feat(gitops): show live git validity status in workflow overview [BE-12885] (#2447)

Co-authored-by: Claude <noreply@anthropic.com>

api/gitops/workflows/git_phases.go

@@ -0,0 +1,59 @@
+package workflows
+
+import (
+	"context"
+	"fmt"
+	"path"
+	"slices"
+)
+
+// ListRefsFunc lists all git refs for a repository.
+type ListRefsFunc func(ctx context.Context) ([]string, error)
+
+// ListFilesFunc lists files in a repository branch filtered by extension.
+type ListFilesFunc func(ctx context.Context, exts []string) ([]string, error)
+
+// ComputeGitPhases checks source (ref reachability) and artifact (config file presence).
+// If source fails, artifact is returned as unknown without making a network call.
+func ComputeGitPhases(ctx context.Context, referenceName, configFilePath string, listRefs ListRefsFunc, listFiles ListFilesFunc) (source, artifact WorkflowPhaseStatus) {
+	source = computeSourcePhase(ctx, referenceName, listRefs)
+	if source.Status == StatusError {
+		return source, WorkflowPhaseStatus{Status: StatusUnknown}
+	}
+	return source, computeArtifactPhase(ctx, configFilePath, listFiles)
+}
+
+func computeSourcePhase(ctx context.Context, referenceName string, listRefs ListRefsFunc) WorkflowPhaseStatus {
+	refs, err := listRefs(ctx)
+	if err != nil {
+		return WorkflowPhaseStatus{Status: StatusError, Error: err.Error()}
+	}
+	if referenceName == "" {
+		return WorkflowPhaseStatus{Status: StatusHealthy}
+	}
+	if !slices.Contains(refs, referenceName) {
+		return WorkflowPhaseStatus{Status: StatusError, Error: fmt.Sprintf("ref %q not found", referenceName)}
+	}
+	return WorkflowPhaseStatus{Status: StatusHealthy}
+}
+
+func computeArtifactPhase(ctx context.Context, configFilePath string, listFiles ListFilesFunc) WorkflowPhaseStatus {
+	if configFilePath == "" {
+		return WorkflowPhaseStatus{Status: StatusError, Error: "no config file path specified"}
+	}
+	ext := path.Ext(configFilePath)
+	var exts []string
+	if len(ext) > 0 {
+		ext = ext[1:]
+		exts = []string{ext}
+	}
+
+	files, err := listFiles(ctx, exts)
+	if err != nil {
+		return WorkflowPhaseStatus{Status: StatusError, Error: err.Error()}
+	}
+	if !slices.Contains(files, configFilePath) {
+		return WorkflowPhaseStatus{Status: StatusError, Error: fmt.Sprintf("file %q not found", configFilePath)}
+	}
+	return WorkflowPhaseStatus{Status: StatusHealthy}
+}