from __future__ import annotations

from sanic import response


async def s_api_metrics(request):
    try:
        from prometheus_client import generate_latest, CONTENT_TYPE_LATEST  # type: ignore
        data = generate_latest()
        return response.raw(data, content_type=CONTENT_TYPE_LATEST)
    except Exception:
        # Fallback: export minimal in-process counters from DHT module, if available
        try:
            from app.core.network.dht import prometheus as dprom

            def dump(metric_obj, metric_name):
                lines = []
                values = getattr(metric_obj, "_values", {})
                for labels, value in values.items():
                    label_str = ",".join(f'{k}="{v}"' for k, v in labels)
                    if label_str:
                        lines.append(f"{metric_name}{{{label_str}}} {value}")
                    else:
                        lines.append(f"{metric_name} {value}")
                return lines

            parts = []
            parts += dump(dprom.replication_under, "dht_replication_under_total")
            parts += dump(dprom.replication_over, "dht_replication_over_total")
            parts += dump(dprom.leader_changes, "dht_leader_changes_total")
            parts += dump(dprom.merge_conflicts, "dht_merge_conflicts_total")
            parts += dump(dprom.view_count_total, "dht_view_count_total")
            parts += dump(dprom.unique_estimate, "dht_unique_view_estimate")
            parts += dump(dprom.watch_time_seconds, "dht_watch_time_seconds")
            body = "\n".join(parts) + ("\n" if parts else "")
            return response.text(body, content_type="text/plain; version=0.0.4")
        except Exception:
            return response.text("")