comment code, minor bug fixes

2 files changed, 211 insertions, 48 deletions

diff --git a/server/templates/server/doc_list.html b/server/templates/server/doc_list.html
index 7bdbb17..66ff997 100644
--- a/server/templates/server/doc_list.html
+++ b/server/templates/server/doc_list.html
@@ -434,6 +434,15 @@
                     </div>
                   </div>
                 </div>
+                <div class="row">
+                  <div class="col s12">
+                    <div class="card">
+                      <div class="card-image">
+                        {% if doc.7 %}<img src="data:;base64,{{ doc.7 }}">{% endif %}
+                      </div>
+                    </div>
+                  </div>
+                </div>
               </span></div>
             </li>
           {% endif %}
diff --git a/server/views.py b/server/views.py
index 01e8109..dec4e11 100644
--- a/server/views.py
+++ b/server/views.py
@@ -16,10 +16,12 @@ from datetime import timedelta
 import pytz
 import pdfkit
 from io import BytesIO
-import os, base64
+import os
+import base64
 from PIL import Image, UnidentifiedImageError
 
 
+# custom staff check function for non primary group staff members
 def isStaff(user):
     if user.is_staff:
         return True
@@ -31,41 +33,46 @@ def isStaff(user):
 @user_passes_test(isStaff)
 def index(request):
     context = {}
+    # primary group name + object
     parent_group = request.user.groups.values_list('name', flat=True)[
         0]
+    group = Group.objects.get(name=parent_group)
+    # users from younger to older
     users = User.objects.filter(groups__name=parent_group).order_by("-id")
     users_out = []
 
+    # only send part of the user data, only if user is approved
     for user in users:
         if not user.has_perm("client.approved") and not user.is_staff:
             continue
 
         users_out.append([user.username, user.first_name,
-                    user.last_name])
+                          user.last_name])
 
-    parent_group = request.user.groups.values_list('name', flat=True)[
-        0]
-    group = Group.objects.get(name=parent_group)
+    # if user is staff of not primary show only public types
     if request.user.is_staff:
         public_types = DocumentType.objects.filter(
             Q(group_private=False) | Q(group=group) & Q(enabled=True)).order_by("-id")
     else:
         public_types = DocumentType.objects.filter(
             Q(group_private=False) & Q(enabled=True)).order_by("-id")
+
+    # count documents of that type to show statistics
     docs = []
     for doc in public_types:
         ref_docs = Document.objects.filter(document_type=doc)
         docs.append([doc, len(ref_docs)])
 
+    # don't list users if user is staff of not primary
     if request.user.is_staff:
         context = {
             'docs': docs,
             'users': users_out,
-            }
+        }
     else:
         context = {
             'docs': docs,
-            }
+        }
     return render(request, 'server/index.html', context)
 
 
@@ -74,13 +81,19 @@ def uapprove(request):
     context = {}
     data = []
     if request.method == "POST":
+        # get group name and obj
         parent_group = request.user.groups.values_list('name', flat=True)[
             0]
         group = Group.objects.get(name=parent_group)
+
+        # get permission object
         permission = Permission.objects.get(codename='approved')
+
+        # parse text to array
         data = request.POST["codes"]
         data.replace("\r", "")
         data = data.split("\n")
+        # check if format is right
         for i in range(len(data)):
             if not data[i].startswith("U"):
                 data[i] = data[i] + " - Formato errato"
@@ -93,13 +106,16 @@ def uapprove(request):
             else:
                 user = UserCode.objects.filter(code=data[i][1:])[0].user
                 user.user_permissions.add(permission)
+                # if user not in any group add to the same group as staff
                 if len(user.groups.values_list('name', flat=True)) == 0:
                     user.groups.add(group)
                     data[i] = data[i] + " - Ok"
                 else:
                     if user.groups.values_list('name', flat=True)[0] == parent_group:
+                        # if user already in group do nothing
                         data[i] = data[i] + " - Ok"
                     else:
+                        # if user in another group notify staff of group change
                         user.groups.clear()
                         user.groups.add(group)
                         data[i] = data[i] + " - Ok, cambio branca"
@@ -116,19 +132,24 @@ def uapprove(request):
 def docapprove(request):
     context = {}
     data = []
+
+    # group name and obj
     parent_group = request.user.groups.values_list('name', flat=True)[
         0]
+    group = Group.objects.get(name=parent_group)
 
