From dff266ec01d9966d8002f096a027a490d26e1b37 Mon Sep 17 00:00:00 2001
From: Umputun <umputun@gmail.com>
Date: Tue, 15 Jan 2019 17:05:30 -0600
Subject: [PATCH] add detection of reply and disable edit for such comments
 #248

---
 backend/app/store/service/service.go      | 25 ++++++++++
 backend/app/store/service/service_test.go | 58 ++++++++++++++++++++++-
 2 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/backend/app/store/service/service.go b/backend/app/store/service/service.go
index 1603dc89..f2e17e4f 100644
--- a/backend/app/store/service/service.go
+++ b/backend/app/store/service/service.go
@@ -49,6 +49,7 @@ type PostMetaData struct {
 }
 
 const defaultCommentMaxSize = 2000
+const maxLastCommentsReply = 1000
 
 // UnlimitedVotes doesn't restrict MaxVotes
 const UnlimitedVotes = -1
@@ -179,6 +180,10 @@ func (s *DataStore) EditComment(locator store.Locator, commentID string, req Edi
 		return comment, errors.Errorf("too late to edit %s", commentID)
 	}
 
+	if s.HasReplies(comment) {
+		return comment, errors.Errorf("parent comment with reply can't be edited, %s", commentID)
+	}
+
 	if req.Delete { // delete request
 		comment.Deleted = true
 		return comment, s.Delete(locator, commentID, store.SoftDelete)
@@ -196,6 +201,26 @@ func (s *DataStore) EditComment(locator store.Locator, commentID string, req Edi
 	return comment, err
 }
 
+// HasReplies checks if there is any reply to the comments
+// Loads last maxLastCommentsReply comments and compare parent id to the comment's id
+// TODO: add caching?
+func (s *DataStore) HasReplies(comment store.Comment) bool {
+	comments, err := s.Last(comment.Locator.SiteID, maxLastCommentsReply)
+	if err != nil {
+		log.Printf("[WARN] can't get last comments for reply check, %v", err)
+		return false
+	}
+
+	for _, c := range comments {
+		if c.ParentID != "" && !c.Deleted && c.User.ID != comment.User.ID { // not interested in replies to yourself and top level
+			if c.ParentID == comment.ID {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // SetTitle puts title from the locator.URL page and overwrites any existing title
 func (s *DataStore) SetTitle(locator store.Locator, commentID string) (comment store.Comment, err error) {
 	if s.TitleExtractor == nil {
diff --git a/backend/app/store/service/service_test.go b/backend/app/store/service/service_test.go
index 609e53f9..ee5454c1 100644
--- a/backend/app/store/service/service_test.go
+++ b/backend/app/store/service/service_test.go
@@ -12,7 +12,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/coreos/bbolt"
+	bolt "github.com/coreos/bbolt"
 	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -404,6 +404,32 @@ func TestService_EditCommentDurationFailed(t *testing.T) {
 	assert.NotNil(t, err)
 }
 
+func TestService_EditCommentReplyFailed(t *testing.T) {
+	defer os.Remove(testDb)
+	b := DataStore{Interface: prepStoreEngine(t), AdminStore: admin.NewStaticKeyStore("secret 123")}
+
+	res, err := b.Last("radio-t", 0)
+	t.Logf("%+v", res[1])
+	assert.Nil(t, err)
+	assert.Equal(t, 2, len(res))
+	assert.Nil(t, res[1].Edit)
+
+	reply := store.Comment{
+		ID:        "123456",
+		ParentID:  "id-1",
+		Text:      "some text",
+		Timestamp: time.Date(2017, 12, 20, 15, 18, 22, 0, time.Local),
+		Locator:   store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"},
+		User:      store.User{ID: "user2", Name: "user name 2"},
+	}
+	_, err = b.Create(reply)
+	assert.NoError(t, err)
+
+	_, err = b.EditComment(store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, res[1].ID,
+		EditRequest{Orig: "yyy", Text: "xxx", Summary: "my edit"})
+	assert.EqualError(t, err, "parent comment with reply can't be edited, id-1")
+}
+
 func TestService_ValidateComment(t *testing.T) {
 
 	b := DataStore{MaxCommentSize: 2000, AdminStore: admin.NewStaticKeyStore("secret 123")}
@@ -523,6 +549,36 @@ func TestService_IsAdmin(t *testing.T) {
 	assert.True(t, b.IsAdmin("radio-t", "user2"))
 }
 
+func TestService_HasReplies(t *testing.T) {
+	defer os.Remove(testDb)
+
+	// two comments for https://radio-t.com, no reply
+	b := DataStore{Interface: prepStoreEngine(t), EditDuration: 100 * time.Millisecond,
+		AdminStore: admin.NewStaticStore("secret 123", []string{"user2"}, "user@email.com")}
+
+	comment := store.Comment{
+		ID:        "id-1",
+		Text:      `some text, <a href="http://radio-t.com">link</a>`,
+		Timestamp: time.Date(2017, 12, 20, 15, 18, 22, 0, time.Local),
+		Locator:   store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"},
+		User:      store.User{ID: "user1", Name: "user name"},
+	}
+
+	assert.False(t, b.HasReplies(comment))
+
+	reply := store.Comment{
+		ID:        "123456",
+		ParentID:  "id-1",
+		Text:      "some text",
+		Timestamp: time.Date(2017, 12, 20, 15, 18, 22, 0, time.Local),
+		Locator:   store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"},
+		User:      store.User{ID: "user2", Name: "user name 2"},
+	}
+	_, err := b.Create(reply)
+	assert.NoError(t, err)
+	assert.True(t, b.HasReplies(comment))
+}
+
 // makes new boltdb, put two records
 func prepStoreEngine(t *testing.T) engine.Interface {
 	os.Remove(testDb)