// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import UIKit
import SessionUIKit
import SessionSnodeKit
import SessionMessagingKit
import SignalUtilitiesKit

final class NukeDataModal: Modal {
    // MARK: - Initialization
    
    override init(targetView: UIView? = nil, dismissType: DismissType = .recursive, afterClosed: (() -> ())? = nil) {
        super.init(targetView: targetView, dismissType: dismissType, afterClosed: afterClosed)
        
        self.modalPresentationStyle = .overFullScreen
        self.modalTransitionStyle = .crossDissolve
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Components
    
    private lazy var titleLabel: UILabel = {
        let result = UILabel()
        result.font = .boldSystemFont(ofSize: Values.mediumFontSize)
        result.text = "modal_clear_all_data_title".localized()
        result.themeTextColor = .textPrimary
        result.textAlignment = .center
        result.lineBreakMode = .byWordWrapping
        result.numberOfLines = 0
        
        return result
    }()
    
    private lazy var explanationLabel: UILabel = {
        let result = UILabel()
        result.font = .systemFont(ofSize: Values.smallFontSize)
        result.text = "modal_clear_all_data_explanation".localized()
        result.themeTextColor = .textPrimary
        result.textAlignment = .center
        result.lineBreakMode = .byWordWrapping
        result.numberOfLines = 0
        
        return result
    }()
    
    private lazy var clearDeviceRadio: RadioButton = {
        let result: RadioButton = RadioButton(size: .small) { [weak self] radio in
            self?.clearNetworkRadio.update(isSelected: false)
            radio.update(isSelected: true)
        }
        result.font = .systemFont(ofSize: Values.smallFontSize)
        result.text = "modal_clear_all_data_device_only_button_title".localized()
        result.update(isSelected: true)
        
        return result
    }()
    
    private lazy var clearNetworkRadio: RadioButton = {
        let result: RadioButton = RadioButton(size: .small) { [weak self] radio in
            self?.clearDeviceRadio.update(isSelected: false)
            radio.update(isSelected: true)
        }
        result.font = .systemFont(ofSize: Values.smallFontSize)
        result.text = "modal_clear_all_data_entire_account_button_title".localized()
        
        return result
    }()
    
    private lazy var clearDataButton: UIButton = {
        let result: UIButton = Modal.createButton(
            title: "modal_clear_all_data_confirm".localized(),
            titleColor: .danger
        )
        result.addTarget(self, action: #selector(clearAllData), for: UIControl.Event.touchUpInside)
        
        return result
    }()
    
    private lazy var buttonStackView: UIStackView = {
        let result = UIStackView(arrangedSubviews: [ clearDataButton, cancelButton ])
        result.axis = .horizontal
        result.distribution = .fillEqually
        
        return result
    }()
    
    private lazy var contentStackView: UIStackView = {
        let result = UIStackView(arrangedSubviews: [
            titleLabel,
            explanationLabel,
            clearDeviceRadio,
            UIView.separator(),
            clearNetworkRadio
        ])
        result.axis = .vertical
        result.spacing = Values.smallSpacing
        result.isLayoutMarginsRelativeArrangement = true
        result.layoutMargins = UIEdgeInsets(
            top: Values.largeSpacing,
            leading: Values.largeSpacing,
            bottom: Values.verySmallSpacing,
            trailing: Values.largeSpacing
        )
        
        return result
    }()
    
    private lazy var mainStackView: UIStackView = {
        let result = UIStackView(arrangedSubviews: [ contentStackView, buttonStackView ])
        result.axis = .vertical
        result.spacing = Values.largeSpacing - Values.smallFontSize / 2
        
        return result
    }()
    
    // MARK: - Lifecycle
    
    override func populateContentView() {
        contentView.addSubview(mainStackView)
        
        mainStackView.pin(to: contentView)
    }
    
    // MARK: - Interaction
    
    @objc private func clearAllData() {
        guard clearNetworkRadio.isSelected else {
            clearDeviceOnly()
            return
        }
        
        let confirmationModal: ConfirmationModal = ConfirmationModal(
            info: ConfirmationModal.Info(
                title: "modal_clear_all_data_title".localized(),
                body: .text("modal_clear_all_data_explanation_2".localized()),
                confirmTitle: "modal_clear_all_data_confirm".localized(),
                confirmStyle: .danger,
                cancelStyle: .alert_text,
                dismissOnConfirm: false
            ) { [weak self] confirmationModal in
                self?.clearEntireAccount(presentedViewController: confirmationModal)
            }
        )
        present(confirmationModal, animated: true, completion: nil)
    }
    
