
    };

    int i = 0;
    while (!stop.load(std::memory_order_relaxed)) {
      setenv("TZ", tzs[i++ % 4], 1);
      tzset();
      std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }
  });

  for (int i = 0; i < kReaderThreads; ++i) {
    threads.emplace_back([&]() {
      struct tm tm1;
      while (!stop.load(std::memory_order_relaxed)) {
        if (!taosLocalTime(&tp, &tm1, nullptr, 0, nullptr)) {
          errors.fetch_add(1, std::memory_order_relaxed);
          continue;
        }

        if (tm1.tm_sec < 0 || tm1.tm_sec > 60 ||
            tm1.tm_min < 0 || tm1.tm_min > 59 ||
            tm1.tm_hour < 0 || tm1.tm_hour > 23 ||
            tm1.tm_mday < 1 || tm1.tm_mday > 31 ||
            tm1.tm_mon < 0 || tm1.tm_mon > 11) {
          errors.fetch_add(1, std::memory_order_relaxed);
        }
      }
    });
  }

  std::this_thread::sleep_for(std::chrono::seconds(kDurationSec));

  stop.store(true, std::memory_order_relaxed);

  for (auto& thread : threads) {
    if (thread.joinable()) {
      thread.join();
    }
  }

  std::cout << "Test completed with " << errors.load() << " errors" << std::endl;
  
  unsetenv("TZ");
  tzset();
}
#endif