chore: import upstream snapshot with attribution

src/shared/utils/featureFlags.ts

@@ -0,0 +1,113 @@
+import { getFeatureFlagOverride } from "@/lib/db/featureFlags";
+import {
+  FEATURE_FLAG_DEFINITIONS,
+  type FeatureFlagDefinition,
+} from "@/shared/constants/featureFlagDefinitions";
+
+/**
+ * Resolve the effective value of a feature flag.
+ * Priority: DB override > process.env > definition.defaultValue
+ */
+export function resolveFeatureFlag(key: string): string {
+  const dbOverride = getFeatureFlagOverride(key);
+  if (dbOverride !== undefined) return dbOverride;
+
+  const envValue = process.env[key];
+  if (envValue !== undefined && envValue !== "") return envValue;
+
+  const definition = FEATURE_FLAG_DEFINITIONS.find((d) => d.key === key);
+  return definition?.defaultValue ?? "false";
+}
+
+/**
+ * Check if a boolean feature flag is enabled.
+ * Treats "true", "1", "yes" as enabled.
+ */
+export function isFeatureFlagEnabled(key: string): boolean {
+  const value = resolveFeatureFlag(key);
+  return value === "true" || value === "1" || value === "yes";
+}
+
+/**
+ * Resolve all feature flags with their effective values and sources.
+ */
+export function resolveAllFeatureFlags(): Array<{
+  key: string;
+  effectiveValue: string;
+  source: "db" | "env" | "default";
+  definition: FeatureFlagDefinition;
+}> {
+  return FEATURE_FLAG_DEFINITIONS.map((definition) => {
+    const dbOverride = getFeatureFlagOverride(definition.key);
+    if (dbOverride !== undefined) {
+      return { key: definition.key, effectiveValue: dbOverride, source: "db", definition };
+    }
+    const envValue = process.env[definition.key];
+    if (envValue !== undefined && envValue !== "") {
+      return { key: definition.key, effectiveValue: envValue, source: "env", definition };
+    }
+    return {
+      key: definition.key,
+      effectiveValue: definition.defaultValue,
+      source: "default",
+      definition,
+    };
+  });
+}
+
+// Backward-compatible wrappers
+export function isRequireApiKeyEnabled(): boolean {
+  try {
+    return isFeatureFlagEnabled("REQUIRE_API_KEY");
+  } catch (error) {
+    console.error(
+      "[featureFlags] Failed to resolve REQUIRE_API_KEY, defaulting to required:",
+      error instanceof Error ? error.message : error
+    );
+    return true;
+  }
+}
+
+export function isCcCompatibleProviderEnabled(): boolean {
+  return isFeatureFlagEnabled("ENABLE_CC_COMPATIBLE_PROVIDER");
+}
+
+export function isApiKeyRevealEnabledFlag(): boolean {
+  try {
+    return isFeatureFlagEnabled("ALLOW_API_KEY_REVEAL");
+  } catch (error) {
+    console.error(
+      "[featureFlags] Failed to resolve ALLOW_API_KEY_REVEAL, defaulting to disabled:",
+      error instanceof Error ? error.message : error
+    );
+    return false;
+  }
+}
+
+export function isModelCatalogNamesEnabled(): boolean {
+  return isFeatureFlagEnabled("MODEL_CATALOG_INCLUDE_NAMES");
+}
+
+export type ModelsCatalogPrefixMode = "dual" | "alias" | "canonical";
+
+export function getModelsCatalogPrefixMode(): ModelsCatalogPrefixMode {
+  const value = resolveFeatureFlag("MODELS_CATALOG_PREFIX_MODE");
+  if (value === "alias" || value === "canonical") return value;
+  return "dual";
+}
+
+export function isArenaEloSyncEnabled(): boolean {
+  return isFeatureFlagEnabled("ARENA_ELO_SYNC_ENABLED");
+}
+
+export function isControlPlaneProxyDirectFallbackEnabled(): boolean {
+  try {
+    return isFeatureFlagEnabled("OMNIROUTE_CONTROL_PLANE_PROXY_DIRECT_FALLBACK");
+  } catch (error) {
+    console.error(
+      "[featureFlags] Failed to resolve OMNIROUTE_CONTROL_PLANE_PROXY_DIRECT_FALLBACK, defaulting to disabled:",
+      error instanceof Error ? error.message : error
+    );
+    return false;
+  }
+}