'''

@author: olivier.massot, 2018
'''
import importlib
import inspect
import logging
import pkgutil
from qgis.core import QgsProject, QgsWkbTypes, QgsGeometry, QgsPoint  #@UnresolvedImport

from PyQt5.QtCore import QVariant, QDate
import yaml

from MnCheck.core.checking import BaseChecker
from MnCheck.core.constants import USER_DATA
from plugins import processing  #@UnresolvedImport


logger = logging.getLogger("mncheck")


def list_schemas():
    import MnCheck.schemas
    return [name for _, name, ispkg in pkgutil.iter_modules(MnCheck.schemas.__path__) if not (ispkg or name[0] == '_')]

def get_schema(schema_name):
    return importlib.import_module("MnCheck.schemas." + schema_name)

def get_checkers(schema):
    return [cls for _, cls in inspect.getmembers(schema, predicate=inspect.isclass) \
            if issubclass(cls, BaseChecker) and not cls is BaseChecker]

def get_user_data():
    try:
        with open(USER_DATA, 'r') as f:
            return yaml.load(f.read()) or {}
    except FileNotFoundError:
        return {}

def dump_user_data(conf):
    with open(USER_DATA, 'w+') as f:
        return yaml.dump(conf, f)


class QgsModel():
    
    GEOM_UNKNOWN = 0
    GEOM_POINT = 1
    GEOM_LINE = 2
    GEOM_POLYGON = 3
    GEOM_MULTIPOINT = 4
    GEOM_MULTILINE = 5
    GEOM_MULTIPOLYGON = 6
    
    layername = ""
    required = True
    geom_type = 0
    bounding_box = (0,0,1,1)
    schema = {}
    pk = ""

    def __init__(self, qgs_feature):
        self._feature = qgs_feature
        
        if self.pk:
            # On affecte une valeur par defaut à la clef primaire pour éviter des erreurs en cascade au chargement des données
            setattr(self, self.pk, None)
        
        for attr, value in self.attributes().items():
            if isinstance(value, QVariant):
                value = value.value() if not value.isNull() else ""
            if isinstance(value, QDate):
                value = value.toString("dd/MM/yyyy")
            setattr(self, attr, value)
    
    def __repr__(self):
        try:
            return "{} {}".format(self.__class__.__name__, getattr(self, self.pk))
        except AttributeError:
            return f"{self.__class__.__name__} (code manquant)"
    
    @property
    def feature(self):
        return self._feature
    
    def attributes(self):
        return dict(zip([f.name() for f in self._feature.fields()], self._feature.attributes()))
    
    @property
    def geom(self):
        if not self._feature:
            return None
        return self._feature.geometry()
    
    def is_geometry_valid(self):
        return self.geom and self.geom.isGeosValid()
        
    def get_geom_type(self):
        return QgsWkbTypes.singleType(self._feature.geometry().wkbType()) if self.geom else None
    
    @classmethod
    def get_geom_name(cls, wkb):
        try:
            return QgsWkbTypes.displayString(wkb)
        except (ValueError, TypeError):
            return "<unknown>"
        
    def get_bounding_box(self):
        bb = self.geom.boundingBox()
        return (bb.xMinimum(), bb.yMinimum(), bb.xMaximum(), bb.yMaximum())
    
    def get_points(self):
        if not self.geom or self.geom.isNull():
            return []
        
        multi_geom = QgsGeometry()
        temp_geom = []
        
        if self.geom.type() == 0: # it's a point
            if self.geom.isMultipart():
                temp_geom = self.geom.asMultiPoint()
            else:
                temp_geom.append(self.geom.asPoint())
        elif self.geom.type() == 1: # it's a line
            if self.geom.isMultipart():
                multi_geom = self.geom.asMultiPolyline() #multi_geog is a multiline
                for i in multi_geom: #i is a line
                    temp_geom.extend( i )
            else:
                temp_geom = self.geom.asPolyline()
        elif self.geom.type() == 2: # it's a polygon
            if self.geom.isMultipart():
                multi_geom = self.geom.asMultiPolygon() #multi_geom is a multipolygon
                for i in multi_geom: #i is a polygon
                    for j in i: #j is a line
                        temp_geom.extend( j )
            else:
                multi_geom = self.geom.asPolygon() #multi_geom is a polygon
                for i in multi_geom: #i is a line
                    temp_geom.extend( i )
                
        return [QgsPoint(p) for p in temp_geom]

    @classmethod
    def full_buffer(cls, distance):
        layer = next((l for l in QgsProject.instance().mapLayers().values() if l.name().lower() == cls.layername.lower()))

        result = processing.run("native:buffer", {'INPUT':layer.dataProvider().dataSourceUri(),  #@UndefinedVariable
                                                 'DISTANCE':distance,
                                                 'SEGMENTS':5,
                                                 'END_CAP_STYLE':0,
                                                 'JOIN_STYLE':0,
                                                 'MITER_LIMIT':2,
                                                 'DISSOLVE':True,
                                                 'OUTPUT':'memory:mncheck_temp'})

        try:
            buffer = next((f for f in result['OUTPUT'].getFeatures()))
        except StopIteration:
            return QgsGeometry.fromPolygonXY([])
        
        if not buffer.geometry().isGeosValid():
            raise ValueError("Buffer: géométrie invalide")
        return buffer.geometry()



def validate(schema_name):
    try:
        schema = get_schema(schema_name)
    except ModuleNotFoundError:
        logger.critical(f"Le schéma {schema_name} n'existe pas")
        return
    
    results = schema.checker.run()
    
    return results