/// PlatformWin32 - Windows platform abstraction layer
/// This module provides window management and input handling for Windows
/// Uses Win32 API or GLFW/SDL bindings

import Foundation
import RendererAPI

#if os(Windows)
// Note: In a real implementation, this would import Win32 API bindings
// import WinSDK or CGLFW
#endif

// MARK: - Windows Window Manager

public final class Win32WindowManager: WindowManager, @unchecked Sendable {
    
    private var hwnd: UnsafeMutableRawPointer? // HWND handle
    private var hinstance: UnsafeMutableRawPointer? // HINSTANCE
    private var config: WindowConfig?
    private var shouldCloseFlag: Bool = false
    private var currentWidth: Int = 0
    private var currentHeight: Int = 0
    
    public init() {
        print("    🪟 Win32WindowManager created")
    }
    
    public func createWindow(config: WindowConfig) async throws {
        print("    → Creating Windows window...")
        self.config = config
        self.currentWidth = config.width
        self.currentHeight = config.height
        
        #if os(Windows)
        // Get HINSTANCE
        // hinstance = GetModuleHandleW(nil)
        
        // Register window class
        // WNDCLASSEXW wc = { ... }
        // wc.lpfnWndProc = WindowProc
        // wc.lpszClassName = L"SportsBallEngineWindowClass"
        // RegisterClassExW(&wc)
        
        // Calculate window size (client area vs window size)
        // RECT rect = { 0, 0, width, height }
        // AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE)
        
        // Create window
        // hwnd = CreateWindowExW(
        //     0, L"SportsBallEngineWindowClass", title,
        //     WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
        //     rect.right - rect.left, rect.bottom - rect.top,
        //     nil, nil, hinstance, nil
        // )
        
        // Show window
        // ShowWindow(hwnd, SW_SHOW)
        // UpdateWindow(hwnd)
        
        print("    ✓ Windows window created: \(config.title) (\(config.width)x\(config.height))")
        #else
        throw PlatformError.unsupportedPlatform("Win32 platform is only available on Windows")
        #endif
    }
    
    public func shouldClose() -> Bool {
        return shouldCloseFlag
    }
    
    public func processEvents() -> [WindowEvent] {
        var events: [WindowEvent] = []
        
        #if os(Windows)
        // Process Win32 message queue
        // MSG msg
        // while PeekMessageW(&msg, nil, 0, 0, PM_REMOVE) {
        //     if msg.message == WM_QUIT {
        //         shouldCloseFlag = true
        //         events.append(.close)
        //     }
        //     TranslateMessage(&msg)
        //     DispatchMessageW(&msg)
        // }
        #endif
        
        return events
    }
    
    public func getSize() -> (width: Int, height: Int) {
        #if os(Windows)
        // RECT rect
        // GetClientRect(hwnd, &rect)
        // return (rect.right - rect.left, rect.bottom - rect.top)
        #endif
        return (currentWidth, currentHeight)
    }
    
    public func setSize(width: Int, height: Int) throws {
        currentWidth = width
        currentHeight = height
        #if os(Windows)
        // SetWindowPos(hwnd, nil, 0, 0, width, height, SWP_NOMOVE | SWP_NOZORDER)
        #endif
    }
    
    public func setTitle(_ title: String) throws {
        #if os(Windows)
        // SetWindowTextW(hwnd, wideTitle)
        #endif
    }
    
    public func setFullscreen(_ fullscreen: Bool) throws {
        #if os(Windows)
        // if fullscreen {
        //     SetWindowLongPtrW(hwnd, GWL_STYLE, WS_POPUP)
        //     SetWindowPos(hwnd, HWND_TOP, 0, 0, screenWidth, screenHeight, SWP_FRAMECHANGED)
        // } else {
        //     SetWindowLongPtrW(hwnd, GWL_STYLE, WS_OVERLAPPEDWINDOW)
        //     SetWindowPos(hwnd, nil, x, y, width, height, SWP_FRAMECHANGED)
        // }
        #endif
    }
    
    public func getNativeHandle() -> UnsafeMutableRawPointer? {
        // Return HWND for DirectX 12 or Vulkan surface creation
        return hwnd
    }
    
    public func swapBuffers() throws {
        // Not needed for Vulkan or DirectX 12 (presentation is handled by renderer)
    }
    
    public func destroyWindow() async {
        print("    → Destroying Windows window...")
        
        #if os(Windows)
        // DestroyWindow(hwnd)
        // UnregisterClassW(L"SportsBallEngineWindowClass", hinstance)
        #endif
        
        hwnd = nil
        print("    ✓ Windows window destroyed")
    }
    
    // MARK: - Win32 Window Procedure (would be separate C function)
    
    // static LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    //     switch (uMsg) {
    //         case WM_CLOSE:
    //             PostQuitMessage(0)
    //             return 0
    //         case WM_SIZE:
    //             // Handle resize
    //             return 0
    //         case WM_KEYDOWN:
    //         case WM_KEYUP:
    //             // Handle keyboard
    //             return 0
    //         default:
    //             return DefWindowProcW(hwnd, uMsg, wParam, lParam)
    //     }
    // }
}

// MARK: - Windows Input Handler

public final class Win32InputHandler: InputHandler, @unchecked Sendable {
    
    private var keyStates: [KeyCode: Bool] = [:]
    private var mouseButtonStates: [MouseButton: Bool] = [:]
    private var mousePosition: (x: Double, y: Double) = (0, 0)
    private var eventQueue: [InputEvent] = []
    
    public init() {
        print("    🪟 Win32InputHandler created")
    }
    
    public func initialize() async throws {
        print("    → Initializing Windows input system...")
        
