//
//  AnalyticsManager.swift
//  SportsTime
//
//  Singleton analytics manager wrapping PostHog SDK.
//  All analytics events flow through this single manager.
//

import Foundation
import PostHog
import SwiftUI

@MainActor
final class AnalyticsManager {

    // MARK: - Singleton

    static let shared = AnalyticsManager()

    // MARK: - Configuration

    private static let apiKey = "phc_SportsTime_production"
    private static let host = "https://analytics.88oakapps.com"
    private static let optOutKey = "analyticsOptedOut"
    private static let sessionReplayKey = "analytics_session_replay_enabled"
    private static let iso8601Formatter = ISO8601DateFormatter()

    // MARK: - State

    var isOptedOut: Bool {
        UserDefaults.standard.bool(forKey: Self.optOutKey)
    }

    var sessionReplayEnabled: Bool {
        get {
            if UserDefaults.standard.object(forKey: Self.sessionReplayKey) == nil {
                return true
            }
            return UserDefaults.standard.bool(forKey: Self.sessionReplayKey)
        }
        set {
            UserDefaults.standard.set(newValue, forKey: Self.sessionReplayKey)
            if newValue {
                PostHogSDK.shared.startSessionRecording()
            } else {
                PostHogSDK.shared.stopSessionRecording()
            }
        }
    }

    private var isConfigured = false

    // MARK: - Initialization

    private init() {}

    // MARK: - Setup

    func configure() {
        guard !isConfigured else { return }

        let config = PostHogConfig(apiKey: Self.apiKey, host: Self.host)

        // Auto-capture
        config.captureElementInteractions = true
        config.captureApplicationLifecycleEvents = true
        config.captureScreenViews = true

        // Session replay
        config.sessionReplay = sessionReplayEnabled
        config.sessionReplayConfig.maskAllTextInputs = true
        config.sessionReplayConfig.maskAllImages = false
        config.sessionReplayConfig.captureNetworkTelemetry = true
        config.sessionReplayConfig.screenshotMode = true // Required for SwiftUI

        // Respect user opt-out preference
        if isOptedOut {
            config.optOut = true
        }

        #if DEBUG
        config.debug = true
        config.flushAt = 1
        #endif

        PostHogSDK.shared.setup(config)
        isConfigured = true

        // Register super properties
        registerSuperProperties()
    }

    // MARK: - Super Properties

    func registerSuperProperties() {
        let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "unknown"
        let build = Bundle.main.infoDictionary?["CFBundleVersion"] as? String ?? "unknown"
        let device = UIDevice.current.model
        let osVersion = UIDevice.current.systemVersion
        let isPro = StoreManager.shared.isPro
        let animationsEnabled = DesignStyleManager.shared.animationsEnabled

        // Load selected sports from UserDefaults
        let selectedSports = UserDefaults.standard.stringArray(forKey: "selectedSports") ?? Sport.supported.map(\.rawValue)

        // Keep super-property keys aligned with Feels so dashboards can compare apps 1:1.
        PostHogSDK.shared.register([
            "app_version": version,
            "build_number": build,
            "device_model": device,
            "os_version": osVersion,
            "is_pro": isPro,
            "animations_enabled": animationsEnabled,
            "selected_sports": selectedSports,
            "theme": "n/a",
            "icon_pack": "n/a",
            "voting_layout": "n/a",
            "day_view_style": "n/a",
            "mood_shape": "n/a",
            "personality_pack": "n/a",
            "privacy_lock_enabled": false,
            "healthkit_enabled": false,
            "days_filter_count": 0,
            "days_filter_all": false,
        ])
    }

    func updateSuperProperties() {
        registerSuperProperties()
    }

    // MARK: - Event Tracking

    func track(_ event: AnalyticsEvent) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture(event.name, properties: event.properties)
    }

    // MARK: - Screen Tracking (manual supplement to auto-capture)

    func trackScreen(_ screenName: String, properties: [String: Any]? = nil) {
        guard isConfigured else { return }
        var props: [String: Any] = ["screen_name": screenName]
        if let properties { props.merge(properties) { _, new in new } }

