import Foundation
import Observation

@Observable
@MainActor
final class WatchCardStore {
    private static let defaultCardIDKey = "WatchDefaultCardID"

    private(set) var cards: [WatchCard] = []
    var defaultCardID: UUID? {
        didSet {
            persistDefaultID()
        }
    }

    init() {
        loadDefaultID()
        WatchDesign.debugLog("WatchCardStore: Initialized, waiting for cards from iPhone")
        
        // Set up callback for when cards are received from iPhone
        WatchConnectivityService.shared.onCardsReceived = { [weak self] cards in
            self?.updateCards(cards)
        }
        
        #if targetEnvironment(simulator)
        // Load sample data on simulator since WatchConnectivity often doesn't work
        if cards.isEmpty {
            loadSimulatorSampleData()
        }
        #endif
    }
    
    #if targetEnvironment(simulator)
    private func loadSimulatorSampleData() {
        WatchDesign.debugLog("WatchCardStore: Loading simulator sample data")
        cards = [
            WatchCard(
                id: UUID(),
                displayName: "Test User",
                role: "iOS Developer",
                company: "Sample Corp",
                email: "test@example.com",
                phone: "+1 555-0123",
                website: "example.com",
                location: "San Francisco, CA",
                isDefault: true,
                qrCodeImageData: nil
            )
        ]
        defaultCardID = cards.first?.id
    }
    #endif

    var defaultCard: WatchCard? {
        guard let defaultCardID else { return cards.first(where: { $0.isDefault }) ?? cards.first }
        return cards.first(where: { $0.id == defaultCardID }) ?? cards.first(where: { $0.isDefault }) ?? cards.first
    }
    
    /// Called by WatchConnectivityService when cards are received from iPhone
    func updateCards(_ newCards: [WatchCard]) {
        WatchDesign.debugLog("WatchCardStore: Received \(newCards.count) cards from iPhone")
        cards = newCards
        
        // Update default card ID if current selection is no longer valid
        if let currentDefault = defaultCardID, !cards.contains(where: { $0.id == currentDefault }) {
            defaultCardID = cards.first(where: { $0.isDefault })?.id ?? cards.first?.id
        } else if defaultCardID == nil {
            defaultCardID = cards.first(where: { $0.isDefault })?.id ?? cards.first?.id
        }
    }

    func setDefault(_ card: WatchCard) {
        defaultCardID = card.id
    }

    private func persistDefaultID() {
        UserDefaults.standard.set(defaultCardID?.uuidString ?? "", forKey: Self.defaultCardIDKey)
    }

    private func loadDefaultID() {
        let storedValue = UserDefaults.standard.string(forKey: Self.defaultCardIDKey) ?? ""
        if let id = UUID(uuidString: storedValue) {
            defaultCardID = id
        }
    }
}