+    # if user not staff of primary has only controll of non primary groups
     if request.user.is_staff:
         groups = request.user.groups.values_list('name', flat=True)
     else:
         groups = request.user.groups.values_list('name', flat=True)[1:]
 
-    group = Group.objects.get(name=parent_group)
     if request.method == "POST":
+        # parse text in array
         data = request.POST["codes"]
         data.replace("\r", "")
         data = data.split("\n")
+        # check if code valid
         for i in range(len(data)):
             print(Document.objects.filter(code=data[i])[0].group.name)
             if not data[i].isdigit():
@@ -138,10 +159,12 @@ def docapprove(request):
             elif len(Document.objects.filter(code=data[i])) == 0:
                 data[i] = data[i] + " - Invalido"
             elif Document.objects.filter(code=data[i])[0].group.name not in groups:
+                # check if user has permission to approve document
                 data[i] = data[i] + " - Invalido"
             else:
                 document = Document.objects.filter(code=data[i])[0]
                 if document.status == 'ok':
+                    # do nothing document already approved
                     data[i] = data[i] + " - Già approvato"
                 else:
                     document.status = 'ok'
@@ -159,54 +182,80 @@ def docapprove(request):
 @staff_member_required
 def ulist(request):
     context = {}
+    # group name and obj
     parent_group = request.user.groups.values_list('name', flat=True)[0]
     group = Group.objects.get(name=parent_group)
+
     if request.method == "POST":
+        # request to download document
         if request.POST["action"][0] == 'f':
             document = Document.objects.get(id=request.POST["action"][1:])
+            # check if user has permission to view document
             if document.group == group:
                 vac_file = ""
                 health_file = ""
                 sign_doc_file = ""
+
+                # prepare pictures in base64
                 if document.medical_data:
                     if document.medical_data.vac_certificate.name:
                         with open(document.medical_data.vac_certificate.name, 'rb') as image_file:
-                            vac_file = base64.b64encode(image_file.read()).decode()
+                            vac_file = base64.b64encode(
+                                image_file.read()).decode()
 
                     if document.medical_data.health_care_certificate.name:
                         with open(document.medical_data.health_care_certificate.name, 'rb') as image_file:
-                            health_file = base64.b64encode(image_file.read()).decode()
+                            health_file = base64.b64encode(
+                                image_file.read()).decode()
                 if document.signed_doc:
                     with open(document.signed_doc.name, 'rb') as image_file:
-                        sign_doc_file = base64.b64encode(image_file.read()).decode()
+                        sign_doc_file = base64.b64encode(
+                            image_file.read()).decode()
 
+                # get template and build context
                 template = get_template('server/download_doc.html')
-                doc = [document, KeyVal.objects.filter(container=document), document.personal_data, document.medical_data, parent_group]
-                context = {'doc': doc, 'vac': vac_file, 'health': health_file, 'sign_doc_file': sign_doc_file}
+                doc = [document, KeyVal.objects.filter(
+                    container=document), document.personal_data, document.medical_data, parent_group]
+                context = {'doc': doc, 'vac': vac_file,
+                           'health': health_file, 'sign_doc_file': sign_doc_file}
+                # render context
                 html = template.render(context)
+                # render pdf using wkhtmltopdf
                 pdf = pdfkit.from_string(html, False)
                 result = BytesIO(pdf)
                 result.seek(0)
 
                 return FileResponse(result, as_attachment=True, filename=document.user.username+"_"+document.document_type.name+".pdf")
+
+        # deapprove user
         elif request.POST["action"][0] == 'd':
             user = User.objects.get(id=request.POST["action"][1:])
+            # check if user has permission to deapprove user
             if user.groups.all()[0] == group:
                 content_type = ContentType.objects.get_for_model(Document)
-                permission = Permission.objects.get(content_type=content_type, codename="approved")
+                permission = Permission.objects.get(
+                    content_type=content_type, codename="approved")
                 user.user_permissions.remove(permission)
                 return HttpResponseRedirect("ulist")
 
