Swiftgram/submodules/SettingsUI/Sources/Language Selection/TranslatonSettingsController.swift

import Foundation
import UIKit
import Display
import SwiftSignalKit
import Postbox
import TelegramCore
import TelegramPresentationData
import TelegramUIPreferences
import ItemListUI
import PresentationDataUtils
import TelegramStringFormatting
import AccountContext
import TranslateUI

private final class TranslationSettingsControllerArguments {
    let context: AccountContext
    let updateLanguageSelected: (String, Bool) -> Void
    
    init(context: AccountContext, updateLanguageSelected: @escaping (String, Bool) -> Void) {
        self.context = context
        self.updateLanguageSelected = updateLanguageSelected
    }
}

private enum TranslationSettingsControllerSection: Int32 {
    case languages
}

private enum TranslationSettingsControllerEntry: ItemListNodeEntry {
    case language(Int32, PresentationTheme, String, String,  Bool, String)
   
    var section: ItemListSectionId {
        switch self {
        case .language:
            return TranslationSettingsControllerSection.languages.rawValue
        }
    }
    
    var stableId: Int32 {
        switch self {
            case let .language(index, _, _, _, _, _):
                return index
        }
    }
    
    static func ==(lhs: TranslationSettingsControllerEntry, rhs: TranslationSettingsControllerEntry) -> Bool {
        switch lhs {
            case let .language(lhsIndex, lhsTheme, lhsTitle, lhsSubtitle, lhsValue, lhsCode):
                if case let .language(rhsIndex, rhsTheme, rhsTitle, rhsSubtitle, rhsValue, rhsCode) = rhs, lhsIndex == rhsIndex, lhsTheme === rhsTheme, lhsTitle == rhsTitle, lhsSubtitle == rhsSubtitle, lhsValue == rhsValue, lhsCode == rhsCode {
                    return true
                } else {
                    return false
                }
        }
    }
    
    static func <(lhs: TranslationSettingsControllerEntry, rhs: TranslationSettingsControllerEntry) -> Bool {
        return lhs.stableId < rhs.stableId
    }
    
    func item(presentationData: ItemListPresentationData, arguments: Any) -> ListViewItem {
        let arguments = arguments as! TranslationSettingsControllerArguments
        switch self {
            case let .language(_, _, title, subtitle, value, code):
                return LocalizationListItem(presentationData: presentationData, id: code, title: title, subtitle: subtitle, checked: value, activity: false, loading: false, editing: LocalizationListItemEditing(editable: false, editing: false, revealed: false, reorderable: false), sectionId: self.section, alwaysPlain: false, action: {
                    arguments.updateLanguageSelected(code, !value)
                }, setItemWithRevealedOptions: { _, _ in }, removeItem: { _ in })
        }
    }
}

private func translationSettingsControllerEntries(theme: PresentationTheme, strings: PresentationStrings, settings: TranslationSettings, languages: [(String, String, String)]) -> [TranslationSettingsControllerEntry] {
    var entries: [TranslationSettingsControllerEntry] = []
  
    var index: Int32 = 0
    var selectedLanguages: Set<String>
    if let ignoredLanguages = settings.ignoredLanguages {
        selectedLanguages = Set(ignoredLanguages)
    } else {
        selectedLanguages = Set([strings.baseLanguageCode])
    }
    for (code, title, subtitle) in languages {
        entries.append(.language(index, theme, title, subtitle, selectedLanguages.contains(code), code))
        index += 1
    }
  
    return entries
}

public func translationSettingsController(context: AccountContext) -> ViewController {
    let actionsDisposable = DisposableSet()
    
    let presentationData = context.sharedContext.currentPresentationData.with { $0 }
    let interfaceLanguageCode = presentationData.strings.baseLanguageCode
    
    let arguments = TranslationSettingsControllerArguments(context: context, updateLanguageSelected: { code, value in
        let _ = updateTranslationSettingsInteractively(accountManager: context.sharedContext.accountManager, { current in
            var updated = current
            var updatedIgnoredLanguages = updated.ignoredLanguages ?? []
            if value {
                if current.ignoredLanguages == nil {
                    updatedIgnoredLanguages.append(interfaceLanguageCode)
                }
                if !updatedIgnoredLanguages.contains(code) {
                    updatedIgnoredLanguages.append(code)
                }
            } else {
                updatedIgnoredLanguages.removeAll(where: { $0 == code })
            }
            updated = updated.withUpdatedIgnoredLanguages(updatedIgnoredLanguages)
            return updated
        }).start()
    })
    
    let enLocale = Locale(identifier: "en")
    var languages: [(String, String, String)] = []
    var addedLanguages = Set<String>()
    for code in popularTranslationLanguages {
        if let title = enLocale.localizedString(forLanguageCode: code) {
            let languageLocale = Locale(identifier: code)
            let subtitle = languageLocale.localizedString(forLanguageCode: code) ?? title
            let value = (code, title.capitalized, subtitle.capitalized)
            if code == interfaceLanguageCode {
                languages.insert(value, at: 0)
            } else {
                languages.append(value)
            }
            addedLanguages.insert(code)
        }
    }

    for code in supportedTranslationLanguages {
        if !addedLanguages.contains(code), let title = enLocale.localizedString(forLanguageCode: code) {
            let languageLocale = Locale(identifier: code)
            let subtitle = languageLocale.localizedString(forLanguageCode: code) ?? title
            let value = (code, title.capitalized, subtitle.capitalized)
            if code == interfaceLanguageCode {
                languages.insert(value, at: 0)
            } else {
                languages.append(value)
            }
        }
    }

    let sharedData = context.sharedContext.accountManager.sharedData(keys: [ApplicationSpecificSharedDataKeys.translationSettings])
    let signal = combineLatest(queue: Queue.mainQueue(), context.sharedContext.presentationData, sharedData)
    |> map { presentationData, sharedData -> (ItemListControllerState, (ItemListNodeState, Any)) in
        let settings = sharedData.entries[ApplicationSpecificSharedDataKeys.translationSettings]?.get(TranslationSettings.self) ?? TranslationSettings.defaultSettings
        let controllerState = ItemListControllerState(presentationData: ItemListPresentationData(presentationData), title: .text(presentationData.strings.DoNotTranslate_Title), leftNavigationButton: nil, rightNavigationButton: nil, backNavigationButton: ItemListBackButton(title: presentationData.strings.Common_Back))
        let listState = ItemListNodeState(presentationData: ItemListPresentationData(presentationData), entries: translationSettingsControllerEntries(theme: presentationData.theme, strings: presentationData.strings, settings: settings, languages: languages), style: .blocks, animateChanges: false)
        
        return (controllerState, (listState, arguments))
    }
    |> afterDisposed {
        actionsDisposable.dispose()
    }
    
    let controller = ItemListController(context: context, state: signal)
    controller.alwaysSynchronous = true
    return controller
}