import Combine
import Foundation
import GRDB

@MainActor
final class ClientsStore: ObservableObject {
    static let shared = ClientsStore()

    @Published private(set) var ready = false
    @Published private(set) var clients: [Client] = []

    func startFetching() {
        Task {
            let observation = ValueObservation.tracking(Credentials.fetchAll)
            do {
                for try await credentials in observation.values(in: Database.shared.dbQueue) {
                    processCredentials(credentials)
                    ready = true
                    print("Fetched \(credentials.count) credentials")
                }
            } catch {}
        }
    }

    func addNewClient(_ client: Client) {
        clients.append(client)
        Task(priority: .background) {
            try? await client.credentials.save()
        }
    }

    private func processCredentials(_ credentials: [Credentials]) {
        let existsJids = clients.map { $0.credentials.bareJid }
        let forAdd = credentials.filter { !existsJids.contains($0.bareJid) }
        let forRemove = existsJids.filter { !credentials.map { $0.bareJid }.contains($0) }

        var newClients = clients.filter { !forRemove.contains($0.credentials.bareJid) }
        newClients.append(contentsOf: forAdd.map { Client(credentials: $0) })
        clients = newClients
    }
}