View+.swift

//
//  View+.swift
//  DevLog
//
//  Created by 최윤진 on 11/22/25.
//

import SwiftUI

extension View {
    @ViewBuilder
    func onScrollOffsetChange(action: @escaping (CGFloat) -> Void) -> some View {
        if #available(iOS 18, *) {
            self.onScrollGeometryChange(for: CGFloat.self) { geo in
                geo.contentOffset.y + geo.contentInsets.top
            } action: { _, newOffset in
                action(newOffset)
            }
        } else {
            self.background(ScrollViewOffsetTracker(onChange: action))
        }
    }
}

private struct ScrollViewOffsetTracker: UIViewRepresentable {
    var onChange: (CGFloat) -> Void

    func makeCoordinator() -> Coordinator {
        Coordinator(onChange: onChange)
    }

    func makeUIView(context: Context) -> UIView {
        let view = UIView()
        view.isHidden = true
        view.isUserInteractionEnabled = false
        DispatchQueue.main.async {
            guard let scrollView = Self.findScrollView(from: view) else { return }
            context.coordinator.observe(scrollView)
        }
        return view
    }

    func updateUIView(_ uiView: UIView, context: Context) {}

    private static func findScrollView(from view: UIView) -> UIScrollView? {
        var current = view.superview
        while let superview = current {
            if let scrollView = superview as? UIScrollView {
                return scrollView
            }
            for sibling in superview.subviews where sibling !== view {
                if let scrollView = findScrollViewInSubviews(of: sibling) {
                    return scrollView
                }
            }
            current = superview.superview
        }
        return nil
    }

    private static func findScrollViewInSubviews(of view: UIView) -> UIScrollView? {
        if let scrollView = view as? UIScrollView {
            return scrollView
        }
        for subview in view.subviews {
            if let scrollView = findScrollViewInSubviews(of: subview) {
                return scrollView
            }
        }
        return nil
    }

    class Coordinator: NSObject {
        private var onChange: (CGFloat) -> Void
        private var observation: NSKeyValueObservation?

        init(onChange: @escaping (CGFloat) -> Void) {
            self.onChange = onChange
        }

        func observe(_ scrollView: UIScrollView) {
            observation = scrollView.observe(\.contentOffset, options: [.new]) { [weak self] scrollView, _ in
                let offset = scrollView.contentOffset.y + scrollView.adjustedContentInset.top
                self?.onChange(offset)
            }
        }

        deinit {
            observation?.invalidate()
        }
    }
}

extension View {
    @ViewBuilder
    func adaptiveButtonStyle<S: InsettableShape>(
        shape: S = Capsule(),
        color: Color = .clear
    ) -> some View {
        if #available(iOS 26.0, *) {
            self.foregroundStyle(Color(.label))
                .padding(8)
                .glassEffect(.regular.tint(color), in: shape)
                .clipShape(shape)
        } else {
            self.foregroundStyle(Color(.label))
                .padding(8)
                .background {
                    shape
                        .fill(color == .clear ? Color(.systemGray5) : color)
                        .strokeBorder(Color.white.opacity(0.2), lineWidth: 1)
                }
        }
    }
}