//
// Copyright 2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//

import SignalServiceKit
import SignalUI

public class NotificationActionHandler: Dependencies {

    private static var callService: CallService { AppEnvironment.shared.callService }

    class func handleNotificationResponse( _ response: UNNotificationResponse, completionHandler: @escaping () -> Void) {
        AssertIsOnMainThread()
        firstly {
            try handleNotificationResponse(response)
        }.done {
            completionHandler()
        }.catch { error in
            owsFailDebug("error: \(error)")
            completionHandler()
        }
    }

    private class func handleNotificationResponse( _ response: UNNotificationResponse) throws -> Promise<Void> {
        AssertIsOnMainThread()
        owsAssertDebug(AppReadiness.isAppReady)

        let userInfo = response.notification.request.content.userInfo

        let action: AppNotificationAction

        switch response.actionIdentifier {
        case UNNotificationDefaultActionIdentifier:
            Logger.debug("default action")
            let defaultActionString = userInfo[AppNotificationUserInfoKey.defaultAction] as? String
            let defaultAction = defaultActionString.flatMap { AppNotificationAction(rawValue: $0) }
            action = defaultAction ?? .showThread
        case UNNotificationDismissActionIdentifier:
            // TODO - mark as read?
            Logger.debug("dismissed notification")
            return Promise.value(())
        default:
            if let responseAction = UserNotificationConfig.action(identifier: response.actionIdentifier) {
                action = responseAction
            } else {
                throw OWSAssertionError("unable to find action for actionIdentifier: \(response.actionIdentifier)")
            }
        }

        if DebugFlags.internalLogging {
            Logger.info("Performing action: \(action)")
        }

        switch action {
        case .callBack:
            return try callBack(userInfo: userInfo)
        case .markAsRead:
            return try markAsRead(userInfo: userInfo)
        case .reply:
            guard let textInputResponse = response as? UNTextInputNotificationResponse else {
                throw OWSAssertionError("response had unexpected type: \(response)")
            }

            return try reply(userInfo: userInfo, replyText: textInputResponse.userText)
        case .showThread:
            return try showThread(userInfo: userInfo)
        case .showMyStories:
            return showMyStories()
        case .reactWithThumbsUp:
            return try reactWithThumbsUp(userInfo: userInfo)
        case .showCallLobby:
            return try showCallLobby(userInfo: userInfo)
        case .submitDebugLogs:
            return submitDebugLogs()
        case .reregister:
            return reregister()
        case .showChatList:
            // No need to do anything.
            return .value(())
        }
    }

    // MARK: -

    private class func callBack(userInfo: [AnyHashable: Any]) throws -> Promise<Void> {
        let aciString = userInfo[AppNotificationUserInfoKey.callBackAciString] as? String
        let phoneNumber = userInfo[AppNotificationUserInfoKey.callBackPhoneNumber] as? String
        let address = SignalServiceAddress.legacyAddress(aciString: aciString, phoneNumber: phoneNumber)
        guard address.isValid else {
            throw OWSAssertionError("Missing or invalid address.")
        }
        let thread = TSContactThread.getOrCreateThread(contactAddress: address)

        callService.callUIAdapter.startAndShowOutgoingCall(thread: thread, hasLocalVideo: false)
        return Promise.value(())
    }

    private class func markAsRead(userInfo: [AnyHashable: Any]) throws -> Promise<Void> {
        return firstly {
            self.notificationMessage(forUserInfo: userInfo)
        }.then(on: DispatchQueue.global()) { (notificationMessage: NotificationMessage) in
            self.markMessageAsRead(notificationMessage: notificationMessage)
        }
    }

    private class func reply(userInfo: [AnyHashable: Any], replyText: String) throws -> Promise<Void> {
        return firstly { () -> Promise<NotificationMessage> in
            self.notificationMessage(forUserInfo: userInfo)
        }.then(on: DispatchQueue.global()) { (notificationMessage: NotificationMessage) -> Promise<Void> in
            let thread = notificationMessage.thread
            let interaction = notificationMessage.interaction
            guard (interaction is TSOutgoingMessage) || (interaction is TSIncomingMessage) else {
                throw OWSAssertionError("Unexpected interaction type.")
            }

            return firstly(on: DispatchQueue.global()) { () -> Promise<Void> in
                self.databaseStorage.write { transaction in
                    let builder: TSOutgoingMessageBuilder = .withDefaultValues(thread: thread)
                    builder.messageBody = replyText

