/**
 * GameModuleTest.cpp
 *
 * Unit tests for Mobile Command GameModule
 * Tests state machine, event subscriptions, and MC-specific logic
 */

#include <gtest/gtest.h>
#include <gmock/gmock.h>
#include "../src/modules/GameModule.h"
#include <grove/JsonDataNode.h>
#include <grove/IIO.h>
#include <grove/ITaskScheduler.h>
#include <memory>
#include <queue>

using namespace mc;
using namespace grove;

// Mock IIO implementation for testing
class MockIIO : public IIO {
public:
    // Published messages storage
    std::vector<std::pair<std::string, std::unique_ptr<IDataNode>>> publishedMessages;

    // Subscribed topics
    std::vector<std::string> subscribedTopics;

    // Message queue for pulling
    std::queue<Message> messageQueue;

    void publish(const std::string& topic, std::unique_ptr<IDataNode> message) override {
        publishedMessages.push_back({topic, std::move(message)});
    }

    void subscribe(const std::string& topicPattern, const SubscriptionConfig& config = {}) override {
        subscribedTopics.push_back(topicPattern);
    }

    void subscribeLowFreq(const std::string& topicPattern, const SubscriptionConfig& config = {}) override {
        subscribedTopics.push_back(topicPattern);
    }

    int hasMessages() const override {
        return static_cast<int>(messageQueue.size());
    }

    Message pullMessage() override {
        if (messageQueue.empty()) {
            throw std::runtime_error("No messages available");
        }
        Message msg = std::move(messageQueue.front());
        messageQueue.pop();
        return msg;
    }

    IOHealth getHealth() const override {
        IOHealth health;
        health.queueSize = static_cast<int>(messageQueue.size());
        health.maxQueueSize = 1000;
        health.dropping = false;
        health.averageProcessingRate = 100.0f;
        health.droppedMessageCount = 0;
        return health;
    }

    IOType getType() const override {
        return IOType::INTRA;
    }

    // Helper methods for testing
    void pushMessage(const std::string& topic, std::unique_ptr<IDataNode> data) {
        Message msg;
        msg.topic = topic;
        msg.data = std::move(data);
        msg.timestamp = 0;
        messageQueue.push(std::move(msg));
    }

    void clearPublished() {
        publishedMessages.clear();
    }

    bool hasPublished(const std::string& topic) const {
        for (const auto& [t, data] : publishedMessages) {
            if (t == topic) return true;
        }
        return false;
    }
};

// Mock ITaskScheduler (not used in tests but required by interface)
class MockTaskScheduler : public ITaskScheduler {
public:
    void scheduleTask(const std::string& taskType, std::unique_ptr<IDataNode> taskData) override {}
    int hasCompletedTasks() const override { return 0; }
    std::unique_ptr<IDataNode> getCompletedTask() override {
        return std::make_unique<JsonDataNode>("empty");
    }
};

class GameModuleTest : public ::testing::Test {
protected:
    void SetUp() override {
        module = std::make_unique<GameModule>();
        mockIO = std::make_unique<MockIIO>();
        mockScheduler = std::make_unique<MockTaskScheduler>();

        // Create test configuration
        config = std::make_unique<JsonDataNode>("config");
        config->setString("initialState", "MainMenu");
        config->setDouble("tickRate", 10.0);
        config->setBool("debugMode", true);

        // Initialize module
        module->setConfiguration(*config, mockIO.get(), mockScheduler.get());
    }

    void TearDown() override {
        module->shutdown();
    }

    std::unique_ptr<GameModule> module;
    std::unique_ptr<MockIIO> mockIO;
    std::unique_ptr<MockTaskScheduler> mockScheduler;
    std::unique_ptr<JsonDataNode> config;
};

// Test 1: State machine initialization
TEST_F(GameModuleTest, InitialStateIsMainMenu) {
    auto health = module->getHealthStatus();
    EXPECT_EQ(health->getString("currentState", ""), "MainMenu");
}

// Test 2: State transitions work
TEST_F(GameModuleTest, StateTransitionsWork) {
    // Simulate combat start event
    auto combatData = std::make_unique<JsonDataNode>("combat_start");
    combatData->setString("location", "urban_ruins");
    combatData->setString("enemy_type", "scavengers");
    mockIO->pushMessage("combat:started", std::move(combatData));

    // Process the message
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // Check state transition
    auto health = module->getHealthStatus();
    EXPECT_EQ(health->getString("currentState", ""), "Combat");

    // Verify state change event was published
    EXPECT_TRUE(mockIO->hasPublished("game:state_changed"));
}

// Test 3: Event subscriptions are setup correctly
TEST_F(GameModuleTest, EventSubscriptionsSetup) {
    // Check that all expected topics are subscribed
    auto& topics = mockIO->subscribedTopics;

    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "resource:craft_complete") != topics.end());
    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "resource:inventory_low") != topics.end());
    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "storage:save_complete") != topics.end());
    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "combat:started") != topics.end());
    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "combat:ended") != topics.end());
    EXPECT_TRUE(std::find(topics.begin(), topics.end(), "event:triggered") != topics.end());
}

// Test 4: Game time advances
TEST_F(GameModuleTest, GameTimeAdvances) {
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);

    // Process 10 frames
    for (int i = 0; i < 10; i++) {
        module->process(*input);
    }

    auto health = module->getHealthStatus();
    double gameTime = health->getDouble("gameTime", 0.0);

    // Should be approximately 1.0 second (10 * 0.1)
    EXPECT_NEAR(gameTime, 1.0, 0.01);
}

