#include "data/BackendInterface.hpp"
#include "data/Types.hpp"
#include "rpc/Errors.hpp"
#include "rpc/FakesAndMocks.hpp"
#include "rpc/RPCEngine.hpp"
#include "rpc/WorkQueue.hpp"
#include "rpc/common/AnyHandler.hpp"
#include "util/AsioContextTestFixture.hpp"
#include "util/MockBackendTestFixture.hpp"
#include "util/MockCounters.hpp"
#include "util/MockCountersFixture.hpp"
#include "util/MockETLServiceTestFixture.hpp"
#include "util/MockHandlerProvider.hpp"
#include "util/MockPrometheus.hpp"
#include "util/NameGenerator.hpp"
#include "util/Taggable.hpp"
#include "util/config/Array.hpp"
#include "util/config/ConfigConstraints.hpp"
#include "util/config/ConfigDefinition.hpp"
#include "util/config/ConfigFileJson.hpp"
#include "util/config/ConfigValue.hpp"
#include "util/config/Types.hpp"
#include "web/Context.hpp"
#include "web/dosguard/DOSGuard.hpp"
#include "web/dosguard/Weights.hpp"
#include "web/dosguard/WhitelistHandler.hpp"

#include <boost/json/object.hpp>
#include <boost/json/parse.hpp>
#include <gmock/gmock.h>
#include <gtest/gtest.h>

#include <exception>
#include <memory>
#include <optional>
#include <string>
#include <vector>

using namespace data;
using namespace rpc;
using namespace util;
namespace json = boost::json;
using namespace testing;
using namespace util::config;

namespace {
constexpr auto kFORWARD_REPLY = R"JSON({
    "result": {
        "status": "success",
        "forwarded": true
    }
})JSON";
}  // namespace

inline static ClioConfigDefinition
generateDefaultRPCEngineConfig()
{
    return ClioConfigDefinition{
        {"server.max_queue_size", ConfigValue{ConfigType::Integer}.defaultValue(2)},
        {"workers",
         ConfigValue{ConfigType::Integer}.defaultValue(4).withConstraint(gValidateUint16)},
        {"rpc.cache_timeout",
         ConfigValue{ConfigType::Double}.defaultValue(0.0).withConstraint(gValidatePositiveDouble)},
        {"log.tag_style", ConfigValue{ConfigType::String}.defaultValue("uint")},
        {"dos_guard.whitelist.[]", Array{ConfigValue{ConfigType::String}.optional()}},
        {"dos_guard.max_fetches",
         ConfigValue{ConfigType::Integer}.defaultValue(1000'000u).withConstraint(gValidateUint32)},
        {"dos_guard.max_connections",
         ConfigValue{ConfigType::Integer}.defaultValue(20u).withConstraint(gValidateUint32)},
        {"dos_guard.max_requests",
         ConfigValue{ConfigType::Integer}.defaultValue(20u).withConstraint(gValidateUint32)}
    };
}

struct RPCEngineTest : util::prometheus::WithPrometheus,
                       MockBackendTest,
                       MockCountersTest,
                       MockLoadBalancerTest,
                       SyncAsioContextTest {
    ClioConfigDefinition cfg = generateDefaultRPCEngineConfig();

    util::TagDecoratorFactory tagFactory{cfg};
    WorkQueue queue = WorkQueue::makeWorkQueue(cfg);
    web::dosguard::WhitelistHandler whitelistHandler{
        web::dosguard::WhitelistHandler::create(cfg).value()
    };
    web::dosguard::Weights weights{1, {}};
    web::dosguard::DOSGuard dosGuard{cfg, whitelistHandler, weights};
    std::shared_ptr<MockHandlerProvider> handlerProvider = std::make_shared<MockHandlerProvider>();
};

struct RPCEngineFlowTestCaseBundle {
    std::string testName;
    bool isAdmin;
    std::string method;
    std::string params;
    bool forwarded;
    std::optional<bool> isTooBusy;
    std::optional<bool> isUnknownCmd;
    bool handlerReturnError;
    std::optional<rpc::Status> status;
    std::optional<boost::json::object> response;
};

struct RPCEngineFlowParameterTest : public RPCEngineTest,
                                    WithParamInterface<RPCEngineFlowTestCaseBundle> {};

static auto
generateTestValuesForParametersTest()
{
    auto const neverCalled = std::nullopt;

