#include <yams/mcp/mcp_server.h>
#include <yams/api/content_store.h>
#include <CLI/CLI.hpp>
#include <spdlog/spdlog.h>
#include <spdlog/sinks/stdout_color_sinks.h>
#include <spdlog/sinks/rotating_file_sink.h>
#include <csignal>
#include <atomic>
#include <thread>
#include <filesystem>

namespace fs = std::filesystem;

std::atomic<bool> g_running{true};

void signalHandler(int signal) {
    spdlog::info("Received signal {}, shutting down...", signal);
    g_running = false;
}

int main(int argc, char* argv[]) {
    CLI::App app{"YAMS MCP Server - Model Context Protocol server for YAMS"};
    
    // Server options
    std::string storage_path = std::getenv("YAMS_STORAGE") ? 
                               std::getenv("YAMS_STORAGE") : 
                               fs::path(std::getenv("HOME")) / "yams";
    uint16_t port = 8080;
    std::string host = "127.0.0.1";
    std::string log_level = "info";
    std::string log_file;
    bool daemon_mode = false;
    
    // CLI options
    app.add_option("-s,--storage", storage_path, "Storage directory path")
       ->envname("YAMS_STORAGE");
    app.add_option("-p,--port", port, "Server port")
       ->default_val(8080);
    app.add_option("--host", host, "Server host")
       ->default_val("127.0.0.1");
    app.add_option("-l,--log-level", log_level, "Log level (trace, debug, info, warn, error)")
       ->default_val("info");
    app.add_option("--log-file", log_file, "Log file path (optional)");
    app.add_flag("-d,--daemon", daemon_mode, "Run as daemon");
    
    // Parse command line
    CLI11_PARSE(app, argc, argv);
    
    // Setup logging
    try {
        std::vector<spdlog::sink_ptr> sinks;
        
        // Console sink
        if (!daemon_mode) {
            auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
            sinks.push_back(console_sink);
        }
        
        // File sink if specified
        if (!log_file.empty()) {
            auto file_sink = std::make_shared<spdlog::sinks::rotating_file_sink_mt>(
                log_file, 10 * 1024 * 1024, 3); // 10MB, 3 files
            sinks.push_back(file_sink);
        }
        
        // Create logger
        auto logger = std::make_shared<spdlog::logger>("yams-mcp", sinks.begin(), sinks.end());
        spdlog::set_default_logger(logger);
        
        // Set log level
        if (log_level == "trace") spdlog::set_level(spdlog::level::trace);
        else if (log_level == "debug") spdlog::set_level(spdlog::level::debug);
        else if (log_level == "info") spdlog::set_level(spdlog::level::info);
        else if (log_level == "warn") spdlog::set_level(spdlog::level::warn);
        else if (log_level == "error") spdlog::set_level(spdlog::level::err);
        
        spdlog::set_pattern("[%Y-%m-%d %H:%M:%S.%e] [%l] [%n] %v");
    } catch (const std::exception& e) {
        std::cerr << "Failed to setup logging: " << e.what() << std::endl;
        return 1;
    }
    
    // Log startup info
    spdlog::info("YAMS MCP Server v{}.{}.{}", 0, 0, 2);
    spdlog::info("Storage path: {}", storage_path);
    spdlog::info("Server address: {}:{}", host, port);
    
    // Check storage directory
    if (!fs::exists(storage_path)) {
        spdlog::error("Storage path does not exist: {}", storage_path);
        spdlog::info("Run 'yams init --storage {}' to initialize storage", storage_path);
        return 1;
    }
    
    // Setup signal handlers
    std::signal(SIGINT, signalHandler);
    std::signal(SIGTERM, signalHandler);
    
    try {
        // Initialize the core components first
        // TODO: Initialize ContentStore and SearchExecutor using storage_path
        
        // For now, create a basic MCP server with StdioTransport
        auto store = std::shared_ptr<yams::api::IContentStore>{nullptr}; // TODO: Initialize
        auto searchExecutor = std::shared_ptr<yams::search::SearchExecutor>{nullptr}; // TODO: Initialize
        
        // Create WebSocket transport if using WebSocket mode
        std::unique_ptr<yams::mcp::ITransport> transport;
        if (!host.empty() && port > 0) {
            yams::mcp::WebSocketTransport::Config wsConfig;
            wsConfig.host = host;
            wsConfig.port = static_cast<uint16_t>(port);
            transport = std::make_unique<yams::mcp::WebSocketTransport>(wsConfig);
        } else {
            transport = std::make_unique<yams::mcp::StdioTransport>();
        }
        
        // Create MCP server
        auto server = std::make_unique<yams::mcp::MCPServer>(store, searchExecutor, std::move(transport));
        
        // Start server in background thread
        std::thread server_thread([&server]() {
            server->start();
        });
        
        spdlog::info("MCP server started successfully");
        spdlog::info("Press Ctrl+C to stop");
        
        // Main loop
        while (g_running) {
            std::this_thread::sleep_for(std::chrono::seconds(1));
            
            // Could add periodic tasks here
            // e.g., stats logging, health checks
        }
        
        // Shutdown
        spdlog::info("Shutting down MCP server...");
        server->stop();
        
        if (server_thread.joinable()) {
            server_thread.join();
        }
        
        spdlog::info("MCP server stopped");
        
    } catch (const std::exception& e) {
        spdlog::error("Fatal error: {}", e.what());
        return 1;
    }
    
    return 0;
}