info_tren/lib/models/train_data.dart

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

import 'package:flutter/widgets.dart';
import 'package:http/http.dart' as http;
import 'package:json_annotation/json_annotation.dart';
import 'package:rxdart/subjects.dart';

part 'train_data.g.dart';

class TrainDataSourceWidget extends InheritedWidget {
  final TrainDataSource dataSource;

  @override
  bool updateShouldNotify(InheritedWidget oldWidget) {
    return true;
  }

  TrainDataSourceWidget({Widget child, Key key})
    : dataSource = TrainDataSource(),
      super(key: key, child: child);

  static TrainDataSource of(BuildContext context) {
    return (context.inheritFromWidgetOfExactType(TrainDataSourceWidget) as TrainDataSourceWidget).dataSource;
  }
}

class TrainDataSource {
  Future lookup(String trainNumber, [bool alternate = false]) async {
    _controller.add(
      TrainDataEvent(
        trainNumber: trainNumber,
        kind: TrainDataEventKind.LOADING
      )
    );

    try {
      final response = await http.get(
        "http://cfr-scrapper.herokuapp.com/train/$trainNumber${alternate ? "?alt" : ""}", headers: {
          "Authorization": "Flutter - Info Tren",
          "X-Issued-By": "Flutter App"
        }
      );

      if (200 <= response.statusCode && response.statusCode <= 299) {
        // OK
        final text = response.body;
        final ser = json.decode(text
        );
        final data = TrainData.fromJson(ser
        );
        _controller.add(
          TrainDataEvent(
            kind: TrainDataEventKind.GOT_DATA,
            trainNumber: trainNumber,
            trainData: data
          )
        );
      }
      else if (response.statusCode == 404) {
        _controller.addError(
          TrainDataEvent(
            kind: TrainDataEventKind.NOT_FOUND,
            trainNumber: trainNumber,
            errorStatusCode: 404
          )
        );
      }
      else if (response.statusCode == 503) {
        _controller.addError(
          TrainDataEvent(
            kind: TrainDataEventKind.TIMEOUT,
            trainNumber: trainNumber,
            errorStatusCode: 503
          )
        );
      }
      else {
        // Throw error
        _controller.addError(
          TrainDataEvent(
            kind: TrainDataEventKind.UNKNOWN_ERROR,
            trainNumber: trainNumber,
            errorStatusCode: response.statusCode
          )
        );
      }
    }
    catch (e) {
      _controller.addError(
        TrainDataEvent(
          kind: TrainDataEventKind.UNKNOWN_ERROR,
          trainNumber: trainNumber,
          errorStatusCode: -1
        )
      );
    }
  }

  TrainDataSource() {
    _controller = BehaviorSubject<TrainDataEvent>();
  }

  dispose() {
    _controller.close();
  }

  BehaviorSubject<TrainDataEvent> _controller;
  Stream<TrainDataEvent> get dataStream => _controller.stream;
}

enum TrainDataEventKind {
  LOADING,
  TIMEOUT,
  NOT_FOUND,
  UNKNOWN_ERROR,
  GOT_DATA
}

class TrainDataEvent {
  final TrainData trainData;
  final TrainDataEventKind kind;
  final String trainNumber;
  final int errorStatusCode;

  TrainDataEvent({this.kind, this.trainData, this.trainNumber, this.errorStatusCode});
}

@JsonSerializable()
class TrainData {
  final String rang;
  @JsonKey(name: "tren")
  final String trainNumber;
  final String operator;
  @JsonKey(name: "relatia")
  final String route;
  @JsonKey(name: "stare")
  final String state;
  @JsonKey(name: "ultima_informatie")
  final LastInfo lastInfo;
  @JsonKey(name: "destinatie")
  final StopInfo destination;
  @JsonKey(name: "urmatoarea_oprire")
  final StopInfo nextStop;
  @JsonKey(name: "durata_calatoriei")
  final String tripLength;
  @JsonKey(name: "distanta")
  final String distance;

  @JsonKey(name: "stations")
  List<StationEntry> stations;

  TrainData({this.rang, this.trainNumber, this.operator, this.lastInfo,
    this.state, this.route, this.tripLength, this.stations, this.nextStop,
    this.distance, this.destination});
  factory TrainData.fromJson(Map<String, dynamic> json) {
    var result = _$TrainDataFromJson(json);
    var foundEstimat = false;
    result.stations = result.stations.map((station) {
      if (station.realOrEstimate == "Estimat") {
        foundEstimat = true;
      }

      station.realOrEstimate = foundEstimat ? "Estimat" : "Real";

      return station;
    }).toList();
    return result;
  }
  Map<String, dynamic> toJson() => _$TrainDataToJson(this);
}

@JsonSerializable()
class LastInfo {
  @JsonKey(name: "statia")
  final String station;
  @JsonKey(name: "eveniment")
  final String event;
  @JsonKey(name: "data_si_ora")
  final String dateAndTime;
  DateTime get formattedDateAndTime {
    return parseCFRDateTime(dateAndTime);
  }
  @JsonKey(name: "intarziere")
  final int delay;


  LastInfo({this.dateAndTime, this.delay, this.event, this.station});

  factory LastInfo.fromJson(Map<String, dynamic> json) => _$LastInfoFromJson(json);
  Map<String, dynamic> toJson() => _$LastInfoToJson(this);
}

@JsonSerializable()
class StopInfo {
  @JsonKey(name: "statia")
  final String station;
  @JsonKey(name: "data_si_ora")
  final String dateAndTime;
  DateTime get formattedDateAndTime {
    return parseCFRDateTime(dateAndTime);
  }

  StopInfo({this.station, this.dateAndTime});

  factory StopInfo.fromJson(Map<String, dynamic> json) => _$StopInfoFromJson(json);
  Map<String, dynamic> toJson() => _$StopInfoToJson(this);
}

@JsonSerializable()
class StationEntry {
  final String km;
  @JsonKey(name: "statia")
  final String name;
  @JsonKey(name: "sosire")
  final String arrivalTime;
  @JsonKey(name: "stationeaza_pentru")
  final String waitTime;
  @JsonKey(name: "plecare")
  final String departureTime;
  @JsonKey(name: "real/estimat")
  String realOrEstimate;
  bool get real {
    return realOrEstimate == "Real";
  }
  @JsonKey(name: "intarziere")
  final int delay;
  @JsonKey(name: "observatii")
  final String observations;

  StationEntry({this.name, this.delay, this.realOrEstimate,
    this.arrivalTime, this.departureTime, this.km, this.observations,
    this.waitTime});

  factory StationEntry.fromJson(Map<String, dynamic> json) => _$StationEntryFromJson(json);
  Map<String, dynamic> toJson() => _$StationEntryToJson(this);
}

DateTime parseCFRDateTime(String dateAndTime) {
  final parts = dateAndTime.split(" ");

  final dateParts = parts[0].split(".");
  final day = int.parse(dateParts[0]);
  final month = int.parse(dateParts[1]);
  final year = int.parse(dateParts[2]);

  final timeParts = parts[1].split(":");
  final hour = int.parse(timeParts[0]);
  final minute = int.parse(timeParts[1]);

  return DateTime(year, month, day, hour, minute);
}