//
//  VPNSettingsCellFactory.swift
//  MullvadVPN
//
//  Created by Jon Petersson on 2023-03-09.
//  Copyright © 2025 Mullvad VPN AB. All rights reserved.
//

import MullvadSettings
import UIKit

protocol VPNSettingsCellEventHandler {
    func showInfo(for button: VPNSettingsInfoButtonItem)
    func showDetails(for button: VPNSettingsDetailsButtonItem)
    func addCustomPort(_ port: UInt16)
    func selectCustomPortEntry(_ port: UInt16) -> Bool
    func selectObfuscationState(_ state: WireGuardObfuscationState)
    func switchMultihop(_ state: MultihopState)
    func setLocalNetworkSharing(_ enabled: Bool, onCancel: @escaping () -> Void)
    func setIncludeAllNetworks(_ enabled: Bool, onCancel: @escaping () -> Void)
}

@MainActor
final class VPNSettingsCellFactory: @preconcurrency CellFactoryProtocol {
    let tableView: UITableView
    var viewModel: VPNSettingsViewModel
    var delegate: VPNSettingsCellEventHandler?
    var isEditing = false

    init(tableView: UITableView, viewModel: VPNSettingsViewModel) {
        self.tableView = tableView
        self.viewModel = viewModel
    }

    func makeCell(for item: VPNSettingsDataSource.Item, indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: item.reuseIdentifier.rawValue, for: indexPath)
        configureCell(cell, item: item, indexPath: indexPath)

        return cell
    }

    func configureCell(_ cell: UITableViewCell, item: VPNSettingsDataSource.Item, indexPath: IndexPath) {
        (cell as? SettingsCell)?.detailTitleLabel.accessibilityIdentifier = nil
        switch item {
        case .includeAllNetworks:
            guard let cell = cell as? SettingsSwitchCell else { return }
            cell.action = { enable in
                self.delegate?.setIncludeAllNetworks(enable) {
                    cell.setOn(self.viewModel.includeAllNetworks, animated: true)
                }
            }

            cell.titleLabel.text = NSLocalizedString("Include all networks", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.setOn(viewModel.includeAllNetworks, animated: true)
        case .localNetworkSharing:
            guard let cell = cell as? SettingsSwitchCell else { return }
            cell.infoButtonHandler = { self.delegate?.showInfo(for: .localNetworkSharing) }
            cell.action = { enable in
                self.delegate?.setLocalNetworkSharing(enable) {
                    cell.setOn(self.viewModel.localNetworkSharing, animated: true)
                }
            }

            cell.titleLabel.text = NSLocalizedString("Local network sharing", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.setOn(viewModel.localNetworkSharing, animated: true)
            cell.setSwitchEnabled(viewModel.includeAllNetworks)

        case .dnsSettings:
            guard let cell = cell as? SettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("DNS settings", comment: "")

            cell.disclosureType = .chevron
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)

        case .ipOverrides:
            guard let cell = cell as? SettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Server IP override", comment: "")

            cell.disclosureType = .chevron
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)

        case let .wireGuardPort(port):
            guard let cell = cell as? SelectableSettingsCell else { return }

            var portString = NSLocalizedString("Automatic", comment: "")
            if let port {
                portString = String(port)
            }

            cell.titleLabel.text = portString
            cell.accessibilityIdentifier = "\(item.accessibilityIdentifier.asString)"
            cell.applySubCellStyling()

        case .wireGuardCustomPort:
            guard let cell = cell as? SettingsInputCell else { return }

            cell.titleLabel.text = NSLocalizedString("Custom", comment: "")
            cell.textField.placeholder = NSLocalizedString("Port", comment: "")

            cell.textField.setAccessibilityIdentifier(.customWireGuardPortTextField)
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()

            cell.inputDidChange = { [weak self] text in
                let port = UInt16(text) ?? UInt16()
                cell.isValidInput = self?.delegate?.selectCustomPortEntry(port) ?? false
            }
            cell.inputWasConfirmed = { [weak self] text in
                if let port = UInt16(text), cell.isValidInput {
                    self?.delegate?.addCustomPort(port)
                }
            }

            if let port = viewModel.customWireGuardPort {
                cell.textField.text = String(port)

                // Only update validity if input is invalid. Otherwise the textcolor will be wrong
                // (active text field color rather than the expected inactive color).
                let isValidInput = delegate?.selectCustomPortEntry(port) ?? false
                if !isValidInput {
                    cell.isValidInput = false
                }
            }

        case .wireGuardObfuscationAutomatic:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Automatic", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()

        case .wireGuardObfuscationUdpOverTcp:
            guard let cell = cell as? SelectableSettingsDetailsCell else { return }

            cell.titleLabel.text = NSLocalizedString("UDP-over-TCP", comment: "")

            cell.detailTitleLabel.text = String(
                format: NSLocalizedString("Port: %@", comment: ""),
                viewModel.obfuscationUpdOverTcpPort.description
            )

            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.detailTitleLabel.setAccessibilityIdentifier(.wireGuardObfuscationUdpOverTcpPort)
            cell.applySubCellStyling()

            cell.buttonAction = { [weak self] in
                self?.delegate?.showDetails(for: .udpOverTcp)
            }

        case .wireGuardObfuscationShadowsocks:
            guard let cell = cell as? SelectableSettingsDetailsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Shadowsocks", comment: "")

            cell.detailTitleLabel.text = String(
                format: NSLocalizedString("Port: %@", comment: ""),
                viewModel.obfuscationShadowsocksPort.description
            )

            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.detailTitleLabel.setAccessibilityIdentifier(.wireGuardObfuscationShadowsocksPort)
            cell.applySubCellStyling()

            cell.buttonAction = { [weak self] in
                self?.delegate?.showDetails(for: .wireguardOverShadowsocks)
            }

        case .wireGuardObfuscationQuic:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("QUIC", comment: "")

            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.detailTitleLabel.setAccessibilityIdentifier(.wireGuardObfuscationQuic)
            cell.applySubCellStyling()

        case .wireGuardObfuscationOff:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Off", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()

        case let .wireGuardObfuscationPort(port):
            guard let cell = cell as? SelectableSettingsCell else { return }

            let portString = port.description
            cell.titleLabel.text = portString
            cell.accessibilityIdentifier = "\(item.accessibilityIdentifier)\(portString)"
            cell.applySubCellStyling()

        case .quantumResistanceAutomatic:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Automatic", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()

        case .quantumResistanceOn:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("On", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()

        case .quantumResistanceOff:
            guard let cell = cell as? SelectableSettingsCell else { return }

            cell.titleLabel.text = NSLocalizedString("Off", comment: "")
            cell.setAccessibilityIdentifier(item.accessibilityIdentifier)
            cell.applySubCellStyling()
        }
    }
}