// Test 5: Hot-reload preserves state
TEST_F(GameModuleTest, HotReloadPreservesState) {
    // Advance game state
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.5);

    for (int i = 0; i < 10; i++) {
        module->process(*input);
    }

    // Get current state
    auto state = module->getState();
    double originalGameTime = state->getDouble("gameTime", 0.0);
    int originalFrameCount = state->getInt("frameCount", 0);

    // Create new module and restore state
    auto newModule = std::make_unique<GameModule>();
    newModule->setConfiguration(*config, mockIO.get(), mockScheduler.get());
    newModule->setState(*state);

    // Verify state was restored
    auto restoredHealth = newModule->getHealthStatus();
    double restoredGameTime = restoredHealth->getDouble("gameTime", 0.0);
    int restoredFrameCount = restoredHealth->getInt("frameCount", 0);

    EXPECT_EQ(restoredGameTime, originalGameTime);
    EXPECT_EQ(restoredFrameCount, originalFrameCount);
}

// Test 6: Drone crafted event triggers MC-specific logic
TEST_F(GameModuleTest, DroneCraftedTriggersCorrectLogic) {
    mockIO->clearPublished();

    // Simulate drone craft completion
    auto craftData = std::make_unique<JsonDataNode>("craft_complete");
    craftData->setString("recipe", "drone_recon");
    craftData->setInt("quantity", 1);
    mockIO->pushMessage("resource:craft_complete", std::move(craftData));

    // Process the message
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // Check that expedition:drone_available was published
    EXPECT_TRUE(mockIO->hasPublished("expedition:drone_available"));
}

// Test 7: Low fuel warning triggers MC-specific logic
TEST_F(GameModuleTest, LowFuelWarningTriggered) {
    // Simulate low fuel inventory
    auto inventoryData = std::make_unique<JsonDataNode>("inventory_low");
    inventoryData->setString("resource_id", "fuel_diesel");
    inventoryData->setInt("current", 10);
    inventoryData->setInt("threshold", 50);
    mockIO->pushMessage("resource:inventory_low", std::move(inventoryData));

    // Process the message
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // In a real test, we'd verify that the warning was shown
    // For now, just verify the message was processed without error
    EXPECT_TRUE(true);
}

// Test 8: Combat victory increments counter
TEST_F(GameModuleTest, CombatVictoryIncrementsCounter) {
    // Start combat
    auto startData = std::make_unique<JsonDataNode>("combat_start");
    startData->setString("location", "urban_ruins");
    startData->setString("enemy_type", "scavengers");
    mockIO->pushMessage("combat:started", std::move(startData));

    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // End combat with victory
    auto input2 = std::make_unique<JsonDataNode>("input");
    input2->setDouble("deltaTime", 0.1);
    auto endData = std::make_unique<JsonDataNode>("combat_end");
    endData->setBool("victory", true);
    mockIO->pushMessage("combat:ended", std::move(endData));
    module->process(*input2);

    // Check that combatsWon was incremented
    auto health = module->getHealthStatus();
    int combatsWon = health->getInt("combatsWon", 0);
    EXPECT_EQ(combatsWon, 1);
}

// Test 9: Event triggers state transition
TEST_F(GameModuleTest, EventTriggersStateTransition) {
    // Trigger an event
    auto eventData = std::make_unique<JsonDataNode>("event");
    eventData->setString("event_id", "scavenger_encounter");
    mockIO->pushMessage("event:triggered", std::move(eventData));

    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // Check state transition to Event
    auto health = module->getHealthStatus();
    EXPECT_EQ(health->getString("currentState", ""), "Event");
}

// Test 10: Module type is correct
TEST_F(GameModuleTest, ModuleTypeIsCorrect) {
    EXPECT_EQ(module->getType(), "GameModule");
}

// Test 11: Module is idle only in MainMenu
TEST_F(GameModuleTest, ModuleIdleInMainMenu) {
    // Initially in MainMenu
    EXPECT_TRUE(module->isIdle());

    // Transition to combat
    auto combatData = std::make_unique<JsonDataNode>("combat_start");
    combatData->setString("location", "urban_ruins");
    combatData->setString("enemy_type", "scavengers");
    mockIO->pushMessage("combat:started", std::move(combatData));

    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // No longer idle
    EXPECT_FALSE(module->isIdle());
}

// Test 12: Multiple messages processed in single frame
TEST_F(GameModuleTest, MultipleMessagesProcessedInSingleFrame) {
    // Queue multiple messages
    auto msg1 = std::make_unique<JsonDataNode>("msg1");
    msg1->setString("resource_id", "scrap_metal");
    msg1->setInt("delta", 10);
    msg1->setInt("total", 100);
    mockIO->pushMessage("resource:inventory_changed", std::move(msg1));

    auto msg2 = std::make_unique<JsonDataNode>("msg2");
    msg2->setString("filename", "savegame.json");
    mockIO->pushMessage("storage:save_complete", std::move(msg2));

    auto msg3 = std::make_unique<JsonDataNode>("msg3");
    msg3->setString("event_id", "test_event");
    mockIO->pushMessage("event:triggered", std::move(msg3));

    // Process all in one frame
    auto input = std::make_unique<JsonDataNode>("input");
    input->setDouble("deltaTime", 0.1);
    module->process(*input);

    // All messages should be consumed
    EXPECT_EQ(mockIO->hasMessages(), 0);

    // State should be Event (last transition)
    auto health = module->getHealthStatus();
    EXPECT_EQ(health->getString("currentState", ""), "Event");
}

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