From c912bb8cbaabe44cb74fa7f1bc93a9c2341dd870 Mon Sep 17 00:00:00 2001
From: Jannis Mattheis <contact@jmattheis.de>
Date: Sun, 1 Apr 2018 10:58:59 +0200
Subject: [PATCH] Delete Clients/Apps/Messages when deleting a user

sqlite3 doesn't support adding a foreign key via gorm.DB#AddForeignKey
this would mean, that we have some hacky solutions for having foreign
keys for sqlite and the other databases. Therefore manually deleting
the referencing models seems to be the best solution. We already have
interfaces for database capsuling, so no api must be adjusted.
---
 database/application.go      |  1 +
 database/application_test.go | 18 ++++++++++++++++++
 database/user.go             |  6 ++++++
 database/user_test.go        | 30 ++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+)

diff --git a/database/application.go b/database/application.go
index 213ef7b..3f001a8 100644
--- a/database/application.go
+++ b/database/application.go
@@ -31,6 +31,7 @@ func (d *GormDatabase) CreateApplication(application *model.Application) error {
 
 // DeleteApplicationByID deletes an application by its id.
 func (d *GormDatabase) DeleteApplicationByID(id uint) error {
+	d.DeleteMessagesByApplication(id)
 	return d.DB.Where("id = ?", id).Delete(&model.Application{}).Error
 }
 
diff --git a/database/application_test.go b/database/application_test.go
index b25cfcb..7a72d7b 100644
--- a/database/application_test.go
+++ b/database/application_test.go
@@ -42,3 +42,21 @@ func (s *DatabaseSuite) TestApplication() {
 
 	assert.Nil(s.T(), s.db.GetApplicationByID(app.ID))
 }
+
+func (s *DatabaseSuite) TestDeleteAppDeletesMessages() {
+	s.db.CreateApplication(&model.Application{ID: 55, Token: "token"})
+	s.db.CreateApplication(&model.Application{ID: 66, Token: "token2"})
+	s.db.CreateMessage(&model.Message{ID: 12, ApplicationID: 55})
+	s.db.CreateMessage(&model.Message{ID: 13, ApplicationID: 66})
+	s.db.CreateMessage(&model.Message{ID: 14, ApplicationID: 55})
+	s.db.CreateMessage(&model.Message{ID: 15, ApplicationID: 55})
+
+	s.db.DeleteApplicationByID(55)
+
+	assert.Nil(s.T(), s.db.GetMessageByID(12))
+	assert.NotNil(s.T(), s.db.GetMessageByID(13))
+	assert.Nil(s.T(), s.db.GetMessageByID(14))
+	assert.Nil(s.T(), s.db.GetMessageByID(15))
+	assert.Empty(s.T(), s.db.GetMessagesByApplication(55))
+	assert.NotEmpty(s.T(), s.db.GetMessagesByApplication(66))
+}
diff --git a/database/user.go b/database/user.go
index abc966f..d14271b 100644
--- a/database/user.go
+++ b/database/user.go
@@ -33,6 +33,12 @@ func (d *GormDatabase) GetUsers() []*model.User {
 
 // DeleteUserByID deletes a user by its id.
 func (d *GormDatabase) DeleteUserByID(id uint) error {
+	for _, app := range d.GetApplicationsByUser(id) {
+		d.DeleteApplicationByID(app.ID)
+	}
+	for _, client := range d.GetClientsByUser(id) {
+		d.DeleteClientByID(client.ID)
+	}
 	return d.DB.Where("id = ?", id).Delete(&model.User{}).Error
 }
 
diff --git a/database/user_test.go b/database/user_test.go
index a6a483a..d40437f 100644
--- a/database/user_test.go
+++ b/database/user_test.go
@@ -45,3 +45,33 @@ func (s *DatabaseSuite) TestUser() {
 	users = s.db.GetUsers()
 	assert.Empty(s.T(), users)
 }
+
+func (s *DatabaseSuite) TestDeleteUserDeletesApplicationsAndClients() {
+	s.db.CreateUser(&model.User{Name: "nicories", ID: 10})
+	s.db.CreateApplication(&model.Application{ID: 100, Token: "apptoken", UserID: 10})
+	s.db.CreateMessage(&model.Message{ID: 1000, ApplicationID: 100})
+	s.db.CreateClient(&model.Client{ID: 10000, Token: "clienttoken", UserID: 10})
+
+	s.db.CreateUser(&model.User{Name: "nicories2", ID: 20})
+	s.db.CreateApplication(&model.Application{ID: 200, Token: "apptoken2", UserID: 20})
+	s.db.CreateMessage(&model.Message{ID: 2000, ApplicationID: 200})
+	s.db.CreateClient(&model.Client{ID: 20000, Token: "clienttoken2", UserID: 20})
+
+	s.db.DeleteUserByID(10)
+
+	assert.Nil(s.T(), s.db.GetApplicationByToken("apptoken"))
+	assert.Nil(s.T(), s.db.GetClientByToken("clienttoken"))
+	assert.Empty(s.T(), s.db.GetClientsByUser(10))
+	assert.Empty(s.T(), s.db.GetApplicationsByUser(10))
+	assert.Empty(s.T(), s.db.GetMessagesByApplication(100))
+	assert.Empty(s.T(), s.db.GetMessagesByUser(10))
+	assert.Nil(s.T(), s.db.GetMessageByID(1000))
+
+	assert.NotNil(s.T(), s.db.GetApplicationByToken("apptoken2"))
+	assert.NotNil(s.T(), s.db.GetClientByToken("clienttoken2"))
+	assert.NotEmpty(s.T(), s.db.GetClientsByUser(20))
+	assert.NotEmpty(s.T(), s.db.GetApplicationsByUser(20))
+	assert.NotEmpty(s.T(), s.db.GetMessagesByApplication(200))
+	assert.NotEmpty(s.T(), s.db.GetMessagesByUser(20))
+	assert.NotNil(s.T(), s.db.GetMessageByID(2000))
+}