From 86f095d13b88d7b643a6c2df63a2919385400601 Mon Sep 17 00:00:00 2001
From: Dariusz Aniszewski <dariusz.aniszewski@polidea.com>
Date: Sun, 14 Jun 2015 21:50:50 +0200
Subject: [PATCH] downloading PDF invoice

---
 python_ifirma/core.py  | 36 ++++++++++++++++++++++++++++++++----
 python_ifirma/tests.py | 14 ++++++++++----
 2 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/python_ifirma/core.py b/python_ifirma/core.py
index 5699009..a6b61ea 100644
--- a/python_ifirma/core.py
+++ b/python_ifirma/core.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+import six
 import json
 import datetime
 from time import strftime
@@ -129,6 +130,12 @@ class iFirmaAPI():
 
         return response_dict
 
+    def __create_authentication_header_value(self, request_hash_text):
+        return "IAPIS user={}, hmac-sha1={}".format(
+            self.__username,
+            Helpers.get_hmac_of_text(self.__invoice_key_value, request_hash_text)
+        )
+
     def __create_invoice_and_return_id(self, invoice, url):
         request_content = json.dumps(invoice.get_request_data(), separators=(',', ':'))
         request_hash_text = "{}{}{}{}".format(
@@ -140,10 +147,7 @@ class iFirmaAPI():
         headers = {
             "Accept": "application/json",
             "Content-type": "application/json; charset=UTF-8",
-            "Authentication": "IAPIS user={}, hmac-sha1={}".format(
-                self.__username,
-                Helpers.get_hmac_of_text(self.__invoice_key_value, request_hash_text)
-            )
+            "Authentication": self.__create_authentication_header_value(request_hash_text)
         }
 
         response_dict = self.__execute_post_request(headers, request_content, url)
@@ -157,3 +161,27 @@ class iFirmaAPI():
     def generate_invoice(self, invoice):
         url = "https://www.ifirma.pl/iapi/fakturakraj.json"
         return self.__create_invoice_and_return_id(invoice, url)
+
+    def get_invoice_pdf(self, invoice_id):
+        url = "https://www.ifirma.pl/iapi/fakturakraj/{}.pdf".format(invoice_id)
+        return self.__download_pdf(url)
+
+    def __download_pdf(self, url):
+        request_hash_text = "{}{}{}".format(
+            url,
+            self.__username,
+            self.__invoice_key_value,
+        )
+        headers = {
+            "Accept": "application/pdf",
+            "Content-type": "application/pdf; charset=UTF-8",
+            "Authentication": self.__create_authentication_header_value(request_hash_text)
+        }
+        resp = requests.get(url, headers=headers)
+
+        content = resp.content
+
+        file_obj = six.BytesIO()
+        file_obj.write(content)
+        file_obj.seek(0)
+        return file_obj
\ No newline at end of file
diff --git a/python_ifirma/tests.py b/python_ifirma/tests.py
index 13d0507..b768266 100644
--- a/python_ifirma/tests.py
+++ b/python_ifirma/tests.py
@@ -5,9 +5,9 @@ from python_ifirma import exceptions
 from python_ifirma.helpers import Helpers
 
 
-TEST_IFIRMA_USER = "$DEMO254271"
-TEST_IFIRMA_INVOICE_KEY = "7B10B300C2C029E2"
-TEST_IFIRMA_USER_KEY = "12EFF84EFE80A28A"
+TEST_IFIRMA_USER = "$DEMO254343"
+TEST_IFIRMA_INVOICE_KEY = "C501C88284462384"
+TEST_IFIRMA_USER_KEY = "B83E825D4D28BD11"
 
 
 class TestHelpers(TestCase):
@@ -113,4 +113,10 @@ class TestCreateInvoice(TestCase):
 
         with self.assertRaises(exceptions.BadRequestParameters):
             invoice = NewInvoiceParams(self.client, [bad_position])
-            self.ifirma_client.generate_invoice(invoice)
\ No newline at end of file
+            self.ifirma_client.generate_invoice(invoice)
+
+    def test_download_invoice(self):
+        invoice = NewInvoiceParams(self.client, [self.position])
+        invoice_id = self.ifirma_client.generate_invoice(invoice)
+
+        self.assertIsNotNone(self.ifirma_client.get_invoice_pdf(invoice_id))
\ No newline at end of file