import { describe, it, expect } from "vitest";
import { checkFallbackError, getQuotaCooldown } from "../../open-sse/services/accountFallback.js";

describe("checkFallbackError — request-scoped errors (P2)", () => {
  it("classifies context-overflow messages as request-scoped: no fallback, no cooldown", () => {
    const msgs = [
      "This model's maximum context length is 16385 tokens",
      "prompt is too long: 250000 tokens > 200000 maximum",
      "input is too long for requested model",
      "Invalid parameter: max_tokens exceed model limit",
      "context_length_exceeded",
      "Please reduce the length of the messages",
      "Your request is too large for the context window",
    ];
    for (const message of msgs) {
      const r = checkFallbackError(400, message);
      expect(r.shouldFallback, message).toBe(false);
      expect(r.requestScoped, message).toBe(true);
      expect(r.cooldownMs).toBe(0);
    }
  });

  it("does NOT classify generic 4xx as request-scoped (legacy transient path preserved)", () => {
    const r = checkFallbackError(400, "Invalid value for 'temperature'");
    expect(r.requestScoped).toBeUndefined();
    expect(r.shouldFallback).toBe(true);
    expect(r.cooldownMs).toBeGreaterThan(0);
  });

  it("rate-limit text still backs off with fallback", () => {
    const r = checkFallbackError(429, "rate limit exceeded", 0);
    expect(r.shouldFallback).toBe(true);
    expect(r.cooldownMs).toBe(getQuotaCooldown(1));
  });

  it("no credentials still falls back with long cooldown", () => {
    const r = checkFallbackError(403, "no credentials found for account");
    expect(r.shouldFallback).toBe(true);
    expect(r.cooldownMs).toBe(2 * 60 * 1000);
  });
});