# eopayment - online payment library
# Copyright (C) 2011-2020 Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import html
import logging
import os
import os.path
import random
import sys
from datetime import date
from decimal import ROUND_DOWN, Decimal
from gettext import gettext as _

try:
    if 'django' in sys.modules:
        from django.utils.translation import gettext_lazy as _
except ImportError:
    pass


__all__ = [
    'PaymentCommon',
    'URL',
    'HTML',
    'RANDOM',
    'RECEIVED',
    'ACCEPTED',
    'PAID',
    'ERROR',
    'WAITING',
    'STATUS_DESCRIPTION',
    'STATUS_NAME',
]


RANDOM = random.SystemRandom()

URL = 1
HTML = 2
FORM = 3

RECEIVED = 1
ACCEPTED = 2
PAID = 3
DENIED = 4
CANCELLED = 5
CANCELED = 5  # typo for backward compatibility
WAITING = 6
EXPIRED = 7
ERROR = 99

STATUS_DESCRIPTION = {
    RECEIVED: _('started'),
    ACCEPTED: _('authorized'),
    PAID: _('captured'),
    DENIED: _('refused'),
    CANCELLED: _('cancelled'),
    WAITING: _('running'),
    EXPIRED: _('expired'),
    ERROR: _('error'),
}

STATUS_NAME = {
    RECEIVED: 'RECEIVED',
    ACCEPTED: 'ACCEPTED',
    PAID: 'PAID',
    DENIED: 'DENIED',
    CANCELLED: 'CANCELLED',
    WAITING: 'WAITING',
    EXPIRED: 'EXPIRED',
    ERROR: 'ERROR',
}


# separator between order and transaction ids
ORDERID_TRANSACTION_SEPARATOR = '!'


def force_text(s, encoding='utf-8'):
    if issubclass(type(s), str):
        return s
    try:
        if not issubclass(type(s), str):
            if isinstance(s, bytes):
                s = str(s, encoding)
            else:
                s = str(s)
        else:
            s = s.decode(encoding)
    except UnicodeDecodeError:
        return str(s, encoding, 'ignore')
    return s


def force_byte(s, encoding='utf-8'):
    if isinstance(s, bytes):
        return s
    try:
        return s.encode(encoding)
    except UnicodeEncodeError:
        return s.encode()


class PaymentException(Exception):
    pass


class ResponseError(PaymentException):
    pass


class BackendNotFound(PaymentException):
    pass


class PaymentResponse:
    """Holds a generic view on the result of payment transaction response.

    result -- holds the declarative result of the transaction, does not use
    it to validate the payment in your backoffice, it's just for informing
    the user that all is well.
    test -- indicates if the transaction was a test
    signed -- holds whether the message was signed
    bank_data -- a dictionnary containing some data depending on the bank,
    you have to log it for audit purpose.
    return_content -- when handling a response in a callback endpoint, i.e.
    a response transmitted directly from the bank to the merchant website,
    you usually have to confirm good reception of the message by returning a
    properly formatted response, this is it.
    bank_status -- if result is False, it contains the reason
    order_id -- the id given by the merchant in the payment request
    transaction_id -- the id assigned by the bank to this transaction, it
    could be the one sent by the merchant in the request, but it is usually
    an identifier internal to the bank.
    """

    def __init__(
        self,
        result=None,
        signed=None,
        bank_data=dict(),
        return_content=None,
        bank_status='',
        transaction_id='',
        order_id='',
        test=False,
        transaction_date=None,
    ):
        self.result = result
        self.signed = signed
        self.bank_data = bank_data
        self.return_content = return_content
        self.bank_status = bank_status
        self.transaction_id = transaction_id
        self.order_id = order_id
        self.test = test
        self.transaction_date = transaction_date

    def __repr__(self):
        return '<%s %s>' % (self.__class__.__name__, repr(self.__dict__))

    def is_received(self):
        return self.result == RECEIVED

    def is_accepted(self):
        return self.result == ACCEPTED

    def is_paid(self):
        return self.result == PAID

    def is_error(self):
        return self.result == ERROR

    def as_dict(self):
        serialization = self.__dict__.copy()
        # serialize datetimes
        if hasattr(self.transaction_date, 'isoformat'):
            serialization['transaction_date'] = self.transaction_date.isoformat()
        return serialization


class PaymentCommon:
    has_free_transaction_id = False
    has_empty_response = False
    min_time_between_transactions = 60 * 20  # 20 minutes

    PATH = '/tmp'
    BANK_ID = '__bank_id'

    def __init__(self, options, logger=None):
        self.logger = logger or logging.getLogger(self.__class__.__module__)
        self.logger.debug('initializing with options %s', options)
        for value in self.description['parameters']:
            key = value['name']
            if 'default' in value:
                setattr(self, key, options.get(key, None) or value['default'])
            else:
                setattr(self, key, options.get(key))

    def transaction_id(self, length, choices, *prefixes):
        while True:
            parts = [RANDOM.choice(choices) for x in range(length)]
            id = ''.join(parts)
            name = '%s_%s_%s' % (str(date.today()), '-'.join(prefixes), str(id))
            try:
                fd = os.open(os.path.join(self.PATH, name), os.O_CREAT | os.O_EXCL)
            except Exception:
                raise
            else:
                os.close(fd)
                return id

    @staticmethod
    def clean_amount(amount, min_amount=0, max_amount=None, cents=True):
        try:
            amount = Decimal(amount)
        except ValueError:
            raise ValueError(
                'invalid amount %s: it must be a decimal integer with two digits '
                'at most after the decimal point',
                amount,
            )
        if int(amount) < min_amount or (max_amount and int(amount) > max_amount):
            raise ValueError('amount %s is not in range [%s, %s]' % (amount, min_amount, max_amount))
        if cents:
            amount *= Decimal('100')  # convert to cents
            amount = amount.to_integral_value(ROUND_DOWN)
            amount = '%03d' % amount
        return str(amount)


class Form:
    def __init__(self, url, method, fields, encoding='utf-8', submit_name='Submit', submit_value='Submit'):
        self.url = url
        self.method = method
        self.fields = fields
        self.encoding = encoding
        self.submit_name = submit_name
        self.submit_value = submit_value

    def __repr__(self):
        s = '%s(' % self.__class__.__name__
        kwargs = []
        for k in ('url', 'method', 'fields', 'encoding', 'submit_name', 'submit_value'):
            kwargs.append('%s=%r' % (k, getattr(self, k)))
        s += ', '.join(kwargs)
        s += ')'
        return s

    def escape(self, s):
        return html.escape(force_text(s, self.encoding))

    def __str__(self):
        s = '<form method="%s" action="%s">' % (self.method, self.url)
        for field in self.fields:
            s += '\n  <input type="%s" name="%s" value="%s"/>' % (
                self.escape(field['type']),
                self.escape(field['name']),
                self.escape(field['value']),
            )
        s += '\n  <input type="submit"'
        if self.submit_name:
            s += ' name="%s"' % self.escape(self.submit_name)
        if self.submit_value:
            s += ' value="%s"' % self.escape(self.submit_value)
        s += ' />'
        s += '\n</form>'
        return s
