/*
 *
 *    Copyright (c) 2020 Project CHIP Authors
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

/**
 *    @file
 *      This file implements a unit test suite for the Platform Time
 *      code functionality.
 *
 */

#include <inttypes.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <lib/support/CodeUtils.h>
#include <lib/support/UnitTestRegistration.h>
#include <lib/support/UnitTestUtils.h>
#include <nlunit-test.h>
#include <system/SystemClock.h>

#include <platform/internal/CHIPDeviceLayerInternal.h>

using namespace chip;
using namespace chip::Logging;
using namespace chip::System;
using namespace chip::System::Clock::Literals;

constexpr Clock::Milliseconds64 kTestTimeMarginMs = 2_ms64;
constexpr Clock::Microseconds64 kTestTimeMarginUs = 500_us64;

// =================================
//      Unit tests
// =================================

static void TestDevice_GetMonotonicMicroseconds(nlTestSuite * inSuite, void * inContext)
{
    static const Clock::Microseconds64 kTestVectorSystemTimeUs[] = {
        600_us64,
        900_us64,
        1500_us64,
    };
    int numOfTestsRan                      = 0;
    constexpr Clock::Microseconds64 margin = kTestTimeMarginUs;

    for (const Clock::Microseconds64 & Tdelay : kTestVectorSystemTimeUs)
    {
        const Clock::Microseconds64 Tstart = System::SystemClock().GetMonotonicMicroseconds64();

        chip::test_utils::SleepMicros(Tdelay.count());

        const Clock::Microseconds64 Tend   = System::SystemClock().GetMonotonicMicroseconds64();
        const Clock::Microseconds64 Tdelta = Tend - Tstart;

        ChipLogProgress(DeviceLayer, "Start=%" PRIu64 " End=%" PRIu64 " Delta=%" PRIu64 " Expected=%" PRIu64, Tstart.count(),
                        Tend.count(), Tdelta.count(), Tdelay.count());

        // verify that timers don't fire early
        NL_TEST_ASSERT(inSuite, Tdelta > (Tdelay - margin));
        // verify they're not too late
        //        NL_TEST_ASSERT(inSuite, Tdelta < (Tdelay + margin));
        numOfTestsRan++;
    }
    NL_TEST_ASSERT(inSuite, numOfTestsRan > 0);
}

static void TestDevice_GetMonotonicMilliseconds(nlTestSuite * inSuite, void * inContext)
{
    static const System::Clock::Milliseconds64 kTestVectorSystemTimeMs[] = {
        10_ms64,
        100_ms64,
        250_ms64,
    };
    int numOfTestsRan                      = 0;
    constexpr Clock::Milliseconds64 margin = kTestTimeMarginMs;

    for (const Clock::Milliseconds64 & Tdelay : kTestVectorSystemTimeMs)
    {
        const Clock::Milliseconds64 Tstart = System::SystemClock().GetMonotonicMilliseconds64();

        chip::test_utils::SleepMillis(Tdelay.count());

        const Clock::Milliseconds64 Tend   = System::SystemClock().GetMonotonicMilliseconds64();
        const Clock::Milliseconds64 Tdelta = Tend - Tstart;

        ChipLogProgress(DeviceLayer, "Start=%" PRIu64 " End=%" PRIu64 " Delta=%" PRIu64 " Expected=%" PRIu64, Tstart.count(),
                        Tend.count(), Tdelta.count(), Tdelay.count());

        // verify that timers don't fire early
        NL_TEST_ASSERT(inSuite, Tdelta > (Tdelay - margin));
        // verify they're not too late
        //        NL_TEST_ASSERT(inSuite, Tdelta < (Tdelay + margin));
        numOfTestsRan++;
    }
    NL_TEST_ASSERT(inSuite, numOfTestsRan > 0);
}

/**
 *   Test Suite. It lists all the test functions.
 */
static const nlTest sTests[] = {

    NL_TEST_DEF("Test DeviceLayer::GetMonotonicMicroseconds", TestDevice_GetMonotonicMicroseconds),
    NL_TEST_DEF("Test DeviceLayer::GetMonotonicMilliseconds", TestDevice_GetMonotonicMilliseconds),

    NL_TEST_SENTINEL()
};

int TestPlatformTime()
{
    nlTestSuite theSuite = { "PlatformTime tests", &sTests[0], nullptr, nullptr };

    // Run test suit againt one context.
    nlTestRunner(&theSuite, nullptr);
    return nlTestRunnerStats(&theSuite);
}

CHIP_REGISTER_TEST_SUITE(TestPlatformTime)