import csv
import json
import base64
import copy
import pandas as pd

from pyhanko.sign import signers

from django import forms
from django.core.cache import cache
from django.utils.translation import gettext_lazy as _
from django.core.exceptions import ValidationError
from utils import credtools, certs
from idhub.models import (
    DID,
    File_datas,
    Membership,
    Schemas,
    Service,
    UserRol,
    VerificableCredential,
)
from idhub_auth.models import User


class ImportForm(forms.Form):
    did = forms.ChoiceField(label=_("Did"), choices=[])
    eidas1 = forms.ChoiceField(
        label=_("Signature with Eidas1"),
        choices=[],
        required=False
    )
    schema = forms.ChoiceField(label=_("Schema"), choices=[])
    file_import = forms.FileField(label=_("File import"))

    def __init__(self, *args, **kwargs):
        self._schema = None
        self._did = None
        self._eidas1 = None
        self.rows = {}
        self.properties = {}
        self.user = kwargs.pop('user', None)
        super().__init__(*args, **kwargs)
        dids = DID.objects.filter(user=self.user)
        self.fields['did'].choices = [
            (x.did, x.label) for x in dids.filter(eidas1=False)
        ]
        self.fields['schema'].choices = [
            (x.id, x.name()) for x in Schemas.objects.filter()
        ]
        if dids.filter(eidas1=True).exists():
            choices = [("", "")]
            choices.extend([
                (x.did, x.label) for x in dids.filter(eidas1=True)
            ])
            self.fields['eidas1'].choices = choices
        else:
          self.fields.pop('eidas1')

    def clean(self):
        data = self.cleaned_data["did"]
        did = DID.objects.filter(
            user=self.user,
            did=data
        )

        if not did.exists():
            raise ValidationError("Did is not valid!")

        self._did = did.first()

        eidas1 = self.cleaned_data.get('eidas1')
        if eidas1:
            self._eidas1 = DID.objects.filter(
                user=self.user,
                eidas1=True,
                did=eidas1
            ).first()
            
        return data

    def clean_schema(self):
        data = self.cleaned_data["schema"]
        schema = Schemas.objects.filter(
            id=data
        )
        if not schema.exists():
            raise ValidationError("Schema is not valid!")

        self._schema = schema.first()
        try:
            self.json_schema = json.loads(self._schema.data)
            props = [x for x in self.json_schema["allOf"] if 'properties' in x.keys()]
            prop = props[0]['properties']
            self.properties = prop['credentialSubject']['properties']
        except Exception:
            raise ValidationError("Schema is not valid!")

        if not self.properties:
            raise ValidationError("Schema is not valid!")

        # TODO we need filter "$ref" of schema for can validate a csv
        self.json_schema_filtered = copy.copy(self.json_schema)
        allOf = [x for x in self.json_schema["allOf"] if '$ref' not in x.keys()]
        self.json_schema_filtered["allOf"] = allOf
        return data

    def clean_file_import(self):
        data = self.cleaned_data["file_import"]
        self.file_name = data.name
        if File_datas.objects.filter(file_name=self.file_name, success=True).exists():
            raise ValidationError("This file already exists!")

        # df = pd.read_csv (data, delimiter="\t", quotechar='"', quoting=csv.QUOTE_ALL)
        df = pd.read_excel(data)
        data_pd = df.fillna('').to_dict()

        if not data_pd:
            self.exception("This file is empty!")

        head_row = {x: '' for x in self.properties.keys()}
        for n in range(df.last_valid_index()+1):
            row = head_row.copy()
            for k in data_pd.keys():
                row[k] = data_pd[k][n] or ''

            user = self.validate_jsonld(n, row)
            self.rows[user] = row

        return data

    def save(self, commit=True):
        table = []
        for k, v in self.rows.items():
            table.append(self.create_credential(k, v)) 

        if commit:
            for cred in table:
              cred.save()
            File_datas.objects.create(file_name=self.file_name)
            return table
        
        return 

    def validate_jsonld(self, line, row):
        try:
            check = credtools.validate_json(row, self.json_schema_filtered)
            if check is not True:
                raise ValidationError("Not valid row")
        except Exception as e:
            msg = "line {}: {}".format(line+1, e)
            self.exception(msg)

