import Foundation
import SwiftUI
import Combine
import GoogleMobileAds
import AppTrackingTransparency
import AdSupport

@MainActor
class AdMobService: ObservableObject {
    // MARK: - Published Properties

    @Published var isConsentObtained = false
    @Published var canShowAds = false
    @Published var isLoading = false

    // MARK: - Ad Unit IDs

    // Test Ad Unit IDs - Replace with production IDs before release
    #if DEBUG
    static let bannerAdUnitID = "ca-app-pub-3940256099942544/2934735716"
    #else
    static let bannerAdUnitID = "ca-app-pub-XXXXXXXXXXXXXXXX/YYYYYYYYYY" // Replace with your Ad Unit ID
    #endif

    // MARK: - Initialization

    init() {
        checkConsentStatus()
    }

    // MARK: - Consent Management

    func checkConsentStatus() {
        // Check if we already have consent
        let consentStatus = UserDefaults.standard.bool(forKey: "adConsentObtained")
        isConsentObtained = consentStatus
        canShowAds = consentStatus
    }

    func requestConsent() async {
        if #available(iOS 14.5, *) {
            let status = await ATTrackingManager.requestTrackingAuthorization()

            switch status {
            case .authorized:
                isConsentObtained = true
                canShowAds = true
            case .denied, .restricted:
                // Can still show non-personalized ads
                isConsentObtained = true
                canShowAds = true
            case .notDetermined:
                // Will be asked again later
                break
            @unknown default:
                break
            }
        } else {
            // iOS 14.4 and earlier - consent assumed
            isConsentObtained = true
            canShowAds = true
        }

        UserDefaults.standard.set(isConsentObtained, forKey: "adConsentObtained")
    }

    // MARK: - GDPR Consent (UMP SDK)

    func requestGDPRConsent() async {
        // Implement UMP SDK consent flow if targeting EU users
        // This is a simplified version - full implementation requires UMP SDK

        let isEUUser = isUserInEU()

        if isEUUser {
            // Show GDPR consent dialog
            // For now, assume consent if user continues
            isConsentObtained = true
            canShowAds = true
        } else {
            isConsentObtained = true
            canShowAds = true
        }

        UserDefaults.standard.set(isConsentObtained, forKey: "adConsentObtained")
    }

    private func isUserInEU() -> Bool {
        let euCountries = [
            "AT", "BE", "BG", "HR", "CY", "CZ", "DK", "EE", "FI", "FR",
            "DE", "GR", "HU", "IE", "IT", "LV", "LT", "LU", "MT", "NL",
            "PL", "PT", "RO", "SK", "SI", "ES", "SE", "GB", "IS", "LI",
            "NO", "CH"
        ]

        let countryCode = Locale.current.region?.identifier ?? ""
        return euCountries.contains(countryCode)
    }

    // MARK: - Analytics

    func logAdImpression() {
        FirebaseService.shared.logAdImpression(adType: "banner")
    }

    func logAdClick() {
        FirebaseService.shared.logAdClick(adType: "banner")
    }
}

// MARK: - Banner Ad Coordinator

class BannerAdCoordinator: NSObject, BannerViewDelegate {
    weak var adMobService: AdMobService?

    func bannerViewDidReceiveAd(_ bannerView: BannerView) {
        print("Banner ad received")
        adMobService?.logAdImpression()
    }

    func bannerView(_ bannerView: BannerView, didFailToReceiveAdWithError error: Error) {
        print("Banner ad failed to load: \(error.localizedDescription)")
    }

    func bannerViewDidRecordImpression(_ bannerView: BannerView) {
        // Impression recorded
    }

    func bannerViewDidRecordClick(_ bannerView: BannerView) {
        adMobService?.logAdClick()
    }

    func bannerViewWillPresentScreen(_ bannerView: BannerView) {
        // Ad will present full screen
    }

    func bannerViewWillDismissScreen(_ bannerView: BannerView) {
        // Ad will dismiss
    }

    func bannerViewDidDismissScreen(_ bannerView: BannerView) {
        // Ad dismissed
    }
}

// MARK: - UIKit Banner View Wrapper

struct BannerAdView: UIViewRepresentable {
    @EnvironmentObject var adMobService: AdMobService

    func makeUIView(context: Context) -> BannerView {
        let bannerView = BannerView(adSize: AdSizeBanner)
        bannerView.adUnitID = AdMobService.bannerAdUnitID

        // Get root view controller
        if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene,
           let rootViewController = windowScene.windows.first?.rootViewController {
            bannerView.rootViewController = rootViewController
        }

        bannerView.delegate = context.coordinator
        bannerView.load(Request())

        return bannerView
    }

    func updateUIView(_ uiView: BannerView, context: Context) {
        // Banner updates automatically
    }

    func makeCoordinator() -> BannerAdCoordinator {
        let coordinator = BannerAdCoordinator()
        coordinator.adMobService = adMobService
        return coordinator
    }
}