// Copyright © 2023 Rangeproof Pty Ltd. All rights reserved.

import SwiftUI
import Combine
import SessionUIKit
import SessionSnodeKit
import SignalUtilitiesKit
import SessionUtilitiesKit

enum PNMode {
    case fast
    case slow
}

struct PNModeView: View {
    @EnvironmentObject var host: HostWrapper
    
    @State private var currentSelection: PNMode = .fast
    
    private let flow: Onboarding.Flow
    
    public init(flow: Onboarding.Flow) {
        self.flow = flow
    }
    
    let options: [PNOptionView.Info] = [
        PNOptionView.Info(
            mode: .fast,
            title: "fast_mode".localized(),
            explanation: "fast_mode_explanation".localized(),
            isRecommended: true
        ),
        PNOptionView.Info(
            mode: .slow,
            title: "slow_mode".localized(),
            explanation: "slow_mode_explanation".localized(),
            isRecommended: false
        )
    ]
    
    var body: some View {
        NavigationView {
            ZStack(alignment: .center) {
                if #available(iOS 14.0, *) {
                    ThemeManager.currentTheme.colorSwiftUI(for: .backgroundPrimary).ignoresSafeArea()
                } else {
                    ThemeManager.currentTheme.colorSwiftUI(for: .backgroundPrimary)
                }
                
                VStack(
                    alignment: .leading,
                    spacing: Values.mediumSpacing
                ) {
                    Spacer()
                    
                    Text("vc_pn_mode_title".localized())
                        .bold()
                        .font(.system(size: Values.veryLargeFontSize))
                        .foregroundColor(themeColor: .textPrimary)
                        .padding(.vertical, Values.mediumSpacing)
                    
                    VStack(
                        alignment: .leading,
                        spacing: Values.mediumSpacing)
                    {
                        ForEach(
                            0...(options.count - 1),
                            id: \.self
                        ) { index in
                            PNOptionView(
                                currentSelection: $currentSelection,
                                info: options[index]
                            )
                        }
                    }
                    
                    Spacer()
                }
                .padding(.horizontal, Values.veryLargeSpacing)
                .padding(.bottom, Values.massiveSpacing + Values.largeButtonHeight)
                
                VStack() {
                    Spacer()
                    
                    Button {
                        register()
                    } label: {
                        Text("continue_2".localized())
                            .bold()
                            .font(.system(size: Values.smallFontSize))
                            .foregroundColor(themeColor: .sessionButton_text)
                            .frame(
                                maxWidth: .infinity,
                                maxHeight: Values.largeButtonHeight,
                                alignment: .center
                            )
                            .overlay(
                                Capsule()
                                    .stroke(themeColor: .sessionButton_border)
                            )
                    }
                    .padding(.horizontal, Values.massiveSpacing)
                }
                .padding(.vertical, Values.mediumSpacing)
            }
        }
    }
    
    private func register() {
        UserDefaults.standard[.isUsingFullAPNs] = (currentSelection == .fast)
        
        // If we are registering then we can just continue on
        guard flow != .register else {
            self.flow.completeRegistration()
            
            // Go to recovery password screen
            if let recoveryPasswordView = try? RecoveryPasswordView(flow: self.flow) {
                let viewController: SessionHostingViewController = SessionHostingViewController(rootView: recoveryPasswordView)
                viewController.setUpNavBarSessionIcon()
                self.host.controller?.navigationController?.pushViewController(viewController, animated: true)
            } else {
                let modal = ConfirmationModal(
                    targetView: self.host.controller?.view,
                    info: ConfirmationModal.Info(
                        title: "ALERT_ERROR_TITLE".localized(),
                        body: .text("LOAD_RECOVERY_PASSWORD_ERROR".localized()),
                        cancelTitle: "BUTTON_OK".localized(),
                        cancelStyle: .alert_text
                    )
                )
                self.host.controller?.present(modal, animated: true)
            }
            
            return
        }
        
        // Check if we already have a profile name (ie. profile retrieval completed while waiting on
        // this screen)
        let existingProfileName: String? = Storage.shared
            .read { db in
                try Profile
                    .filter(id: getUserHexEncodedPublicKey(db))
                    .select(.name)
                    .asRequest(of: String.self)
                    .fetchOne(db)
            }
        
        guard existingProfileName?.isEmpty != false else {
            // If we have one then we can go straight to the home screen
            self.flow.completeRegistration()
            
            // Go to the home screen
            let homeVC: HomeVC = HomeVC()
            self.host.controller?.navigationController?.setViewControllers([ homeVC ], animated: true)
            return
        }
        
        // If we don't have one then show a loading indicator and try to retrieve the existing name
        let viewController: SessionHostingViewController = SessionHostingViewController(rootView: LoadingView(flow: flow))
        viewController.setUpNavBarSessionIcon()
        self.host.controller?.navigationController?.pushViewController(viewController, animated: true)
    }
}

struct PNOptionView: View {
    
    struct Info {
        let mode: PNMode
        let title: String
        let explanation: String
        let isRecommended: Bool
    }
    
    @Binding var currentSelection: PNMode
    
    let info: Info
    
    static let cornerRadius: CGFloat = 8
    static let radioBorderSize: CGFloat = 22
    static let radioSelectionSize: CGFloat = 17
    
    var body: some View {
        HStack(
            spacing: Values.largeSpacing
        ) {
            VStack(
                alignment: .leading,
                spacing: Values.smallSpacing
            ) {
                Text(info.title)
                    .bold()
                    .font(.system(size: Values.mediumFontSize))
                    .foregroundColor(themeColor: .textPrimary)
                
                Text(info.explanation)
                    .font(.system(size: Values.verySmallFontSize))
                    .foregroundColor(themeColor: .textPrimary)
                    .frame(
                        maxWidth: .infinity,
                        alignment: .leading
                    )
                
                if info.isRecommended {
                    Text("vc_pn_mode_recommended_option_tag".localized())
                        .bold()
                        .font(.system(size: Values.smallFontSize))
                        .foregroundColor(themeColor: .primary)
                }
            }
            .frame(maxWidth: .infinity)
            .padding(.all, Values.mediumSpacing)
            .overlay(
                RoundedRectangle(
                    cornerSize: CGSize(
                        width: Self.cornerRadius,
                        height: Self.cornerRadius
                    )
                )
                .stroke(themeColor: .borderSeparator)
            )
            
            ZStack(alignment: .center) {
                Circle()
                    .stroke(themeColor: .textPrimary)
                    .frame(
                        width: Self.radioBorderSize,
                        height: Self.radioBorderSize
                    )
                
                if currentSelection == info.mode {
                    Circle()
                        .fill(themeColor: .primary)
                        .frame(
                            width: Self.radioSelectionSize,
                            height: Self.radioSelectionSize
                        )
                }
            }
        }
        .frame(
            maxWidth: .infinity
        )
        .onTapGesture {
            currentSelection = info.mode
        }
    }
}

struct PNModeView_Previews: PreviewProvider {
    static var previews: some View {
        PNModeView(flow: .register)
    }
}