// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import Foundation
import GRDB
import PromiseKit
import SessionUtilitiesKit

extension MessageSender {

    // MARK: Durable
    
    public static func send(_ db: Database, interaction: Interaction, with attachments: [SignalAttachment], in thread: SessionThread) throws {
        guard let interactionId: Int64 = interaction.id else { throw GRDBStorageError.objectNotSaved }
        // TODO: Is the 'prep' method needed anymore?
//        prep(db, attachments, for: message)
        try send(
            db,
            message: VisibleMessage.from(db, interaction: interaction),
            interactionId: interactionId,
            in: thread
        )
    }
    
    public static func send(_ db: Database, interaction: Interaction, in thread: SessionThread) throws {
        guard let interactionId: Int64 = interaction.id else { throw GRDBStorageError.objectNotSaved }
        
        return try send(db, message: VisibleMessage.from(db, interaction: interaction), interactionId: interactionId, in: thread)
    }
    
    public static func send(_ db: Database, message: Message, interactionId: Int64?, in thread: SessionThread) throws {
        
        JobRunner.add(
            db,
            job: Job(
                variant: .messageSend,
                threadId: thread.id,
                interactionId: interactionId,
                details: MessageSendJob.Details(
                    destination: try Message.Destination.from(db, thread: thread),
                    message: message
                )
            )
        )
    }

    
    public static func sendNonDurably(_ db: Database, interaction: Interaction, in thread: SessionThread) -> Promise<Void> {
        guard let interactionId: Int64 = interaction.id else {
            return Promise(error: GRDBStorageError.objectNotSaved)
        }
        
        let openGroup: OpenGroup? = try? thread.openGroup.fetchOne(db)
        let attachmentStateInfo: [Attachment.StateInfo] = (try? Attachment
            .stateInfo(interactionId: interactionId, state: .pending)
            .fetchAll(db))
            .defaulting(to: [])
        let attachmentUploadPromises: [Promise<Void>] = (try? Attachment
            .filter(ids: attachmentStateInfo.map { $0.attachmentId })
            .fetchAll(db))
            .defaulting(to: [])
            .map { attachment -> Promise<Void> in
                let (promise, seal) = Promise<Void>.pending()
                
                attachment.upload(
                    using: { data in
                        if let openGroup: OpenGroup = openGroup {
                            return OpenGroupAPIV2.upload(data, to: openGroup.room, on: openGroup.server)
                        }
                        
                        return FileServerAPIV2.upload(data)
                    },
                    encrypt: (openGroup == nil),
                    success: { seal.fulfill(()) },
                    failure: { seal.reject($0) }
                )
                
                return promise
            }
        
        return when(resolved: attachmentUploadPromises)
            .then(on: DispatchQueue.global(qos: .userInitiated)) { results -> Promise<Void> in
                let errors = results
                    .compactMap { result -> Swift.Error? in
                        if case .rejected(let error) = result { return error }
                        
                        return nil
                    }
                
                if let error = errors.first { return Promise(error: error) }
                
                return sendNonDurably(db, interaction: interaction, in: thread)
            }
    }
    
    public static func sendNonDurably(_ db: Database, _ message: VisibleMessage, with attachmentIds: [String], in thread: TSThread) -> Promise<Void> {
    }

    
    public static func sendNonDurably(_ db: Database, message: Message, interactionId: Int64?, in thread: SessionThread) throws -> Promise<Void> {
        return try MessageSender.send(
            db,
            message: message,
            to: try Message.Destination.from(db, thread: thread),
            interactionId: interactionId
        )
    }
    
    public static func sendNonDurably(_ message: VisibleMessage, with attachments: [SignalAttachment], in thread: TSThread) -> Promise<Void> {
    }
    
    public static func sendNonDurably(_ db: Database, message: Message, interactionId: Int64?, to destination: Message.Destination) throws -> Promise<Void> {
        return try MessageSender.send(
            db,
            message: message,
            to: destination,
            interactionId: interactionId
        )
    }
    
    /// This method requires the `db` value to be passed in because if it's called within a `writeAsync` completion block
    /// it will throw a "re-entrant" fatal error when attempting to write again
    public static func syncConfiguration(_ db: Database, forceSyncNow: Bool = true) throws -> Promise<Void> {
        // If we don't have a userKeyPair yet then there is no need to sync the configuration
        // as the user doesn't exist yet (this will get triggered on the first launch of a
        // fresh install due to the migrations getting run)
        guard Identity.userExists(db) else {
            return Promise(error: GRDBStorageError.generic)
        }
        
        let destination: Message.Destination = Message.Destination.contact(
            publicKey: getUserHexEncodedPublicKey(db)
        )
        let configurationMessage = try ConfigurationMessage.getCurrent(db)
        let (promise, seal) = Promise<Void>.pending()
        
        if forceSyncNow {
            try MessageSender
                .send(db, message: configurationMessage, to: destination, interactionId: nil)
                .done { seal.fulfill(()) }
                .catch { _ in seal.reject(GRDBStorageError.generic) }
                .retainUntilComplete()
        }
        else {
            JobRunner.add(
                db,
                job: Job(
                    variant: .messageSend,
                    details: MessageSendJob.Details(
                        destination: destination,
                        message: configurationMessage
                    )
                )
            )
            seal.fulfill(())
        }
        
        return promise
    }
}

extension MessageSender {
    @objc(forceSyncConfigurationNow)
    public static func objc_forceSyncConfigurationNow() {
        GRDBStorage.shared.write { db in
            try syncConfiguration(db, forceSyncNow: true).retainUntilComplete()
        }
    }
}