                    // If we're replying to a group story reply, keep the reply within that context.
                    if
                        let incomingMessage = interaction as? TSIncomingMessage,
                        notificationMessage.isGroupStoryReply,
                        let storyTimestamp = incomingMessage.storyTimestamp,
                        let storyAuthorAci = incomingMessage.storyAuthorAci
                    {
                        builder.storyTimestamp = storyTimestamp
                        builder.storyAuthorAci = storyAuthorAci
                    } else {
                        // We only use the thread's DM timer for normal messages & 1:1 story
                        // replies -- group story replies last for the lifetime of the story.
                        let dmConfigurationStore = DependenciesBridge.shared.disappearingMessagesConfigurationStore
                        builder.expiresInSeconds = dmConfigurationStore.durationSeconds(for: thread, tx: transaction.asV2Read)
                    }

                    let unpreparedMessage = UnpreparedOutgoingMessage.forMessage(TSOutgoingMessage(
                        outgoingMessageWith: builder,
                        additionalRecipients: [],
                        explicitRecipients: [],
                        skippedRecipients: [],
                        transaction: transaction
                    ))
                    do {
                        let preparedMessage = try unpreparedMessage.prepare(tx: transaction)
                        return ThreadUtil.enqueueMessagePromise(message: preparedMessage, transaction: transaction)
                    } catch {
                        return Promise(error: error)
                    }
                }
            }.recover(on: DispatchQueue.global()) { error -> Promise<Void> in
                Logger.warn("Failed to send reply message from notification with error: \(error)")
                self.notificationPresenterImpl.notifyForFailedSend(inThread: thread)
                throw error
            }.then(on: DispatchQueue.global()) { () -> Promise<Void> in
                self.markMessageAsRead(notificationMessage: notificationMessage)
            }
        }
    }

    private class func showThread(userInfo: [AnyHashable: Any]) throws -> Promise<Void> {
        return firstly { () -> Promise<NotificationMessage> in
            self.notificationMessage(forUserInfo: userInfo)
        }.done(on: DispatchQueue.main) { notificationMessage in
            if notificationMessage.isGroupStoryReply {
                self.showGroupStoryReplyThread(notificationMessage: notificationMessage)
            } else {
                self.showThread(notificationMessage: notificationMessage)
            }
        }
    }

    private class func showMyStories() -> Promise<Void> {
        return Promise { future in
            AppReadiness.runNowOrWhenMainAppDidBecomeReadyAsync {
                SignalApp.shared.showMyStories(animated: UIApplication.shared.applicationState == .active)
                future.resolve()
            }
        }
    }

    private class func showThread(notificationMessage: NotificationMessage) {
        // If this happens when the app is not visible we skip the animation so the thread
        // can be visible to the user immediately upon opening the app, rather than having to watch
        // it animate in from the homescreen.
        SignalApp.shared.presentConversationAndScrollToFirstUnreadMessage(
            forThreadId: notificationMessage.thread.uniqueId,
            animated: UIApplication.shared.applicationState == .active
        )
    }

    private class func showGroupStoryReplyThread(notificationMessage: NotificationMessage) {
        guard notificationMessage.isGroupStoryReply, let storyMessage = notificationMessage.storyMessage else {
            return owsFailDebug("Unexpectedly missing story message")
        }

        guard let frontmostViewController = CurrentAppContext().frontmostViewController() else { return }

        if let replySheet = frontmostViewController as? StoryGroupReplier {
            if replySheet.storyMessage.uniqueId == storyMessage.uniqueId {
                return // we're already in the right place
            } else {
                // we need to drop the viewer before we present the new viewer
                replySheet.presentingViewController?.dismiss(animated: false) {
                    showGroupStoryReplyThread(notificationMessage: notificationMessage)
                }
                return
            }
        } else if let storyPageViewController = frontmostViewController as? StoryPageViewController {
            if storyPageViewController.currentMessage?.uniqueId == storyMessage.uniqueId {
                // we're in the right place, just pop the replies sheet
                storyPageViewController.currentContextViewController.presentRepliesAndViewsSheet()
                return
            } else {
                // we need to drop the viewer before we present the new viewer
                storyPageViewController.dismiss(animated: false) {
                    showGroupStoryReplyThread(notificationMessage: notificationMessage)
                }
                return
            }
        }

        let vc = StoryPageViewController(
            context: storyMessage.context,
            // Fresh state when coming in from a notification; no need to share.
            spoilerState: SpoilerRenderState(),
            loadMessage: storyMessage,
            action: .presentReplies
        )
        frontmostViewController.present(vc, animated: true)
    }

    private class func reactWithThumbsUp(userInfo: [AnyHashable: Any]) throws -> Promise<Void> {
        return firstly { () -> Promise<NotificationMessage> in
            self.notificationMessage(forUserInfo: userInfo)
        }.then(on: DispatchQueue.global()) { (notificationMessage: NotificationMessage) -> Promise<Void> in
            let thread = notificationMessage.thread
            let interaction = notificationMessage.interaction
            guard let incomingMessage = interaction as? TSIncomingMessage else {
                throw OWSAssertionError("Unexpected interaction type.")
            }

