fcs/lib/pages/carton/model/consignee_selection_model.dart

import 'dart:async';
import 'dart:convert';

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:logging/logging.dart';

import '../../../constants.dart';
import '../../../data/services/services.dart';
import '../../../domain/entities/user.dart';
import '../../../helpers/api_helper.dart';
import '../../../helpers/firebase_helper.dart';
import '../../main/model/base_model.dart';

class ConsigneeSelectionModel extends BaseModel {
  final log = Logger("ConsigneeSearchModel");
  // for search
  String query = "";
  List<User> _consignees = [];

  List<User> get getConsginees {
    var users = new List<User>.from(_consignees);
    if (query == "") {
      return users..insert(0, User(id: all, name: "All"));
    }
    return users;
  }

  bool isLoading = false;

  // for default user
  DocumentSnapshot? _lastDocument;
  bool ended = false;

  Timer? t;
  search(String term, {bool imm = false}) async {
    query = term;
    _consignees.clear();
    t?.cancel();
    t = Timer(Duration(milliseconds: imm ? 0 : 800), () async {
      await loadMoreSearch(term: term);
    });
  }

  Future<void> loadMoreSearch({required String term}) async {
    if (term == "") {
      await _refresh();
      return;
    }
    var bytes = utf8.encode(term);
    var base64Str = base64.encode(bytes);
    HtmlEscape htmlEscape = const HtmlEscape();
    String escapeSender = htmlEscape.convert(base64Str);

    int rowPerPage = 20;
    List<User> list = [];

    var result = await requestAPI(
        "/api/fts/$user_collection/$escapeSender/$rowPerPage", "GET",
        url: Services.setting.reportURL, token: await getToken());

    if (result != null) {
      for (var row in result) {
        var item = User.fromJson(row);
        list.add(item);
      }
    }

    _consignees = List.from(list);
    notifyListeners();
  }

  addDefaultConsginees() async {
    _consignees.clear();
    await _refresh();
  }

  Future<void> _refresh() async {
    _consignees.clear();
    _lastDocument = null;
    ended = false;
    await loadMoreData();
    notifyListeners();
  }

  Future<void> loadMoreData() async {
    int rowPerPage = 20;

    try {
      isLoading = true;
      String path = "/$user_collection";
      Query query = FirebaseFirestore.instance
          .collection(path)
          .where("is_sys_admin", isEqualTo: false)
          .where("delete_time", isEqualTo: 0)
          .orderBy("update_time", descending: true);

      if (_lastDocument != null) {
        query = query.startAfterDocument(_lastDocument!);
      }

      QuerySnapshot querySnap = await query.limit(rowPerPage).get();

      if (querySnap.docs.isEmpty) return;
      _lastDocument = querySnap.docs[querySnap.docs.length - 1];

      List<User> list = querySnap.docs.map((documentSnapshot) {
        var p = User.fromMap(documentSnapshot.data() as Map<String, dynamic>,
            documentSnapshot.id);
        return p;
      }).toList();

      _consignees.addAll(list);
      if (list.length < rowPerPage) ended = true;
      notifyListeners();
    } catch (e) {
      log.warning("error:$e");
    } finally {
      isLoading = false;
    }
  }

  clear() {
    _consignees.clear();
    query = "";
  }
}