-    users = User.objects.filter(groups__name=parent_group).order_by("first_name")
+    # list users with their documents
+    users = User.objects.filter(
+        groups__name=parent_group).order_by("first_name")
     out = []
     for user in users:
+        # list only approved users
         if not user.has_perm("client.approved") and not user.is_staff:
             continue
 
         usercode = UserCode.objects.filter(user=user)[0]
-        documents = Document.objects.filter(Q(user=user) & ~Q(status='archive') & Q(group__name=parent_group))
+        # get all user documents
+        documents = Document.objects.filter(Q(user=user) & ~Q(
+            status='archive') & Q(group__name=parent_group))
+
+        # encode images in base64
         vac_file = ""
         health_file = ""
+        sign_doc_file = ""
         if usercode.medic:
             if usercode.medic.vac_certificate.name:
                 with open(usercode.medic.vac_certificate.name, 'rb') as image_file:
@@ -215,7 +264,8 @@ def ulist(request):
             if usercode.medic.health_care_certificate.name:
                 with open(usercode.medic.health_care_certificate.name, 'rb') as image_file:
                     health_file = base64.b64encode(image_file.read()).decode()
-        out.append([user, usercode, parent_group, documents, vac_file, health_file])
+        out.append([user, usercode, parent_group,
+                    documents, vac_file, health_file])
     context = {'users': out}
     return render(request, 'server/user_list.html', context)
 
@@ -223,9 +273,12 @@ def ulist(request):
 @user_passes_test(isStaff)
 def doctype(request):
     context = {}
+
+    # error variables to throw at user
     error = False
     error_text = ""
 
+    # init checkboxes
     public = True
     selfsign = True
     hidden = False
@@ -242,21 +295,28 @@ def doctype(request):
     custom_check = 'checked="checked"'
     message_check = 'checked="checked"'
     group_check = 'checked="checked"'
+
     if request.method == "POST":
         selected = []
+        # if user not staff of primary get only non primary groups
         if request.user.is_staff:
             parent_groups = request.user.groups.values_list('name', flat=True)
         else:
-            parent_groups = request.user.groups.values_list('name', flat=True)[1:]
+            parent_groups = request.user.groups.values_list('name', flat=True)[
+                1:]
+
+        # list all selected types
         for i in request.POST.keys():
             if i.isdigit():
                 docc = DocumentType.objects.get(id=i)
+                # check if user has permission
                 if docc.group.name in parent_groups:
                     selected.append(docc)
                 else:
                     error = True
                     error_text = "Non puoi modificare un documento non del tuo gruppo"
 
+        # execute action on selected types
         for i in selected:
             if request.POST["action"] == 'delete':
                 try:
@@ -271,6 +331,7 @@ def doctype(request):
                 i.enabled = True
                 i.save()
 
+        # check which filters are applied
         public = "filter_public" in request.POST
         selfsign = "filter_selfsign" in request.POST
         hidden = "filter_hidden" in request.POST
@@ -280,6 +341,7 @@ def doctype(request):
         message = "filter_message" in request.POST
         group_bool = "filter_group" in request.POST
 
+        # check if request to clear filters
         if request.POST["action"] == 'clear':
             public = True
             selfsign = True
@@ -290,15 +352,20 @@ def doctype(request):
             message = True
             group_bool = True
 
