AnalyticsService.swift

//
//  AnalyticsService.swift
//  Plotwist
//

import Foundation

// MARK: - Analytics Events
enum AnalyticsEvent {
  // Auth
  case signUp(method: String)
  case login(method: String)
  case logout
  
  // App Lifecycle
  case appOpen
  
  // Onboarding
  case onboardingStart
  case onboardingContentTypeSelected(type: String)
  case onboardingGenresSelected(count: Int)
  case onboardingTitleAdded(tmdbId: Int, mediaType: String, status: String)
  case onboardingComplete(titlesAdded: Int)
  
  // Screens
  case screenView(name: String)
  
  // Content Discovery
  case searchPerformed(query: String, resultsCount: Int)
  case mediaViewed(tmdbId: Int, mediaType: String, title: String)
  case categoryViewed(category: String, subcategory: String)
  
  // Core Actions
  case mediaStatusChanged(tmdbId: Int, mediaType: String, status: String, source: String)
  case mediaStatusRemoved(tmdbId: Int, mediaType: String)
  case rewatchAdded(tmdbId: Int, mediaType: String, count: Int)
  case episodeCheckin(showId: Int, season: Int, episode: Int)
  
  // Reviews
  case reviewStarted(tmdbId: Int, mediaType: String)
  case reviewSubmitted(tmdbId: Int, mediaType: String, rating: Double, hasText: Bool)
  case reviewDeleted(tmdbId: Int, mediaType: String)
  
  // Stats
  case statsView
  
  // Feedback
  case feedbackOpen(contextScreen: String)
  case feedbackSubmit(type: String)
  
  // Error tracking
  case errorAPI(endpoint: String, statusCode: Int)
  
  // Engagement
  case shareContent(tmdbId: Int, mediaType: String)
  case profileViewed(userId: String, isOwnProfile: Bool)
  
  var name: String {
    switch self {
    case .signUp: return "sign_up"
    case .login: return "login"
    case .logout: return "logout"
    case .appOpen: return "app_open"
    case .onboardingStart: return "onboarding_start"
    case .onboardingContentTypeSelected: return "onboarding_content_type"
    case .onboardingGenresSelected: return "onboarding_genres"
    case .onboardingTitleAdded: return "onboarding_title_added"
    case .onboardingComplete: return "onboarding_complete"
    case .screenView: return "screen_view"
    case .searchPerformed: return "search"
    case .mediaViewed: return "media_viewed"
    case .categoryViewed: return "category_viewed"
    case .mediaStatusChanged: return "status_changed"
    case .mediaStatusRemoved: return "status_removed"
    case .rewatchAdded: return "rewatch_added"
    case .episodeCheckin: return "episode_checkin"
    case .reviewStarted: return "review_started"
    case .reviewSubmitted: return "review_submitted"
    case .reviewDeleted: return "review_deleted"
    case .statsView: return "stats_view"
    case .feedbackOpen: return "feedback_open"
    case .feedbackSubmit: return "feedback_submit"
    case .errorAPI: return "error_api"
    case .shareContent: return "share"
    case .profileViewed: return "profile_viewed"
    }
  }
  
  var properties: [String: Any] {
    switch self {
    case .signUp(let method), .login(let method):
      return ["method": method]
    case .logout, .appOpen, .onboardingStart, .statsView:
      return [:]
    case .onboardingContentTypeSelected(let type):
      return ["content_type": type]
    case .onboardingGenresSelected(let count):
      return ["genres_count": count]
    case .onboardingTitleAdded(let tmdbId, let mediaType, let status):
      return ["tmdb_id": tmdbId, "media_type": mediaType, "status": status]
    case .onboardingComplete(let titlesAdded):
      return ["titles_added": titlesAdded]
    case .screenView(let name):
      return ["screen_name": name]
    case .searchPerformed(let query, let resultsCount):
      return ["query": query, "results_count": resultsCount]
    case .mediaViewed(let tmdbId, let mediaType, let title):
      return ["tmdb_id": tmdbId, "media_type": mediaType, "title": title]
    case .categoryViewed(let category, let subcategory):
      return ["category": category, "subcategory": subcategory]
    case .mediaStatusChanged(let tmdbId, let mediaType, let status, let source):
      return ["tmdb_id": tmdbId, "media_type": mediaType, "status": status, "source": source]
    case .mediaStatusRemoved(let tmdbId, let mediaType):
      return ["tmdb_id": tmdbId, "media_type": mediaType]
    case .rewatchAdded(let tmdbId, let mediaType, let count):
      return ["tmdb_id": tmdbId, "media_type": mediaType, "rewatch_count": count]
    case .episodeCheckin(let showId, let season, let episode):
      return ["show_id": showId, "season": season, "episode": episode]
    case .reviewStarted(let tmdbId, let mediaType):
      return ["tmdb_id": tmdbId, "media_type": mediaType]
    case .reviewSubmitted(let tmdbId, let mediaType, let rating, let hasText):
      return ["tmdb_id": tmdbId, "media_type": mediaType, "rating": rating, "has_text": hasText]
    case .reviewDeleted(let tmdbId, let mediaType):
      return ["tmdb_id": tmdbId, "media_type": mediaType]
    case .feedbackOpen(let contextScreen):
      return ["context_screen": contextScreen]
    case .feedbackSubmit(let type):
      return ["type": type]
    case .errorAPI(let endpoint, let statusCode):
      return ["endpoint": endpoint, "status_code": statusCode]
    case .shareContent(let tmdbId, let mediaType):
      return ["tmdb_id": tmdbId, "media_type": mediaType]
    case .profileViewed(let userId, let isOwnProfile):
      return ["user_id": userId, "is_own_profile": isOwnProfile]
    }
  }
}

