import Foundation
#if os(macOS)
    import PostboxMac
    import SwiftSignalKitMac
#else
    import Postbox
    import SwiftSignalKit
#endif

public func currentlySuggestedLocalization(network: Network, extractKeys: [String]) -> Signal<SuggestedLocalizationInfo?, NoError> {
    return network.request(Api.functions.help.getConfig())
        |> retryRequest
        |> mapToSignal { result -> Signal<SuggestedLocalizationInfo?, NoError> in
            switch result {
                case let .config(flags, date, expires, testMode, thisDc, dcOptions, chatSizeMax, megagroupSizeMax, forwardedCountMax, onlineUpdatePeriodMs, offlineBlurTimeoutMs, offlineIdleTimeoutMs, onlineCloudTimeoutMs, notifyCloudDelayMs, notifyDefaultDelayMs, chatBigSize, pushChatPeriodMs, pushChatLimit, savedGifsLimit, editTimeLimit, ratingEDecay, stickersRecentLimit, tmpSessions, pinnedDialogsCountMax, callReceiveTimeoutMs, callRingTimeoutMs, callConnectTimeoutMs, callPacketTimeoutMs, meUrlPrefix, suggestedLangCode, _, disabledFeatures):
                    if let suggestedLangCode = suggestedLangCode {
                        return suggestedLocalizationInfo(network: network, languageCode: suggestedLangCode, extractKeys: extractKeys) |> map { Optional($0) }
                    } else {
                        return .single(nil)
                    }
            }
        }
}

public func suggestedLocalizationInfo(network: Network, languageCode: String, extractKeys: [String]) -> Signal<SuggestedLocalizationInfo, NoError> {
    return combineLatest(network.request(Api.functions.langpack.getLanguages()), network.request(Api.functions.langpack.getStrings(langCode: languageCode, keys: extractKeys)))
        |> retryRequest
        |> map { languages, strings -> SuggestedLocalizationInfo in
            var entries: [LocalizationEntry] = []
            for string in strings {
                switch string {
                    case let .langPackString(key, value):
                        entries.append(.string(key: key, value: value))
                    case let .langPackStringPluralized(_, key, zeroValue, oneValue, twoValue, fewValue, manyValue, otherValue):
                        entries.append(.pluralizedString(key: key, zero: zeroValue, one: oneValue, two: twoValue, few: fewValue, many: manyValue, other: otherValue))
                    case let .langPackStringDeleted(key):
                        entries.append(.string(key: key, value: ""))
                }
            }
            var infos: [LocalizationInfo] = []
            for language in languages {
                switch language {
                    case let .langPackLanguage(name, nativeName, langCode):
                        infos.append(LocalizationInfo(languageCode: langCode, title: name, localizedTitle: nativeName))
                }
            }
            return SuggestedLocalizationInfo(languageCode: languageCode, extractedEntries: entries, availableLocalizations: infos)
        }
}

public func availableLocalizations(network: Network) -> Signal<[LocalizationInfo], NoError> {
    return network.request(Api.functions.langpack.getLanguages())
        |> retryRequest
        |> map { languages -> [LocalizationInfo] in
            var infos: [LocalizationInfo] = []
            for language in languages {
                switch language {
                case let .langPackLanguage(name, nativeName, langCode):
                    infos.append(LocalizationInfo(languageCode: langCode, title: name, localizedTitle: nativeName))
                }
            }
            return infos
        }
}

public func downloadLocalization(network: Network, languageCode: String) -> Signal<Localization, NoError> {
    return network.request(Api.functions.langpack.getLangPack(langCode: languageCode))
        |> retryRequest
        |> map { result -> Localization in
            let version: Int32
            var entries: [LocalizationEntry] = []
            switch result {
                case let .langPackDifference(_, _, versionValue, strings):
                    version = versionValue
                    for string in strings {
                        switch string {
                            case let .langPackString(key, value):
                                entries.append(.string(key: key, value: value))
                            case let .langPackStringPluralized(_, key, zeroValue, oneValue, twoValue, fewValue, manyValue, otherValue):
                                entries.append(.pluralizedString(key: key, zero: zeroValue, one: oneValue, two: twoValue, few: fewValue, many: manyValue, other: otherValue))
                            case let .langPackStringDeleted(key):
                                entries.append(.string(key: key, value: ""))
                        }
                    }
            }
            
            return Localization(version: version, entries: entries)
        }
}

public func downoadAndApplyLocalization(postbox: Postbox, network: Network, languageCode: String) -> Signal<Void, NoError> {
    return downloadLocalization(network: network, languageCode: languageCode)
        |> mapToSignal { language -> Signal<Void, NoError> in
            return postbox.modify { modifier -> Void in
                modifier.updatePreferencesEntry(key: PreferencesKeys.localizationSettings, { _ in
                    return LocalizationSettings(languageCode: languageCode, localization: language)
                })
                
                network.context.updateApiEnvironment { current in
                    return current?.withUpdatedLangPackCode(languageCode)
                }
            }
        }
}