+    # group name and obj
     parent_group = request.user.groups.values_list('name', flat=True)[
         0]
     group = Group.objects.get(name=parent_group)
+
+    # if user not staff of primary group show only public types
     if request.user.is_staff:
         public_types = DocumentType.objects.filter(
             Q(group_private=False) | Q(group=group))
     else:
         public_types = DocumentType.objects.filter(
             Q(group_private=False))
+
+    # apply filters
     if not public:
         public_types = public_types.filter(group_private=True)
         public_check = ""
@@ -324,6 +391,7 @@ def doctype(request):
         public_types = public_types.filter(custom_group=False)
         group_check = ""
 
+    # get custom keys from types
     out = []
     for doc in public_types:
         custom_keys = Keys.objects.filter(container=doc)
@@ -342,26 +410,33 @@ def doctype(request):
         'group_check': group_check,
         'error': error,
         'error_text': error_text,
-        }
+    }
     return render(request, 'server/doc_type.html', context)
 
 
 @user_passes_test(isStaff)
 def doccreate(request):
     context = {}
+
+    # if user is not staff of primary set default group to secondary and default public type
     if request.user.is_staff:
         groups = request.user.groups.values_list('name', flat=True)
         parent_group = request.user.groups.values_list('name', flat=True)[
             0]
+        group_private = False
+        private_check = 'checked="checked"'
     else:
         groups = request.user.groups.values_list('name', flat=True)[1:]
         parent_group = request.user.groups.values_list('name', flat=True)[
             1]
+        group_private = True
+        private_check = ''
 
+    # get group obj
     group = Group.objects.get(name=parent_group)
 
+    # init checkboxes
     enabled = False
-    group_private = False
     personal_data = False
     medical_data = False
     custom_data = False
@@ -370,22 +445,15 @@ def doccreate(request):
     custom_group = ""
 
     enabled_check = 'checked="checked"'
-    private_check = 'checked="checked"'
     personal_check = 'checked="checked"'
     sign_check = 'checked="checked"'
     medical_check = ""
     custom_check = ""
     custom_message_check = ""
-    context = {
-        "enabled_check": enabled_check,
-        "private_check": private_check,
-        "sign_check": sign_check,
-        "personal_check": personal_check,
-        "medical_check": medical_check,
-        "custom_check": custom_check,
-        "custom_message_check": custom_message_check,
-    }
+
+    # if type create request sent
     if request.method == "POST":
+        # gather inserted data
         enabled = "enabled" in request.POST.keys()
         auto_sign = "sign" not in request.POST.keys()
         group_private = "group_private" in request.POST.keys()
@@ -397,12 +465,24 @@ def doccreate(request):
         name = request.POST["name"]
         custom_group = request.POST["custom_group"]
 
+        # if group not primary and not public throw error
+        if group_private == True and not request.user.is_staff:
+            context["error"] = "true"
+            context["error_text"] = "Non puoi creare un documento non pubblico per un gruppo non primario"
+            return render(request, 'server/doc_create.html', context)
+
+        # if already existing name throw error
         if len(DocumentType.objects.filter(name=name)) > 0:
             context["error"] = "true"
             context["error_text"] = "Questo nome esiste già. Prego usarne un altro."
             return render(request, 'server/doc_create.html', context)
 
+        # check if custom group permissions not met or non public document
         if custom_group != "":
+            if group_private == True:
+                context["error"] = "true"
+                context["error_text"] = "Non puoi creare un documento non pubblico per un gruppo non primario"
+                return render(request, 'server/doc_create.html', context)
             if custom_group not in groups:
                 context["error"] = "true"
                 context["error_text"] = "Non puoi creare un tipo assegnato ad un gruppo di cui non fai parte"
@@ -411,9 +491,12 @@ def doccreate(request):
                 group = Group.objects.filter(name=custom_group)[0]
                 custom_group_bool = True
 
