import AVFoundation
import Combine
import Foundation
import GRDB
import Photos

@MainActor
final class ConversationStore: ObservableObject {
    @Published private(set) var messages: [Message] = []
    @Published var replyText = ""

    private(set) var roster: Roster
    private let client: Client

    private var messagesCancellable: AnyCancellable?

    init(roster: Roster, client: Client) {
        self.client = client
        self.roster = roster
        subscribe()
    }
}

extension ConversationStore {
    func sendMessage(_ message: String) async {
        var msg = Message.blank
        msg.from = roster.bareJid
        msg.to = roster.contactBareJid
        msg.body = message

        // store as pending on db, and send
        do {
            try await msg.save()
            try await client.sendMessage(msg)
            try await msg.setStatus(.sent)
        } catch {
            try? await msg.setStatus(.error)
        }
    }
}

extension ConversationStore {
    var attachmentsStore: AttachmentsStore {
        AttachmentsStore()
    }

    func sendMedia(_ items: [GalleryItem]) async {
        for item in items {
            Task {
                var message = Message.blank
                message.from = roster.bareJid
                message.to = roster.contactBareJid

                switch item.type {
                case .photo:
                    guard let asset = PHAsset.fetchAssets(withLocalIdentifiers: [item.id], options: nil).firstObject else { return }
                    guard let photo = try? await PHImageManager.default().getPhoto(for: asset) else { return }
                    guard let data = photo.jpegData(compressionQuality: 1.0) else { return }
                    let localName = "\(message.id)_\(UUID().uuidString).jpg"
                    let localUrl = Const.fileFolder.appendingPathComponent(localName)
                    try? data.write(to: localUrl)
                    message.contentType = .attachment(
                        Attachment(
                            type: .image,
                            localName: localName,
                            thumbnailName: nil,
                            remotePath: nil
                        )
                    )
                    try? await message.save()

                case .video:
                    guard let asset = PHAsset.fetchAssets(withLocalIdentifiers: [item.id], options: nil).firstObject else { return }
                    guard let video = try? await PHImageManager.default().getVideo(for: asset) else { return }
                    // swiftlint:disable:next force_cast
                    let assetURL = video as! AVURLAsset
                    let url = assetURL.url
                    let localName = "\(message.id)_\(UUID().uuidString).mov"
                    let localUrl = Const.fileFolder.appendingPathComponent(localName)
                    try? FileManager.default.copyItem(at: url, to: localUrl)
                    message.contentType = .attachment(
                        Attachment(
                            type: .video,
                            localName: localName,
                            thumbnailName: nil,
                            remotePath: nil
                        )
                    )
                    try? await message.save()
                }

                await upload(message)
            }
        }
    }

    func sendCaptured(_ data: Data, _ type: GalleryMediaType) async {
        // save locally and make message
        var message = Message.blank
        message.from = roster.bareJid
        message.to = roster.contactBareJid

        let localName: String
        let msgType: AttachmentType
        do {
            (localName, msgType) = try await Task {
                // local name
                let fileId = UUID().uuidString
                let localName: String
                let msgType: AttachmentType
                switch type {
                case .photo:
                    localName = "\(message.id)_\(fileId).jpg"
                    msgType = .image

                case .video:
                    localName = "\(message.id)_\(fileId).mov"
                    msgType = .video
                }

                // save
                let localUrl = Const.fileFolder.appendingPathComponent(localName)
                try data.write(to: localUrl)
                return (localName, msgType)
            }.value
        } catch {
            logIt(.error, "Can't save file for uploading: \(error)")
            return
        }

        // save message
        message.contentType = .attachment(
            Attachment(
                type: msgType,
                localName: localName,
                thumbnailName: nil,
                remotePath: nil
            )
        )
        do {
            try await message.save()
        } catch {
            logIt(.error, "Can't save message: \(error)")
            return
        }

        // upload and save
        await upload(message)
    }

    func sendDocuments(_ data: [Data], _ extensions: [String]) async {
        for (index, data) in data.enumerated() {
            Task {
                let newMessageId = UUID().uuidString
                let fileId = UUID().uuidString
                let localName = "\(newMessageId)_\(fileId).\(extensions[index])"
                let localUrl = Const.fileFolder.appendingPathComponent(localName)
                do {
                    try data.write(to: localUrl)
                } catch {
                    print("FileProcessing: Error writing document: \(error)")
                    return
                }

                var message = Message.blank
                message.from = roster.bareJid
                message.to = roster.contactBareJid
                message.contentType = .attachment(
                    Attachment(
                        type: localName.attachmentType,
                        localName: localName,
                        thumbnailName: nil,
                        remotePath: nil
                    )
                )
                do {
                    try await message.save()
                    await upload(message)
                } catch {
                    print("FileProcessing: Error saving document: \(error)")
                }
            }
        }
    }

    func sendContact(_ jidStr: String) async {
        await sendMessage("contact:\(jidStr)")
    }

    func sendLocation(_ lat: Double, _ lon: Double) async {
        await sendMessage("geo:\(lat),\(lon)")
    }

    private func upload(_ message: Message) async {
        do {
            try await message.setStatus(.pending)
            var message = message
            guard case .attachment(let attachment) = message.contentType else {
                throw ClientStoreError.invalidContentType
            }
            guard let localName = attachment.localPath else {
                throw ClientStoreError.invalidLocalName
            }
            let remotePath = try await client.uploadFile(localName)
            message.contentType = .attachment(
                Attachment(
                    type: attachment.type,
                    localName: attachment.localName,
                    thumbnailName: nil,
                    remotePath: remotePath
                )
            )
            message.body = remotePath
            message.oobUrl = remotePath
            try await message.save()
            try await client.sendMessage(message)
            try await message.setStatus(.sent)
        } catch {
            try? await message.setStatus(.error)
        }
    }

    func downloadAttachment(_ message: Message) async {
        guard case .attachment(let attachment) = message.contentType else {
            return
        }
        guard let remotePath = attachment.remotePath, let remoteUrl = URL(string: remotePath) else {
            return
        }
        do {
            let localName = "\(message.id)_\(UUID().uuidString).\(remoteUrl.lastPathComponent)"
            let localUrl = Const.fileFolder.appendingPathComponent(localName)

            // Download the file
            let (tempUrl, _) = try await URLSession.shared.download(from: remoteUrl)
            try FileManager.default.moveItem(at: tempUrl, to: localUrl)

            var message = message
            message.contentType = .attachment(
                Attachment(
                    type: attachment.type,
                    localName: localName,
                    thumbnailName: attachment.thumbnailName,
                    remotePath: remotePath
                )
            )
            try await message.save()
        } catch {
            logIt(.error, "Can't download attachment: \(error)")
        }
    }
}

extension ConversationStore {
    var contacts: [Roster] {
        get async {
            do {
                let rosters = try await Database.shared.dbQueue.read { db in
                    try Roster
                        .filter(Column("locallyDeleted") == false)
                        .fetchAll(db)
                }
                return rosters
            } catch {
                return []
            }
        }
    }
}

private extension ConversationStore {
    func subscribe() {
        messagesCancellable = ValueObservation.tracking(Message
            .filter(
                (Column("to") == roster.bareJid && Column("from") == roster.contactBareJid) ||
                    (Column("from") == roster.bareJid && Column("to") == roster.contactBareJid)
            )
            .order(Column("date").desc)
            .fetchAll
        )
        .publisher(in: Database.shared.dbQueue, scheduling: .immediate)
        .receive(on: DispatchQueue.main)
        .sink { _ in
        } receiveValue: { [weak self] messages in
            self?.messages = messages
        }
    }
}