    return std::vector<RPCEngineFlowTestCaseBundle>{
        {.testName = "ForwardedSubmit",
         .isAdmin = true,
         .method = "submit",
         .params = "{}",
         .forwarded = true,
         .isTooBusy = neverCalled,
         .isUnknownCmd = neverCalled,
         .handlerReturnError = false,
         .status = rpc::Status{},
         .response = boost::json::parse(kFORWARD_REPLY).as_object()},
        {.testName = "ForwardAdminCmd",
         .isAdmin = false,
         .method = "ledger",
         .params = R"JSON({"full": true, "ledger_index": "current"})JSON",
         .forwarded = false,
         .isTooBusy = neverCalled,
         .isUnknownCmd = neverCalled,
         .handlerReturnError = false,
         .status = rpc::Status{RippledError::rpcNO_PERMISSION},
         .response = std::nullopt},
        {.testName = "BackendTooBusy",
         .isAdmin = false,
         .method = "ledger",
         .params = "{}",
         .forwarded = false,
         .isTooBusy = true,
         .isUnknownCmd = neverCalled,
         .handlerReturnError = false,
         .status = rpc::Status{RippledError::rpcTOO_BUSY},
         .response = std::nullopt},
        {.testName = "HandlerUnknown",
         .isAdmin = false,
         .method = "ledger",
         .params = "{}",
         .forwarded = false,
         .isTooBusy = false,
         .isUnknownCmd = true,
         .handlerReturnError = false,
         .status = rpc::Status{RippledError::rpcUNKNOWN_COMMAND},
         .response = std::nullopt},
        {.testName = "HandlerReturnError",
         .isAdmin = false,
         .method = "ledger",
         .params = R"JSON({"hello": "world", "limit": 50})JSON",
         .forwarded = false,
         .isTooBusy = false,
         .isUnknownCmd = false,
         .handlerReturnError = true,
         .status = rpc::Status{"Very custom error"},
         .response = std::nullopt},
        {.testName = "HandlerReturnResponse",
         .isAdmin = false,
         .method = "ledger",
         .params = R"JSON({"hello": "world", "limit": 50})JSON",
         .forwarded = false,
         .isTooBusy = false,
         .isUnknownCmd = false,
         .handlerReturnError = false,
         .status = std::nullopt,
         .response = boost::json::parse(R"JSON({"computed": "world_50"})JSON").as_object()},
    };
}

INSTANTIATE_TEST_CASE_P(
    RPCEngineFlow,
    RPCEngineFlowParameterTest,
    ValuesIn(generateTestValuesForParametersTest()),
    tests::util::kNAME_GENERATOR
);

TEST_P(RPCEngineFlowParameterTest, Test)
{
    auto const& testBundle = GetParam();

    std::shared_ptr<RPCEngine<MockCounters>> engine = RPCEngine<MockCounters>::makeRPCEngine(
        generateDefaultRPCEngineConfig(),
        backend_,
        mockLoadBalancerPtr_,
        dosGuard,
        queue,
        *mockCountersPtr_,
        handlerProvider
    );

    if (testBundle.forwarded) {
        EXPECT_CALL(*mockLoadBalancerPtr_, forwardToRippled)
            .WillOnce(Return(
                std::expected<boost::json::object, rpc::ClioError>(
                    json::parse(kFORWARD_REPLY).as_object()
                )
            ));
        EXPECT_CALL(*handlerProvider, contains).WillOnce(Return(true));
        EXPECT_CALL(*mockCountersPtr_, rpcForwarded(testBundle.method));
    }

    if (testBundle.isTooBusy.has_value()) {
        EXPECT_CALL(*backend_, isTooBusy).WillOnce(Return(*testBundle.isTooBusy));
        if (testBundle.isTooBusy.value())
            EXPECT_CALL(*mockCountersPtr_, onTooBusy);
    }

    EXPECT_CALL(*handlerProvider, isClioOnly).WillOnce(Return(false));

    if (testBundle.isUnknownCmd.has_value()) {
        if (testBundle.isUnknownCmd.value()) {
            EXPECT_CALL(*handlerProvider, getHandler).WillOnce(Return(std::nullopt));
            EXPECT_CALL(*mockCountersPtr_, onUnknownCommand);
        } else {
            if (testBundle.handlerReturnError) {
                EXPECT_CALL(*handlerProvider, getHandler)
                    .WillOnce(Return(AnyHandler{tests::common::FailingHandlerFake{}}));
                EXPECT_CALL(*mockCountersPtr_, rpcErrored(testBundle.method));
                EXPECT_CALL(*handlerProvider, contains(testBundle.method)).WillOnce(Return(true));
            } else {
                EXPECT_CALL(*handlerProvider, getHandler(testBundle.method))
                    .WillOnce(Return(AnyHandler{tests::common::HandlerFake{}}));
            }
        }
    }

    runSpawn([&](auto yield) {
        auto const ctx = web::Context(
            yield,
            testBundle.method,
            1,  // api version
            boost::json::parse(testBundle.params).as_object(),
            nullptr,
            tagFactory,
            LedgerRange{.minSequence = 0, .maxSequence = 30},
            "127.0.0.2",
            testBundle.isAdmin
        );

        auto const res = engine->buildResponse(ctx);
        ASSERT_EQ(res.response.has_value(), testBundle.response.has_value());
        if (testBundle.response.has_value()) {
            EXPECT_EQ(res.response.value(), testBundle.response.value());
        } else {
            EXPECT_EQ(res.response.error(), testBundle.status.value());
        }
    });
}

TEST_F(RPCEngineTest, ThrowDatabaseError)
{
    auto const method = "subscribe";
    std::shared_ptr<RPCEngine<MockCounters>> engine = RPCEngine<MockCounters>::makeRPCEngine(
        cfg, backend_, mockLoadBalancerPtr_, dosGuard, queue, *mockCountersPtr_, handlerProvider
    );
    EXPECT_CALL(*backend_, isTooBusy).WillOnce(Return(false));
    EXPECT_CALL(*handlerProvider, getHandler(method))
        .WillOnce(Return(AnyHandler{tests::common::FailingHandlerFake{}}));
    EXPECT_CALL(*mockCountersPtr_, rpcErrored(method)).WillOnce(Throw(data::DatabaseTimeout{}));
    EXPECT_CALL(*handlerProvider, contains(method)).WillOnce(Return(true));
    EXPECT_CALL(*mockCountersPtr_, onTooBusy());

    runSpawn([&](auto yield) {
        auto const ctx = web::Context(
            yield,
            method,
            1,
            boost::json::parse("{}").as_object(),
            nullptr,
            tagFactory,
            LedgerRange{.minSequence = 0, .maxSequence = 30},
            "127.0.0.2",
            false
        );

        auto const res = engine->buildResponse(ctx);
        ASSERT_FALSE(res.response.has_value());
        EXPECT_EQ(res.response.error(), Status{RippledError::rpcTOO_BUSY});
    });
}

TEST_F(RPCEngineTest, ThrowException)
{
    auto const method = "subscribe";
    std::shared_ptr<RPCEngine<MockCounters>> engine = RPCEngine<MockCounters>::makeRPCEngine(
        cfg, backend_, mockLoadBalancerPtr_, dosGuard, queue, *mockCountersPtr_, handlerProvider
    );
    EXPECT_CALL(*backend_, isTooBusy).WillOnce(Return(false));
    EXPECT_CALL(*handlerProvider, getHandler(method))
        .WillOnce(Return(AnyHandler{tests::common::FailingHandlerFake{}}));
    EXPECT_CALL(*mockCountersPtr_, rpcErrored(method)).WillOnce(Throw(std::exception{}));
    EXPECT_CALL(*handlerProvider, contains(method)).WillOnce(Return(true));
    EXPECT_CALL(*mockCountersPtr_, onInternalError());

    runSpawn([&](auto yield) {
        auto const ctx = web::Context(
            yield,
            method,
            1,
            boost::json::parse("{}").as_object(),
            nullptr,
            tagFactory,
            LedgerRange{.minSequence = 0, .maxSequence = 30},
            "127.0.0.2",
            false
        );

        auto const res = engine->buildResponse(ctx);
        ASSERT_FALSE(res.response.has_value());
        EXPECT_EQ(res.response.error(), Status{RippledError::rpcINTERNAL});
    });
}

struct RPCEngineCacheTestCaseBundle {
    std::string testName;
    std::string config;
    std::string method;
    bool isAdmin;
    bool expectedCacheEnabled;
};

struct RPCEngineCacheParameterTest : public RPCEngineTest,
                                     WithParamInterface<RPCEngineCacheTestCaseBundle> {};

static auto
generateCacheTestValuesForParametersTest()
{
    return std::vector<RPCEngineCacheTestCaseBundle>{
        {.testName = "CacheEnabled",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": {"cache_timeout": 10}
         })JSON",
         .method = "server_info",
         .isAdmin = false,
         .expectedCacheEnabled = true},
        {.testName = "CacheDisabledWhenNoConfig",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": {"cache_timeout": 0}
         })JSON",
         .method = "server_info",
         .isAdmin = false,
         .expectedCacheEnabled = false},
        {.testName = "CacheDisabledWhenNoTimeout",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": {"cache_timeout": 0}
         })JSON",
         .method = "server_info",
         .isAdmin = false,
         .expectedCacheEnabled = false},
        {.testName = "CacheDisabledWhenTimeoutIsZero",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": {"cache_timeout": 0}
         })JSON",
         .method = "server_info",
         .isAdmin = false,
         .expectedCacheEnabled = false},
        {.testName = "CacheNotWorkForAdmin",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": { "cache_timeout": 10}
         })JSON",
         .method = "server_info",
         .isAdmin = true,
         .expectedCacheEnabled = false},
        {.testName = "CacheDisabledWhenCmdNotMatch",
         .config = R"JSON({
             "server": {"max_queue_size": 2},
             "workers": 4,
             "rpc": {"cache_timeout": 10}
         })JSON",
         .method = "server_info2",
         .isAdmin = false,
         .expectedCacheEnabled = false},
    };
}

