/// PlatformLinux - Linux platform abstraction layer
/// This module provides window management and input handling for Linux
/// Uses X11/Wayland via GLFW or SDL bindings

import Foundation
import RendererAPI

// Note: In a real implementation, this would import GLFW or SDL bindings
// import CGLFW or import CSDL2

// MARK: - Linux Window Manager

public final class LinuxWindowManager: WindowManager, @unchecked Sendable {
    
    private var window: UnsafeMutableRawPointer?
    private var config: WindowConfig?
    private var shouldCloseFlag: Bool = false
    private var currentWidth: Int = 0
    private var currentHeight: Int = 0
    
    public init() {
        print("    🐧 LinuxWindowManager created")
    }
    
    public func createWindow(config: WindowConfig) async throws {
        print("    → Creating Linux window...")
        self.config = config
        self.currentWidth = config.width
        self.currentHeight = config.height
        
        // Initialize GLFW or SDL
        // glfwInit() or SDL_Init(SDL_INIT_VIDEO)
        
        // Set window hints for Vulkan (no OpenGL context)
        // glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API)
        // glfwWindowHint(GLFW_RESIZABLE, config.resizable ? GLFW_TRUE : GLFW_FALSE)
        
        // Create window
        // window = glfwCreateWindow(width, height, title, monitor, share)
        // or
        // window = SDL_CreateWindow(title, x, y, width, height, SDL_WINDOW_VULKAN)
        
        // Set up event callbacks
        // glfwSetWindowSizeCallback(window, sizeCallback)
        // glfwSetWindowCloseCallback(window, closeCallback)
        
        print("    ✓ Linux window created: \(config.title) (\(config.width)x\(config.height))")
    }
    
    public func shouldClose() -> Bool {
        // return glfwWindowShouldClose(window) != 0
        // or check SDL event queue for SDL_QUIT
        return shouldCloseFlag
    }
    
    public func processEvents() -> [WindowEvent] {
        var events: [WindowEvent] = []
        
        // Poll events from GLFW or SDL
        // glfwPollEvents()
        // or
        // while SDL_PollEvent(&event) {
        //     switch event.type {
        //         case SDL_QUIT: events.append(.close)
        //         case SDL_WINDOWEVENT: ...
        //     }
        // }
        
        return events
    }
    
    public func getSize() -> (width: Int, height: Int) {
        // glfwGetWindowSize(window, &width, &height)
        // or SDL_GetWindowSize(window, &width, &height)
        return (currentWidth, currentHeight)
    }
    
    public func setSize(width: Int, height: Int) throws {
        currentWidth = width
        currentHeight = height
        // glfwSetWindowSize(window, width, height)
        // or SDL_SetWindowSize(window, width, height)
    }
    
    public func setTitle(_ title: String) throws {
        // glfwSetWindowTitle(window, title)
        // or SDL_SetWindowTitle(window, title)
    }
    
    public func setFullscreen(_ fullscreen: Bool) throws {
        // glfwSetWindowMonitor(...) for GLFW
        // or SDL_SetWindowFullscreen(window, fullscreen ? SDL_WINDOW_FULLSCREEN : 0)
    }
    
    public func getNativeHandle() -> UnsafeMutableRawPointer? {
        // For Vulkan surface creation on Linux:
        // X11: glfwGetX11Window(window) or SDL_GetProperty(window, SDL_PROP_WINDOW_X11_WINDOW_POINTER)
        // Wayland: glfwGetWaylandWindow(window) or SDL_GetProperty(window, SDL_PROP_WINDOW_WAYLAND_SURFACE_POINTER)
        return window
    }
    
    public func swapBuffers() throws {
        // Not needed for Vulkan (presentation is handled by renderer)
        // For OpenGL: glfwSwapBuffers(window) or SDL_GL_SwapWindow(window)
    }
    
    public func destroyWindow() async {
        print("    → Destroying Linux window...")
        
        // glfwDestroyWindow(window)
        // glfwTerminate()
        // or
        // SDL_DestroyWindow(window)
        // SDL_Quit()
        
        window = nil
        print("    ✓ Linux window destroyed")
    }
}

// MARK: - Linux Input Handler

public final class LinuxInputHandler: InputHandler, @unchecked Sendable {
    
    private var window: UnsafeMutableRawPointer?
    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("    🐧 LinuxInputHandler created")
    }
    
    public func initialize() async throws {
        print("    → Initializing Linux input system...")
        
