# Copyright 2009-2020 Noviat.
# License LGPL-3 or later (http://www.gnu.org/licenses/lpgl).

import base64
import logging
import os
from sys import exc_info
from traceback import format_exception
from urllib.error import URLError

from odoo import _, api, fields, models
from odoo.exceptions import UserError

_logger = logging.getLogger(__name__)


"""
logging.basicConfig(
    level=logging.DEBUG,
    format='[%(asctime)s] %(levelname)s - %(name)s: %(message)s')
"""


try:
    import fintech
    from fintech.ebics import EbicsKeyRing, EbicsBank, EbicsUser,\
        EbicsClient, EbicsFunctionalError, EbicsTechnicalError
    fintech.cryptolib = 'cryptography'
except ImportError:
    _logger.warning('Failed to import fintech')


class EbicsBank(EbicsBank):

    def _next_order_id(self, partnerid):
        """
        EBICS protocol version H003 requires generation of the OrderID.
        The OrderID must be a string between 'A000' and 'ZZZZ' and
        unique for each partner id.
        """
        return hasattr(self, '_order_number') and self._order_number or 'A000'


class EbicsUserID(models.Model):
    _name = 'ebics.userid'
    _description = 'EBICS UserID'
    _order = 'name'

    name = fields.Char(
        string='EBICS UserID', required=True,
        readonly=True, states={'draft': [('readonly', False)]},
        help="Human users or a technical system that is/are "
             "assigned to a customer. "
             "\nOn the EBICS bank server it is identified "
             "by the combination of UserID and PartnerID. "
             "The technical subscriber serves only for the data exchange "
             "between customer and financial institution. "
             "The human user also can authorise orders.")
    ebics_config_id = fields.Many2one(
        comodel_name='ebics.config',
        string='EBICS Configuration',
        ondelete='cascade')
    user_ids = fields.Many2many(
        comodel_name='res.users',
        string='Users',
        required=True,
        help="Users who are allowed to use this EBICS UserID for "
             " bank transactions.")
    # Currently only a singe signature class per user is supported
    # Classes A and B are not yet supported.
    signature_class = fields.Selection(
        selection=[('E', 'Single signature'),
                   ('T', 'Transport signature')],
        string='Signature Class',
        required=True, default='T',
        readonly=True, states={'draft': [('readonly', False)]},
        help="Default signature class."
             "This default can be overriden for specific "
             "EBICS transactions (cf. File Formats).")
    ebics_keys_fn = fields.Char(
        compute='_compute_ebics_keys_fn')
    ebics_keys_found = fields.Boolean(
        compute='_compute_ebics_keys_found')
    ebics_passphrase = fields.Char(
        string='EBICS Passphrase')
    ebics_ini_letter = fields.Binary(
        string='EBICS INI Letter', readonly=True,
        help="INI-letter PDF document to be sent to your bank.")
    ebics_ini_letter_fn = fields.Char(
        string='INI-letter Filename', readonly=True)
    ebics_public_bank_keys = fields.Binary(
        string='EBICS Public Bank Keys', readonly=True,
        help="EBICS Public Bank Keys to be checked for consistency.")
    ebics_public_bank_keys_fn = fields.Char(
        string='EBICS Public Bank Keys Filename', readonly=True)
    # X.509 Distinguished Name attributes used to
    # create self-signed X.509 certificates
    ebics_key_x509 = fields.Boolean(
        string='X509 support',
        help="Set this flag in order to work with "
             "self-signed X.509 certificates")
    ebics_key_x509_dn_cn = fields.Char(
        string='Common Name [CN]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_o = fields.Char(
        string='Organization Name [O]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_ou = fields.Char(
        string='Organizational Unit Name [OU]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_c = fields.Char(
        string='Country Name [C]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_st = fields.Char(
        string='State Or Province Name [ST]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_l = fields.Char(
        string='Locality Name [L]',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    ebics_key_x509_dn_e = fields.Char(
        string='Email Address',
        readonly=True, states={'draft': [('readonly', False)]},
    )
    state = fields.Selection(
        [('draft', 'Draft'),
         ('init', 'Initialisation'),
         ('get_bank_keys', 'Get Keys from Bank'),
         ('to_verify', 'Verification'),
         ('active_keys', 'Active Keys')],
        string='State',
        default='draft',
        required=True, readonly=True)
    active = fields.Boolean(
        string='Active', default=True)
    company_ids = fields.Many2many(
        comodel_name='res.company',
        string='Companies',
        required=True,
        help="Companies sharing this EBICS contract.")