        #if DEBUG
        print("[Analytics] screen_viewed: \(screenName)")
        #endif
        PostHogSDK.shared.capture("screen_viewed", properties: props)
    }

    // MARK: - Subscription Funnel

    func trackPaywallViewed(source: String) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture("paywall_viewed", properties: [
            "source": source
        ])
    }

    func trackPurchaseStarted(productId: String, source: String) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture("purchase_started", properties: [
            "product_id": productId,
            "source": source
        ])
    }

    func trackPurchaseCompleted(productId: String, source: String) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture("purchase_completed", properties: [
            "product_id": productId,
            "source": source
        ])
    }

    func trackPurchaseFailed(productId: String?, source: String, error: String) {
        guard isConfigured else { return }
        var props: [String: Any] = [
            "source": source,
            "error": error
        ]
        if let productId {
            props["product_id"] = productId
        }
        PostHogSDK.shared.capture("purchase_failed", properties: props)
    }

    func trackPurchaseRestored(source: String) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture("purchase_restored", properties: [
            "source": source
        ])
    }

    // MARK: - Opt In / Opt Out

    func optIn() {
        UserDefaults.standard.set(false, forKey: Self.optOutKey)
        if isConfigured {
            PostHogSDK.shared.optIn()
            PostHogSDK.shared.capture("analytics_toggled", properties: ["enabled": true])
        }
    }

    func optOut() {
        if isConfigured {
            PostHogSDK.shared.capture("analytics_toggled", properties: ["enabled": false])
        }
        UserDefaults.standard.set(true, forKey: Self.optOutKey)
        if isConfigured {
            PostHogSDK.shared.optOut()
        }
    }

    // MARK: - Person Properties (subscription segmentation)

    func updateSubscriptionStatus(_ status: String, type: String) {
        guard isConfigured else { return }
        PostHogSDK.shared.capture("$set", properties: [
            "$set": [
                "subscription_status": status,
                "subscription_type": type
            ]
        ])
    }

    func trackSubscriptionStatusObserved(
        status: String,
        type: String,
        source: String,
        isSubscribed: Bool,
        hasFullAccess: Bool,
        productId: String?,
        willAutoRenew: Bool?,
        isInGracePeriod: Bool?,
        trialDaysRemaining: Int?,
        expirationDate: Date?
    ) {
        guard isConfigured else { return }

        var props: [String: Any] = [
            "status": status,
            "type": type,
            "source": source,
            "is_subscribed": isSubscribed,
            "has_full_access": hasFullAccess
        ]

        if let productId {
            props["product_id"] = productId
        }
        if let willAutoRenew {
            props["will_auto_renew"] = willAutoRenew
        }
        if let isInGracePeriod {
            props["is_in_grace_period"] = isInGracePeriod
        }
        if let trialDaysRemaining {
            props["trial_days_remaining"] = trialDaysRemaining
        }
        if let expirationDate {
            props["expiration_date"] = Self.iso8601Formatter.string(from: expirationDate)
        }

        PostHogSDK.shared.capture("subscription_status_changed", properties: props)
        updateSubscriptionStatus(status, type: type)
    }

    // MARK: - Lifecycle

    func flush() {
        guard isConfigured else { return }
        PostHogSDK.shared.flush()
    }

    func reset() {
        guard isConfigured else { return }
        PostHogSDK.shared.reset()
    }
}

// MARK: - SwiftUI Screen Tracking Modifier

struct ScreenTrackingModifier: ViewModifier {
    let screenName: String
    let properties: [String: Any]?

    func body(content: Content) -> some View {
        content.onAppear {
            AnalyticsManager.shared.trackScreen(screenName, properties: properties)
        }
    }
}

extension View {
    func trackScreen(_ screenName: String, properties: [String: Any]? = nil) -> some View {
        modifier(ScreenTrackingModifier(screenName: screenName, properties: properties))
    }
}