+        # create type
         doctype = DocumentType(
             custom_group=custom_group_bool, auto_sign=auto_sign, custom_message=custom_message, custom_message_text=custom_message_text, name=request.POST["name"], enabled=enabled, group_private=group_private, group=group, personal_data=personal_data, medical_data=medical_data, custom_data=custom_data)
         doctype.save()
+
+        # create custom keys
         if custom_data:
             custom = request.POST["custom"]
             custom.replace("\r", "")
@@ -421,27 +504,46 @@ def doccreate(request):
             for i in custom:
                 key = Keys(key=i, container=doctype)
                 key.save()
+
         return HttpResponseRedirect('doctype')
 
+    # build context
+    context = {
+        "enabled_check": enabled_check,
+        "private_check": private_check,
+        "sign_check": sign_check,
+        "personal_check": personal_check,
+        "medical_check": medical_check,
+        "custom_check": custom_check,
+        "custom_message_check": custom_message_check,
+    }
+
     return render(request, 'server/doc_create.html', context)
 
 
 @user_passes_test(isStaff)
 def doclist(request):
     context = {}
+
+    # group name and obj
     parent_group = request.user.groups.values_list('name', flat=True)[
         0]
     group = Group.objects.get(name=parent_group)
 
+    # if user not staff of primary get secondary groups
     if request.user.is_staff:
         parent_groups = request.user.groups.values_list('name', flat=True)
     else:
         parent_groups = request.user.groups.values_list('name', flat=True)[1:]
 
+    # create typezone
     zurich = pytz.timezone('Europe/Zurich')
+
+    # init error variables for users
     error = False
     error_text = ""
 
+    # init checkboxes for filter
     hidden = False
     wait = True
     selfsign = True
@@ -453,8 +555,12 @@ def doclist(request):
     selfsign_check = 'checked="checked"'
     ok_check = 'checked="checked"'
     signdoc_check = 'checked="checked"'
+
+    # set default dates for filters
     newer = zurich.localize(dateparser.parse("1970-01-01"))
     older = zurich.localize(datetime.now())
+
+    # init chips values
     owner = []
     types = []
     groups = []
@@ -463,28 +569,38 @@ def doclist(request):
     chips_groups = []
 
     if request.method == "POST":
+        # if download request
         if request.POST["action"][0] == 'k':
             document = Document.objects.get(id=request.POST["action"][1:])
+            # check if user has permission to view doc
             if document.group.name in parent_groups:
                 vac_file = ""
                 health_file = ""
                 sign_doc_file = ""
+
+                # prepare images in base64
                 if document.medical_data:
                     if document.medical_data.vac_certificate.name:
                         with open(document.medical_data.vac_certificate.name, 'rb') as image_file:
-                            vac_file = base64.b64encode(image_file.read()).decode()
+                            vac_file = base64.b64encode(
+                                image_file.read()).decode()
 
                     if document.medical_data.health_care_certificate.name:
                         with open(document.medical_data.health_care_certificate.name, 'rb') as image_file:
-                            health_file = base64.b64encode(image_file.read()).decode()
-                
+                            health_file = base64.b64encode(
+                                image_file.read()).decode()
+
                 if document.signed_doc:
                     with open(document.signed_doc.name, 'rb') as image_file:
-                        sign_doc_file = base64.b64encode(image_file.read()).decode()
+                        sign_doc_file = base64.b64encode(
+                            image_file.read()).decode()
 
+                # build with template and render
                 template = get_template('server/download_doc.html')
-                doc = [document, KeyVal.objects.filter(container=document), document.personal_data, document.medical_data, parent_group]
-                context = {'doc': doc, 'vac': vac_file, 'health': health_file, 'sign_doc_file': sign_doc_file}
+                doc = [document, KeyVal.objects.filter(
+                    container=document), document.personal_data, document.medical_data, parent_group]
+                context = {'doc': doc, 'vac': vac_file,
+                           'health': health_file, 'sign_doc_file': sign_doc_file}
                 html = template.render(context)
                 pdf = pdfkit.from_string(html, False)
                 result = BytesIO(pdf)
@@ -492,6 +608,7 @@ def doclist(request):
 
                 return FileResponse(result, as_attachment=True, filename=document.user.username+"_"+document.document_type.name+".pdf")
 
