datacheck/core/validation.py

'''


    @author: olivier.massot, sept. 2018
'''
import time
import zipfile

from cerberus.validator import Validator
from path import Path, TempDir

from core import gis
from core.cerberus_extend import CerberusErrorHandler, GeoValidator
from core.validation_errors import MissingFile, \
    UnreadableFile, FormatError, WrongSrid
from schemas.common import SRID


class BaseModel():
    filename = ""
    pk = ""
    schema = {}
    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)
        
    @classmethod
    def index_item(cls, instance):
        if getattr(instance, cls.pk) in cls.index:
            raise ValueError("Duplicate PK")
        cls.index[getattr(instance, cls.pk)] = instance
        
class BaseGeoModel(BaseModel):
    def __init__(self, geom, **kwargs):
        super(BaseGeoModel, self).__init__(**kwargs)
        self.geom = geom

class ValidatorInterruption(BaseException): 
    pass

class Checkpoint():
    def __init__(self, name, valid=True):
        self.name = name
        self.valid = valid

class BaseValidator():
    schema_name = ""
    models = {}
    dataset = {}
    
    def __init__(self):
        self.valid = True
        self.checkpoints = []
        self.errors = []
        self.dt = 0
    
    def checkpoint(self, name):
        valid = (len(self.errors) == 0)
        self.checkpoints.append(Checkpoint(name, valid))
        if not valid:
            self.valid = False
            raise ValidatorInterruption()
             
    def log_error(self, validation_error):
        self.errors.append(validation_error)
         
    @classmethod
    def submit(cls, subject):    
        """ prends un dossier ou une archive en entrée et vérifie son contenu  """
        subject = Path(subject)
        
        if subject.isfile():
            with TempDir() as dirname:
                zip_ref = zipfile.ZipFile(subject, 'r')
                zip_ref.extractall(dirname)
                zip_ref.close()
                if Path(dirname / subject.stem).isdir(): # cas où l'archive contient un dossier qui lui-même contient les fichiers
                    dirname /= subject.stem
                return cls._submit_folder(dirname)
            
        elif subject.isdir():
            return cls._submit_folder(subject)
        else:
            raise FileNotFoundError(f"Impossible de trouver le fichier ou répertoire: {subject}")

    @classmethod
    def _submit_folder(cls, folder):
        
        validator = cls()
        t0 = time.time()
        try:
            validator.validate(folder)
        except ValidatorInterruption:
            pass
        validator.dt = time.time() - t0
        
        report = validator.build_report("{} - Validation de {}".format(validator.schema_name, folder.name))
        return report
    
    def validate(self, folder):
        
        # Chargement des données en mémoire
        self._load_files(folder)
        self.checkpoint("Chargement des données")
        
        # Controle la structure des données (champs, formats et types)
        self._structure_validation()
        self.checkpoint("Contrôle de la structure des données")
        
        # Validation technique
        self._technical_validation()
        self.checkpoint("Validation Métier")
    
    
    def _load_files(self, folder):
        """ Charge les données du fichier et les associe à un modèle.
        Attention: pas de contrôle de format ou de validité à ce niveau!  """
        raise NotImplementedError()
    
    def _structure_validation(self):
        
        for model in self.models:
            v = GeoValidator(model.schema, error_handler=CerberusErrorHandler)
            
            for item in self.dataset[model]:
                v.validate(item.__dict__)
            
                for field, verrors in v.errors.items():
                    for err in verrors:
                        self.log_error(FormatError(err, filename=model.filename, field=field))
    
    @classmethod
    def _technical_validation(cls):
        raise NotImplementedError()
    
    def build_report(self, title):
        report = {}
        report["title"] = title
        report["exec_time"] = "{} s.".format(self.dt)
        report["checkpoints"] = [{"name": chk.name, "valid": chk.valid} for chk in self.checkpoints]
        
        report["errors"] = {}
        
        for err in self.errors:
            if not err.name in report["errors"]:
                report["errors"][err.name] = {"help": err.help, "list": []}
            
            err_report = {"filename": err.filename or "-",
                          "field": err.field or "-",
                          "message": err.message}
            if err_report not in report["errors"][err.name]["list"]:
                report["errors"][err.name]["list"].append(err_report)
            
        return report
    
        
class NetgeoValidator(BaseValidator):
    
    def _load_files(self, folder):
        
        for model in self.models:
            filename = model.filename
            path_ = Path(folder) / filename
            
            if not path_.isfile():
                self.log_error(MissingFile("Fichier manquant: '{}'".format(filename)))
                continue
            
            self.dataset[model] = []
            try:
                with gis.ShapeFile(path_, srid=SRID) as sf:
                    fields = sf.fields()
                    
                    for record in sf.records():
                        
                        data = dict(zip(fields, record.record))
                    
                        item = model(record.shape, **data)
                        
                        self.dataset[model].append(item)
                        
            except gis.ShapeError as e:
                self.log_error(UnreadableFile(str(e)))
            except gis.SridError:
                self.log_error(WrongSrid(str(e)))