    @api.depends('name')
    def _compute_ebics_keys_fn(self):
        for rec in self:
            keys_dir = rec.ebics_config_id.ebics_keys
            rec.ebics_keys_fn = (
                rec.name
                and keys_dir
                and (keys_dir + '/' + rec.name + '_keys'))

    @api.depends('ebics_keys_fn')
    def _compute_ebics_keys_found(self):
        for rec in self:
            rec.ebics_keys_found = (
                rec.ebics_keys_fn
                and os.path.isfile(rec.ebics_keys_fn)
            )

    @api.constrains('ebics_passphrase')
    def _check_ebics_passphrase(self):
        for rec in self:
            if not rec.ebics_passphrase or len(rec.ebics_passphrase) < 8:
                raise UserError(_(
                    "The passphrase must be at least 8 characters long"))

    def set_to_draft(self):
        return self.write({'state': 'draft'})

    def set_to_active_keys(self):
        return self.write({'state': 'active_keys'})

    def set_to_get_bank_keys(self):
        return self.write({'state': 'get_bank_keys'})

    def ebics_init_1(self):
        """
        Initialization of bank keys - Step 1:
        Create new keys and certificates for this user
        """
        self.ensure_one()
        self.ebics_config_id._check_ebics_files()
        if self.state != 'draft':
            raise UserError(
                _("Set state to 'draft' before Bank Key (re)initialisation."))

        if not self.ebics_passphrase:
            raise UserError(
                _("Set a passphrase."))

        ebics_version = self.ebics_config_id.ebics_version
        try:
            keyring = EbicsKeyRing(
                keys=self.ebics_keys_fn,
                passphrase=self.ebics_passphrase)
            bank = EbicsBank(
                keyring=keyring,
                hostid=self.ebics_config_id.ebics_host,
                url=self.ebics_config_id.ebics_url)
            user = EbicsUser(
                keyring=keyring,
                partnerid=self.ebics_config_id.ebics_partner,
                userid=self.name)
        except Exception:
            exctype, value = exc_info()[:2]
            error = _("EBICS Initialisation Error:")
            error += '\n' + str(exctype) + '\n' + str(value)
            raise UserError(error)

        self.ebics_config_id._check_ebics_keys()
        if not os.path.isfile(self.ebics_keys_fn):
            try:
                user.create_keys(
                    keyversion=self.ebics_config_id.ebics_key_version,
                    bitlength=self.ebics_config_id.ebics_key_bitlength)
            except Exception:
                exctype, value = exc_info()[:2]
                error = _("EBICS Initialisation Error:")
                error += '\n' + str(exctype) + '\n' + str(value)
                raise UserError(error)

        if self.ebics_key_x509:
            dn_attrs = {
                'commonName': self.ebics_key_x509_dn_cn,
                'organizationName': self.ebics_key_x509_dn_o,
                'organizationalUnitName': self.ebics_key_x509_dn_ou,
                'countryName': self.ebics_key_x509_dn_c,
                'stateOrProvinceName': self.ebics_key_x509_dn_st,
                'localityName': self.ebics_key_x509_dn_l,
                'emailAddress': self.ebics_key_x509_dn_e,
            }
            kwargs = {k: v for k, v in dn_attrs.items() if v}
            user.create_certificates(**kwargs)

        client = EbicsClient(
            bank, user, version=ebics_version)

        # Send the public electronic signature key to the bank.
        try:
            supported_versions = client.HEV()
            if ebics_version not in supported_versions:
                err_msg = _("EBICS version mismatch.") + "\n"
                err_msg += _("Versions supported by your bank:")
                for k in supported_versions:
                    err_msg += "\n%s: %s " % (k, supported_versions[k])
                raise UserError(err_msg)
            if ebics_version == 'H003':
                bank._order_number = self.ebics_config_id._get_order_number()
            OrderID = client.INI()
            _logger.info(
                '%s, EBICS INI command, OrderID=%s', self._name, OrderID)
            if ebics_version == 'H003':
                self.ebics_config_id._update_order_number(OrderID)
        except URLError:
            exctype, value = exc_info()[:2]
            tb = "".join(format_exception(*exc_info()))
            _logger.error(
                "EBICS INI command error\nUserID: %s\n%s",
                self.name,
                tb,
            )
            raise UserError(_(
                "urlopen error:\n url '%s' - %s")
                % (self.ebics_config_id.ebics_url, str(value)))
        except EbicsFunctionalError:
            e = exc_info()
            error = _("EBICS Functional Error:")
            error += '\n'
            error += '%s (code: %s)' % (e[1].message, e[1].code)
            raise UserError(error)
        except EbicsTechnicalError:
            e = exc_info()
            error = _("EBICS Technical Error:")
            error += '\n'
            error += '%s (code: %s)' % (e[1].message, e[1].code)
            raise UserError(error)

