internal/gaby: connect labeler to gaby

Add the labeler as part of the gaby main program.

For #64.

Change-Id: I935888d46daf25018345c605bdcc0bf9b758159b
Reviewed-on: https://go-review.googlesource.com/c/oscar/+/639735
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

internal/gaby/github_event.go

@@ -99,6 +99,9 @@ func (g *Gaby) handleGitHubIssueEvent(ctx context.Context, event *github.Webhook
 		if err := g.fixGitHubIssue(ctx, project, event.Issue.Number); err != nil {
 			return false, err
 		}
+		if err := g.labeler.LabelIssue(ctx, project, event.Issue.Number); err != nil {
+			return false, err
+		}
 		return true, nil
 	}
 

internal/gaby/github_event_test.go

@@ -17,6 +17,7 @@ import (
 	"golang.org/x/oscar/internal/docs"
 	"golang.org/x/oscar/internal/github"
 	"golang.org/x/oscar/internal/httprr"
+	"golang.org/x/oscar/internal/labels"
 	"golang.org/x/oscar/internal/llm"
 	"golang.org/x/oscar/internal/related"
 	"golang.org/x/oscar/internal/secret"
@@ -140,6 +141,7 @@ func testGaby(t *testing.T, secret secret.DB) *Gaby {
 
 	vdb := storage.MemVectorDB(db, lg, "vecs")
 	emb := llm.QuoteEmbedder()
+	cgen := llm.EchoContentGenerator()
 
 	rp := related.New(lg, db, gh, vdb, dc, "related")
 	rp.EnableProject(testProject)
@@ -152,6 +154,8 @@ func testGaby(t *testing.T, secret secret.DB) *Gaby {
 	// No fixes yet.
 	cf.EnableEdits()
 
+	lab := labels.New(lg, db, gh, cgen, "labels")
+
 	return &Gaby{
 		githubProjects: []string{testProject, testProject2},
 		github:         gh,
@@ -163,6 +167,7 @@ func testGaby(t *testing.T, secret secret.DB) *Gaby {
 		docs:           dc,
 		commentFixer:   cf,
 		relatedPoster:  rp,
+		labeler:        lab,
 	}
 }
 

internal/gaby/main.go

@@ -39,6 +39,7 @@ import (
 	"golang.org/x/oscar/internal/gerrit"
 	"golang.org/x/oscar/internal/github"
 	"golang.org/x/oscar/internal/googlegroups"
+	"golang.org/x/oscar/internal/labels"
 	"golang.org/x/oscar/internal/llm"
 	"golang.org/x/oscar/internal/llmapp"
 	"golang.org/x/oscar/internal/overview"
@@ -110,6 +111,7 @@ type Gaby struct {
 	rulesPoster   *rules.Poster     // used to post rule violations
 	commentFixer  *commentfix.Fixer // used to fix GitHub comments
 	overview      *overview.Client  // used to generate and post overviews
+	labeler       *labels.Labeler   // used to assign labels to issues
 }
 
 func main() {
@@ -226,6 +228,20 @@ func main() {
 	}
 	g.rulesPoster = rulep
 
+	labeler := labels.New(g.slog, g.db, g.github, ai, "gabyhelp")
+	for _, proj := range g.githubProjects {
+		// TODO: support other projects.
+		if proj != "golang/go" {
+			continue
+		}
+		labeler.EnableProject(proj)
+	}
+	labeler.EnableLabels()
+	if !slices.Contains(autoApprovePkgs, "labels") {
+		labeler.RequireApproval()
+	}
+	g.labeler = labeler
+
 	// Named functions to retrieve latest Watcher times.
 	watcherLatests := map[string]func() timed.DBTime{
 		github.DocWatcherID:       docs.LatestFunc(g.github),
@@ -239,6 +255,7 @@ func main() {
 		"gerritlinks fix": cf.Latest,
 		"related":         rp.Latest,
 		"rules":           rulep.Latest,
+		"labeler":         labeler.Latest,
 	}
 
