//
// Copyright 2026 Aarav Ravindra Kharade
//

import CSystem

/// A custom widget node tree for SwiftCrossUI over ArkGraphics IPC
public class ArkGraphicsWidget {
    public var children: [ArkGraphicsWidget] = []
    public var x: Int = 0
    public var y: Int = 0
    public var width: Int = 0
    public var height: Int = 0
    
    public init() {}
}

public class ArkGraphicsWindow {
    public var rootWidget: ArkGraphicsWidget?
    public var title: String = ""
    public init() {}
}

/// The Backend bridging SwiftCrossUI to ArkGraphics IPC
public class ArkGraphicsBackend: BackendFeatures.BaseStubs {
    public struct Widget {
        var node: ArkGraphicsWidget
    }
    
    public struct Window {
        var node: ArkGraphicsWindow
    }
    
    public required init() {}
    
    public var deviceClass: DeviceClass { .desktop }
    
    public static func earlySetup() {}
    
    public func runMainLoop(_ callback: @escaping @MainActor () -> Void) {
        // Setup ArkGraphics IPC
        let graphics = ArkGraphics()
        if !graphics.isConnected {
            print("ArkGraphicsBackend: FATAL - Cannot connect to display daemon")
            return
        }
        
        callback()
        
        // Main run loop
        while true {
            usleep(16000) // ~60fps
            // Poll for inputs, trigger UI redraws, etc
        }
    }
    
    public nonisolated func runInMainThread(action: @escaping @MainActor () -> Void) {
        // Run on the single main thread
        Task { @MainActor in
            action()
        }
    }
    
    public func computeRootEnvironment(defaultEnvironment: EnvironmentValues) -> EnvironmentValues {
        return defaultEnvironment
    }
    
    public func setRootEnvironmentChangeHandler(to action: @escaping @Sendable @MainActor () -> Void) {}
    
    // - CoreWindowing -
    public func createWindow(withDefaultSize defaultSize: SIMD2<Int>?, id: String) -> Window {
        return Window(node: ArkGraphicsWindow())
    }
    public func updateWindow(_ window: Window, title: String) {
        window.node.title = title
    }
    public func updateWindow(_ window: Window, resizability: WindowResizability) {}
    public func setChild(ofWindow window: Window, to child: Widget) {
        window.node.rootWidget = child.node
    }
    public func showWindow(_ window: Window) {}
    
    // - GenericContainers -
    public func createContainer() -> Widget {
        return Widget(node: ArkGraphicsWidget())
    }
    public func addChild(_ child: Widget, to container: Widget) {
        container.node.children.append(child.node)
    }
    public func setChildren(_ children: [Widget], of container: Widget) {
        container.node.children = children.map { $0.node }
    }
    public func removeChild(_ child: Widget, from container: Widget) {
        container.node.children.removeAll(where: { $0 === child.node })
    }
    
    public func removeAllChildren(of container: Widget) {
        container.node.children.removeAll()
    }
    public func insert(_ child: Widget, into container: Widget, at index: Int) {
        container.node.children.insert(child.node, at: index)
    }
    public func swap(childAt firstIndex: Int, withChildAt secondIndex: Int, in container: Widget) {
        container.node.children.swapAt(firstIndex, secondIndex)
    }
    public func setPosition(ofChildAt index: Int, in container: Widget, to position: SIMD2<Int>) {
        container.node.children[index].x = position.x
        container.node.children[index].y = position.y
    }
    public func remove(childAt index: Int, from container: Widget) {
        container.node.children.remove(at: index)
    }
    
    // - TextViews -
    public func createTextView() -> Widget {
        return Widget(node: ArkGraphicsWidget())
    }
    public func updateTextView(_ textView: Widget, content: String, environment: EnvironmentValues) {}
    
    public func size(of text: String, whenDisplayedIn widget: Widget, proposedWidth: Int?, proposedHeight: Int?, environment: EnvironmentValues) -> SIMD2<Int> {
        return SIMD2<Int>(text.count * 8, 16)
    }
    
    // - Buttons -
    public func createSimpleButton() -> Widget {
        return Widget(node: ArkGraphicsWidget())
    }
    public func updateSimpleButton(_ button: Widget, label: String, environment: EnvironmentValues, action: @escaping () -> Void) {}
    
    public func createButton(wrapping: Widget) -> Widget {
        return Widget(node: ArkGraphicsWidget())
    }
    public func updateButton(_ button: Widget, environment: EnvironmentValues, action: @escaping () -> Void) {}
    
    public func buttonPadding(in environment: EnvironmentValues) -> SIMD2<Int> {
        return SIMD2<Int>(8, 8)
    }
    public func defaultButtonStyle() -> ButtonStyle {
        return .bordered
    }
    

    public var scrollBarWidth: Int { return 10 }
    public var requiresImageUpdateOnScaleFactorChange: Bool { return false }
    public var requiresToggleSwitchSpacer: Bool { return false }
    public var supportedPickerStyles: [BackendPickerStyle] { return [] }
    
    // Windowing extra methods
    public func show(window: Window) {}
    public func setTitle(ofWindow window: Window, to title: String) {}
    public func updateWindow(_ window: Window, environment: EnvironmentValues) {}
    public func size(ofWindow window: Window) -> SIMD2<Int> { return SIMD2<Int>(1024, 768) }
    public func setSize(ofWindow window: Window, to newSize: SIMD2<Int>) {}
    public func setSizeLimits(ofWindow window: Window, minimum minimumSize: SIMD2<Int>, maximum maximumSize: SIMD2<Int>?) {}
    public func isWindowProgrammaticallyResizable(_ window: Window) -> Bool { return false }
    public func setResizeHandler(ofWindow window: Window, to action: @escaping (SIMD2<Int>) -> Void) {}
    public func activate(window: Window) {}
    public func computeWindowEnvironment(window: Window, rootEnvironment: EnvironmentValues) -> EnvironmentValues { return rootEnvironment }
    public func setWindowEnvironmentChangeHandler(of window: Window, to action: @escaping @Sendable @MainActor () -> Void) {}
    
    public var defaultPaddingAmount: Int { return 10 }
    
    public func naturalSize(of widget: Widget) -> SIMD2<Int> { return SIMD2<Int>(0, 0) }
    public func setSize(of widget: Widget, to size: SIMD2<Int>) {
        widget.node.width = size.x
        widget.node.height = size.y
    }
    public func show(widget: Widget) {}
    
    public var supportsMultipleWindows: Bool { return false }
    public var canOverrideWindowColorScheme: Bool { return false }
    public var restoresWindowFrames: Bool { return false }
}