import "dart:async";

import "package:flutter/material.dart";
import "package:quotegen_client/services/quote_api_v2.dart";


class SessionProvider extends ChangeNotifier {

  String? currentSessionId;
  bool isLoading = true;
  bool canRender = true;

  Timer? _renderEnableTimer;
  int _submitCount = 0;


  Future<void> initializeSession(QuoteSessionRequest request) async {
    try {
      QuoteSession session = await QuoteGeneratorApiV2.createSession(request);
      currentSessionId = session.id;
      print("Session created: ${session.id}");
    } catch (e) {
      print("Failed to creat session: $e");
    }
  }

  void setLoaded() {
    isLoading = false;
    notifyListeners();
  }

  void onSubmit({
    String? changedField,
    required QuoteSessionRequest request,
    VoidCallback? onDebounceSettled,
  }) async {

    int currentSubmit = ++_submitCount;

    _renderEnableTimer?.cancel();
    if (canRender) {
      canRender = false;
      notifyListeners();
    }

    _renderEnableTimer = Timer(Duration(seconds: 5), () {
      canRender = true;
      notifyListeners();
    });

    await Future.delayed(Duration(milliseconds: 700));

    if (currentSubmit != _submitCount) return;

    // fire the callback so render gets cleared
    onDebounceSettled?.call();

    print("Submitting field: $changedField");

    // wait for session to be ready
    while (currentSessionId == null) {
      await Future.delayed(Duration(milliseconds: 100));
    }

    QuoteSessionRequest updateRequest;

    if (changedField == null) {
      updateRequest = request;
    } else {
      final engagement = (changedField == "engagement" || changedField.startsWith("engagement_"))
          ? _buildPartialEngagement(changedField, request)
          : null;

      final shouldClearEngagement = changedField == "engagement" && engagement == null;

      updateRequest = QuoteSessionRequest(
        displayName: changedField == "display_name" ? request.displayName : null,
        username: changedField == "handle" ? request.username : null,
        text: changedField == "content" ? request.text : null,
        timestamp: changedField == "datetime" ? request.timestamp : null,
        avatarUrl: changedField == "avatar_image" ? request.avatarUrl : null,
        imageUrl: changedField == "post_image" ? request.imageUrl : null,
        verified: changedField == "verified" ? request.verified : null,
        engagement: engagement,
        clearAvatarUrl: changedField == "avatar_image" && request.avatarUrl == null,
        clearImageUrl: changedField == "post_image" && request.imageUrl == null,
        clearEngagement: shouldClearEngagement,
      );
    }

    await QuoteGeneratorApiV2.updateSession(currentSessionId!, updateRequest);
    print("Session updated");
  }

  QuoteEngagement? _buildPartialEngagement(String field, QuoteSessionRequest req) {
    final eng = req.engagement;
    if (field == "engagement") {
      return eng;
    }
    return QuoteEngagement(
      likes: field == "engagement_likes" ? eng?.likes : null,
      retweets: field == "engagement_retweets" ? eng?.retweets : null,
      replies: field == "engagement_replies" ? eng?.replies : null,
      views: field == "engagement_views" ? eng?.views : null,
    );
  }

  @override
  void dispose() {
    _renderEnableTimer?.cancel();
    super.dispose();
  }
}