        #if os(Windows)
        // Initialize Raw Input or XInput for gamepads
        // RAWINPUTDEVICE rid[2]
        // rid[0].usUsagePage = 0x01  // HID_USAGE_PAGE_GENERIC
        // rid[0].usUsage = 0x02      // HID_USAGE_GENERIC_MOUSE
        // rid[1].usUsagePage = 0x01
        // rid[1].usUsage = 0x06      // HID_USAGE_GENERIC_KEYBOARD
        // RegisterRawInputDevices(rid, 2, sizeof(RAWINPUTDEVICE))
        #endif
        
        print("    ✓ Windows input system initialized")
    }
    
    public func pollEvents() -> [InputEvent] {
        let events = eventQueue
        eventQueue.removeAll()
        return events
    }
    
    public func isKeyPressed(_ key: KeyCode) -> Bool {
        #if os(Windows)
        // GetAsyncKeyState(virtualKeyCode) & 0x8000
        #endif
        return keyStates[key] ?? false
    }
    
    public func isMouseButtonPressed(_ button: MouseButton) -> Bool {
        #if os(Windows)
        // GetAsyncKeyState(VK_LBUTTON/VK_RBUTTON/VK_MBUTTON) & 0x8000
        #endif
        return mouseButtonStates[button] ?? false
    }
    
    public func getMousePosition() -> (x: Double, y: Double) {
        #if os(Windows)
        // POINT pt
        // GetCursorPos(&pt)
        // ScreenToClient(hwnd, &pt)
        #endif
        return mousePosition
    }
    
    public func setCursorVisible(_ visible: Bool) {
        #if os(Windows)
        // ShowCursor(visible ? TRUE : FALSE)
        #endif
    }
    
    public func setCursorMode(_ mode: CursorMode) {
        #if os(Windows)
        // switch mode {
        // case .normal:
        //     ShowCursor(TRUE)
        //     ClipCursor(nil)
        // case .hidden:
        //     ShowCursor(FALSE)
        // case .locked:
        //     ShowCursor(FALSE)
        //     RECT rect; GetClientRect(hwnd, &rect)
        //     ClipCursor(&rect) // Confine cursor to window
        // }
        #endif
    }
    
    public func getGamepadCount() -> Int {
        #if os(Windows)
        // Check XInput connected controllers (max 4)
        // for i in 0..<4 {
        //     XINPUT_STATE state
        //     if XInputGetState(i, &state) == ERROR_SUCCESS {
        //         count++
        //     }
        // }
        #endif
        return 0
    }
    
    public func isGamepadConnected(_ gamepadId: Int) -> Bool {
        #if os(Windows)
        // XINPUT_STATE state
        // return XInputGetState(gamepadId, &state) == ERROR_SUCCESS
        #endif
        return false
    }
    
    public func getGamepadName(_ gamepadId: Int) -> String? {
        return "Xbox Controller \(gamepadId)"
    }
    
    public func shutdown() async {
        print("    → Shutting down Windows input system...")
        keyStates.removeAll()
        mouseButtonStates.removeAll()
        eventQueue.removeAll()
        print("    ✓ Windows input system shutdown")
    }
    
    // MARK: - Event Processing Helpers
    
    internal func handleKeyEvent(key: KeyCode, action: InputAction) {
        keyStates[key] = (action == .press || action == .repeat_)
        eventQueue.append(.keyEvent(key: key, action: action))
    }
    
    internal func handleMouseButton(button: MouseButton, action: InputAction) {
        mouseButtonStates[button] = (action == .press)
        eventQueue.append(.mouseButton(button: button, action: action))
    }
    
    internal func handleMouseMove(x: Double, y: Double) {
        mousePosition = (x, y)
        eventQueue.append(.mouseMove(x: x, y: y))
    }
}

// MARK: - Windows Audio Engine (Stub)

public final class Win32AudioEngine: AudioEngine, @unchecked Sendable {
    
    public init() {
        print("    🪟 Win32AudioEngine created")
    }
    
    public func initialize(config: AudioConfig) async throws {
        print("    → Initializing Windows audio (WASAPI/XAudio2)...")
        // Initialize audio backend (WASAPI, XAudio2, or OpenAL)
        print("    ✓ Windows audio initialized")
    }
    
    public func loadAudio(path: String) async throws -> AudioHandle {
        return AudioHandle()
    }
    
    public func loadAudioFromData(data: Data, sampleRate: Int, channels: Int) async throws -> AudioHandle {
        return AudioHandle()
    }
    
    public func play(handle: AudioHandle, source: AudioSource3D) throws {}
    public func stop(handle: AudioHandle) throws {}
    public func pause(handle: AudioHandle) throws {}
    public func resume(handle: AudioHandle) throws {}
    public func updateSource(handle: AudioHandle, source: AudioSource3D) throws {}
    public func setListener(listener: AudioListener) throws {}
    public func setMasterVolume(_ volume: Float) throws {}
    public func update(deltaTime: Float) throws {}
    
    public func shutdown() async {
        print("    → Shutting down Windows audio...")
        print("    ✓ Windows audio shutdown")
    }
}

// MARK: - Errors

private enum PlatformError: Error {
    case unsupportedPlatform(String)
}