// MARK: - Analytics Service
class AnalyticsService {
  static let shared = AnalyticsService()

  private var apiKey: String { Env.posthogAPIKey }
  private var ingestionURL: String {
    let host = Env.posthogHost
    if host.contains("app.posthog.com") {
      return "https://us.i.posthog.com/i/v0/e/"
    }
    let base = host.hasSuffix("/") ? String(host.dropLast()) : host
    return "\(base)/i/v0/e/"
  }

  private var distinctId: String {
    if let userId = UserDefaults.standard.string(forKey: "analyticsUserId") {
      return userId
    }
    if let deviceId = UserDefaults.standard.string(forKey: "analyticsDeviceId") {
      return deviceId
    }
    let newDeviceId = UUID().uuidString
    UserDefaults.standard.set(newDeviceId, forKey: "analyticsDeviceId")
    return newDeviceId
  }
  
  private init() {}
  
  func track(_ event: AnalyticsEvent) {
    #if DEBUG
    print("📊 Analytics: \(event.name) - \(event.properties)")
    #endif
    sendEvent(name: event.name, properties: event.properties)
  }
  
  func identify(userId: String, properties: [String: Any] = [:]) {
    let previousId = UserDefaults.standard.string(forKey: "analyticsDeviceId")
    UserDefaults.standard.set(userId, forKey: "analyticsUserId")
    #if DEBUG
    print("📊 Analytics: Identified user \(userId)")
    #endif
    sendIdentify(userId: userId, previousAnonymousId: previousId, properties: properties)
  }
  
  func reset() {
    UserDefaults.standard.removeObject(forKey: "analyticsUserId")
    #if DEBUG
    print("📊 Analytics: Reset user")
    #endif
  }
  
  /// Convenience for tracking API errors
  static func trackAPIError(endpoint: String, statusCode: Int) {
    shared.track(.errorAPI(endpoint: endpoint, statusCode: statusCode))
  }
  
  // MARK: - Private
  
  private func sendEvent(name: String, properties: [String: Any]) {
    guard !apiKey.isEmpty, !apiKey.contains("$(") else { return }
    var allProperties = properties
    allProperties["$lib"] = "ios"
    allProperties["$lib_version"] = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0"
    allProperties["$platform"] = "iOS"
    allProperties["$device_type"] = "Mobile"
    Task {
      await sendToPostHog(payload: [
        "api_key": apiKey,
        "event": name,
        "distinct_id": distinctId,
        "properties": allProperties,
        "timestamp": ISO8601DateFormatter().string(from: Date()),
      ])
    }
  }

  private func sendIdentify(userId: String, previousAnonymousId: String?, properties: [String: Any]) {
    guard !apiKey.isEmpty, !apiKey.contains("$(") else { return }
    var personProperties = properties
    personProperties["$platform"] = "iOS"
    personProperties["$lib"] = "ios"
    var identifyProperties: [String: Any] = ["$set": personProperties]
    if let previousId = previousAnonymousId, previousId != userId {
      identifyProperties["$anon_distinct_id"] = previousId
    }
    Task {
      await sendToPostHog(payload: [
        "api_key": apiKey,
        "event": "$identify",
        "distinct_id": userId,
        "properties": identifyProperties,
        "timestamp": ISO8601DateFormatter().string(from: Date()),
      ])
    }
  }

  private func sendToPostHog(payload: [String: Any]) async {
    guard let url = URL(string: ingestionURL) else { return }

    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")

    do {
      request.httpBody = try JSONSerialization.data(withJSONObject: payload)
      let (_, response) = try await URLSession.shared.data(for: request)
      #if DEBUG
      if let http = response as? HTTPURLResponse, http.statusCode != 200 {
        print("📊 Analytics HTTP \(http.statusCode): \(ingestionURL)")
      }
      #endif
    } catch {
      #if DEBUG
      print("📊 Analytics error: \(error)")
      #endif
    }
  }
}

// MARK: - SwiftUI View Extension
import SwiftUI

extension View {
  func trackScreen(_ name: String) -> some View {
    self.onAppear {
      AnalyticsService.shared.track(.screenView(name: name))
    }
  }
}