MM-45494: Add endpoint for message history (#20945)

* add api url

* write sql in store

* update app and client golang driver

* update layers and tests

* change sql query sort

* update layers

* fix style

* fix style post_store.go

* fix comments

* add test for app/post_test.go

* update layers

* fix test

* fix style

* fix style again :)

* add permission check

* add additional checks and tests

* change from nil to empty

* update app-layers

* fix style

* add index for OriginalId for Posts table

* fix postgres query

* update migration file names

* update app-layers

* address PR reviews

* write tests for post store

* fix style

* Update file name

* Update file name 2

* Update file name 3

* Update file name 4

* change the error orders

* update migration file name

---------

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

app/app_iface.go

@@ -637,6 +637,7 @@ type AppIface interface {
 	GetDeletedChannels(c request.CTX, teamID string, offset int, limit int, userID string) (model.ChannelList, *model.AppError)
 	GetDraft(userID, channelID, rootID string) (*model.Draft, *model.AppError)
 	GetDraftsForUser(userID, teamID string) ([]*model.Draft, *model.AppError)
+	GetEditHistoryForPost(postID string) ([]*model.Post, *model.AppError)
 	GetEmoji(c request.CTX, emojiId string) (*model.Emoji, *model.AppError)
 	GetEmojiByName(c request.CTX, emojiName string) (*model.Emoji, *model.AppError)
 	GetEmojiImage(c request.CTX, emojiId string) ([]byte, string, *model.AppError)

app/opentracing/opentracing_layer.go

@@ -5960,6 +5960,28 @@ func (a *OpenTracingAppLayer) GetDraftsForUser(userID string, teamID string) ([]
 	return resultVar0, resultVar1
 }
 
+func (a *OpenTracingAppLayer) GetEditHistoryForPost(postID string) ([]*model.Post, *model.AppError) {
+	origCtx := a.ctx
+	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetEditHistoryForPost")
+
+	a.ctx = newCtx
+	a.app.Srv().Store().SetContext(newCtx)
+	defer func() {
+		a.app.Srv().Store().SetContext(origCtx)
+		a.ctx = origCtx
+	}()
+
+	defer span.Finish()
+	resultVar0, resultVar1 := a.app.GetEditHistoryForPost(postID)
+
+	if resultVar1 != nil {
+		span.LogFields(spanlog.Error(resultVar1))
+		ext.Error.Set(span, true)
+	}
+
+	return resultVar0, resultVar1
+}
+
 func (a *OpenTracingAppLayer) GetEmoji(c request.CTX, emojiId string) (*model.Emoji, *model.AppError) {
 	origCtx := a.ctx
 	span, newCtx := tracing.StartSpanWithParentByContext(a.ctx, "app.GetEmoji")

app/post.go

@@ -1998,6 +1998,22 @@ func (a *App) GetPostsByIds(postIDs []string) ([]*model.Post, int64, *model.AppE
 	return posts, firstInaccessiblePostTime, nil
 }
 
+func (a *App) GetEditHistoryForPost(postID string) ([]*model.Post, *model.AppError) {
+	posts, err := a.Srv().Store().Post().GetEditHistoryForPost(postID)
+
+	if err != nil {
+		var nfErr *store.ErrNotFound
+		switch {
+		case errors.As(err, &nfErr):
+			return nil, model.NewAppError("GetEditHistoryForPost", "app.post.get.app_error", nil, "", http.StatusNotFound).Wrap(err)
+		default:
+			return nil, model.NewAppError("GetEditHistoryForPost", "app.post.get.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+		}
+	}
+
+	return posts, nil
+}
+
 func (a *App) GetTopThreadsForTeamSince(c request.CTX, teamID, userID string, opts *model.InsightsOpts) (*model.TopThreadList, *model.AppError) {
 	if !a.Config().FeatureFlags.InsightsEnabled {
 		return nil, model.NewAppError("GetTopChannelsForTeamSince", "app.insights.feature_disabled", nil, "", http.StatusNotImplemented)

app/post_test.go

@@ -3149,6 +3149,51 @@ func TestGetTopThreadsForUserSince(t *testing.T) {
 	require.Len(t, topUser2ThreadsAfterPrivateReplyDelete.Items, 0)
 }
 
+func TestGetEditHistoryForPost(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	post := &model.Post{
+		ChannelId: th.BasicChannel.Id,
+		Message:   "new message",
+		UserId:    th.BasicUser.Id,
+	}
+
+	rpost, err := th.App.CreatePost(th.Context, post, th.BasicChannel, false, true)
+	require.Nil(t, err)
+
+	// update the post message
+	patch := &model.PostPatch{
+		Message: model.NewString("new message edited"),
+	}
+	_, err1 := th.App.PatchPost(th.Context, rpost.Id, patch)
+	require.Nil(t, err1)
+
+	// update the post message again
+	patch = &model.PostPatch{
+		Message: model.NewString("new message edited again"),
+	}
+
+	_, err2 := th.App.PatchPost(th.Context, rpost.Id, patch)
+	require.Nil(t, err2)
+
+	// get the edit history
+	edits, err := th.App.GetEditHistoryForPost(post.Id)
+	require.Nil(t, err)
+
+	t.Run("should return the edit history", func(t *testing.T) {
+		require.Len(t, edits, 2)
+		require.Equal(t, "new message edited", edits[0].Message)
+		require.Equal(t, "new message", edits[1].Message)
+	})
+
+	t.Run("should return an error if the post is not found", func(t *testing.T) {
+		edits, err := th.App.GetEditHistoryForPost("invalid-post-id")
+		require.NotNil(t, err)
+		require.Empty(t, edits)
+	})
+}
+
 func TestGetTopDMsForUserSince(t *testing.T) {
 	th := Setup(t).InitBasic()
 	defer th.TearDown()