#include "util/AsioContextTestFixture.hpp"
#include "util/CoroutineGroup.hpp"
#include "util/Spawn.hpp"
#include "util/Taggable.hpp"
#include "util/TestHttpServer.hpp"
#include "util/TestWebSocketClient.hpp"
#include "util/config/ConfigDefinition.hpp"
#include "util/config/ConfigValue.hpp"
#include "util/config/Types.hpp"
#include "web/ng/Error.hpp"
#include "web/ng/Request.hpp"
#include "web/ng/Response.hpp"
#include "web/ng/impl/HttpConnection.hpp"
#include "web/ng/impl/WsConnection.hpp"

#include <boost/asio/error.hpp>
#include <boost/asio/executor_work_guard.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/post.hpp>
#include <boost/asio/spawn.hpp>
#include <boost/beast/core/flat_buffer.hpp>
#include <boost/beast/http/status.hpp>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include <chrono>
#include <condition_variable>
#include <cstddef>
#include <memory>
#include <mutex>
#include <ranges>
#include <string>
#include <thread>
#include <utility>

using namespace web::ng::impl;
using namespace web::ng;
using namespace util;

struct WebWsConnectionTests : SyncAsioContextTest {
    std::unique_ptr<PlainWsConnection>
    acceptConnection(boost::asio::yield_context yield)
    {
        auto expectedSocket = httpServer_.accept(yield);
        [&]() { ASSERT_TRUE(expectedSocket.has_value()) << expectedSocket.error().message(); }();
        auto ip = expectedSocket->remote_endpoint().address().to_string();

        PlainHttpConnection httpConnection{
            std::move(expectedSocket).value(),
            std::move(ip),
            boost::beast::flat_buffer{},
            tagDecoratorFactory_,
        };

        auto expectedTrue = httpConnection.isUpgradeRequested(yield);
        [&]() {
            ASSERT_TRUE(expectedTrue.has_value()) << expectedTrue.error().message();
            ASSERT_TRUE(expectedTrue.value()) << "Expected upgrade request";
        }();

        auto expectedWsConnection = httpConnection.upgrade(tagDecoratorFactory_, yield);
        [&]() {
            ASSERT_TRUE(expectedWsConnection.has_value()) << expectedWsConnection.error().message();
        }();
        auto connection = std::move(expectedWsConnection).value();
        auto wsConnectionPtr = dynamic_cast<PlainWsConnection*>(connection.release());
        [&]() { ASSERT_NE(wsConnectionPtr, nullptr) << "Expected PlainWsConnection"; }();
        wsConnectionPtr->setTimeout(std::chrono::milliseconds{100});
        return std::unique_ptr<PlainWsConnection>{wsConnectionPtr};
    }

protected:
    util::TagDecoratorFactory tagDecoratorFactory_{config::ClioConfigDefinition{
        {"log.tag_style", config::ConfigValue{config::ConfigType::String}.defaultValue("int")}
    }};
    TestHttpServer httpServer_{ctx_, "localhost"};
    WebSocketAsyncClient wsClient_{ctx_};
    Request::HttpHeaders const headers_;
    Request request_{"some request", headers_};
};

TEST_F(WebWsConnectionTests, WasUpgraded)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
    });
    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        EXPECT_TRUE(wsConnection->wasUpgraded());
    });
}

TEST_F(WebWsConnectionTests, DisconnectClientOnInactivity)
{
    boost::asio::io_context clientCtx;
    auto work = boost::asio::make_work_guard(clientCtx);
    std::thread clientThread{[&clientCtx]() { clientCtx.run(); }};

    std::mutex mutex;
    std::condition_variable cv;
    bool finished{false};

    util::spawn(clientCtx, [&](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        std::unique_lock lock{mutex};
        // Wait for 2 seconds to not block the test infinitely in case of failure
        auto const gotNotified =
            cv.wait_for(lock, std::chrono::seconds{2}, [&finished]() { return finished; });
        [&]() { EXPECT_TRUE(gotNotified); }();
        work.reset();
    });

    runSpawn([&, this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        wsConnection->setTimeout(std::chrono::milliseconds{1});

