"""class ReliableCopilotClient:
    def __init__(self):
        self.failure_count = 0
        self.circuit_open_until = None

    def call_with_reliability(self, prompt, model='gpt-5'):
        # Circuit breaker
        if self.circuit_open_until and time.time() < self.circuit_open_until:
            return self.fallback_response(prompt)

        # Try with retries and fallback
        models_to_try = [model] + FALLBACK_CHAIN.get(model, [])
        for m in models_to_try:
            for attempt in range(3):
                try:
                    response = self._call_copilot(prompt, model=m)
                    self.failure_count = 0  # reset on success
                    return response
                except (TimeoutError, ServerError) as e:
                    wait = min(2 ** attempt, 60)
                    time.sleep(wait)
                    continue
                except ClientError:
                    break  # don't retry client errors

            self.failure_count += 1

        # All models failed
        if self.failure_count >= 5:
            self.circuit_open_until = time.time() + 300  # 5 min
            alert('Circuit breaker opened')

        return self.fallback_response(prompt)

    def fallback_response(self, prompt):
        # Graceful degradation
        return cached_response(prompt) or 'Copilot unavailable. Try again later.'
"""