import sys
import types
import unittest
from unittest.mock import patch

if "qgis" not in sys.modules:
    qgis_mod = types.ModuleType("qgis")
    qgis_utils = types.ModuleType("qgis.utils")
    qgis_utils.iface = types.SimpleNamespace()
    qgis_utils.plugins = {}
    qgis_mod.utils = qgis_utils
    sys.modules["qgis"] = qgis_mod
    sys.modules["qgis.utils"] = qgis_utils

from sn_verfahrensgebiet.functions import verfahrensgebiet_alkis as vg


class _DummyMessageBox:
    class StandardButton:
        Yes = 1
        No = 2

    last_critical = None
    next_reply = StandardButton.No

    @staticmethod
    def question(_parent, _title, _message, _buttons, _default):
        return _DummyMessageBox.next_reply

    @staticmethod
    def critical(parent, title, message):
        _DummyMessageBox.last_critical = (parent, title, message)


class _DummyProject:
    def __init__(self, layers=None):
        self._layers = layers or []
        self.removed = []

    def mapLayersByName(self, _name):
        return self._layers

    def removeMapLayer(self, layer_id):
        self.removed.append(layer_id)


class _DummyExistingLayer:
    def __init__(self, layer_id="existing"):
        self._id = layer_id

    def id(self):
        return self._id


class _DummyGeom:
    def __init__(self, empty=False):
        self._empty = empty

    def isEmpty(self):
        return self._empty


class _DummyFeature:
    def __init__(self, geom=None):
        self._geom = geom or _DummyGeom()

    def geometry(self):
        return self._geom


class _DummyTempLayer:
    def __init__(self, valid=True, features=None):
        self._valid = valid
        self._features = features or []

    def isValid(self):
        return self._valid

    def getFeatures(self):
        return self._features

    def crs(self):
        class _Crs:
            @staticmethod
            def authid():
                return "EPSG:25833"

        return _Crs()


class _DummyProvider:
    def addAttributes(self, _attrs):
        return True

    def addFeatures(self, _features):
        return True


class _DummyMemoryLayer:
    def __init__(self):
        self._provider = _DummyProvider()

    def dataProvider(self):
        return self._provider

    def updateFields(self):
        return None

    def updateExtents(self):
        return None


class TestVerfahrensgebietAlkis(unittest.TestCase):

    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsProject.instance")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QMessageBox", new=_DummyMessageBox)
    def test_check_existing_layer_first_load(self, mock_project_instance):
        mock_project_instance.return_value = _DummyProject(layers=[])

        layer, status = vg._check_existing_layer(tab_widget=None)

        self.assertIsNone(layer)
        self.assertEqual(status, vg.LoadStatus.FIRST)

    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsProject.instance")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QMessageBox", new=_DummyMessageBox)
    def test_check_existing_layer_keep_existing(self, mock_project_instance):
        existing = _DummyExistingLayer("L1")
        mock_project_instance.return_value = _DummyProject(layers=[existing])
        _DummyMessageBox.next_reply = _DummyMessageBox.StandardButton.No

        layer, status = vg._check_existing_layer(tab_widget=None)

        self.assertIs(layer, existing)
        self.assertEqual(status, vg.LoadStatus.KEEP)

    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QMessageBox", new=_DummyMessageBox)
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.get_variable", return_value="")
    def test_verfahrensgebiet_alkis_fails_when_verfahrensnummer_missing(self, _mock_get_var):
        _DummyMessageBox.last_critical = None

        layer, status = vg.verfahrensgebiet_alkis(tab_widget=None)

        self.assertIsNone(layer)
        self.assertEqual(status, vg.LoadStatus.NONE)
        self.assertIsNotNone(_DummyMessageBox.last_critical)

    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis._check_existing_layer", return_value=(None, vg.LoadStatus.FIRST))
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QMessageBox", new=_DummyMessageBox)
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.get_variable", return_value="VKZ123")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsVectorLayer")
    def test_verfahrensgebiet_alkis_fails_on_invalid_wfs_layer(self, mock_qgsvectorlayer, _mock_get_var, _mock_check):
        _DummyMessageBox.last_critical = None
        mock_qgsvectorlayer.return_value = _DummyTempLayer(valid=False)

        layer, status = vg.verfahrensgebiet_alkis(tab_widget=None)

        self.assertIsNone(layer)
        self.assertEqual(status, vg.LoadStatus.NONE)
        self.assertIsNotNone(_DummyMessageBox.last_critical)

    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsFeature")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsGeometry.unaryUnion", return_value=_DummyGeom(empty=False))
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis._check_existing_layer", return_value=(None, vg.LoadStatus.FIRST))
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.get_variable", return_value="VKZ123")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QgsVectorLayer")
    @patch("sn_verfahrensgebiet.functions.verfahrensgebiet_alkis.QMessageBox", new=_DummyMessageBox)
    def test_verfahrensgebiet_alkis_success_returns_memory_layer(self, mock_qgsvectorlayer, _mock_get_var, _mock_check, _mock_union, mock_feature_cls):
        temp_layer = _DummyTempLayer(valid=True, features=[_DummyFeature()])
        memory_layer = _DummyMemoryLayer()
        mock_qgsvectorlayer.side_effect = [temp_layer, memory_layer]

        mock_feature = mock_feature_cls.return_value
        mock_feature.setGeometry.return_value = None
        mock_feature.setAttributes.return_value = None

        layer, status = vg.verfahrensgebiet_alkis(tab_widget=None)

        self.assertIs(layer, memory_layer)
        self.assertEqual(status, vg.LoadStatus.FIRST)


if __name__ == "__main__":
    unittest.main()