        // Client will not respond to pings because there is no reading operation scheduled for it.
        auto const receivedMessage = wsConnection->receive(yield);

        {
            std::unique_lock const lock{mutex};
            finished = true;
            cv.notify_one();
        }

        EXPECT_FALSE(receivedMessage.has_value());
        EXPECT_EQ(receivedMessage.error().value(), boost::asio::error::no_permission);
    });
    clientThread.join();
}

TEST_F(WebWsConnectionTests, Send)
{
    Response const response{boost::beast::http::status::ok, "some response", request_};

    util::spawn(ctx_, [this, &response](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        auto const expectedMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
        [&]() { ASSERT_TRUE(expectedMessage.has_value()) << expectedMessage.error().message(); }();
        EXPECT_EQ(expectedMessage.value(), response.message());
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        auto expectedSuccess = wsConnection->send(response, yield);
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
    });
}

TEST_F(WebWsConnectionTests, SendShared)
{
    auto const response = std::make_shared<std::string>("some response");

    util::spawn(ctx_, [this, &response](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        auto const expectedMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
        [&]() { ASSERT_TRUE(expectedMessage.has_value()) << expectedMessage.error().message(); }();
        EXPECT_EQ(expectedMessage.value(), *response);
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        auto expectedSuccess = wsConnection->sendShared(response, yield);
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
    });
}

TEST_F(WebWsConnectionTests, MultipleSend)
{
    Response const response{boost::beast::http::status::ok, "some response", request_};

    util::spawn(ctx_, [this, &response](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();

        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            auto const expectedMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
            [&]() {
                ASSERT_TRUE(expectedMessage.has_value()) << expectedMessage.error().message();
            }();
            EXPECT_EQ(expectedMessage.value(), response.message());
        }
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);

        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            auto expectedSuccess = wsConnection->send(response, yield);
            [&]() {
                ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message();
            }();
        }
    });
}

TEST_F(WebWsConnectionTests, MultipleSendFromMultipleCoroutines)
{
    Response const response{boost::beast::http::status::ok, "some response", request_};

    util::spawn(ctx_, [this, &response](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();

        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            auto const expectedMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
            [&]() {
                ASSERT_TRUE(expectedMessage.has_value()) << expectedMessage.error().message();
            }();
            EXPECT_EQ(expectedMessage.value(), response.message());
        }
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);

        util::CoroutineGroup group{yield};
        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            group.spawn(yield, [&wsConnection, &response](boost::asio::yield_context innerYield) {
                auto expectedSuccess = wsConnection->send(response, innerYield);
                [&]() {
                    ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message();
                }();
            });
        }
        group.asyncWait(yield);
    });
}

TEST_F(WebWsConnectionTests, SendFailed)
{
    Response const response{boost::beast::http::status::ok, "some response", request_};

    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        wsClient_.close();
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        wsConnection->setTimeout(std::chrono::milliseconds{1});
        std::expected<void, Error> expectedSuccess;
        size_t counter = 0;
        while (expectedSuccess.has_value() and counter < 100) {
            expectedSuccess = wsConnection->send(response, yield);
            ++counter;
        }
        EXPECT_FALSE(expectedSuccess.has_value());
        EXPECT_LT(counter, 100);
    });
}

TEST_F(WebWsConnectionTests, SendFailedSendingFromMultipleCoroutines)
{
    Response const response{boost::beast::http::status::ok, "some response", request_};

    util::spawn(ctx_, [this, &response](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();

        auto const expectedMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
        [&]() { ASSERT_TRUE(expectedMessage.has_value()) << expectedMessage.error().message(); }();
        EXPECT_EQ(expectedMessage.value(), response.message());
        wsClient_.close();
    });

    runSpawn([this, &response](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        wsConnection->setTimeout(std::chrono::milliseconds{1});
        std::expected<void, Error> expectedSuccess;
        size_t counter = 0;
        while (expectedSuccess.has_value() and counter < 100) {
            expectedSuccess = wsConnection->send(response, yield);
            ++counter;
        }
        // Sending after getting an error should be safe
        expectedSuccess = wsConnection->send(response, yield);
        EXPECT_FALSE(expectedSuccess.has_value());
        EXPECT_LT(counter, 100);
    });
}

