From 9fc974af206db2414a8cedc2d812a342a076ad50 Mon Sep 17 00:00:00 2001
From: Maximilian Grundke <maximiliangrundke@googlemail.com>
Date: Tue, 10 May 2016 16:03:52 +0200
Subject: [PATCH] Implement file name validation based on path, name, and
 filetype upon file creation

---
 app/controllers/code_ocean/files_controller.rb | 15 +++++++++++++++
 app/models/code_ocean/file.rb                  | 13 +++++++++++++
 config/locales/de.yml                          |  2 ++
 config/locales/en.yml                          |  2 ++
 4 files changed, 32 insertions(+)

diff --git a/app/controllers/code_ocean/files_controller.rb b/app/controllers/code_ocean/files_controller.rb
index 3c255ffa..74c1932f 100644
--- a/app/controllers/code_ocean/files_controller.rb
+++ b/app/controllers/code_ocean/files_controller.rb
@@ -14,6 +14,21 @@ module CodeOcean
       create_and_respond(object: @file, path: proc { implement_exercise_path(@file.context.exercise, tab: 2) })
     end
 
+    def create_and_respond(options = {})
+      @object = options[:object]
+      respond_to do |format|
+        if @object.save
+          yield if block_given?
+          path = options[:path].try(:call) || @object
+          respond_with_valid_object(format, notice: t('shared.object_created', model: @object.class.model_name.human), path: path, status: :created)
+        else
+          filename = (@object.path || '') + '/' + (@object.name || '') + (@object.file_type.file_extension || '')
+          format.html { redirect_to(options[:path]); flash[:danger] = t('files.error.filename', name: filename) }
+          format.json { render(json: @object.errors, status: :unprocessable_entity) }
+        end
+      end
+    end
+
     def destroy
       @file = CodeOcean::File.find(params[:id])
       authorize!
diff --git a/app/models/code_ocean/file.rb b/app/models/code_ocean/file.rb
index 48ec97d0..7b00cbdd 100644
--- a/app/models/code_ocean/file.rb
+++ b/app/models/code_ocean/file.rb
@@ -2,6 +2,17 @@ require File.expand_path('../../../uploaders/file_uploader', __FILE__)
 require File.expand_path('../../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
 
 module CodeOcean
+
+  class FileNameValidator < ActiveModel::Validator
+    def validate(record)
+      existing_files = File.where(name: record.name, path: record.path, file_type_id: record.file_type_id,
+                                  context_id: record.context_id, context: record.context).to_a
+      unless existing_files.empty?
+        record.errors[:base] << 'Duplicate'
+      end
+    end
+  end
+
   class File < ActiveRecord::Base
     include DefaultValues
 
@@ -44,6 +55,8 @@ module CodeOcean
     validates :weight, if: :teacher_defined_test?, numericality: true, presence: true
     validates :weight, absence: true, unless: :teacher_defined_test?
 
+    validates_with FileNameValidator, fields: [:name, :path, :file_type_id]
+
     ROLES.each do |role|
       define_method("#{role}?") { self.role == role }
     end
diff --git a/config/locales/de.yml b/config/locales/de.yml
index ddc6bfa4..ed66f79a 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -292,6 +292,8 @@ de:
       teacher_defined_test: Test als Bewertungsgrundlage
       user_defined_file: Benutzerdefinierte Datei
       user_defined_test: Benutzerdefinierter Test
+    error:
+      filename: "Die Datei konnte nicht gespeichert werden, da eine Datei mit dem Namen '%{name}' bereits existiert."
   hints:
     form:
       hints:
diff --git a/config/locales/en.yml b/config/locales/en.yml
index f083f5f9..f86a6963 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -292,6 +292,8 @@ en:
       teacher_defined_test: Test for Assessment
       user_defined_file: User-defined File
       user_defined_test: User-defined Test
+    error:
+      filename: "The file could not be saved, because another file with the name '%{name}' already exists."
   hints:
     form:
       hints: