// ================================================================================================
// Audio Backend - 音频引擎代理测试
// ================================================================================================

#include <gtest/gtest.h>
#include <gmock/gmock.h>
#include "frontend/proxy/engine_proxy.h"
#include "tests/common/test_fixtures.h"
#include <thread>
#include <chrono>
#include <memory>
#include <string>
#include <future>

using namespace audio_backend;
using namespace audio_backend::frontend;
using namespace std::chrono_literals;

// 创建模拟引擎通信层
class MockEngineCommLayer {
public:
    explicit MockEngineCommLayer() = default;
    ~MockEngineCommLayer() = default;
    
    // 模拟接收命令并返回响应
    void expect_command(EngineCommand cmd, const std::string& params, common::ErrorCode response_code, const std::string& response_data) {
        expected_commands_.push_back({cmd, params, response_code, response_data});
    }
    
    // 模拟状态更新
    void send_status_update(const EngineStatus& status) {
        status_callback_(status);
    }
    
    // 模拟音频数据发送
    void send_audio_data(const engine::AudioBuffer& buffer) {
        audio_data_callback_(buffer);
    }
    
    // 模拟错误消息
    void send_error(common::ErrorCode error, const std::string& message) {
        error_callback_(error, message);
    }
    
    // 设置回调
    void set_status_callback(std::function<void(const EngineStatus&)> callback) {
        status_callback_ = std::move(callback);
    }
    
    void set_audio_data_callback(std::function<void(const engine::AudioBuffer&)> callback) {
        audio_data_callback_ = std::move(callback);
    }
    
    void set_error_callback(std::function<void(common::ErrorCode, const std::string&)> callback) {
        error_callback_ = std::move(callback);
    }
    
    // 处理命令
    common::ErrorCode process_command(EngineCommand cmd, const std::string& params, std::string& response_data) {
        for (const auto& expected : expected_commands_) {
            if (expected.command == cmd && (expected.params.empty() || expected.params == params)) {
                response_data = expected.response_data;
                return expected.response_code;
            }
        }
        
        // 命令不匹配
        response_data = "Unexpected command";
        return common::ErrorCode::InvalidOperation;
    }

private:
    struct ExpectedCommand {
        EngineCommand command;
        std::string params;
        common::ErrorCode response_code;
        std::string response_data;
    };
    
    std::vector<ExpectedCommand> expected_commands_;
    std::function<void(const EngineStatus&)> status_callback_;
    std::function<void(const engine::AudioBuffer&)> audio_data_callback_;
    std::function<void(common::ErrorCode, const std::string&)> error_callback_;
};

// 创建模拟引擎事件监听器
class MockEngineProxyListener : public IEngineProxyListener {
public:
    MOCK_METHOD(void, on_engine_connected, (), (override));
    MOCK_METHOD(void, on_engine_disconnected, (), (override));
    MOCK_METHOD(void, on_engine_state_changed, (EngineState, EngineState), (override));
    MOCK_METHOD(void, on_engine_status_updated, (const EngineStatus&), (override));
    MOCK_METHOD(void, on_audio_data_available, (const engine::AudioBuffer&), (override));
    MOCK_METHOD(void, on_engine_error, (common::ErrorCode, const std::string&), (override));
};

// 创建可测试引擎代理实现
class TestableEngineProxy : public EngineProxy {
public:
    explicit TestableEngineProxy(const EngineProxyConfig& config, MockEngineCommLayer* comm_layer)
        : EngineProxy(config), comm_layer_(comm_layer) {
        // 替换内部通信层为模拟实现
    }
    
    // 模拟通信层函数
    common::ErrorCode override_connect(bool success) {
        connected_ = success;
        return success ? common::ErrorCode::Success : common::ErrorCode::ConnectionFailed;
    }
    
    common::ErrorCode override_send_command(EngineCommand command, const std::string& params, std::string& response) {
        return comm_layer_->process_command(command, params, response);
    }
    
    void simulate_status_update(const EngineStatus& status) {
        // 设置当前状态
        EngineState old_state = current_state_;
        current_state_ = status.state;
        
        // 通知状态变更
        if (old_state != status.state) {
            notify_state_changed(old_state, status.state);
        }
        