TEST_F(WebWsConnectionTests, Receive)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();

        expectedSuccess = wsClient_.send(yield, request_.message(), std::chrono::milliseconds{100});
        EXPECT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message();
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);

        auto maybeRequest = wsConnection->receive(yield);
        [&]() { ASSERT_TRUE(maybeRequest.has_value()) << maybeRequest.error().message(); }();
        EXPECT_EQ(maybeRequest->message(), request_.message());
    });
}

TEST_F(WebWsConnectionTests, MultipleReceive)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();

        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            expectedSuccess =
                wsClient_.send(yield, request_.message(), std::chrono::milliseconds{100});
            EXPECT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message();
        }
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);

        for ([[maybe_unused]] auto i : std::ranges::iota_view{0, 3}) {
            auto maybeRequest = wsConnection->receive(yield);
            [&]() { ASSERT_TRUE(maybeRequest.has_value()) << maybeRequest.error().message(); }();
            EXPECT_EQ(maybeRequest->message(), request_.message());
        }
    });
}

TEST_F(WebWsConnectionTests, ReceiveTimeout)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        wsConnection->setTimeout(std::chrono::milliseconds{2});
        auto maybeRequest = wsConnection->receive(yield);
        EXPECT_FALSE(maybeRequest.has_value());
        EXPECT_EQ(maybeRequest.error().value(), boost::system::errc::operation_not_permitted);
    });
}

TEST_F(WebWsConnectionTests, ReceiveFailed)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        wsClient_.close();
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        auto maybeRequest = wsConnection->receive(yield);
        EXPECT_FALSE(maybeRequest.has_value());
        EXPECT_EQ(maybeRequest.error().value(), boost::asio::error::eof);
    });
}

TEST_F(WebWsConnectionTests, Close)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        auto const maybeMessage = wsClient_.receive(yield, std::chrono::milliseconds{100});
        EXPECT_FALSE(maybeMessage.has_value());
        EXPECT_THAT(maybeMessage.error().message(), testing::HasSubstr("was gracefully closed"));
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        wsConnection->close(yield);
    });
}

TEST_F(WebWsConnectionTests, CloseWhenConnectionIsAlreadyClosed)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
        wsClient_.close();
    });

    runSpawn([this](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        boost::asio::post(yield);
        wsConnection->close(yield);
        wsConnection->close(yield);
    });
}

TEST_F(WebWsConnectionTests, CloseCalledFromMultipleSubCoroutines)
{
    util::spawn(ctx_, [this](boost::asio::yield_context yield) {
        auto expectedSuccess = wsClient_.connect(
            "localhost", httpServer_.port(), yield, std::chrono::milliseconds{100}
        );
        [&]() { ASSERT_TRUE(expectedSuccess.has_value()) << expectedSuccess.error().message(); }();
    });

    testing::StrictMock<testing::MockFunction<void()>> closeCalled;
    EXPECT_CALL(closeCalled, Call).Times(2);

    runSpawn([&](boost::asio::yield_context yield) {
        auto wsConnection = acceptConnection(yield);
        util::CoroutineGroup coroutines{yield};
        for ([[maybe_unused]] int const i : std::ranges::iota_view{0, 2}) {
            coroutines.spawn(
                yield, [&wsConnection, &closeCalled](boost::asio::yield_context innerYield) {
                    wsConnection->close(innerYield);
                    closeCalled.Call();
                }
            );
        }
        auto const receivedMessage = wsConnection->receive(yield);
        EXPECT_FALSE(receivedMessage.has_value());
        coroutines.asyncWait(yield);
    });
}