Sportstime/SportsTime/Features/Polls/ViewModels/PollCreationViewModel.swift

//
//  PollCreationViewModel.swift
//  SportsTime
//
//  ViewModel for creating trip polls
//

import Foundation
import SwiftUI

@Observable
@MainActor
final class PollCreationViewModel {
    var title: String = ""
    var selectedTripIds: Set<UUID> = []
    var isLoading = false
    var error: PollError?
    var createdPoll: TripPoll?

    private let pollService = PollService.shared

    var canCreate: Bool {
        !title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
            && selectedTripIds.count >= 2
    }

    var validationMessage: String? {
        if title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
            return "Enter a title for your poll"
        }
        if selectedTripIds.count < 2 {
            return "Select at least 2 trips to create a poll"
        }
        return nil
    }

    func createPoll(trips: [Trip]) async {
        guard canCreate else { return }

        isLoading = true
        error = nil

        do {
            let userId = try await pollService.getCurrentUserRecordID()
            let selectedTrips = trips.filter { selectedTripIds.contains($0.id) }

            let poll = TripPoll(
                title: title.trimmingCharacters(in: .whitespacesAndNewlines),
                ownerId: userId,
                tripSnapshots: selectedTrips
            )

            createdPoll = try await pollService.createPoll(poll)
        } catch let pollError as PollError {
            error = pollError
        } catch {
            self.error = .unknown(error)
        }

        isLoading = false
    }

    func toggleTrip(_ tripId: UUID) {
        if selectedTripIds.contains(tripId) {
            selectedTripIds.remove(tripId)
        } else {
            selectedTripIds.insert(tripId)
        }
    }

    func reset() {
        title = ""
        selectedTripIds = []
        error = nil
        createdPoll = nil
    }
}