//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2025, the clio developers.

    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#include "cluster/impl/RepeatedTask.hpp"
#include "util/AsioContextTestFixture.hpp"

#include <boost/asio/io_context.hpp>
#include <boost/asio/spawn.hpp>
#include <boost/asio/steady_timer.hpp>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include <atomic>
#include <chrono>
#include <semaphore>
#include <thread>

using namespace cluster::impl;
using namespace testing;

struct RepeatedTaskTest : AsyncAsioContextTest {
    static constexpr auto kTIMEOUT = std::chrono::seconds{5};
};

template <typename MockFunctionType>
struct RepeatedTaskTypedTest : RepeatedTaskTest {
    std::atomic_int32_t callCount{0};
    std::binary_semaphore semaphore{0};
    testing::StrictMock<MockFunctionType> mockFn;

    void
    expectCalls(int const expectedCalls)
    {
        callCount = 0;

        EXPECT_CALL(mockFn, Call).Times(AtLeast(expectedCalls)).WillRepeatedly([this, expectedCalls](auto&&...) {
            ++callCount;
            if (callCount >= expectedCalls) {
                semaphore.release();
            }
        });
    }
};

namespace {

using TypesToTest = Types<MockFunction<void()>, MockFunction<void(boost::asio::yield_context)>>;

}  // namespace

TYPED_TEST_SUITE(RepeatedTaskTypedTest, TypesToTest);

TYPED_TEST(RepeatedTaskTypedTest, CallsFunctionRepeatedly)
{
    RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), this->ctx_);

    this->expectCalls(3);

    task.run(this->mockFn.AsStdFunction());

    EXPECT_TRUE(this->semaphore.try_acquire_for(TestFixture::kTIMEOUT));

    task.stop();
}

TYPED_TEST(RepeatedTaskTypedTest, StopsImmediately)
{
    auto const interval = std::chrono::seconds(5);
    RepeatedTask<boost::asio::io_context> task(interval, this->ctx_);

    task.run(this->mockFn.AsStdFunction());

    std::this_thread::sleep_for(std::chrono::milliseconds(5));

    auto start = std::chrono::steady_clock::now();
    task.stop();
    EXPECT_LT(std::chrono::steady_clock::now() - start, interval);
}

TYPED_TEST(RepeatedTaskTypedTest, MultipleStops)
{
    RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), this->ctx_);

    this->expectCalls(3);

    task.run(this->mockFn.AsStdFunction());

    EXPECT_TRUE(this->semaphore.try_acquire_for(TestFixture::kTIMEOUT));

    task.stop();
    task.stop();
    task.stop();
}

TYPED_TEST(RepeatedTaskTypedTest, DestructorStopsTask)
{
    this->expectCalls(3);

    {
        RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), this->ctx_);

        task.run(this->mockFn.AsStdFunction());

        EXPECT_TRUE(this->semaphore.try_acquire_for(TestFixture::kTIMEOUT));

        // Destructor will call stop()
    }

    auto const countAfterDestruction = this->callCount.load();

    // Wait a bit - no more calls should happen
    std::this_thread::sleep_for(std::chrono::milliseconds(10));

    EXPECT_EQ(this->callCount, countAfterDestruction);
}

TYPED_TEST(RepeatedTaskTypedTest, StopWithoutRunIsNoOp)
{
    RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), this->ctx_);

    // Should not crash or hang
    task.stop();
}

TEST_F(RepeatedTaskTest, MultipleTasksRunConcurrently)
{
    StrictMock<MockFunction<void()>> mockFn1;
    StrictMock<MockFunction<void()>> mockFn2;

    RepeatedTask<boost::asio::io_context> task1(std::chrono::milliseconds(1), ctx_);
    RepeatedTask<boost::asio::io_context> task2(std::chrono::milliseconds(2), ctx_);

    std::atomic_int32_t callCount1{0};
    std::atomic_int32_t callCount2{0};
    std::binary_semaphore semaphore1{0};
    std::binary_semaphore semaphore2{0};

    EXPECT_CALL(mockFn1, Call).Times(AtLeast(10)).WillRepeatedly([&]() {
        if (++callCount1 >= 10) {
            semaphore1.release();
        }
    });

    EXPECT_CALL(mockFn2, Call).Times(AtLeast(5)).WillRepeatedly([&]() {
        if (++callCount2 >= 5) {
            semaphore2.release();
        }
    });

    task1.run(mockFn1.AsStdFunction());
    task2.run(mockFn2.AsStdFunction());

    EXPECT_TRUE(semaphore1.try_acquire_for(kTIMEOUT));
    EXPECT_TRUE(semaphore2.try_acquire_for(kTIMEOUT));

    task1.stop();
    task2.stop();
}

TYPED_TEST(RepeatedTaskTypedTest, TaskStateTransitionsCorrectly)
{
    RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), this->ctx_);

    task.stop();  // Should be no-op

    this->expectCalls(3);

    task.run(this->mockFn.AsStdFunction());

    EXPECT_TRUE(this->semaphore.try_acquire_for(TestFixture::kTIMEOUT));

    task.stop();

    // Stop again should be no-op
    task.stop();
}

TEST_F(RepeatedTaskTest, FunctionCanAccessYieldContext)
{
    StrictMock<MockFunction<void(boost::asio::yield_context)>> mockFn;
    std::atomic_bool yieldContextUsed = false;
    std::binary_semaphore semaphore{0};

    RepeatedTask<boost::asio::io_context> task(std::chrono::milliseconds(1), ctx_);

    EXPECT_CALL(mockFn, Call).Times(AtLeast(1)).WillRepeatedly([&](boost::asio::yield_context yield) {
        if (yieldContextUsed)
            return;

        // Use the yield context to verify it's valid
        boost::asio::steady_timer timer(yield.get_executor());
        timer.expires_after(std::chrono::milliseconds(1));
        boost::system::error_code ec;
        timer.async_wait(yield[ec]);
        EXPECT_FALSE(ec) << ec.message();
        yieldContextUsed = true;
        semaphore.release();
    });

    task.run(mockFn.AsStdFunction());

    EXPECT_TRUE(semaphore.try_acquire_for(kTIMEOUT));

    task.stop();

    EXPECT_TRUE(yieldContextUsed);
}