lib/best-provider.ts

export const getBestProvider = async (model: string, provider?: string) => {
  const lower = model?.toLowerCase?.() ?? "";

  // Handle Google models without querying HF router
  if (
    lower.startsWith("gemini-") ||
    lower.startsWith("gemma-") ||
    lower.startsWith("learnlm-")
  ) {
    return {
      provider: provider && provider !== "auto" ? provider : "google",
      status: "live",
      // Generous context length for Gemini models; exact value varies by SKU
      context_length: 1_000_000,
    };
  }

  try {
    const response = await fetch(`https://router.huggingface.co/v1/models/${model}`)
    const { data } = await response.json()
    let bestProvider = null;
    if (provider === "auto") {
      const sortedProviders = data.providers.sort((a: any, b: any) => {
        if (a.status === "live" && b.status !== "live") return -1
        if (a.status !== "live" && b.status === "live") return 1
        return a?.pricing?.output - b?.pricing?.output + a?.pricing?.input - b?.pricing?.input
      })
      bestProvider = sortedProviders[0]
    } else {
      const providerData = data.providers.find((p: any) => p.provider === provider)
      if (providerData?.status === "live") {
        bestProvider = providerData
      } else {
        bestProvider = data.providers?.find((p: any) => p.status === "live")
      }
    }

    return bestProvider
  } catch {
    // Graceful fallback
    return { provider: provider || "auto", status: "unknown", context_length: 4096 }
  }
}