// gets all quotes from the database and returns them in a list

import 'package:flutter/material.dart';

import 'package:frontend/model/quote.dart';
import 'package:frontend/repository/quote_repository.dart';
import 'dart:math';

class QuoteProvider extends ChangeNotifier {
  List<Quote> _quotes = [];
  Set<String> _authors = {};
  bool _loading = false;
  String? _error;

  List<Quote> get quotes => _quotes;
  Set<String> get authors => _authors;
  bool get loading => _loading;
  String? get error => _error;
  List<Quote> get filteredQuotes {
    final query = filterController.text.toLowerCase();

    final filtered = _quotes.where((quote) {
      switch (filterBy) {
        case 0:
          return quote.author.toLowerCase().contains(query);
        case 1:
          return quote.body.toLowerCase().contains(query);
        default:
          return true;
      }
    }).toList();

    // sort descending
    filtered.sort((a, b) => b.id.compareTo(a.id));

    return filtered;
  }

  final QuoteRepository repo = QuoteRepository();

  int filterBy = 0; // 0 = by author, 1 = by quote
  var filterController = TextEditingController(text: '');

  void clearFilterController() {
    filterController.text = '';
  }

  Quote randomQuote = Quote(
    id: 0,
    body: "quote text",
    author: "dummy"
  );
  bool randomQuoteDeterminator = true;
  String get randomQuoteText { 
    if (randomQuoteDeterminator) {
      return randomQuote.body;
    } else {
      return randomQuote.author;
    }
  }

  void flipRandomQuote() {
    randomQuoteDeterminator = !randomQuoteDeterminator;
    notifyListeners();
  }

  void nextRandomQuote() {
    final random = Random();
    randomQuote = filteredQuotes[random.nextInt(filteredQuotes.length)];
    notifyListeners();
  }

  void filterQuotes() {
    notifyListeners();
  }

  QuoteProvider() {
    readQuotes(); // auto-load on creation
  }

  void populateAuthors() {
    _authors = {};
    for (var i = 0; i < quotes.length; i++) {
      _authors.add(quotes[i].author);
    }
  }

  void setFilterBy(int value) {
    filterBy = value;
    notifyListeners();
  }

  Future<void> readQuotes() async {
    _loading = true;
    _error = null;
    notifyListeners();

    try {
      _quotes = await repo.readQuotes();
    } catch (e) {
      _error = e.toString();
    }

    populateAuthors();

    _loading = false;
    notifyListeners();
  }

  Future<void> createQuote(Quote quote) async {
    final newQuote = await repo.createQuote(quote);
    _quotes.add(newQuote);
    populateAuthors();
    notifyListeners();
  }

  Future<void> updateQuote(Quote quote) async {
    try {
      _loading = true;
      notifyListeners();

      final updated = await repo.updateQuote(quote);

      final index = _quotes.indexWhere((q) => q.id == quote.id);
      if (index != -1) {
        final oldAuthor = _quotes[index].author;
        final newList = List<Quote>.from(_quotes);
        newList[index] = updated;
        _quotes = newList;
        Map<String, int> authorMap = {};
        for (final q in quotes) {
          authorMap[q.author] = (authorMap[q.author] ?? 0) + 1;
        }
        if (authorMap[oldAuthor] == 1) {
          _authors.remove(oldAuthor);
        }
        _authors.add(updated.author);
      }
    } finally {      
      _loading = false;
      notifyListeners();
    }
  }

  Future<void> deleteQuote(Quote quote) async {
    await repo.deleteQuote(quote);

    _quotes.removeWhere((q) => q.id == quote.id);
    populateAuthors();
    notifyListeners();
  }
}