    private func clearDeviceOnly() {
        ModalActivityIndicatorViewController.present(fromViewController: self, canCancel: false) { [weak self] _ in
            ConfigurationSyncJob.run()
                .subscribe(on: DispatchQueue.global(qos: .userInitiated))
                .receive(on: DispatchQueue.main)
                .sinkUntilComplete(
                    receiveCompletion: { _ in
                        self?.deleteAllLocalData()
                        self?.dismiss(animated: true, completion: nil) // Dismiss the loader
                    }
                )
        }
    }
    
    private func clearEntireAccount(presentedViewController: UIViewController) {
        ModalActivityIndicatorViewController
            .present(fromViewController: presentedViewController, canCancel: false) { [weak self] _ in
                SnodeAPI.deleteAllMessages(namespace: .all)
                    .subscribe(on: DispatchQueue.global(qos: .userInitiated))
                    .receive(on: DispatchQueue.main)
                    .sinkUntilComplete(
                        receiveCompletion: { result in
                            switch result {
                                case .finished: break
                                case .failure(let error):
                                    self?.dismiss(animated: true, completion: nil) // Dismiss the loader
                                    
                                    let modal: ConfirmationModal = ConfirmationModal(
                                        targetView: self?.view,
                                        info: ConfirmationModal.Info(
                                            title: "ALERT_ERROR_TITLE".localized(),
                                            body: .text(error.localizedDescription),
                                            cancelTitle: "BUTTON_OK".localized(),
                                            cancelStyle: .alert_text
                                        )
                                    )
                                    self?.present(modal, animated: true)
                            }
                        },
                        receiveValue: { confirmations in
                            self?.dismiss(animated: true, completion: nil) // Dismiss the loader
                            
                            let potentiallyMaliciousSnodes = confirmations
                                .compactMap { ($0.value == false ? $0.key : nil) }
                            
                            if potentiallyMaliciousSnodes.isEmpty {
                                self?.deleteAllLocalData()
                            }
                            else {
                                let message: String
                                if potentiallyMaliciousSnodes.count == 1 {
                                    message = String(format: "dialog_clear_all_data_deletion_failed_1".localized(), potentiallyMaliciousSnodes[0])
                                }
                                else {
                                    message = String(format: "dialog_clear_all_data_deletion_failed_2".localized(), String(potentiallyMaliciousSnodes.count), potentiallyMaliciousSnodes.joined(separator: ", "))
                                }
                                
                                let modal: ConfirmationModal = ConfirmationModal(
                                    targetView: self?.view,
                                    info: ConfirmationModal.Info(
                                        title: "ALERT_ERROR_TITLE".localized(),
                                        body: .text(message),
                                        cancelTitle: "BUTTON_OK".localized(),
                                        cancelStyle: .alert_text
                                    )
                                )
                                self?.present(modal, animated: true)
                            }
                        }
                    )
            }
    }
    
    private func deleteAllLocalData() {
        // Unregister push notifications if needed
        let isUsingFullAPNs: Bool = UserDefaults.standard[.isUsingFullAPNs]
        let maybeDeviceToken: String? = UserDefaults.standard[.deviceToken]
        
        if isUsingFullAPNs, let deviceToken: String = maybeDeviceToken {
            let data: Data = Data(hex: deviceToken)
            PushNotificationAPI.unregister(data).sinkUntilComplete()
        }
        
        /// Stop and cancel all current jobs (don't want to inadvertantly have a job store data after it's table has already been cleared)
        ///
        /// **Note:** This is file as long as this process kills the app, if it doesn't then we need an alternate mechanism to flag that
        /// the `JobRunner` is allowed to start it's queues again
        JobRunner.stopAndClearPendingJobs()
        
        // Clear the app badge and notifications
        AppEnvironment.shared.notificationPresenter.clearAllNotifications()
        CurrentAppContext().setMainAppBadgeNumber(0)
        
        // Clear out the user defaults
        UserDefaults.removeAll()
        
        // Remove the cached key so it gets re-cached on next access
        General.cache.mutate { $0.encodedPublicKey = nil }
        
        // Clear the Snode pool
        SnodeAPI.clearSnodePool()
        
        // Stop any pollers
        (UIApplication.shared.delegate as? AppDelegate)?.stopPollers()
        
        // Call through to the SessionApp's "resetAppData" which will wipe out logs, database and
        // profile storage
        let wasUnlinked: Bool = UserDefaults.standard[.wasUnlinked]
        
        SessionApp.resetAppData {
            // Resetting the data clears the old user defaults. We need to restore the unlink default.
            UserDefaults.standard[.wasUnlinked] = wasUnlinked
        }
    }
}