        // 通知状态更新
        notify_status_updated(status);
    }
    
    void simulate_audio_data(const engine::AudioBuffer& buffer) {
        notify_audio_data(buffer);
    }
    
    void simulate_error(common::ErrorCode error, const std::string& message) {
        notify_error(error, message);
    }
    
    void simulate_connection_lost() {
        bool was_connected = connected_.exchange(false);
        if (was_connected) {
            notify_disconnected();
        }
    }
    
    void simulate_connection_restored() {
        bool was_disconnected = !connected_.exchange(true);
        if (was_disconnected) {
            notify_connected();
        }
    }
    
    // 暴露内部函数和状态用于测试
    using EngineProxy::notify_connected;
    using EngineProxy::notify_disconnected;
    using EngineProxy::notify_state_changed;
    using EngineProxy::notify_status_updated;
    using EngineProxy::notify_audio_data;
    using EngineProxy::notify_error;
    
    std::atomic<bool> connected_{false};
    std::atomic<EngineState> current_state_{EngineState::Unknown};

private:
    MockEngineCommLayer* comm_layer_;
};

// 引擎代理测试固定装置
class EngineProxyTest : public test::FrontendTest {
protected:
    void SetUp() override {
        test::FrontendTest::SetUp();
        
        // 创建模拟通信层
        comm_layer_ = std::make_unique<MockEngineCommLayer>();
        
        // 创建代理配置
        EngineProxyConfig config;
        config.engine_endpoint = "tcp://localhost:5555";
        config.connection_timeout = 1000ms;
        config.command_timeout = 500ms;
        config.status_poll_interval = 200ms;
        config.auto_reconnect = true;
        config.enable_heartbeat = true;
        
        // 创建可测试引擎代理
        proxy_ = std::make_unique<TestableEngineProxy>(config, comm_layer_.get());
        
        // 创建模拟事件监听器
        listener_ = std::make_shared<::testing::NiceMock<MockEngineProxyListener>>();
        
        // 添加事件监听器
        proxy_->add_listener(listener_);
        
        // 设置通信层回调
        comm_layer_->set_status_callback([this](const EngineStatus& status) {
            proxy_->simulate_status_update(status);
        });
        
        comm_layer_->set_audio_data_callback([this](const engine::AudioBuffer& buffer) {
            proxy_->simulate_audio_data(buffer);
        });
        
        comm_layer_->set_error_callback([this](common::ErrorCode error, const std::string& message) {
            proxy_->simulate_error(error, message);
        });
    }
    
    void TearDown() override {
        // 移除事件监听器
        if (listener_ && proxy_) {
            proxy_->remove_listener(listener_);
        }
        
        // 关闭代理
        if (proxy_ && proxy_->is_initialized()) {
            proxy_->shutdown();
        }
        
        proxy_.reset();
        listener_.reset();
        comm_layer_.reset();
        
        test::FrontendTest::TearDown();
    }
    
    // 创建测试引擎配置
    EngineConfiguration create_test_config() {
        EngineConfiguration config;
        config.sample_rate = 48000;
        config.channels = 2;
        config.format = engine::AudioFormat::FLOAT32;
        config.buffer_size = 512;
        config.enable_simd = true;
        config.worker_threads = 4;
        return config;
    }
    
    // 创建测试引擎状态
    EngineStatus create_test_status(EngineState state = EngineState::Running) {
        EngineStatus status;
        status.state = state;
        status.config = create_test_config();
        status.cpu_usage = 10.0;
        status.memory_usage_mb = 128.0;
        status.frames_processed = 1000;
        status.active_plugins = 2;
        status.buffer_underruns = 0;
        status.current_latency_ms = 8.5;
        status.last_update = std::chrono::system_clock::now();
        return status;
    }

protected:
    std::unique_ptr<MockEngineCommLayer> comm_layer_;
    std::unique_ptr<TestableEngineProxy> proxy_;
    std::shared_ptr<MockEngineProxyListener> listener_;
};

// 测试初始化和关闭
TEST_F(EngineProxyTest, InitializeAndShutdown) {
    // 设置命令期望
    comm_layer_->expect_command(EngineCommand::Initialize, "", common::ErrorCode::Success, "{}");
    comm_layer_->expect_command(EngineCommand::Shutdown, "", common::ErrorCode::Success, "{}");
    
    // 初始化代理
    auto result = proxy_->initialize();
    
