from PyQt5.QtCore import QVariant
from qgis._core import QgsCoordinateReferenceSystem
from qgis.core import QgsFields, QgsField

from .po_station_reader import PoStationReader


class PoStationReaderQgs(PoStationReader):

    def __init__(self):
        """
        Initialisiert die Super-Klasse und das Koordinaten-System der Features
        """
        super().__init__()
        self.fields = None
        self.crs = QgsCoordinateReferenceSystem(4326, QgsCoordinateReferenceSystem.EpsgCrsId)

    def get_features(self):
        """
        Erzeugt Features aus allen Stationen von super.get_stations() oder None im Fehlerfall
        :return: list[QgsFeature] | None
        """
        print("PoStationReaderQgs::get_features: Erzeuge Features...")

        self.fields = QgsFields()
        self.fields.append(QgsField('uuid', QVariant.String))
        self.fields.append(QgsField('number', QVariant.LongLong))
        self.fields.append(QgsField('shortname', QVariant.String))
        self.fields.append(QgsField('longname', QVariant.String))
        self.fields.append(QgsField('km', QVariant.Double))
        self.fields.append(QgsField('agency', QVariant.String))
        self.fields.append(QgsField('water', QVariant.String))

        features = []
        stations = self.get_stations()

        if stations is None or len(stations) == 0:
            # Keine Stationen erhalten → Abbruch
            print("PoStationReaderQgs::get_features: Fehler: Keine Stationen erhalten")
            return None

        for station in stations:
            feature = station.new_feature(self.fields)
            if feature is not None:
                # Feature-Erzeugung erfolgreich, füge zu Liste hinzu
                features.append(feature)

        print("PoStationReaderQgs::get_features: %d Features erzeugt" % (len(features),))
        return features