refactor(hooks): fix empty catches and remove AI slop from code comments

src/hooks/model-fallback/next-fallback.ts

@@ -0,0 +1,70 @@
+import type { FallbackEntry } from "../../shared/model-requirements"
+import { readConnectedProvidersCache, readProviderModelsCache } from "../../shared/connected-providers-cache"
+import { selectFallbackProvider } from "../../shared/model-error-classifier"
+import { transformModelForProvider } from "../../shared/provider-model-id-transform"
+import { log } from "../../shared/logger"
+import type { ModelFallbackState } from "./hook"
+
+function canonicalizeModelID(modelID: string): string {
+  return modelID
+    .toLowerCase()
+    .replace(/\./g, "-")
+}
+
+function createReachabilityChecker(state: ModelFallbackState): (entry: FallbackEntry) => boolean {
+  const providerModelsCache = readProviderModelsCache()
+  const connectedProviders = providerModelsCache?.connected ?? readConnectedProvidersCache()
+  const connectedSet = connectedProviders
+    ? new Set(connectedProviders.map((provider) => provider.toLowerCase()))
+    : null
+
+  return (entry: FallbackEntry): boolean => {
+    if (!connectedSet) return true
+
+    if (entry.providers.some((provider) => connectedSet.has(provider.toLowerCase()))) {
+      return true
+    }
+
+    return connectedSet.has(state.providerID.toLowerCase())
+  }
+}
+
+export function getNextReachableFallback(
+  sessionID: string,
+  state: ModelFallbackState,
+): { providerID: string; modelID: string; variant?: string } | null {
+  const isReachable = createReachabilityChecker(state)
+
+  while (state.attemptCount < state.fallbackChain.length) {
+    const attemptCount = state.attemptCount
+    const fallback = state.fallbackChain[attemptCount]
+    state.attemptCount++
+
+    if (!isReachable(fallback)) {
+      log("[model-fallback] Skipping unreachable fallback for session: " + sessionID + ", attempt: " + attemptCount + ", model: " + fallback.model)
+      continue
+    }
+
+    const providerID = selectFallbackProvider(fallback.providers, state.providerID)
+    const modelID = transformModelForProvider(providerID, fallback.model)
+    const isNoOpFallback =
+      providerID.toLowerCase() === state.providerID.toLowerCase()
+      && canonicalizeModelID(modelID) === canonicalizeModelID(state.modelID)
+
+    if (isNoOpFallback) {
+      log("[model-fallback] Skipping no-op fallback for session: " + sessionID + ", attempt: " + attemptCount + ", model: " + fallback.model)
+      continue
+    }
+
+    state.pending = false
+    log("[model-fallback] Using fallback for session: " + sessionID + ", attempt: " + attemptCount + ", model: " + fallback.model)
+
+    return {
+      providerID,
+      modelID,
+      variant: fallback.variant,
+    }
+  }
+
+  return null
+}