+        # get selected documents and check if user has permission to view
         selected = []
         for i in request.POST.keys():
             if i.isdigit():
@@ -499,6 +616,7 @@ def doclist(request):
                 if docc.group.name in parent_groups:
                     selected.append(docc)
 
+        # execute action on selected documents
         for i in selected:
             if request.POST["action"] == 'delete' and settings.DEBUG:
                 i.delete()
@@ -522,35 +640,41 @@ def doclist(request):
                 else:
                     error = True
                     error_text = "Non puoi dearchiviare un documento non archiviato"
-        
+
+        # get filter values
         hidden = "filter_hidden" in request.POST
         wait = "filter_wait" in request.POST
         selfsign = "filter_selfsign" in request.POST
         ok = "filter_ok" in request.POST
         signdoc = "filter_signdoc" in request.POST
         newer = zurich.localize(dateparser.parse(request.POST["newer"]))
-        older = zurich.localize(dateparser.parse(request.POST["older"]) + timedelta(days=1))
+        older = zurich.localize(dateparser.parse(
+            request.POST["older"]) + timedelta(days=1))
         owner = request.POST["owner"].split("^|")
         types = request.POST["type"].split("^|")
         groups = request.POST["groups"].split("^|")
 
+        # clear filters
         if request.POST["action"] == 'clear':
             hidden = False
             wait = True
             selfsign = True
             ok = True
+            signdoc = False
             newer = zurich.localize(dateparser.parse("1970-01-01"))
             older = zurich.localize(datetime.now())
             owner = []
             types = []
             groups = []
 
+    # filter documents based on group of staff
     q_obj = Q()
     for i in parent_groups:
         q_obj |= Q(group__name=i)
 
     documents = Document.objects.filter(q_obj)
 
+    # filter documents
     if not hidden:
         documents = documents.filter(~Q(status="archive"))
         hidden_check = ""
@@ -566,8 +690,10 @@ def doclist(request):
     if not signdoc:
         signdoc_check = ""
 
+    # filter date range
     documents = documents.filter(compilation_date__range=[newer, older])
 
+    # filter types, owner, groups using chips
     if len(types) > 0:
         if types[0] != "":
             q_obj = Q()
@@ -598,14 +724,17 @@ def doclist(request):
 
     out = []
     for i in documents:
+        # filter for confirmed with attachment documents and approved
         if signdoc:
             if i.status == "ok" and not i.signed_doc:
                 continue
 
+        # prepare images in base64
         personal = None
         medical = None
         vac_file = ""
         health_file = ""
+        sign_doc_file = ""
         if i.personal_data:
             personal = i.personal_data
         if i.medical_data:
@@ -618,12 +747,21 @@ def doclist(request):
                 with open(medical.health_care_certificate.name, 'rb') as image_file:
                     health_file = base64.b64encode(image_file.read()).decode()
 
+        if i.signed_doc:
+            with open(i.signed_doc.name, 'rb') as image_file:
+                sign_doc_file = base64.b64encode(
+                    image_file.read()).decode()
+
         doc_group = i.user.groups.values_list('name', flat=True)[0]
 
-        out.append([i, KeyVal.objects.filter(container=i), personal, medical, doc_group, vac_file, health_file])
+        out.append([i, KeyVal.objects.filter(container=i), personal,
+                    medical, doc_group, vac_file, health_file, sign_doc_file])
 
