import 'package:appwrite/appwrite.dart';
import 'package:appwrite/models.dart';
import 'package:flutter/material.dart';
import 'package:ltx_flutter/appwrite/auth_api.dart';
import 'package:ltx_flutter/constants/constants.dart';
import 'package:intl/intl.dart';

class DatabaseAPI extends ChangeNotifier {
  Client client = Client();
  late final Account account;
  late final Databases databases;
  late final Realtime realtime;
  final AuthAPI auth = AuthAPI();

  late List<Document> _entries = [];
  bool _ready = false;

  // Getter methods
  List<Document> get entries => _entries;
  int get length => _entries.length;
  bool get ready => _ready;
  double get progress => length / total();

  final DateFormat formatter = DateFormat('yyyy-MM-dd');

  // Constructor
  DatabaseAPI() {
    init();
    getAll();
    subscribeRealtime();
  }

  init() {
    client.setEndpoint(APPWRITE_URL).setProject(APPWRITE_PROJECT_ID);
    account = Account(client);
    databases = Databases(client);
    realtime = Realtime(client);
  }

  elDate(dynamic el) {
    return formatter.format(DateTime.parse(el.data['date']));
  }

  sortByDate(entries) {
    return entries.sort(
      (a, b) => a.$id.compareTo(b.$id),
    );
  }

  subscribeRealtime() {
    final subscription = realtime.subscribe(
        ['databases.$APPWRITE_DATABASE_ID.collections.$COLLECTION.documents']);

    print("Subscribed to realtime");
    subscription.stream.listen((response) {
      String dateISO =
          formatter.format(DateTime.parse(response.payload['date']));
      if (response.events.contains(
          'databases.$APPWRITE_DATABASE_ID.collections.$COLLECTION.documents.*.update')) {
        // Entry was updated

        int entryIndex =
            _entries.indexWhere((element) => elDate(element) == dateISO);
        Document newEntry = _entries[entryIndex];
        newEntry.data['hours'] = response.payload['hours'];
        newEntry.data['mood'] = response.payload['mood'];
        newEntry.data['comments'] = response.payload['comments'];

        _entries.removeAt(entryIndex);
        _entries.add(newEntry);
        notifyListeners();
        // _entries.add(entry);
        // sortByDate(_entries);
      }
    });
  }

  int total() {
    String dateISO = DateTime.now().toIso8601String();

    var referenceDate = DateTime.parse("2023-01-01");

    final date = DateTime.parse(dateISO);
    return date.difference(referenceDate).inDays + 1;
  }

  getAll() async {
    String paginationQuery = Query.offset(0);
    int max = total();

    while (_entries.length < max) {
      int remainder = max - _entries.length;
      int limit = remainder > 100 ? 100 : remainder;

      if (_entries.isNotEmpty) {
        String lastDate = _entries.last.$id;
        paginationQuery = Query.cursorAfter(lastDate);
      }

      List<Document> newEntries = await getEntries(
        limit: limit,
        paginationQuery: paginationQuery,
      );

      _entries.addAll(newEntries);
      notifyListeners();
    }
    _ready = true;
  }

  getOne({required String date}) async {
    try {
      // print(date);
      // print(_entries.last.$id);
      return _entries.singleWhere((element) => element.$id == date);
    } catch (e) {
      int offset =
          DateTime.parse(date).difference(DateTime.parse("2023-01-01")).inDays +
              1;

      List<Document> response = await getEntries(
        limit: 1,
        paginationQuery: Query.offset(offset),
      );
      _entries.add(response.first);
      notifyListeners();
    }
  }

  getEntries({int limit = 100, paginationQuery}) async {
    var response = await databases.listDocuments(
        databaseId: APPWRITE_DATABASE_ID,
        collectionId: COLLECTION,
        queries: [
          Query.orderAsc("date"),
          paginationQuery,
          Query.limit(limit),
        ]);
    return response.documents;
  }

  Future<Document> updateEntry(
      {String? dateISO,
      List<dynamic>? hours,
      int? mood,
      String? comments}) async {
    String date = formatter.format(DateTime.parse(dateISO!));

    int entryIndex = _entries.indexWhere((element) => elDate(element) == date);

    hours ??= _entries[entryIndex].data['hours'];
    comments ??= _entries[entryIndex].data['comments'];
    mood ??= _entries[entryIndex].data['mood'];

    Document newEntry = await databases.updateDocument(
      databaseId: APPWRITE_DATABASE_ID,
      collectionId: COLLECTION,
      documentId: date,
      data: {'hours': hours, 'mood': mood, 'comments': comments},
    );

    print("Updated $date.");

    _entries.removeAt(entryIndex);
    _entries.add(newEntry);
    notifyListeners();
    return newEntry;
  }

  updateHours(dayEntry, index, value) {
    List<dynamic> hours = dayEntry.data['hours'];
    try {
      hours[index] = num.parse(value);
    } catch (e) {
      if (hours.length == index) {
        hours.add(num.parse(value));
      } else {
        hours.addAll(List.generate(index - hours.length, (i) => -1));
        hours.add(num.parse(value));
      }
    }
    updateEntry(dateISO: dayEntry.data['date'], hours: hours);
  }

  Future<Document> addEntry(
      {required String date,
      List hours = const [],
      int mood = -1,
      String comments = ""}) {
    return databases.createDocument(
        databaseId: APPWRITE_DATABASE_ID,
        collectionId: COLLECTION,
        documentId: date,
        data: {
          'date': DateTime.parse(date),
          'hours': hours,
          'mood': mood,
          'comments': comments
        });
  }

  Future<dynamic> deleteEntry({required String date}) {
    return databases.deleteDocument(
        databaseId: APPWRITE_DATABASE_ID,
        collectionId: COLLECTION,
        documentId: date);
  }
}