        # Send the public authentication and encryption keys to the bank.
        if ebics_version == 'H003':
            bank._order_number = self.ebics_config_id._get_order_number()
        OrderID = client.HIA()
        _logger.info('%s, EBICS HIA command, OrderID=%s', self._name, OrderID)
        if ebics_version == 'H003':
            self.ebics_config_id._update_order_number(OrderID)

        # Create an INI-letter which must be printed and sent to the bank.
        bank = self.ebics_config_id.journal_ids[0].bank_id
        cc = bank.country.code
        if cc in ['FR', 'DE']:
            lang = cc
        else:
            lang = self.env.user.lang or \
                self.env['res.lang'].search([])[0].code
            lang = lang[:2]
        tmp_dir = os.path.normpath(self.ebics_config_id.ebics_files + '/tmp')
        if not os.path.isdir(tmp_dir):
            os.makedirs(tmp_dir, mode=0o700)
        fn_date = fields.Date.today().isoformat()
        fn = '_'.join(
            [self.ebics_config_id.ebics_host, 'ini_letter', fn_date]) + '.pdf'
        full_tmp_fn = os.path.normpath(tmp_dir + '/' + fn)
        user.create_ini_letter(
            bankname=bank.name,
            path=full_tmp_fn,
            lang=lang)
        with open(full_tmp_fn, 'rb') as f:
            letter = f.read()
            self.write({
                'ebics_ini_letter': base64.encodestring(letter),
                'ebics_ini_letter_fn': fn,
            })

        return self.write({'state': 'init'})

    def ebics_init_2(self):
        """
        Initialization of bank keys - Step 2:
        Activation of the account by the bank.
        """
        if self.state != 'init':
            raise UserError(
                _("Set state to 'Initialisation'."))
        self.ensure_one()
        return self.write({'state': 'get_bank_keys'})

    def ebics_init_3(self):
        """
        Initialization of bank keys - Step 3:

        After the account has been activated the public bank keys
        must be downloaded and checked for consistency.
        """
        self.ensure_one()
        self.ebics_config_id._check_ebics_files()
        if self.state != 'get_bank_keys':
            raise UserError(
                _("Set state to 'Get Keys from Bank'."))
        keyring = EbicsKeyRing(
            keys=self.ebics_keys_fn, passphrase=self.ebics_passphrase)
        bank = EbicsBank(
            keyring=keyring,
            hostid=self.ebics_config_id.ebics_host,
            url=self.ebics_config_id.ebics_url)
        user = EbicsUser(
            keyring=keyring,
            partnerid=self.ebics_config_id.ebics_partner,
            userid=self.name)
        client = EbicsClient(
            bank, user, version=self.ebics_config_id.ebics_version)

        public_bank_keys = client.HPB()
        public_bank_keys = public_bank_keys.encode()
        tmp_dir = os.path.normpath(self.ebics_config_id.ebics_files + '/tmp')
        if not os.path.isdir(tmp_dir):
            os.makedirs(tmp_dir, mode=0o700)
        fn_date = fields.Date.today().isoformat()
        fn = '_'.join(
            [self.ebics_config_id.ebics_host, 'public_bank_keys', fn_date]
        ) + '.txt'
        self.write({
            'ebics_public_bank_keys': base64.encodestring(public_bank_keys),
            'ebics_public_bank_keys_fn': fn,
            'state': 'to_verify',
        })

        return True

    def ebics_init_4(self):
        """
        Initialization of bank keys - Step 2:
        Confirm Verification of the public bank keys
        and activate the bank keyu.
        """
        self.ensure_one()
        if self.state != 'to_verify':
            raise UserError(
                _("Set state to 'Verification'."))

        keyring = EbicsKeyRing(
            keys=self.ebics_keys_fn, passphrase=self.ebics_passphrase)
        bank = EbicsBank(
            keyring=keyring,
            hostid=self.ebics_config_id.ebics_host,
            url=self.ebics_config_id.ebics_url)
        bank.activate_keys()
        return self.write({'state': 'active_keys'})

    def change_passphrase(self):
        self.ensure_one()
        ctx = dict(self._context, default_ebics_userid_id=self.id)
        module = __name__.split('addons.')[1].split('.')[0]
        view = self.env.ref(
            '%s.ebics_change_passphrase_view_form' % module)
        return {
            'name': _('EBICS keys change passphrase'),
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'ebics.change.passphrase',
            'view_id': view.id,
            'target': 'new',
            'context': ctx,
            'type': 'ir.actions.act_window',
        }