        // Set up GLFW or SDL input callbacks
        // glfwSetKeyCallback(window, keyCallback)
        // glfwSetMouseButtonCallback(window, mouseButtonCallback)
        // glfwSetCursorPosCallback(window, cursorPosCallback)
        // glfwSetScrollCallback(window, scrollCallback)
        // glfwSetJoystickCallback(joystickCallback)
        
        print("    ✓ Linux input system initialized")
    }
    
    public func pollEvents() -> [InputEvent] {
        // Events are accumulated in callbacks, return and clear the queue
        let events = eventQueue
        eventQueue.removeAll()
        return events
    }
    
    public func isKeyPressed(_ key: KeyCode) -> Bool {
        return keyStates[key] ?? false
    }
    
    public func isMouseButtonPressed(_ button: MouseButton) -> Bool {
        return mouseButtonStates[button] ?? false
    }
    
    public func getMousePosition() -> (x: Double, y: Double) {
        // glfwGetCursorPos(window, &xpos, &ypos)
        // or SDL_GetMouseState(&x, &y)
        return mousePosition
    }
    
    public func setCursorVisible(_ visible: Bool) {
        // glfwSetInputMode(window, GLFW_CURSOR, visible ? GLFW_CURSOR_NORMAL : GLFW_CURSOR_HIDDEN)
        // or SDL_ShowCursor(visible ? SDL_ENABLE : SDL_DISABLE)
    }
    
    public func setCursorMode(_ mode: CursorMode) {
        // switch mode {
        // case .normal:
        //     glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_NORMAL)
        // case .hidden:
        //     glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN)
        // case .locked:
        //     glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED)
        // }
    }
    
    public func getGamepadCount() -> Int {
        // Check for connected joysticks
        // glfwJoystickPresent(GLFW_JOYSTICK_1) through GLFW_JOYSTICK_16
        // or SDL_NumJoysticks()
        return 0
    }
    
    public func isGamepadConnected(_ gamepadId: Int) -> Bool {
        // glfwJoystickPresent(gamepadId) != 0
        // or SDL_JoystickGetAttached(joystick)
        return false
    }
    
    public func getGamepadName(_ gamepadId: Int) -> String? {
        // glfwGetJoystickName(gamepadId)
        // or SDL_JoystickName(joystick)
        return nil
    }
    
    public func shutdown() async {
        print("    → Shutting down Linux input system...")
        keyStates.removeAll()
        mouseButtonStates.removeAll()
        eventQueue.removeAll()
        print("    ✓ Linux 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))
    }
    
    internal func handleMouseScroll(xOffset: Double, yOffset: Double) {
        eventQueue.append(.mouseScroll(xOffset: xOffset, yOffset: yOffset))
    }
}

// MARK: - Linux Audio Engine (Stub)

public final class LinuxAudioEngine: AudioEngine, @unchecked Sendable {
    
    public init() {
        print("    🐧 LinuxAudioEngine created")
    }
    
    public func initialize(config: AudioConfig) async throws {
        print("    → Initializing Linux audio (ALSA/PulseAudio/PipeWire)...")
        // Initialize audio backend (ALSA, PulseAudio, PipeWire, or OpenAL)
        print("    ✓ Linux audio initialized")
    }
    
    public func loadAudio(path: String) async throws -> AudioHandle {
        // Load audio file (WAV, OGG, MP3)
        return AudioHandle()
    }
    
    public func loadAudioFromData(data: Data, sampleRate: Int, channels: Int) async throws -> AudioHandle {
        return AudioHandle()
    }
    
    public func play(handle: AudioHandle, source: AudioSource3D) throws {
        // Play audio source
    }
    
    public func stop(handle: AudioHandle) throws {
        // Stop audio source
    }
    
    public func pause(handle: AudioHandle) throws {
        // Pause audio source
    }
    
    public func resume(handle: AudioHandle) throws {
        // Resume audio source
    }
    
    public func updateSource(handle: AudioHandle, source: AudioSource3D) throws {
        // Update 3D audio properties
    }
    
    public func setListener(listener: AudioListener) throws {
        // Set listener (camera) position and orientation
    }
    
    public func setMasterVolume(_ volume: Float) throws {
        // Set master volume
    }
    
    public func update(deltaTime: Float) throws {
        // Update audio system
    }
    
    public func shutdown() async {
        print("    → Shutting down Linux audio...")
        print("    ✓ Linux audio shutdown")
    }
}