        user = User.objects.filter(email=row.get('email'))
        if not user:
            txt = _('The user does not exist!')
            msg = "line {}: {}".format(line+1, txt)
            self.exception(msg)

        return user.first()

    def create_credential(self, user, row):
        return VerificableCredential(
            verified=False,
            user=user,
            csv_data=json.dumps(row),
            issuer_did=self._did,
            schema=self._schema,
            eidas1_did=self._eidas1
        )

    def exception(self, msg):
        File_datas.objects.create(file_name=self.file_name, success=False)
        raise ValidationError(msg)


class SchemaForm(forms.Form):
    file_template = forms.FileField(label=_("File template"))

    
class MembershipForm(forms.ModelForm):

    class Meta:
        model = Membership
        fields = ['type', 'start_date', 'end_date']

    def clean_end_date(self):
        data = super().clean()
        start_date = data['start_date']
        end_date = data.get('end_date')
        members = Membership.objects.filter(
            type=data['type'],
            user=self.instance.user
        )
        if self.instance.id:
            members = members.exclude(id=self.instance.id)

        if members.filter(start_date__lte=start_date, end_date=None).exists():
            msg = _("This membership already exists!")
            raise forms.ValidationError(msg)
            
        if (start_date and end_date):
            if start_date > end_date:
                msg = _("The end date is less than the start date")
                raise forms.ValidationError(msg)

            members = members.filter(
                start_date__lte=end_date,
                end_date__gte=start_date,
            )

            if members.exists():
                msg = _("This membership already exists!")
                raise forms.ValidationError(msg)

        if not end_date:
            members = members.filter(
                start_date__gte=start_date,
            )

            if members.exists():
                msg = _("This membership already exists!")
                raise forms.ValidationError(msg)
            
        
        return end_date


class UserRolForm(forms.ModelForm):

    class Meta:
        model = UserRol
        fields = ['service']

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if not self.instance.id:
            user = self.instance.user
            choices = self.fields['service'].choices
            choices.queryset = choices.queryset.exclude(users__user=user)
            self.fields['service'].choices = choices
    
    def clean_service(self):
        data = super().clean()
        service = UserRol.objects.filter(
            service=data['service'],
            user=self.instance.user
        )

        if service.exists():
            msg = _("Is not possible to have a duplicate role")
            raise forms.ValidationError(msg)

        return data['service']


class ImportCertificateForm(forms.Form):
    label = forms.CharField(label=_("Label"))
    password = forms.CharField(
        label=_("Password of certificate"),
        widget=forms.PasswordInput
    )
    file_import = forms.FileField(label=_("File import"))

    def __init__(self, *args, **kwargs):
        self._did = None
        self._s = None
        self._label = None
        self.user = kwargs.pop('user', None)
        super().__init__(*args, **kwargs)

    def clean(self):
        data = super().clean()
        file_import = data.get('file_import')
        self.pfx_file = file_import.read()
        self.file_name = file_import.name
        self._pss = data.get('password')
        self._label = data.get('label')
        if not self.pfx_file or not self._pss:
            msg = _("Is not a valid certificate")
            raise forms.ValidationError(msg)

        self.signer_init()
        if not self._s:
            msg = _("Is not a valid certificate")
            raise forms.ValidationError(msg)

        self.new_did()
        return data

    def new_did(self):
        cert = self.pfx_file
        keys = {
            "cert": base64.b64encode(self.pfx_file).decode('utf-8'),
            "passphrase": self._pss
        }
        key_material = json.dumps(keys)
        self._did = DID(
            key_material=key_material,
            did=self.file_name,
            label=self._label,
            eidas1=True,
            user=self.user,
            type=DID.Types.KEY
        )

        pw = cache.get("KEY_DIDS")
        self._did.set_key_material(key_material, pw)

    def save(self, commit=True):

        if commit:
            self._did.save()
            return self._did

        return

    def signer_init(self):
        self._s = certs.load_cert(
            self.pfx_file, self._pss.encode('utf-8')
        )