import Combine
import Foundation
import Photos
import SwiftUI

@MainActor
final class AttachmentsStore: ObservableObject {
    @Published private(set) var cameraAccessGranted = false
    @Published private(set) var galleryAccessGranted = false
    @Published private(set) var galleryItems: [GalleryItem] = []

    private let client: Client
    private let roster: Roster

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

// MARK: - Camera and Gallery access
extension AttachmentsStore {
    func checkCameraAuthorization() async {
        let status = AVCaptureDevice.authorizationStatus(for: .video)
        var isAuthorized = status == .authorized
        if status == .notDetermined {
            isAuthorized = await AVCaptureDevice.requestAccess(for: .video)
        }
        cameraAccessGranted = isAuthorized
    }

    func checkGalleryAuthorization() async {
        let status = PHPhotoLibrary.authorizationStatus()
        var isAuthorized = status == .authorized
        if status == .notDetermined {
            let req = await PHPhotoLibrary.requestAuthorization(for: .readWrite)
            isAuthorized = (req == .authorized) || (req == .limited)
        }
        galleryAccessGranted = isAuthorized
    }

    func fetchGalleryItems() async {
        guard galleryAccessGranted else { return }
        galleryItems = await GalleryItem.fetchAll()
    }
}

// MARK: - Save outgoing attachments for future uploadings
extension AttachmentsStore {
    func sendMedia(_ items: [GalleryItem]) async {
        galleryItems = []
        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()
                }
            }
        }
    }

    func sendCaptured(_ data: Data, _ type: GalleryMediaType) async {
        galleryItems = []
        // 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
        }
    }

    func sendDocuments(_ data: [Data], _ extensions: [String]) async {
        galleryItems = []
        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()
                } catch {
                    print("FileProcessing: Error saving document: \(error)")
                }
            }
        }
    }
}