import 'dart:async';
import 'dart:convert' show HtmlEscape, base64, utf8;

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:logging/logging.dart';
import 'package:fcs/config.dart';
import 'package:fcs/fcs/common/helpers/theme.dart';
import 'package:fcs/vo/buyer.dart';
import 'package:fcs/vo/popup_menu.dart';

import 'base_model.dart';
import 'constants.dart';
import 'firebase_helper.dart';

class BuyerModel extends BaseModel {
  final log = Logger('BuyerModel');

  StreamSubscription<QuerySnapshot> listener;

  List<Buyer> buyers = [];
  PopupMenu popupMenu = new PopupMenu(index: 0);
  PopupMenu sortMenu = new PopupMenu();
  Buyer searchBuyer;
  void initUser(user) {
    super.initUser(user);
    _loadBuyers();
  }

  Future<void> _loadBuyers() async {
    if (!user.isOwnerAndAbove() && !user.hasBuyer()) {
      return;
    }

    listener = getQuerySnapshotByOrder(
            "/$biz_collection/${setting.okEnergyId}/$buyer_collection",
            'user_name')
        .listen((snaps) async {
      buyers.clear();
      snaps.documents.forEach((d) {
        buyers.add(Buyer.fromMap(d.data, d.documentID));
      });
      notifyListeners();
    });
  }

  @override
  logout() async {
    if (listener != null) await listener.cancel();
    buyers = [];
  }

  Future<Buyer> getBuyer(String buyerID) async {
    var snap = await getDocSnap(
        "/$biz_collection/${setting.okEnergyId}/$buyer_collection", buyerID);
    return Buyer.fromMap(snap.data, snap.documentID);
  }

  Future<Buyer> loadBuyerProducts(Buyer buyer, {bool force = false}) async {
    if (!force && buyer.buyerProducts != null && buyer.buyerProducts.length > 0)
      return buyer;
    var snaps = await getSnapshot(
        "/$biz_collection/${setting.okEnergyId}/$buyer_collection/${buyer.id}/$product_collection");
    buyer.buyerProducts = snaps.documents
        .map((s) => BuyerProduct.fromMap(s.data, s.documentID))
        .toList();
    return buyer;
  }

  Future<void> delete(Buyer buyer) async {
    await request("/buyer/${buyer.id}", "DELETE", token: await getToken());
  }

  Future<void> approve(Buyer buyer) async {
    await request("/buyer/approve", "PUT",
        payload: buyer.toMap(), token: await getToken());
  }

  Future<void> reject(Buyer buyer) async {
    await request("/buyer/reject", "POST",
        payload: buyer.toMap(), token: await getToken());
  }

  Future<void> allocate(Buyer buyer) async {
    await request("/buyer/allocate", "POST",
        payload: buyer.toMap(), token: await getToken());
  }

  void filterStatus(String status, int _selectedIndex, int _sleectedSortIndex) {
    this.sortMenu.index = _sleectedSortIndex;
    buyers.clear();
    if (listener != null) {
      listener.cancel();
    }

    this.popupMenu.index = _selectedIndex;
    String path = "/$biz_collection/${setting.okEnergyId}/$buyer_collection";
    listener = getFilterStatusSnapshot(path, status, 'user_name')
        .listen((snaps) async {
      buyers.clear();
      snaps.documents.forEach((d) {
        buyers.add(Buyer.fromMap(d.data, d.documentID));
      });
      notifyListeners();
    });
    notifyListeners();
  }

  Future<List<Buyer>> search(String searchBuyer) async {
    if (searchBuyer == null || searchBuyer == '') return List();

    var bytes = utf8.encode(searchBuyer);
    var base64Str = base64.encode(bytes);
    HtmlEscape htmlEscape = const HtmlEscape();
    String escapeBuyer = htmlEscape.convert(base64Str);

    int limit = 20;
    List<Buyer> _buyers = [];

    try {
      var data = await request(
          "/api/fts/$buyer_collection/$escapeBuyer/$limit", "GET",
          token: await getToken(), url: Config.instance.reportURL);
      if (data == null) return List();

      data.forEach((buyer) {
        var _buyer = Buyer.fromJson(buyer);
        _buyers.add(_buyer);
      });
    } catch (e) {
      // permission error
      log.warning("buyer error:" + e.toString());
      return null;
    }
    return _buyers;
  }

  void filterSorting(int _sleectedSortIndex, int _selectedIndex) {
    this.popupMenu.index = _selectedIndex;
    buyers.clear();
    if (listener != null) {
      listener.cancel();
    }
    String _fieldName;
    bool descending = false;

    if (_sleectedSortIndex == 0) {
      _fieldName = 'user_name';
      descending = false;
    }
    if (_sleectedSortIndex == 1) {
      _fieldName = 'user_name';
      descending = true;
    }
    if (_sleectedSortIndex == 2) {
      _fieldName = 'phone_number';
      descending = false;
    }
    if (_sleectedSortIndex == 3) {
      _fieldName = 'phone_number';
      descending = true;
    }

    this.sortMenu.index = _sleectedSortIndex;
    String path = "/$biz_collection/${setting.okEnergyId}/$buyer_collection";
    listener =
        getFilterSnapshot(path, descending, _fieldName).listen((snaps) async {
      buyers.clear();
      snaps.documents.forEach((d) {
        buyers.add(Buyer.fromMap(d.data, d.documentID));
        notifyListeners();
      });

      notifyListeners();
    });
    notifyListeners();
  }
}