 	// Install a metric that observes the latest values of the watchers each time metrics are sampled.
@@ -254,7 +271,7 @@ func main() {
 	select {}
 }
 
-var validApprovalPkgs = []string{"commentfix", "related", "rules"}
+var validApprovalPkgs = []string{"commentfix", "related", "rules", "labels"}
 
 // parseApprovalPkgs parses a comma-separated list of package names,
 // checking that the packages are valid.
@@ -693,10 +710,12 @@ func (g *Gaby) syncAndRunAll(ctx context.Context) (errs []error) {
 	}
 
 	if flags.enablechanges {
-		// Changes can run in any order.
+		// Changes can run in almost any order; the labeler should
+		// run before anything that uses labels.
 		// Write all changes to the action log.
 		check(g.fixAllComments(ctx))
 		check(g.postAllRelated(ctx))
+		check(g.labelAll(ctx))
 		check(g.postAllRules(ctx))
 		// Apply all actions.
 		actions.Run(ctx, g.slog, g.db)
@@ -716,6 +735,7 @@ const (
 	gabyFixCommentLock  = "gabyfixcommentaction"
 	gabyPostRelatedLock = "gabyrelatedaction"
 	gabyPostRulesLock   = "gabyrulesaction"
+	gabyLabelLock       = "gabylabelaction"
 )
 
 func (g *Gaby) syncGitHubIssues(ctx context.Context) error {
@@ -803,6 +823,13 @@ func (g *Gaby) postAllRules(ctx context.Context) error {
 	return g.rulesPoster.Run(ctx)
 }
 
+func (g *Gaby) labelAll(ctx context.Context) error {
+	g.db.Lock(gabyLabelLock)
+	defer g.db.Unlock(gabyLabelLock)
+
+	return g.labeler.Run(ctx)
+}
+
 // localCron simulates Cloud Scheduler by fetching our server's /cron endpoint once per minute.
 func (g *Gaby) localCron() {
 	for ; ; time.Sleep(1 * time.Minute) {

internal/labels/labeler.go

@@ -162,6 +162,34 @@ func (l *Labeler) Run(ctx context.Context) error {
 	return nil
 }
 
+// LabelIssue labels a single issue.
+//
+// It follows the same logic as [Labeler.Run] for a single issue, except
+// that it does not rely on or modify the Labeler's watcher.
+// This means that [Labeler.LabelIssue] can be called on any issue without
+// affecting the starting point of future calls to [Labeler.Run].
+//
+// It requires that there be a database entry for the given issue.
+func (l *Labeler) LabelIssue(ctx context.Context, project string, issue int64) error {
+	e := lookupIssueEvent(project, issue, l.github)
+	if e == nil {
+		return fmt.Errorf("labels.Labeler.LabelIssue(project=%s, issue=%d): event not found", project, issue)
+	}
+	_, err := l.logLabelIssue(ctx, e)
+	return err
+}
+
+// lookupIssueEvent returns the first event for the "/issues" API with
+// the given ID in the database, or nil if not found.
+func lookupIssueEvent(project string, issue int64, gh *github.Client) *github.Event {
+	for event := range gh.Events(project, issue, issue) {
+		if event.API == "/issues" {
+			return event
+		}
+	}
+	return nil
+}
+
 // logLabelIssue logs an action to post an issue for the event.
 // advance is true if the event should be considered to have been
 // handled by this or a previous run function, indicating
@@ -179,7 +207,7 @@ func (l *Labeler) logLabelIssue(ctx context.Context, e *github.Event) (advance b
 		return false, nil
 	}
 	// If an action has already been logged for this event, do nothing.
-	// we don't need a lock. [actions.before] will lock to avoid multiple log entries.
+	// We don't need a lock. [actions.before] will lock to avoid multiple log entries.
 	if _, ok := actions.Get(l.db, l.actionKind, logKey(e)); ok {
 		l.slog.Info("labels.Labeler already logged", "name", l.name, "project", e.Project, "issue", e.Issue, "event", e)
 		// If labeling is enabled, we can advance the watcher because