    // 验证初始化成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    EXPECT_TRUE(proxy_->is_initialized());
    
    // 关闭代理
    result = proxy_->shutdown();
    
    // 验证关闭成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    EXPECT_FALSE(proxy_->is_initialized());
}

// 测试连接管理
TEST_F(EngineProxyTest, ConnectionManagement) {
    // 设置回调期望
    EXPECT_CALL(*listener_, on_engine_connected())
        .Times(1);
    
    EXPECT_CALL(*listener_, on_engine_disconnected())
        .Times(1);
    
    // 模拟连接成功
    auto result = proxy_->override_connect(true);
    
    // 验证连接成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    EXPECT_TRUE(proxy_->is_connected());
    
    // 模拟断开连接
    proxy_->simulate_connection_lost();
    
    // 验证断开连接
    EXPECT_FALSE(proxy_->is_connected());
}

// 测试状态变更事件
TEST_F(EngineProxyTest, StateChangeEvents) {
    // 初始化状态
    EngineState initial_state = EngineState::Stopped;
    EngineState new_state = EngineState::Running;
    
    // 设置事件期望
    EXPECT_CALL(*listener_, on_engine_state_changed(initial_state, new_state))
        .Times(1);
    
    // 创建状态并设置初始状态
    proxy_->current_state_ = initial_state;
    
    // 创建新状态
    EngineStatus status = create_test_status(new_state);
    
    // 模拟状态更新
    proxy_->simulate_status_update(status);
    
    // 验证状态已更新
    EXPECT_EQ(proxy_->get_current_state(), new_state);
}

// 测试状态更新事件
TEST_F(EngineProxyTest, StatusUpdateEvents) {
    // 创建测试状态
    EngineStatus status = create_test_status();
    
    // 设置事件期望
    EXPECT_CALL(*listener_, on_engine_status_updated(::testing::_))
        .Times(1)
        .WillOnce(::testing::Invoke([&status](const EngineStatus& updated_status) {
            EXPECT_EQ(updated_status.state, status.state);
            EXPECT_EQ(updated_status.config.sample_rate, status.config.sample_rate);
            EXPECT_EQ(updated_status.config.channels, status.config.channels);
            EXPECT_DOUBLE_EQ(updated_status.cpu_usage, status.cpu_usage);
            EXPECT_DOUBLE_EQ(updated_status.memory_usage_mb, status.memory_usage_mb);
            EXPECT_EQ(updated_status.frames_processed, status.frames_processed);
        }));
    
    // 模拟状态更新
    proxy_->simulate_status_update(status);
}

// 测试音频数据事件
TEST_F(EngineProxyTest, AudioDataEvents) {
    // 创建测试音频缓冲区
    engine::AudioBuffer buffer(512, 2, engine::AudioFormat::FLOAT32);
    
    // 填充测试数据
    float* data = buffer.interleaved_data<float>();
    for (size_t i = 0; i < 512 * 2; ++i) {
        data[i] = 0.1f * std::sin(2.0f * M_PI * i / 100.0f);
    }
    
    // 设置事件期望
    EXPECT_CALL(*listener_, on_audio_data_available(::testing::_))
        .Times(1);
    
    // 模拟音频数据
    proxy_->simulate_audio_data(buffer);
}

// 测试错误事件
TEST_F(EngineProxyTest, ErrorEvents) {
    // 定义测试错误
    common::ErrorCode test_error = common::ErrorCode::CommandFailed;
    std::string error_message = "测试错误消息";
    
    // 设置事件期望
    EXPECT_CALL(*listener_, on_engine_error(test_error, error_message))
        .Times(1);
    
    // 模拟错误
    proxy_->simulate_error(test_error, error_message);
}

// 测试命令发送
TEST_F(EngineProxyTest, CommandSending) {
    // 设置命令期望
    comm_layer_->expect_command(EngineCommand::Start, "", common::ErrorCode::Success, "{}");
    
    // 设置状态期望
    EXPECT_CALL(*listener_, on_engine_state_changed(EngineState::Stopped, EngineState::Starting))
        .Times(::testing::AtLeast(0));
    
    // 初始化状态
    proxy_->current_state_ = EngineState::Stopped;
    
    // 发送命令
    auto result = proxy_->send_command(EngineCommand::Start);
    
