From 6d916029bbb5f5c5d7cf8571bf071c69eb937a31 Mon Sep 17 00:00:00 2001
From: Jens Langhammer <jens.langhammer@haufe-lexware.com>
Date: Thu, 21 Mar 2019 16:22:07 +0100
Subject: [PATCH] implement actual Rewriting logic

---
 passbook/app_gw/middleware.py         | 34 +++++++++---------------
 passbook/app_gw/rewrite.py            | 38 +++++++++++++++++++++++++++
 passbook/core/static/css/passbook.css |  4 +++
 3 files changed, 55 insertions(+), 21 deletions(-)
 create mode 100644 passbook/app_gw/rewrite.py

diff --git a/passbook/app_gw/middleware.py b/passbook/app_gw/middleware.py
index b50341dfa..208cdd937 100644
--- a/passbook/app_gw/middleware.py
+++ b/passbook/app_gw/middleware.py
@@ -7,15 +7,14 @@ import certifi
 import urllib3
 from django.core.cache import cache
 from django.utils.http import urlencode
-from django.views.generic import RedirectView
 from revproxy.exceptions import InvalidUpstream
 from revproxy.response import get_django_response
 from revproxy.utils import encode_items, normalize_request_headers
 
 from passbook.app_gw.models import ApplicationGatewayProvider
+from passbook.app_gw.rewrite import Rewriter
 from passbook.core.models import Application
 from passbook.core.policies import PolicyEngine
-from passbook.lib.config import CONFIG
 
 IGNORED_HOSTNAMES_KEY = 'passbook_app_gw_ignored'
 LOGGER = getLogger(__name__)
@@ -100,15 +99,12 @@ class ApplicationGatewayMiddleware:
 
         return upstream
 
-    # def _format_path_to_redirect(self, request):
-    #     full_path = request.get_full_path()
-    #     LOGGER.debug("Dispatch full path: %s", full_path)
-    #     for from_re, to_pattern in []:
-    #         if from_re.match(full_path):
-    #             redirect_to = from_re.sub(to_pattern, full_path)
-    #             LOGGER.debug("Redirect to: %s", redirect_to)
-    #             return redirect_to
-    #     return None
+    def _format_path_to_redirect(self, request):
+        LOGGER.debug("Path before: %s", request.get_full_path())
+        rewriter = Rewriter(self.app_gw, request)
+        after = rewriter.build()
+        LOGGER.debug("Path after: %s", after)
+        return after
 
     def get_proxy_request_headers(self, request):
         """Get normalized headers for the upstream
@@ -152,12 +148,11 @@ class ApplicationGatewayMiddleware:
         get_data = encode_items(self.request.GET.lists())
         return urlencode(get_data)
 
-    def _created_proxy_response(self, request):
+    def _created_proxy_response(self, request, path):
         request_payload = request.body
 
         LOGGER.debug("Request headers: %s", self._request_headers)
 
-        path = request.get_full_path()
         request_url = self.get_upstream() + path
         LOGGER.debug("Request URL: %s", request_url)
 
@@ -215,17 +210,14 @@ class ApplicationGatewayMiddleware:
 
     def dispatch(self, request):
         """Build proxied request and pass to upstream"""
-        if not self.check_permission():
-            to_url = 'https://%s/?next=%s' % (CONFIG.get('domains')[0], request.get_full())
-            return RedirectView.as_view(url=to_url)(request)
+        # if not self.check_permission():
+        #     to_url = 'https://%s/?next=%s' % (CONFIG.get('domains')[0], request.get_full_path())
+        #     return RedirectView.as_view(url=to_url)(request)
 
         self._request_headers = self.get_request_headers()
 
-        # redirect_to = self._format_path_to_redirect(request)
-        # if redirect_to:
-        #     return redirect(redirect_to)
-
-        proxy_response = self._created_proxy_response(request)
+        path = self._format_path_to_redirect(request)
+        proxy_response = self._created_proxy_response(request, path)
 
         self._replace_host_on_redirect_location(request, proxy_response)
         self._set_content_type(request, proxy_response)
diff --git a/passbook/app_gw/rewrite.py b/passbook/app_gw/rewrite.py
new file mode 100644
index 000000000..dc8d6531f
--- /dev/null
+++ b/passbook/app_gw/rewrite.py
@@ -0,0 +1,38 @@
+"""passbook app_gw rewriter"""
+
+from passbook.app_gw.models import RewriteRule
+
+
+class Context:
+    """Empty class which we dynamically add attributes to"""
+
+class Rewriter:
+    """Apply rewrites"""
+
+    __application = None
+    __request = None
+
+    def __init__(self, application, request):
+        self.__application = application
+        self.__request = request
+
+    def __build_context(self, matches):
+        """Build object with .0, .1, etc as groups and give access to request"""
+        context = Context()
+        for index, group_match in enumerate(matches.groups()):
+            setattr(context, "g%d" % (index + 1), group_match)
+        setattr(context, 'request', self.__request)
+        return context
+
+    def build(self):
+        """Run all rules over path and return final path"""
+        path = self.__request.get_full_path()
+        for rule in RewriteRule.objects.filter(provider__in=[self.__application]):
+            matches = rule.compiled_matcher.search(path)
+            if not matches:
+                continue
+            replace_context = self.__build_context(matches)
+            path = rule.replacement.format(context=replace_context)
+            if rule.halt:
+                return path
+        return path
diff --git a/passbook/core/static/css/passbook.css b/passbook/core/static/css/passbook.css
index ca643f80d..b76bdd833 100644
--- a/passbook/core/static/css/passbook.css
+++ b/passbook/core/static/css/passbook.css
@@ -195,3 +195,7 @@ form .form-row p.datetime {
 .selector-remove {
     background: url(../admin/img/selector-icons.svg) 0 -64px no-repeat;
 }
+
+input[data-is-monospace] {
+    font-family: monospace;
+}