"""backend/api/dashboard.py — Unified observability snapshot (INT-2).

GET /api/dashboard/snapshot

Aggrega in una sola chiamata HTTP:
  • provider health + score (da heartbeat + benchmark)
  • telemetry timing p50/p90
  • _BENCH_LAST_RUN (ultimo quality benchmark)
  • incident count + ultimi 5
  • LLM router stats (routing table + provider ok/fail)
  • plugin registry (total/loaded/list)

Auth: nessuna (zero PII, solo aggregate). I valori sensibili rimangono mascherati.
"""
from __future__ import annotations

import time
import logging

from fastapi import APIRouter
from fastapi.responses import JSONResponse

router = APIRouter()
_logger = logging.getLogger("api.dashboard")


@router.get("/api/dashboard/snapshot")
async def dashboard_snapshot() -> JSONResponse:
    """Snapshot unificato — un endpoint, tutte le metriche operative."""
    t0 = time.monotonic()
    out: dict = {
        "ok":           True,
        "generated_at": int(time.time()),
        "version":      "1.0",
    }

    # ── 1. Provider health + scores ──────────────────────────────────────────
    try:
        from api.state import _ai_health_cache, _PROVIDER_SCORES, _BENCH_LAST_RUN
        cached_data = _ai_health_cache.get("data") or {}
        raw_providers = cached_data.get("providers", [])

        out["providers"] = {
            r.get("name", r.get("provider", "?")): {
                "ok":         r.get("ok", False),
                "status":     r.get("status", "unknown"),
                "latency_ms": r.get("latency_ms"),
                "model":      r.get("model"),
                "error":      r.get("error") if not r.get("ok") else None,
                "score":      _PROVIDER_SCORES.get(
                    r.get("name", r.get("provider", "")), None
                ),
            }
            for r in raw_providers
        }

        # Sintesi: quanti ok, best provider per score
        scores_live = {k: v for k, v in _PROVIDER_SCORES.items() if v > 0}
        best = max(scores_live, key=scores_live.get) if scores_live else None
        out["provider_summary"] = {
            "total":          len(raw_providers),
            "ok":             sum(1 for r in raw_providers if r.get("ok")),
            "best_provider":  best,
            "best_score":     scores_live.get(best) if best else None,
            "checked_at_ago_s": round(time.monotonic() - _ai_health_cache.get("at", 0)),
        }

        out["bench_last_run"] = {
            "total_score":    _BENCH_LAST_RUN.get("total_score"),
            "categories_run": _BENCH_LAST_RUN.get("categories_run", 0),
            "age_s":          round(time.time() - _BENCH_LAST_RUN.get("timestamp", 0))
                              if _BENCH_LAST_RUN.get("timestamp") else None,
        }
    except Exception as exc:
        out["providers"] = {"_error": str(exc)}

    # ── 2. Telemetry (timing + repair) ──────────────────────────────────────
    try:
        from api.state import _TIMING_STORE, _REPAIR_STATS
        from api.telemetry import _percentile

        timing: dict = {}
        for key, buf in _TIMING_STORE.items():
            samples = list(buf)
            if samples:
                timing[key] = {
                    "p50": _percentile(samples, 50),
                    "p90": _percentile(samples, 90),
                    "n":   len(samples),
                }

        # Repair summary: solo contatori non-zero
        repair_nonzero = {k: v for k, v in _REPAIR_STATS.items() if v > 0}
        out["telemetry"] = {
            "timing":         timing,
            "repair_summary": repair_nonzero,
            "repair_total":   sum(_REPAIR_STATS.values()),
        }
    except Exception as exc:
        out["telemetry"] = {"_error": str(exc)}

    # ── 3. Incidents ─────────────────────────────────────────────────────────
    try:
        from api.incident_registry import _incidents  # type: ignore[attr-defined]
        incidents_list = list(_incidents.values()) if isinstance(_incidents, dict) else []
        recent = sorted(
            incidents_list,
            key=lambda i: i.get("created_at", 0),
            reverse=True,
        )[:5]
        out["incidents"] = {
            "total":    len(incidents_list),
            "recent_5": [
                {
                    "id":       i.get("id", "?"),
                    "provider": i.get("provider"),
                    "severity": i.get("severity"),
                    "message":  str(i.get("message", ""))[:120],
                    "at":       i.get("created_at"),
                }
                for i in recent
            ],
        }
    except Exception as exc:
        out["incidents"] = {"_error": str(exc), "total": 0}

    # ── 4. LLM Router stats ──────────────────────────────────────────────────
    try:
        # LLMProviderRouter è un singleton lazy — usa la classe direttamente
        from api.llm_router import LLMProviderRouter
        rtr = LLMProviderRouter()
        out["llm_router"] = rtr.status()
    except Exception as exc:
        out["llm_router"] = {"_error": str(exc)}

    # ── 5. Plugin registry ────────────────────────────────────────────────────
    try:
        from api.plugin_system import registry as _plugin_reg
        # list_plugins() ritorna lista di dict con stato
        plugins_raw = [
            {
                "id":      pid,
                "version": m.version,
                "state":   _plugin_reg._states.get(pid, "unknown"),
                "caps":    m.capabilities,
            }
            for pid, m in _plugin_reg._plugins.items()
        ]
        out["plugins"] = {
            "total":  len(plugins_raw),
            "loaded": sum(1 for p in plugins_raw if p["state"] == "loaded"),
            "list":   plugins_raw,
        }
    except Exception as exc:
        out["plugins"] = {"_error": str(exc), "total": 0}

    # ── 6. System health (da HealthManager) ─────────────────────────────────
    try:
        from api.health_manager import HealthManager
        hm = HealthManager()
        report = await hm.get_report()
        out["system_health"] = {
            "status":         report.system_health.value if report else "unknown",
            "active_alerts":  report.active_alerts if report else [],
            "recovery_actions": report.recovery_actions if report else [],
        }
    except Exception as exc:
        out["system_health"] = {"_error": str(exc)}

    out["elapsed_ms"] = round((time.monotonic() - t0) * 1000, 1)
    return JSONResponse(out)