    // 验证命令成功
    EXPECT_EQ(result, common::ErrorCode::Success);
}

// 测试异步命令发送
TEST_F(EngineProxyTest, AsyncCommandSending) {
    // 设置命令期望
    comm_layer_->expect_command(EngineCommand::Start, "", common::ErrorCode::Success, "{}");
    
    // 初始化状态
    proxy_->current_state_ = EngineState::Stopped;
    
    // 创建异步命令完成标志
    std::promise<bool> command_completed;
    std::future<bool> future = command_completed.get_future();
    
    // 发送异步命令
    proxy_->send_command_async(EngineCommand::Start, "", 
        [&command_completed](common::ErrorCode result, const std::string&) {
            command_completed.set_value(result == common::ErrorCode::Success);
        });
    
    // 等待异步命令完成（带超时）
    auto status = future.wait_for(1s);
    EXPECT_EQ(status, std::future_status::ready);
    
    // 验证命令结果
    if (status == std::future_status::ready) {
        EXPECT_TRUE(future.get());
    }
}

// 测试配置管理
TEST_F(EngineProxyTest, ConfigurationManagement) {
    // 创建测试配置
    EngineConfiguration config = create_test_config();
    
    // 设置命令期望 - 设置配置
    std::string config_params = "{"
        "\"sample_rate\":48000,"
        "\"channels\":2,"
        "\"format\":\"FLOAT32\","
        "\"buffer_size\":512,"
        "\"enable_simd\":true,"
        "\"worker_threads\":4,"
        "\"processing_mode\":\"realtime\""
    "}";
    
    comm_layer_->expect_command(EngineCommand::SetConfig, config_params, common::ErrorCode::Success, "{}");
    
    // 设置配置
    auto result = proxy_->set_engine_config(config);
    
    // 验证设置成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    
    // 设置命令期望 - 获取配置
    comm_layer_->expect_command(EngineCommand::GetConfig, "", common::ErrorCode::Success, config_params);
    
    // 获取配置
    EngineConfiguration retrieved_config;
    result = proxy_->get_engine_config(retrieved_config);
    
    // 验证获取成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    
    // 验证配置内容
    EXPECT_EQ(retrieved_config.sample_rate, config.sample_rate);
    EXPECT_EQ(retrieved_config.channels, config.channels);
    EXPECT_EQ(retrieved_config.format, config.format);
    EXPECT_EQ(retrieved_config.buffer_size, config.buffer_size);
    EXPECT_EQ(retrieved_config.enable_simd, config.enable_simd);
    EXPECT_EQ(retrieved_config.worker_threads, config.worker_threads);
}

// 测试状态查询
TEST_F(EngineProxyTest, StatusQuery) {
    // 创建测试状态
    EngineStatus expected_status = create_test_status();
    
    // 设置命令期望
    std::string status_response = "{"
        "\"state\":\"Running\","
        "\"cpu_usage\":10.0,"
        "\"memory_usage_mb\":128.0,"
        "\"frames_processed\":1000,"
        "\"active_plugins\":2,"
        "\"buffer_underruns\":0,"
        "\"current_latency_ms\":8.5"
    "}";
    
    comm_layer_->expect_command(EngineCommand::GetStatus, "", common::ErrorCode::Success, status_response);
    
    // 获取状态
    EngineStatus status;
    auto result = proxy_->get_engine_status(status);
    
    // 验证获取成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    
    // 验证状态内容
    EXPECT_EQ(status.state, expected_status.state);
    EXPECT_DOUBLE_EQ(status.cpu_usage, expected_status.cpu_usage);
    EXPECT_DOUBLE_EQ(status.memory_usage_mb, expected_status.memory_usage_mb);
    EXPECT_EQ(status.frames_processed, expected_status.frames_processed);
    EXPECT_EQ(status.active_plugins, expected_status.active_plugins);
    EXPECT_EQ(status.buffer_underruns, expected_status.buffer_underruns);
    EXPECT_DOUBLE_EQ(status.current_latency_ms, expected_status.current_latency_ms);
}

// 测试音频数据传输
TEST_F(EngineProxyTest, AudioDataTransfer) {
    // 创建测试音频缓冲区
    engine::AudioBuffer buffer(512, 2, engine::AudioFormat::FLOAT32);
    
