secretive/Sources/Secretive/Views/CopyableView.swift

import SwiftUI
import UniformTypeIdentifiers

struct CopyableView: View {

    var title: LocalizedStringKey
    var image: Image
    var text: String

    @State private var interactionState: InteractionState = .normal
    @Namespace var namespace
    
    var content: some View {
        VStack(alignment: .leading) {
            HStack {
                image
                    .renderingMode(.template)
                    .imageScale(.large)
                    .foregroundColor(primaryTextColor)
                Text(title)
                    .font(.headline)
                    .foregroundColor(primaryTextColor)
                Spacer()
                if interactionState != .normal {
                    hoverIcon
                        .bold()
                        .textCase(.uppercase)
                        .foregroundColor(secondaryTextColor)
                        .transition(.opacity)
                }

            }
            .padding(EdgeInsets(top: 20, leading: 20, bottom: 10, trailing: 20))
            Divider()
            Text(text)
                .fixedSize(horizontal: false, vertical: true)
                .foregroundColor(primaryTextColor)
                .padding(EdgeInsets(top: 10, leading: 20, bottom: 20, trailing: 20))
                .multilineTextAlignment(.leading)
                .font(.system(.body, design: .monospaced))
        }
        ._background(interactionState: interactionState)
        .frame(minWidth: 150, maxWidth: .infinity)
    }

    var body: some View {
        content
        .onHover { hovering in
            withAnimation {
                interactionState = hovering ? .hovering : .normal
            }
        }
        .onDrag({
            NSItemProvider(item: NSData(data: text.data(using: .utf8)!), typeIdentifier: UTType.utf8PlainText.identifier)
        }, preview: {
            content
                ._background(interactionState: .dragging)
        })
        .onTapGesture {
            copy()
            withAnimation {
                interactionState = .clicking
            }
        }
        .gesture(
            TapGesture()
                .onEnded {
                    withAnimation {
                        interactionState = .normal
                    }
                }
        )
    }

    var hoverIcon: Image {
        switch interactionState {
        case .hovering, .dragging:
            return Image(systemName: "document.on.document")
        case .clicking:
            return Image(systemName: "checkmark.circle.fill")
        case .normal:
            fatalError()
        }
    }

    var primaryTextColor: Color {
        switch interactionState {
        case .normal, .hovering, .dragging:
            return Color(.textColor)
        case .clicking:
            return .white
        }
    }

    var secondaryTextColor: Color {
        switch interactionState {
        case .normal, .hovering, .dragging:
            return Color(.secondaryLabelColor)
        case .clicking:
            return .white
        }
    }

    func copy() {
        NSPasteboard.general.declareTypes([.string], owner: nil)
        NSPasteboard.general.setString(text, forType: .string)
    }

}

fileprivate enum InteractionState {
    case normal, hovering, clicking, dragging
}

extension View {
       
    fileprivate func _background(interactionState: InteractionState) -> some View {
        modifier(BackgroundViewModifier(interactionState: interactionState))
    }
    
}

fileprivate struct BackgroundViewModifier: ViewModifier {
    
    @Environment(\.colorScheme) private var colorScheme
    
    let interactionState: InteractionState

    func body(content: Content) -> some View {
        if interactionState == .dragging {
            content
                .background(backgroundColor(interactionState: interactionState), in: RoundedRectangle(cornerRadius: 15))
        } else {
            if #available(macOS 26.0, *) {
                content
                // Very thin opacity lets user hover anywhere over the view, glassEffect doesn't allow.
                    .background(.white.opacity(0.01), in: RoundedRectangle(cornerRadius: 15))
                    .glassEffect(.regular.tint(backgroundColor(interactionState: interactionState)), in: RoundedRectangle(cornerRadius: 15))
                
            } else {
                content
                    .background(backgroundColor(interactionState: interactionState))
                    .cornerRadius(10)
            }
        }
    }
    
    func backgroundColor(interactionState: InteractionState) -> Color {
        switch interactionState {
        case .normal:
            return colorScheme == .dark ? Color(white: 0.2) : Color(white: 0.885)
        case .hovering, .dragging:
            return colorScheme == .dark ? Color(white: 0.275) : Color(white: 0.82)
        case .clicking:
            return .accentColor
        }
    }

    
}

#if DEBUG

struct CopyableView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            CopyableView(title: "secret_detail_sha256_fingerprint_label", image: Image(systemName: "figure.wave"), text: "Hello world.")
                .padding()
            CopyableView(title: "secret_detail_sha256_fingerprint_label", image: Image(systemName: "figure.wave"), text: "Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. Long text. ")
                .padding()
        }
    }
}

#endif