import 'package:flutter/material.dart';
import 'package:tm_app/core/utils/result.dart';
import 'package:tm_app/data/repositories/liked_tenders_repository.dart';
import 'package:tm_app/data/services/model/liked_tender_feedback/liked_tender_feedback.dart';
import 'package:tm_app/data/services/model/liked_tenders_response/liked_tenders_response.dart';

class LikedTendersViewModel with ChangeNotifier {
  final LikedTendersRepository likedTendersRepository;
  LikedTendersViewModel({required this.likedTendersRepository}) {
    getLikedTenders(reset: true);
  }

  bool isLoading = false;
  bool isLoadingMore = false;
  bool hasMore = true;
  String? errorMessage;
  LikedTendersResponse? data;

  int _offset = 0;
  final int _limit = 20;

  Future<void> getLikedTenders({bool reset = false}) async {
    if (!reset && (isLoadingMore || !hasMore)) {
      return;
    }

    if (reset) {
      _offset = 0;
      hasMore = true;
    }

    if (_offset == 0) {
      isLoading = true;
    } else {
      isLoadingMore = true;
    }
    errorMessage = null;
    notifyListeners();

    final result = await likedTendersRepository.getLikedTenders(
      offset: _offset,
      limit: _limit,
    );

    switch (result) {
      case Ok<LikedTendersResponse>():
        final incoming = result.value;
        final incomingList = incoming.data?.feedback ?? [];

        if (reset || data == null) {
          data = incoming;
        } else {
          final existingList = data!.data!.feedback ?? [];
          final combined = List<LikedTenderFeedback>.of(existingList)
            ..addAll(incomingList);

          final newMeta = incoming.data?.meta ?? data!.data!.meta;

          data = data!.copyWith(
            data: data!.data!.copyWith(feedback: combined, meta: newMeta),
          );
        }

        // چون offset بر اساس limit حرکت می‌کنه
        hasMore = incomingList.length == _limit;
        _offset += _limit;

        errorMessage = null;
        break;

      case Error<LikedTendersResponse>():
        errorMessage = result.error.toString();
        break;
    }

    isLoading = false;
    isLoadingMore = false;
    notifyListeners();
  }

  Future<void> loadMoreIfNeeded() async {
    if (isLoadingMore || !hasMore) {
      return;
    }
    await getLikedTenders(reset: false);
  }

  void removeTenderById(String id) {
    final current = data;
    final list = current?.data?.feedback;
    if (current == null || list == null) {
      return;
    }

    final List<LikedTenderFeedback> updatedList = List<LikedTenderFeedback>.of(
      list,
    )..removeWhere((e) => e.id == id);

    final updatedMeta = current.data?.meta?.copyWith(total: updatedList.length);

    data = current.copyWith(
      data: current.data?.copyWith(feedback: updatedList, meta: updatedMeta),
    );

    notifyListeners();
  }
}