import SwiftUI

struct SetupView: View {

    @State var stepIndex = 0
    @Binding var visible: Bool
    @Binding var setupComplete: Bool

    var body: some View {
        GeometryReader { proxy in
            VStack {
                StepView(numberOfSteps: 3, currentStep: stepIndex, width: proxy.size.width)
                GeometryReader { _ in
                    HStack(spacing: 0) {
                        SecretAgentSetupView(buttonAction: advance)
                            .frame(width: proxy.size.width)
                        SSHAgentSetupView(buttonAction: advance)
                            .frame(width: proxy.size.width)
                        UpdaterExplainerView {
                            visible = false
                            setupComplete = true
                        }
                        .frame(width: proxy.size.width)
                    }
                    .offset(x: -proxy.size.width * CGFloat(stepIndex), y: 0)
                }
            }
        }
        .frame(idealWidth: 500, idealHeight: 500)
    }


    func advance() {
        withAnimation(.spring()) {
            stepIndex += 1
        }
    }

}

struct StepView: View {

    let numberOfSteps: Int
    let currentStep: Int

    // Ideally we'd have a geometry reader inside this view doing this for us, but that crashes on 11.0b7
    let width: CGFloat

    var body: some View {
        ZStack(alignment: .leading) {
            Rectangle()
                .foregroundColor(.blue)
                .frame(height: 5)
            Rectangle()
                .foregroundColor(.green)
                .frame(width: max(0, ((width - (Constants.padding * 2)) / CGFloat(numberOfSteps - 1)) * CGFloat(currentStep) - (Constants.circleWidth / 2)), height: 5)
                .animation(.spring())
            HStack {
                ForEach(0..<numberOfSteps) { index in
                    ZStack {
                        if currentStep > index {
                            Circle()
                                .foregroundColor(.green)
                                .frame(width: Constants.circleWidth, height: Constants.circleWidth)
                            Text("✓")
                                .foregroundColor(.white)
                                .bold()
                        } else {
                            Circle()
                                .foregroundColor(.blue)
                                .frame(width: Constants.circleWidth, height: Constants.circleWidth)
                            if currentStep == index {
                                Circle()
                                    .strokeBorder(Color.white, lineWidth: 3)
                                    .frame(width: Constants.circleWidth, height: Constants.circleWidth)
                            }
                            Text(String(describing: index + 1))
                                .foregroundColor(.white)
                                .bold()
                        }
                    }
                    if index < numberOfSteps - 1 {
                        Spacer(minLength: 30)
                    }
                }
            }
        }.padding(Constants.padding)
    }

}

extension StepView {

    enum Constants {

        static let padding: CGFloat = 15
        static let circleWidth: CGFloat = 30

    }

}

struct SetupStepView<Content> : View where Content : View {

    let title: String
    let image: Image
    let bodyText: String
    let buttonTitle: String
    let buttonAction: () -> Void
    let content: Content

    init(title: String, image: Image, bodyText: String, buttonTitle: String, buttonAction: @escaping () -> Void = {}, @ViewBuilder content: () -> Content) {
        self.title = title
        self.image = image
        self.bodyText = bodyText
        self.buttonTitle = buttonTitle
        self.buttonAction = buttonAction
        self.content = content()
    }

    var body: some View {
        VStack {
            Text(title)
                .font(.title)
            Spacer()
            image
                .resizable()
                .aspectRatio(contentMode: .fit)
                .frame(width: 64)
            Spacer()
            Text(bodyText)
                .multilineTextAlignment(.center)
            Spacer()
            content
            Spacer()
            Button(buttonTitle) {
                buttonAction()
            }
        }.padding()
    }

}

struct SecretAgentSetupView: View {

    let buttonAction: () -> Void

    var body: some View {
        SetupStepView(title: "Setup Secret Agent",
                      image: Image(nsImage: NSApp.applicationIconImage),
                      bodyText: "Secretive needs to set up a helper app to work properly. It will sign requests from SSH clients in the background, so you don't need to keep the main Secretive app open.",
                      buttonTitle: "Install",
                      buttonAction: install) {
            (Text("This helper app is called ") + Text("Secret Agent").bold().underline() + Text(" and you may see it in Activity Manager from time to time."))
                .multilineTextAlignment(.center)
        }
    }

    func install() {
        _ = LaunchAgentController().install()
        buttonAction()
    }

}

struct SSHAgentSetupView: View {

    let buttonAction: () -> Void

    private static let controller = ShellConfigurationController()
    @State private var selectedShellInstruction: ShellConfigInstruction = controller.shellInstructions.first!

    var body: some View {
        SetupStepView(title: "Configure your SSH Agent",
                      image: Image(systemName: "terminal"),
                      bodyText: "Add this line to your shell config telling SSH to talk to Secret Agent when it wants to authenticate. Secretive can either do this for you automatically, or you can copy and paste this into your config file.",
                      buttonTitle: "I Added it Manually",
                      buttonAction: buttonAction) {
            Picker(selection: $selectedShellInstruction, label: EmptyView()) {
                ForEach(SSHAgentSetupView.controller.shellInstructions) { instruction in
                    Text(instruction.shell)
                        .tag(instruction)
                        .padding()
                }
            }.pickerStyle(SegmentedPickerStyle())
            CopyableView(title: "Add to \(selectedShellInstruction.shellConfigPath)", image: Image(systemName: "greaterthan.square"), text: selectedShellInstruction.text)
            Button("Add it For Me") {
                let controller = ShellConfigurationController()
                if controller.addToShell(shellInstructions: selectedShellInstruction) {
                    buttonAction()
                }
            }
        }
    }

}

class Delegate: NSObject, NSOpenSavePanelDelegate {

    private let name: String

    init(name: String) {
        self.name = name
    }

    func panel(_ sender: Any, shouldEnable url: URL) -> Bool {
        return url.lastPathComponent == name
    }

}

struct UpdaterExplainerView: View {

    let buttonAction: () -> Void

    var body: some View {
        SetupStepView(title: "Updates",
                      image: Image(systemName: "dot.radiowaves.left.and.right"),
                      bodyText: "Secretive will periodically check with GitHub to see if there's a new release. If you see any network requests to GitHub, that's why.",
                      buttonTitle: "Okay",
                      buttonAction: buttonAction) {
            Link("Read more about this here.", destination: SetupView.Constants.updaterFAQURL)
        }
    }

}

extension SetupView {

    enum Constants {
        static let updaterFAQURL = URL(string: "https://github.com/maxgoedjen/secretive/blob/main/FAQ.md#whats-this-network-request-to-github")!
    }

}

struct ShellConfigInstruction: Identifiable, Hashable {

    var shell: String
    var shellConfigDirectory: String
    var shellConfigFilename: String
    var text: String

    var id: String {
        shell
    }

    var shellConfigPath: String {
        return (shellConfigDirectory as NSString).appendingPathComponent(shellConfigFilename)
    }

}

#if DEBUG

struct SetupView_Previews: PreviewProvider {

    static var previews: some View {
        Group {
            SetupView(visible: .constant(true), setupComplete: .constant(false))
        }
    }

}

struct SecretAgentSetupView_Previews: PreviewProvider {

    static var previews: some View {
        Group {
            SecretAgentSetupView(buttonAction: {})
        }
    }

}

struct SSHAgentSetupView_Previews: PreviewProvider {

    static var previews: some View {
        Group {
            SSHAgentSetupView(buttonAction: {})
        }
    }

}

struct UpdaterExplainerView_Previews: PreviewProvider {

    static var previews: some View {
        Group {
            UpdaterExplainerView(buttonAction: {})
        }
    }
    
}

#endif