INSTANTIATE_TEST_CASE_P(
    RPCEngineCache,
    RPCEngineCacheParameterTest,
    ValuesIn(generateCacheTestValuesForParametersTest()),
    tests::util::kNAME_GENERATOR
);

TEST_P(RPCEngineCacheParameterTest, Test)
{
    auto const& testParam = GetParam();
    auto const json = ConfigFileJson{json::parse(testParam.config).as_object()};

    auto cfgCache{generateDefaultRPCEngineConfig()};
    auto const errors = cfgCache.parse(json);
    EXPECT_TRUE(!errors.has_value());

    auto const admin = testParam.isAdmin;
    auto const method = testParam.method;
    std::shared_ptr<RPCEngine<MockCounters>> engine = RPCEngine<MockCounters>::makeRPCEngine(
        cfgCache,
        backend_,
        mockLoadBalancerPtr_,
        dosGuard,
        queue,
        *mockCountersPtr_,
        handlerProvider
    );
    int callTime = 2;
    EXPECT_CALL(*handlerProvider, isClioOnly).Times(callTime).WillRepeatedly(Return(false));
    if (testParam.expectedCacheEnabled) {
        EXPECT_CALL(*backend_, isTooBusy).WillOnce(Return(false));
        EXPECT_CALL(*handlerProvider, getHandler)
            .WillOnce(Return(AnyHandler{tests::common::HandlerFake{}}));

    } else {
        EXPECT_CALL(*backend_, isTooBusy).Times(callTime).WillRepeatedly(Return(false));
        EXPECT_CALL(*handlerProvider, getHandler)
            .Times(callTime)
            .WillRepeatedly(Return(AnyHandler{tests::common::HandlerFake{}}));
    }

    while (callTime-- != 0) {
        runSpawn([&](auto yield) {
            auto const ctx = web::Context(
                yield,
                method,
                1,
                boost::json::parse(R"JSON({"hello": "world", "limit": 50})JSON").as_object(),
                nullptr,
                tagFactory,
                LedgerRange{.minSequence = 0, .maxSequence = 30},
                "127.0.0.2",
                admin
            );

            auto const res = engine->buildResponse(ctx);
            ASSERT_TRUE(res.response.has_value());
            EXPECT_EQ(
                res.response.value(),
                boost::json::parse(R"JSON({ "computed": "world_50"})JSON").as_object()
            );
        });
    }
}

TEST_F(RPCEngineTest, NotCacheIfErrorHappen)
{
    auto const cfgCache = ClioConfigDefinition{
        {"server.max_queue_size", ConfigValue{ConfigType::Integer}.defaultValue(2)},
        {"workers",
         ConfigValue{ConfigType::Integer}.defaultValue(4).withConstraint(gValidateUint16)},
        {"rpc.cache_timeout",
         ConfigValue{ConfigType::Double}.defaultValue(10.0).withConstraint(gValidatePositiveDouble)}
    };

    auto const notAdmin = false;
    auto const method = "server_info";
    std::shared_ptr<RPCEngine<MockCounters>> engine = RPCEngine<MockCounters>::makeRPCEngine(
        cfgCache,
        backend_,
        mockLoadBalancerPtr_,
        dosGuard,
        queue,
        *mockCountersPtr_,
        handlerProvider
    );

    int callTime = 2;
    EXPECT_CALL(*backend_, isTooBusy).Times(callTime).WillRepeatedly(Return(false));
    EXPECT_CALL(*handlerProvider, getHandler)
        .Times(callTime)
        .WillRepeatedly(Return(AnyHandler{tests::common::FailingHandlerFake{}}));
    EXPECT_CALL(*mockCountersPtr_, rpcErrored(method)).Times(callTime);
    EXPECT_CALL(*handlerProvider, isClioOnly).Times(callTime).WillRepeatedly(Return(false));
    EXPECT_CALL(*handlerProvider, contains).Times(callTime).WillRepeatedly(Return(true));

    while (callTime-- != 0) {
        runSpawn([&](auto yield) {
            auto const ctx = web::Context(
                yield,
                method,
                1,
                boost::json::parse(R"JSON({"hello": "world", "limit": 50})JSON").as_object(),
                nullptr,
                tagFactory,
                LedgerRange{.minSequence = 0, .maxSequence = 30},
                "127.0.0.2",
                notAdmin
            );

            auto const res = engine->buildResponse(ctx);
            ASSERT_FALSE(res.response.has_value());
            EXPECT_EQ(res.response.error(), rpc::Status{"Very custom error"});
        });
    }
}