import SwiftUI
import PencilKit

struct LeadSignatureCanvas: UIViewRepresentable {
    @Binding var drawing: PKDrawing
    @Environment(\.colorScheme) private var colorScheme

    func makeUIView(context: Context) -> PKCanvasView {
        let view = PKCanvasView()
        view.delegate = context.coordinator
        view.drawingPolicy = .anyInput
        // PencilKit renders black ink as white in Dark Mode, including existing strokes.
        // Keep the stored ink black; the PDF service exports onto a white document.
        view.tool = PKInkingTool(.pen, color: .black, width: 2)
        view.overrideUserInterfaceStyle = colorScheme == .dark ? .dark : .light
        view.backgroundColor = .clear
        view.isOpaque = false
        view.isScrollEnabled = false
        view.drawing = drawing
        view.accessibilityLabel = "Unterschrift"
        view.accessibilityHint = "Mit Finger oder Apple Pencil unterschreiben"
        return view
    }

    func updateUIView(_ view: PKCanvasView, context: Context) {
        context.coordinator.parent = self
        view.overrideUserInterfaceStyle = colorScheme == .dark ? .dark : .light
        if view.drawing != drawing {
            view.drawing = drawing
        }
    }

    func makeCoordinator() -> Coordinator { Coordinator(parent: self) }

    final class Coordinator: NSObject, PKCanvasViewDelegate {
        var parent: LeadSignatureCanvas

        init(parent: LeadSignatureCanvas) { self.parent = parent }

        func canvasViewDrawingDidChange(_ canvasView: PKCanvasView) {
            parent.drawing = canvasView.drawing
        }
    }
}