//
//  SettingsViewModel.swift
//  SportsTime
//

import Foundation
import SwiftUI

@MainActor
@Observable
final class SettingsViewModel {

    // MARK: - User Preferences (persisted via UserDefaults)

    var selectedTheme: AppTheme {
        didSet {
            ThemeManager.shared.currentTheme = selectedTheme
        }
    }

    var selectedSports: Set<Sport> {
        didSet { savePreferences() }
    }

    var maxDrivingHoursPerDay: Int {
        didSet { savePreferences() }
    }

    var maxTripOptions: Int {
        didSet { savePreferences() }
    }

    // MARK: - Sync State

    private(set) var isSyncing = false
    private(set) var lastSyncDate: Date?
    private(set) var syncError: String?

    // MARK: - App Info

    let appVersion: String
    let buildNumber: String

    // MARK: - Initialization

    init() {
        // Load from UserDefaults using local variables first
        let defaults = UserDefaults.standard

        // Theme
        self.selectedTheme = ThemeManager.shared.currentTheme

        // Selected sports
        if let sportStrings = defaults.stringArray(forKey: "selectedSports") {
            self.selectedSports = Set(sportStrings.compactMap { Sport(rawValue: $0) })
        } else {
            self.selectedSports = Set(Sport.supported)
        }

        // Travel preferences
        let savedDrivingHours = defaults.integer(forKey: "maxDrivingHoursPerDay")
        self.maxDrivingHoursPerDay = savedDrivingHours == 0 ? 8 : savedDrivingHours

        let savedMaxTripOptions = defaults.integer(forKey: "maxTripOptions")
        self.maxTripOptions = savedMaxTripOptions == 0 ? 10 : savedMaxTripOptions

        // Last sync
        self.lastSyncDate = defaults.object(forKey: "lastSyncDate") as? Date

        // App info
        self.appVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0.0"
        self.buildNumber = Bundle.main.infoDictionary?["CFBundleVersion"] as? String ?? "1"
    }

    // MARK: - Actions

    func syncSchedules() async {
        isSyncing = true
        syncError = nil

        // Trigger data reload from provider
        await AppDataProvider.shared.loadInitialData()

        lastSyncDate = Date()
        UserDefaults.standard.set(lastSyncDate, forKey: "lastSyncDate")

        isSyncing = false
    }

    func toggleSport(_ sport: Sport) {
        if selectedSports.contains(sport) {
            // Don't allow removing all sports
            guard selectedSports.count > 1 else { return }
            selectedSports.remove(sport)
        } else {
            selectedSports.insert(sport)
        }
    }

    func resetToDefaults() {
        selectedTheme = .teal
        selectedSports = Set(Sport.supported)
        maxDrivingHoursPerDay = 8
        maxTripOptions = 10
    }

    // MARK: - Persistence

    private func savePreferences() {
        let defaults = UserDefaults.standard
        defaults.set(selectedSports.map(\.rawValue), forKey: "selectedSports")
        defaults.set(maxDrivingHoursPerDay, forKey: "maxDrivingHoursPerDay")
        defaults.set(maxTripOptions, forKey: "maxTripOptions")
    }
}