From cb88bdd068da8ea756e048ef784f11f8c57daa78 Mon Sep 17 00:00:00 2001
From: Tom Limoncelli <tlimoncelli@stackoverflow.com>
Date: Tue, 24 Jan 2023 12:07:33 -0500
Subject: [PATCH] GCLOUD: Adopt diff2 in compatibility mode (#1982)

---
 providers/gcloud/gcloudProvider.go | 154 +++++++++++++++--------------
 1 file changed, 78 insertions(+), 76 deletions(-)

diff --git a/providers/gcloud/gcloudProvider.go b/providers/gcloud/gcloudProvider.go
index de46d1b23..5a817e259 100644
--- a/providers/gcloud/gcloudProvider.go
+++ b/providers/gcloud/gcloudProvider.go
@@ -205,85 +205,87 @@ func (g *gcloudProvider) GetDomainCorrections(dc *models.DomainConfig) ([]*model
 	models.PostProcessRecords(existingRecords)
 	txtutil.SplitSingleLongTxt(dc.Records) // Autosplit long TXT records
 
-	var corrections []*models.Correction
-	if !diff2.EnableDiff2 || true { // Remove "|| true" when diff2 version arrives
-
-		// first collect keys that have changed
-		differ := diff.New(dc)
-		_, create, delete, modify, err := differ.IncrementalDiff(existingRecords)
-		if err != nil {
-			return nil, fmt.Errorf("incdiff error: %w", err)
-		}
-
-		changedKeys := map[key]bool{}
-		desc := ""
-		for _, c := range create {
-			desc += fmt.Sprintln(c)
-			changedKeys[keyForRec(c.Desired)] = true
-		}
-		for _, d := range delete {
-			desc += fmt.Sprintln(d)
-			changedKeys[keyForRec(d.Existing)] = true
-		}
-		for _, m := range modify {
-			desc += fmt.Sprintln(m)
-			changedKeys[keyForRec(m.Existing)] = true
-		}
-		if len(changedKeys) == 0 {
-			return nil, nil
-		}
-		chg := &gdns.Change{Kind: "dns#change"}
-		for ck := range changedKeys {
-			// remove old version (if present)
-			if old, ok := oldRRs[ck]; ok {
-				chg.Deletions = append(chg.Deletions, old)
-			}
-			// collect records to replace with
-			newRRs := &gdns.ResourceRecordSet{
-				Name: ck.Name,
-				Type: ck.Type,
-				Kind: "dns#resourceRecordSet",
-			}
-			for _, r := range dc.Records {
-				if keyForRec(r) == ck {
-					newRRs.Rrdatas = append(newRRs.Rrdatas, r.GetTargetCombined())
-					newRRs.Ttl = int64(r.TTL)
-				}
-			}
-			if len(newRRs.Rrdatas) > 0 {
-				chg.Additions = append(chg.Additions, newRRs)
-			}
-		}
-
-		// FIXME(tlim): Google will return an error if too many changes are
-		// specified in a single request. We should split up very large
-		// batches.  This can be reliably reproduced with the 1201
-		// integration test.  The error you get is:
-		// googleapi: Error 403: The change would exceed quota for additions per change., quotaExceeded
-		//log.Printf("PAUSE STT = %+v %v\n", err, resp)
-		//log.Printf("PAUSE ERR = %+v %v\n", err, resp)
-
-		runChange := func() error {
-		retry:
-			resp, err := g.client.Changes.Create(g.project, zoneName, chg).Do()
-			if retryNeeded(resp, err) {
-				goto retry
-			}
-			if err != nil {
-				return fmt.Errorf("runChange error: %w", err)
-			}
-			return nil
-		}
-
-		return []*models.Correction{{
-			Msg: desc,
-			F:   runChange,
-		}}, nil
+	// first collect keys that have changed
+	var differ diff.Differ
+	if !diff2.EnableDiff2 {
+		differ = diff.New(dc)
+	} else {
+		differ = diff.NewCompat(dc)
+	}
+	_, create, delete, modify, err := differ.IncrementalDiff(existingRecords)
+	if err != nil {
+		return nil, err
 	}
 
-	// Insert Future diff2 version here.
+	if err != nil {
+		return nil, fmt.Errorf("incdiff error: %w", err)
+	}
+
+	changedKeys := map[key]bool{}
+	desc := ""
+	for _, c := range create {
+		desc += fmt.Sprintln(c)
+		changedKeys[keyForRec(c.Desired)] = true
+	}
+	for _, d := range delete {
+		desc += fmt.Sprintln(d)
+		changedKeys[keyForRec(d.Existing)] = true
+	}
+	for _, m := range modify {
+		desc += fmt.Sprintln(m)
+		changedKeys[keyForRec(m.Existing)] = true
+	}
+	if len(changedKeys) == 0 {
+		return nil, nil
+	}
+	chg := &gdns.Change{Kind: "dns#change"}
+	for ck := range changedKeys {
+		// remove old version (if present)
+		if old, ok := oldRRs[ck]; ok {
+			chg.Deletions = append(chg.Deletions, old)
+		}
+		// collect records to replace with
+		newRRs := &gdns.ResourceRecordSet{
+			Name: ck.Name,
+			Type: ck.Type,
+			Kind: "dns#resourceRecordSet",
+		}
+		for _, r := range dc.Records {
+			if keyForRec(r) == ck {
+				newRRs.Rrdatas = append(newRRs.Rrdatas, r.GetTargetCombined())
+				newRRs.Ttl = int64(r.TTL)
+			}
+		}
+		if len(newRRs.Rrdatas) > 0 {
+			chg.Additions = append(chg.Additions, newRRs)
+		}
+	}
+
+	// FIXME(tlim): Google will return an error if too many changes are
+	// specified in a single request. We should split up very large
+	// batches.  This can be reliably reproduced with the 1201
+	// integration test.  The error you get is:
+	// googleapi: Error 403: The change would exceed quota for additions per change., quotaExceeded
+	//log.Printf("PAUSE STT = %+v %v\n", err, resp)
+	//log.Printf("PAUSE ERR = %+v %v\n", err, resp)
+
+	runChange := func() error {
+	retry:
+		resp, err := g.client.Changes.Create(g.project, zoneName, chg).Do()
+		if retryNeeded(resp, err) {
+			goto retry
+		}
+		if err != nil {
+			return fmt.Errorf("runChange error: %w", err)
+		}
+		return nil
+	}
+
+	return []*models.Correction{{
+		Msg: desc,
+		F:   runChange,
+	}}, nil
 
-	return corrections, nil
 }
 
 func nativeToRecord(set *gdns.ResourceRecordSet, rec, origin string) (*models.RecordConfig, error) {