    // 填充测试数据
    float* data = buffer.interleaved_data<float>();
    for (size_t i = 0; i < 512 * 2; ++i) {
        data[i] = 0.1f * std::sin(2.0f * M_PI * i / 100.0f);
    }
    
    // 设置命令期望
    comm_layer_->expect_command(EngineCommand::Initialize, "", common::ErrorCode::Success, "{}");
    
    // 初始化代理
    ASSERT_EQ(proxy_->initialize(), common::ErrorCode::Success);
    
    // 模拟连接
    ASSERT_EQ(proxy_->override_connect(true), common::ErrorCode::Success);
    
    // 发送音频数据
    auto result = proxy_->send_audio_data(buffer);
    
    // 验证发送成功
    EXPECT_EQ(result, common::ErrorCode::Success);
}

// 测试插件管理
TEST_F(EngineProxyTest, PluginManagement) {
    // 设置命令期望 - 加载插件
    std::string load_params = "{\"path\":\"/plugins/test_plugin.dll\"}";
    std::string load_response = "{\"plugin_id\":\"plugin-123\"}";
    
    comm_layer_->expect_command(EngineCommand::LoadPlugin, load_params, common::ErrorCode::Success, load_response);
    
    // 加载插件
    std::string plugin_id;
    auto result = proxy_->load_plugin("/plugins/test_plugin.dll", plugin_id);
    
    // 验证加载成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    EXPECT_EQ(plugin_id, "plugin-123");
    
    // 设置命令期望 - 卸载插件
    std::string unload_params = "{\"plugin_id\":\"plugin-123\"}";
    
    comm_layer_->expect_command(EngineCommand::UnloadPlugin, unload_params, common::ErrorCode::Success, "{}");
    
    // 卸载插件
    result = proxy_->unload_plugin(plugin_id);
    
    // 验证卸载成功
    EXPECT_EQ(result, common::ErrorCode::Success);
}

// 测试参数管理
TEST_F(EngineProxyTest, ParameterManagement) {
    // 设置命令期望 - 设置参数
    std::string set_param_params = "{\"plugin_id\":\"plugin-123\",\"param_name\":\"gain\",\"param_value\":\"0.8\"}";
    
    comm_layer_->expect_command(EngineCommand::SetParameter, set_param_params, common::ErrorCode::Success, "{}");
    
    // 设置参数
    auto result = proxy_->set_parameter("plugin-123", "gain", "0.8");
    
    // 验证设置成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    
    // 设置命令期望 - 获取参数
    std::string get_param_params = "{\"plugin_id\":\"plugin-123\",\"param_name\":\"gain\"}";
    std::string get_param_response = "{\"param_value\":\"0.8\"}";
    
    comm_layer_->expect_command(EngineCommand::GetParameter, get_param_params, common::ErrorCode::Success, get_param_response);
    
    // 获取参数
    std::string param_value;
    result = proxy_->get_parameter("plugin-123", "gain", param_value);
    
    // 验证获取成功
    EXPECT_EQ(result, common::ErrorCode::Success);
    EXPECT_EQ(param_value, "0.8");
}

// 测试统计信息
TEST_F(EngineProxyTest, Statistics) {
    // 设置命令期望
    comm_layer_->expect_command(EngineCommand::Initialize, "", common::ErrorCode::Success, "{}");
    
    // 初始化代理
    ASSERT_EQ(proxy_->initialize(), common::ErrorCode::Success);
    
    // 发送一些命令
    comm_layer_->expect_command(EngineCommand::Start, "", common::ErrorCode::Success, "{}");
    proxy_->send_command(EngineCommand::Start);
    
    comm_layer_->expect_command(EngineCommand::Stop, "", common::ErrorCode::Success, "{}");
    proxy_->send_command(EngineCommand::Stop);
    
    // 获取统计信息
    const auto& stats = proxy_->get_statistics();
    
    // 验证命令计数
    EXPECT_GE(stats.commands_sent.load(), 2);
    
    // 重置统计信息
    proxy_->reset_statistics();
    
    // 验证统计信息已重置
    EXPECT_EQ(stats.commands_sent.load(), 0);
    EXPECT_EQ(stats.commands_received.load(), 0);
    EXPECT_EQ(stats.audio_buffers_sent.load(), 0);
    EXPECT_EQ(stats.audio_buffers_received.load(), 0);
}

int main(int argc, char** argv) {
    ::testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}