-    auto_types = DocumentType.objects.filter(Q(group_private=False) | Q(group=group))
+    # get types and users for chips autocompletation
+    auto_types = DocumentType.objects.filter(
+        Q(group_private=False) | Q(group=group))
     users = User.objects.filter(groups__name=parent_group)
+
     context = {
         "types": auto_types,
         "users": users,
@@ -642,12 +780,13 @@ def doclist(request):
         'error': error,
         'error_text': error_text,
         'settings': settings,
-        }
+    }
     return render(request, 'server/doc_list.html', context)
 
 
 @user_passes_test(isStaff)
 def upload_doc(request):
+    # setup group based on staff primary or not
     parent_group = request.user.groups.values_list('name', flat=True)[
         0]
     group = Group.objects.get(name=parent_group)
@@ -656,12 +795,14 @@ def upload_doc(request):
     else:
         groups = request.user.groups.values_list('name', flat=True)[1:]
 
-    message = ""
+    # setup variables for error text and success text
     error = False
     success = False
     error_text = ""
     success_text = ""
+
     document = None
+    # parse document code and check for permissions
     if request.method == "POST":
         data = request.POST["code"]
         if not data.isdigit():
@@ -677,7 +818,10 @@ def upload_doc(request):
             error_text = "Codice invalido"
             error = True
         else:
+            # get document
             document = Document.objects.filter(code=data)[0]
+
+            # prepare success message
             if document.status == 'ok':
                 success_text = "File caricato"
                 success = True
@@ -687,11 +831,13 @@ def upload_doc(request):
                 success_text = "Documento approvato e file caricato"
                 success = True
 
+            # check for errors and upload files
             if "doc_sign" in request.FILES and not error:
                 myfile = request.FILES['doc_sign']
                 try:
                     im = Image.open(myfile)
                     im_io = BytesIO()
+                    # compress image in WEBP
                     im.save(im_io, 'WEBP', quality=50)
                     document.signed_doc.save(data+"_"+myfile.name, im_io)
                     document.save()
@@ -703,26 +849,29 @@ def upload_doc(request):
                 error_text = "Prego caricare un file"
 
     context = {
-        "message": message,
         "error": error,
         "error_text": error_text,
         "success": success,
         "success_text": success_text,
-
     }
+
     return render(request, 'server/upload_doc.html', context)
 
 
 @user_passes_test(isStaff)
 def docpreview(request):
     context = {}
+    # check for permissions
     if request.user.is_staff:
         groups = request.user.groups.values_list('name', flat=True)
     else:
         groups = request.user.groups.values_list('name', flat=True)[1:]
 
     if request.method == "POST":
+        # get document code
         code = request.POST["preview"]
+
+        # check if code valid and user has permission
         if not code.isdigit():
             return render(request, 'server/download_doc.html', context)
         if len(Document.objects.filter(code=code)) == 0:
@@ -730,7 +879,10 @@ def docpreview(request):
         if Document.objects.filter(code=code)[0].group.name not in groups:
             return render(request, 'server/download_doc.html', context)
 
+        # get document
         document = Document.objects.filter(code=code)[0]
+
+        # prepare images in base64
         vac_file = ""
         health_file = ""
         sign_doc_file = ""
@@ -746,8 +898,10 @@ def docpreview(request):
             with open(document.signed_doc.name, 'rb') as image_file:
                 sign_doc_file = base64.b64encode(image_file.read()).decode()
 
-        template = get_template('server/download_doc.html')
-        doc = [document, KeyVal.objects.filter(container=document), document.personal_data, document.medical_data, parent_group]
-        context = {'doc': doc, 'vac': vac_file, 'health': health_file, 'sign_doc_file': sign_doc_file}
+        # prepare context
+        doc = [document, KeyVal.objects.filter(
+            container=document), document.personal_data, document.medical_data, parent_group]
+        context = {'doc': doc, 'vac': vac_file,
+                   'health': health_file, 'sign_doc_file': sign_doc_file}
 
-    return render(request, 'server/download_doc.html', context)
\ No newline at end of file
+    return render(request, 'server/download_doc.html', context)