// MARK: Swiftgram
import SGSimpleSettings
import SGItemListUI
import Foundation
import UIKit
import Display
import SwiftSignalKit
import TelegramCore
import TelegramPresentationData
import TelegramUIPreferences
import ItemListUI
import PresentationDataUtils
import AccountContext

private enum TabOrganizerSection: Int32, SGItemListSection {
    case order
    case visibility
}

private enum TabOrganizerBoolSetting: Hashable {
    case showContactsTab
    case showCallsTab
}

private typealias TabOrganizerEntry = SGItemListUIEntry<TabOrganizerSection, TabOrganizerBoolSetting, AnyHashable, AnyHashable, AnyHashable, AnyHashable>

private func tabTitle(_ tabId: String, _ lang: String) -> String {
    switch tabId {
    case "chats":    return lang == "ru" ? "Чаты"      : "Chats"
    case "contacts": return lang == "ru" ? "Контакты"  : "Contacts"
    case "calls":    return lang == "ru" ? "Звонки"    : "Calls"
    case "settings": return lang == "ru" ? "Настройки" : "Settings"
    default: return tabId
    }
}

private func tabIconName(_ tabId: String) -> String? {
    switch tabId {
    case "chats":    return "bubble.left.and.bubble.right.fill"
    case "contacts": return "person.2.fill"
    case "calls":    return "phone.fill"
    case "settings": return "gearshape.fill"
    default: return nil
    }
}

private func tabOrganizerEntries(presentationData: PresentationData, settings: CallListSettings) -> [TabOrganizerEntry] {
    let lang = presentationData.strings.baseLanguageCode
    var entries: [TabOrganizerEntry] = []
    let id = SGItemListCounter()

    // — Order section —
    entries.append(.header(id: id.count, section: .order,
        text: lang == "ru" ? "ПОРЯДОК" : "ORDER", badge: nil))
    entries.append(.notice(id: id.count, section: .order,
        text: lang == "ru"
            ? "Удерживайте и перетащите строку, чтобы изменить порядок вкладок."
            : "Hold and drag a row to reorder tabs."))

    let order = settings.tabOrder.isEmpty ? CallListSettings.tabOrderDefault : settings.tabOrder
    for tabId in order {
        entries.append(.reorderableRow(
            id: id.count,
            section: .order,
            text: tabTitle(tabId, lang),
            reorderId: tabId as AnyHashable,
            iconName: tabIconName(tabId)
        ))
    }

    // — Visibility section —
    entries.append(.header(id: id.count, section: .visibility,
        text: lang == "ru" ? "ВИДИМОСТЬ" : "VISIBILITY", badge: nil))

    if order.contains("contacts") {
        entries.append(.toggle(id: id.count, section: .visibility,
            settingName: .showContactsTab,
            value: settings.showContactsTab,
            text: lang == "ru" ? "Показывать вкладку «Контакты»" : "Show Contacts tab",
            enabled: true))
    }
    if order.contains("calls") {
        entries.append(.toggle(id: id.count, section: .visibility,
            settingName: .showCallsTab,
            value: settings.showTab,
            text: lang == "ru" ? "Показывать вкладку «Звонки»" : "Show Calls tab",
            enabled: true))
    }

    return entries
}

public func TabOrganizerController(context: AccountContext, presentationData: PresentationData, onSave: @escaping () -> Void) -> ViewController {
    let reloadPromise = ValuePromise(true, ignoreRepeated: false)
    var backAction: (() -> Void)?

    let arguments = SGItemListArguments<TabOrganizerBoolSetting, AnyHashable, AnyHashable, AnyHashable, AnyHashable>(
        context: context,
        setBoolValue: { setting, value in
            let _ = updateCallListSettingsInteractively(accountManager: context.sharedContext.accountManager) { current in
                switch setting {
                case .showContactsTab: return current.withUpdatedShowContactsTab(value)
                case .showCallsTab:    return current.withUpdatedShowTab(value)
                }
            }.start()
            reloadPromise.set(true)
        },
        updateSliderValue: { _, _ in },
        setOneFromManyValue: { _ in },
        openDisclosureLink: { _ in },
        action: { _ in },
        searchInput: { _ in }
    )

    let signal = combineLatest(
        reloadPromise.get(),
        context.sharedContext.accountManager.sharedData(keys: [ApplicationSpecificSharedDataKeys.callListSettings]),
        context.sharedContext.presentationData
    )
    |> map { _, sharedData, presentationData -> (ItemListControllerState, (ItemListNodeState, SGItemListArguments<TabOrganizerBoolSetting, AnyHashable, AnyHashable, AnyHashable, AnyHashable>)) in
        let settings = sharedData.entries[ApplicationSpecificSharedDataKeys.callListSettings]?.get(CallListSettings.self) ?? .defaultSettings

        let title = presentationData.strings.baseLanguageCode == "ru" ? "Органайзер таббара" : "Tab Bar Organizer"
        let controllerState = ItemListControllerState(
            presentationData: ItemListPresentationData(presentationData),
            title: .text(title),
            leftNavigationButton: ItemListNavigationButton(content: .text(presentationData.strings.Common_Back), style: .regular, enabled: true, action: {
                backAction?()
            }),
            rightNavigationButton: nil,
            backNavigationButton: ItemListBackButton(title: presentationData.strings.Common_Back)
        )

        let entries = tabOrganizerEntries(presentationData: presentationData, settings: settings)
        let listState = ItemListNodeState(
            presentationData: ItemListPresentationData(presentationData),
            entries: entries,
            style: .blocks,
            ensureVisibleItemTag: nil,
            initialScrollToItem: nil
        )
        return (controllerState, (listState, arguments))
    }

    let controller = ItemListController(context: context, state: signal)
    controller.setReorderEntry { (fromIndex: Int, toIndex: Int, entries: [TabOrganizerEntry]) -> Signal<Bool, NoError> in
        let reorderableListIndices = entries.enumerated().compactMap { i, e -> Int? in
            if case .reorderableRow = e { return i }; return nil
        }
        guard let fromPos = reorderableListIndices.firstIndex(of: fromIndex),
              let toPos = reorderableListIndices.firstIndex(of: toIndex),
              fromPos != toPos,
              reorderableListIndices.count >= 2 else { return .single(false) }
        var tabOrder: [String] = entries.compactMap { e in
            if case .reorderableRow(_, _, _, let id, _) = e, let tabId = id as? String { return tabId }; return nil
        }
        guard tabOrder.count == reorderableListIndices.count else { return .single(false) }
        let moved = tabOrder.remove(at: fromPos)
        tabOrder.insert(moved, at: toPos)
        let _ = updateCallListSettingsInteractively(accountManager: context.sharedContext.accountManager) { current in
            current.withUpdatedTabOrder(tabOrder)
        }.start()
        reloadPromise.set(true)
        return .single(true)
    }
    controller.setReorderCompleted { (_: [TabOrganizerEntry]) in
        onSave()
    }
    backAction = { [weak controller] in
        guard let controller else { return }
        if let nav = controller.navigationController, nav.viewControllers.count > 1 {
            nav.popViewController(animated: true)
        } else {
            (controller.navigationController ?? controller).dismiss(animated: true)
        }
    }
    return controller
}