            return firstly(on: DispatchQueue.global()) { () -> Promise<Void> in
                self.databaseStorage.write { transaction in
                    ReactionManager.localUserReacted(
                        to: incomingMessage.uniqueId,
                        emoji: "👍",
                        isRemoving: false,
                        isHighPriority: false,
                        tx: transaction
                    )
                }
            }.recover(on: DispatchQueue.global()) { error -> Promise<Void> in
                Logger.warn("Failed to send reply message from notification with error: \(error)")
                self.notificationPresenterImpl.notifyForFailedSend(inThread: thread)
                throw error
            }.then(on: DispatchQueue.global()) { () -> Promise<Void> in
                self.markMessageAsRead(notificationMessage: notificationMessage)
            }
        }
    }

    private class func showCallLobby(userInfo: [AnyHashable: Any]) throws -> Promise<Void> {
        return firstly { () -> Promise<NotificationMessage> in
            self.notificationMessage(forUserInfo: userInfo)
        }.done(on: DispatchQueue.main) { notificationMessage in
            let thread = notificationMessage.thread
            let currentCall = Self.callService.callServiceState.currentCall

            let isCurrentCallForNotificationThread = { () -> Bool in
                switch currentCall?.mode {
                case .individual(let call) where call.thread.uniqueId == thread.uniqueId:
                    return true
                case .groupThread(let call) where call.groupThread.uniqueId == thread.uniqueId:
                    return true
                case nil, .individual, .groupThread, .callLink:
                    return false
                }
            }()

            if isCurrentCallForNotificationThread {
                WindowManager.shared.returnToCallView()
            } else if let thread = thread as? TSGroupThread, currentCall == nil {
                GroupCallViewController.presentLobby(thread: thread)
            } else {
                // If currentCall is non-nil, we can't join a call anyway, fallback to showing the thread.
                // Individual calls don't have a lobby, just show the thread.
                return self.showThread(notificationMessage: notificationMessage)
            }
        }
    }

    private class func submitDebugLogs() -> Promise<Void> {
        Promise { future in
            DebugLogs.submitLogsWithSupportTag(nil) {
                future.resolve()
            }
        }
    }

    private class func reregister() -> Promise<Void> {
        Promise { future in
            AppReadiness.runNowOrWhenMainAppDidBecomeReadyAsync {
                guard let viewController = CurrentAppContext().frontmostViewController() else {
                    Logger.error("Responding to reregister notification action without a view controller!")
                    future.resolve()
                    return
                }
                Logger.info("Reregistering from deregistered notification")
                RegistrationUtils.reregister(fromViewController: viewController)
                future.resolve()
            }
        }
    }

    private struct NotificationMessage {
        let thread: TSThread
        let interaction: TSInteraction?
        let storyMessage: StoryMessage?
        let isGroupStoryReply: Bool
        let hasPendingMessageRequest: Bool
    }

    private class func notificationMessage(forUserInfo userInfo: [AnyHashable: Any]) -> Promise<NotificationMessage> {
        firstly(on: DispatchQueue.global()) { () throws -> NotificationMessage in
            guard let threadId = userInfo[AppNotificationUserInfoKey.threadId] as? String else {
                throw OWSAssertionError("threadId was unexpectedly nil")
            }
            let messageId = userInfo[AppNotificationUserInfoKey.messageId] as? String

            return try self.databaseStorage.read { (transaction) throws -> NotificationMessage in
                guard let thread = TSThread.anyFetch(uniqueId: threadId, transaction: transaction) else {
                    throw OWSAssertionError("unable to find thread with id: \(threadId)")
                }

                let interaction: TSInteraction?
                if let messageId = messageId {
                    interaction = TSInteraction.anyFetch(uniqueId: messageId, transaction: transaction)
                } else {
                    interaction = nil
                }

                let storyMessage: StoryMessage?
                if
                    let message = interaction as? TSMessage,
                    let storyTimestamp = message.storyTimestamp?.uint64Value,
                    let storyAuthorAci = message.storyAuthorAci
                {
                    storyMessage = StoryFinder.story(timestamp: storyTimestamp, author: storyAuthorAci.wrappedAciValue, transaction: transaction)
                } else {
                    storyMessage = nil
                }

                let hasPendingMessageRequest = thread.hasPendingMessageRequest(transaction: transaction)

                return NotificationMessage(
                    thread: thread,
                    interaction: interaction,
                    storyMessage: storyMessage,
                    isGroupStoryReply: (interaction as? TSMessage)?.isGroupStoryReply == true,
                    hasPendingMessageRequest: hasPendingMessageRequest
                )
            }
        }
    }

    private class func markMessageAsRead(notificationMessage: NotificationMessage) -> Promise<Void> {
        guard let interaction = notificationMessage.interaction else {
            return Promise(error: OWSAssertionError("missing interaction"))
        }
        let (promise, future) = Promise<Void>.pending()
        self.receiptManager.markAsReadLocally(
            beforeSortId: interaction.sortId,
            thread: notificationMessage.thread,
            hasPendingMessageRequest: notificationMessage.hasPendingMessageRequest
        ) {
            future.resolve()
        }
        return promise
    }
}