[ADD] hw_blackbox_be: implements the Belgian blackbox protocol

To be used together with the pos_blackbox_be module.

The protocol specification is available in:
http://www.minfin.fgov.be/portail2/fr/current/spokesperson-12-06-05.htm

4 files changed, 194 insertions, 0 deletions

diff --git a/addons/hw_blackbox_be/__init__.py b/addons/hw_blackbox_be/__init__.py
new file mode 100644
index 00000000000..bf7fb7b45c1
--- /dev/null
+++ b/addons/hw_blackbox_be/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import controllers
diff --git a/addons/hw_blackbox_be/__openerp__.py b/addons/hw_blackbox_be/__openerp__.py
new file mode 100644
index 00000000000..d33930e2143
--- /dev/null
+++ b/addons/hw_blackbox_be/__openerp__.py
@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+{
+    'name': 'Blackbox Hardware Driver',
+    'version': '1.0',
+    'category': 'Hardware Drivers',
+    'sequence': 6,
+    'summary': 'Hardware Driver for Belgian Fiscal Data Modules',
+    'website': 'https://www.odoo.com/page/point-of-sale',
+    'description': """
+Fiscal Data Module Hardware Driver
+==================================
+
+This module allows a Point Of Sale client to communicate with a
+connected Belgian Fiscal Data Module.
+""",
+    'author': 'OpenERP SA',
+    'depends': ['hw_proxy'],
+    'external_dependencies': {'python': ['serial']},
+    'test': [
+    ],
+    'installable': True,
+    'auto_install': False,
+}
diff --git a/addons/hw_blackbox_be/controllers/__init__.py b/addons/hw_blackbox_be/controllers/__init__.py
new file mode 100644
index 00000000000..f48716d3a69
--- /dev/null
+++ b/addons/hw_blackbox_be/controllers/__init__.py
@@ -0,0 +1,4 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import main
diff --git a/addons/hw_blackbox_be/controllers/main.py b/addons/hw_blackbox_be/controllers/main.py
new file mode 100644
index 00000000000..fbc7664cbc0
--- /dev/null
+++ b/addons/hw_blackbox_be/controllers/main.py
@@ -0,0 +1,162 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import logging
+import serial
+from os import listdir
+from threading import Thread, Lock
+
+from openerp import http
+
+import openerp.addons.hw_proxy.controllers.main as hw_proxy
+
+_logger = logging.getLogger(__name__)
+
+class Blackbox(Thread):
+    def __init__(self):
+        Thread.__init__(self)
+        self.blackbox_lock = Lock()
+        self.set_status('connecting')
+        self.device_path = self._find_device_path_by_probing()
+
+    def set_status(self, status, messages=[]):
+        self.status = {
+            'status': status,
+            'messages': messages
+        }
+
+    def get_status(self):
+        return self.status
+
+    # There is no real way to find a serial device, all you can really
+    # find is the name of the serial to usb interface, which in the
+    # case of the blackbox is not defined because it doesn't always
+    # come with it's own interface (eg. Retail Cleancash SC-B). So, in
+    # order to differentiate between other devices like this, what
+    # we'll do is probe every serial device with an FDM status
+    # request. The first device to give an answer that makes sense
+    # wins.
+    def _find_device_path_by_probing(self):
+        path = "/dev/serial/by-id/"
+        probe_message = self._wrap_low_level_message_around("S000")
+
+        try:
+            devices = listdir(path)
+        except OSError:
+            _logger.warning(path + " doesn't exist")
+        else:
+            for device in listdir(path):
+                path_to_device = path + device
+                _logger.debug("Probing " + device)
+
+                if self._send_to_blackbox(probe_message, 21, path_to_device, just_wait_for_ack=True):
+                    _logger.info(device + " will be used as the blackbox")
+                    self.set_status("connected", [device])
+                    return path_to_device
+
+            _logger.warning("Blackbox could not be found")
+            self.set_status("error", ["Couldn't find the Fiscal Data Module"])
+            return ""
+
+    def _lrc(self, msg):
+        lrc = 0
+
+        for character in msg:
+            byte = ord(character)
+            lrc = (lrc + byte) & 0xFF
+
+        lrc = ((lrc ^ 0xFF) + 1) & 0xFF
+
+        return lrc
+
+    def _wrap_low_level_message_around(self, high_level_message):
+        bcc = self._lrc(high_level_message)
+        high_level_message_bytes = map(ord, high_level_message)
+
+        low_level_message = bytearray()
+        low_level_message.append(0x02)
+        low_level_message.extend(high_level_message_bytes)
+        low_level_message.append(0x03)
+        low_level_message.append(bcc)
+
+        return low_level_message
+
+    def _send_and_wait_for_ack(self, packet, serial):
+        ack = 0
+        MAX_RETRIES = 1
+
+        while ack != 0x06 and int(chr(packet[4])) < MAX_RETRIES:
+            serial.write(packet)
+            ack = serial.read(1)
+
+            # This violates the principle that we do high level
+            # client-side and low level posbox-side but the retry
+            # counter is always in a fixed position in the high level
+            # message so it's safe to do it. Also it would be a pain
+            # to have to throw this all the way back to js just so it
+            # can increment the retry counter and then try again.
+            packet = packet[:4] + str(int(packet[4]) + 1) + packet[5:]
+
+            if ack:
+                ack = ord(ack)
+            else:
+                _logger.warning("did not get ACK, retrying...")
+                ack = 0
+
+        if ack == 0x06:
+            return True
+        else:
+            _logger.error("retried " + str(MAX_RETRIES) + " times without receiving ACK, is blackbox properly connected?")
+            return False
+
+    def _send_to_blackbox(self, packet, response_size, device_path, just_wait_for_ack=False):
+        if not device_path:
+            return ""
+
+        ser = serial.Serial(port=device_path,
+                            baudrate=19200,
+                            timeout=3)
+        MAX_NACKS = 1
+        got_response = False
+        sent_nacks = 0
+
+        if self._send_and_wait_for_ack(packet, ser):
+            if just_wait_for_ack:
+                return True
+
+            while not got_response and sent_nacks < MAX_NACKS:
+                stx = ser.read(1)
+                response = ser.read(response_size)
+                etx = ser.read(1)
+                bcc = ser.read(1)
+
+                if stx == chr(0x02) and etx == chr(0x03) and bcc and self._lrc(response) == ord(bcc):
+                    got_response = True
+                    ser.write(chr(0x06))
+                else:
+                    _logger.warning("received ACK but not a valid response, sending NACK...")
+                    sent_nacks += 1
+                    ser.write(chr(0x15))
+
+            if not got_response:
+                _logger.error("sent " + str(MAX_NACKS) + " NACKS without receiving response, giving up.")
+                return ""
+
+            ser.close()
+            return response
+        else:
+            ser.close()
+            return ""
+
+blackbox_thread = Blackbox()
+hw_proxy.drivers['fiscal_data_module'] = blackbox_thread
+
+class BlackboxDriver(hw_proxy.Proxy):
+    @http.route('/hw_proxy/request_blackbox/', type='json', auth='none', cors='*')
+    def request_blackbox(self, high_level_message, response_size):
+        to_send = blackbox_thread._wrap_low_level_message_around(high_level_message)
+
+        with blackbox_thread.blackbox_lock:
+            response = blackbox_thread._send_to_blackbox(to_send, response_size, blackbox_thread.device_path)
+
+        return response