#include <xrpld/core/detail/Workers.h>
#include <xrpld/perflog/PerfLog.h>

#include <xrpl/beast/unit_test.h>
#include <xrpl/json/json_value.h>

#include <chrono>
#include <cstdint>
#include <memory>
#include <mutex>
#include <string>

namespace ripple {

/**
 * Dummy class for unit tests.
 */

namespace perf {

class PerfLogTest : public PerfLog
{
    void
    rpcStart(std::string const& method, std::uint64_t requestId) override
    {
    }

    void
    rpcFinish(std::string const& method, std::uint64_t requestId) override
    {
    }

    void
    rpcError(std::string const& method, std::uint64_t dur) override
    {
    }

    void
    jobQueue(JobType const type) override
    {
    }

    void
    jobStart(
        JobType const type,
        std::chrono::microseconds dur,
        std::chrono::time_point<std::chrono::steady_clock> startTime,
        int instance) override
    {
    }

    void
    jobFinish(JobType const type, std::chrono::microseconds dur, int instance)
        override
    {
    }

    Json::Value
    countersJson() const override
    {
        return Json::Value();
    }

    Json::Value
    currentJson() const override
    {
        return Json::Value();
    }

    void
    resizeJobs(int const resize) override
    {
    }

    void
    rotate() override
    {
    }
};

}  // namespace perf

//------------------------------------------------------------------------------

class Workers_test : public beast::unit_test::suite
{
public:
    struct TestCallback : Workers::Callback
    {
        void
        processTask(int instance) override
        {
            std::lock_guard lk{mut};
            if (--count == 0)
                cv.notify_all();
        }

        std::condition_variable cv;
        std::mutex mut;
        int count = 0;
    };

    void
    testThreads(int const tc1, int const tc2, int const tc3)
    {
        testcase(
            "threadCounts: " + std::to_string(tc1) + " -> " +
            std::to_string(tc2) + " -> " + std::to_string(tc3));

        TestCallback cb;
        std::unique_ptr<perf::PerfLog> perfLog =
            std::make_unique<perf::PerfLogTest>();

        Workers w(cb, perfLog.get(), "Test", tc1);
        BEAST_EXPECT(w.getNumberOfThreads() == tc1);

        auto testForThreadCount = [this, &cb, &w](int const threadCount) {
            // Prepare the callback.
            cb.count = threadCount;

            // Execute the test.
            w.setNumberOfThreads(threadCount);
            BEAST_EXPECT(w.getNumberOfThreads() == threadCount);

            for (int i = 0; i < threadCount; ++i)
                w.addTask();

            // 10 seconds should be enough to finish on any system
            //
            using namespace std::chrono_literals;
            std::unique_lock<std::mutex> lk{cb.mut};
            bool const signaled =
                cb.cv.wait_for(lk, 10s, [&cb] { return cb.count == 0; });
            BEAST_EXPECT(signaled);
            BEAST_EXPECT(cb.count == 0);
        };
        testForThreadCount(tc1);
        testForThreadCount(tc2);
        testForThreadCount(tc3);
        w.stop();

        // We had better finished all our work!
        BEAST_EXPECT(cb.count == 0);
    }

    void
    run() override
    {
        testThreads(0, 0, 0);
        testThreads(1, 0, 1);
        testThreads(2, 1, 2);
        testThreads(4, 3, 5);
        testThreads(16, 4, 15);
        testThreads(64, 3, 65);
    }
};

BEAST_DEFINE_TESTSUITE(Workers, core, ripple);

}  // namespace ripple