// agentLoop/capabilityRouterBlock.ts
// S567: estratto da agentLoop.ts — CapabilityRouter + Consensus routing block.
// Determina: reasoningDepth, isCodeTask, capRouteResult, preferredModel,
//            useConsensus, topicBoundary, maxTokensBudget.
// Se consensus raggiunge quorum (≥2 provider OK) → action:"return" (skip ReAct loop).
//
// GAP-CTX: maxTokensBudget ora calcolato dinamicamente da providerContextWindows
//   invece delle soglie fisse (2048/4096). Valori reali per ciascun modello:
//   Gemini-2.5 1M ctx → 8192 output, Cerebras 8k ctx → 2048 output, ecc.

import { detectAmbiguity } from "../ambiguityDetector";
import {
  route as capRoute,
  shouldUseConsensus,
  routeWithLocalFallback,
  isLocalPyodideRoute,
} from "../capabilityRouter";
import { setCurrentProvider } from "../contextBridge";
import { detectTopicBoundary, updateCurrentSegment } from "../topicBoundary";
import { getHFToken } from "../providerChain";
import { runConsensus } from "../consensusMode";
import type { ChatMessage } from "../types";
import { getModelContextWindow, computeMaxOutputTokens } from "../providerContextWindows"; // GAP-CTX
import "../errorLogSink"; // side-effect: persistent error log sink (IndexedDB)
import { decide as hybridDecide } from "../hybridRouter"; // AUT-E
import { workerManager } from "../runtime/WorkerManager"; // AUT-E: Worker health
import { getProviderBridgeState } from "../providerBridge"; // AUT-E: backend latency

/** Tipo di risultato capRoute (alias per export forward-compat). */
type CapRouteResult = ReturnType<typeof capRoute>;

/** Classificazione task minima necessaria per il routing. */
interface TaskCls {
  type: string;
  modelTier: "premium" | "standard" | "basic" | string;
  complexity: number;
}

export interface CapabilityRouteOutput {
  /** "return" se consensus ha già prodotto la risposta — il loop deve uscire. */
  action: "continue" | "return";
  reasoningDepth: "low" | "medium" | "high";
  isCodeTask: boolean;
  capRouteResult: CapRouteResult;
  preferredModel: string | undefined;
  useConsensus: boolean;
  topicBoundary: "same" | "continuation" | "new_topic";
  /** AUT-E: Attiva delegazione al backend HF Space / Railway per code exec. */
  useBackendDelegation: boolean;
  /** AUT-E: Forza Pyodide locale — ignora backend per code exec. */
  forcePyodideMode: boolean;
  /**
   * Budget output token (max_tokens nell'API call).
   * GAP-CTX: calcolato dinamicamente da getModelContextWindow + computeMaxOutputTokens.
   * Esempi: Gemini-2.5 → 8192 (code), Cerebras 8k → 2048, Groq 131k → 8192 (code).
   */
  maxTokensBudget: number;
}

export async function resolveCapabilityRoute(params: {
  lastUserMsg: string;
  preCls: TaskCls;
  prevTopicSegment: unknown;
  isBackendHealthy: () => boolean;
  initialMessages: Array<{ role: string; content: string }>;
  signal: AbortSignal | undefined;
  onStatus: (s: string) => void;
  onChunk: (s: string) => void;
}): Promise<CapabilityRouteOutput> {
  const {
    lastUserMsg, preCls: _cls, prevTopicSegment,
    isBackendHealthy, initialMessages, signal, onStatus, onChunk,
  } = params;

  let reasoningDepth: "low" | "medium" | "high" = "medium";
  let isCodeTask = false;
  let capRouteResult: CapRouteResult = null;
  let preferredModel: string | undefined;
  let useConsensus = false;
  let topicBoundary: "same" | "continuation" | "new_topic" = "same";

  try {
    // S104: ambiguity detection — non-blocking signal only
    try {
      const _ambig = detectAmbiguity(lastUserMsg, _cls as Parameters<typeof detectAmbiguity>[1], [_cls as Parameters<typeof detectAmbiguity>[2][0]]);
      if (_ambig.isAmbiguous) onStatus("Richiesta ambigua — procedo con l'interpretazione più probabile");
    } catch { /* non-blocking */ }

    const _capReq = {
      reasoning_depth: (
        _cls.modelTier === "premium"  ? "high"   :
        _cls.modelTier === "standard" ? "medium" : "low"
      ) as "low" | "medium" | "high",
      code:              _cls.type === "code_generation" || _cls.type === "code_fix" || _cls.type === "refactor" || _cls.type === "debug",
      requires_tools:    _cls.type === "search_and_report" || _cls.type === "debug",
      prefer_free:       true,
      speed:             _cls.complexity <= 3,
      requires_consensus: _cls.complexity >= 9 || _cls.modelTier === "premium",
    };

    reasoningDepth = _capReq.reasoning_depth;
    isCodeTask     = _capReq.code;

    // S222: routeWithLocalFallback — Pyodide locale se backend offline + task.code
    const _routeFallback = routeWithLocalFallback(_capReq, isBackendHealthy());
    if (isLocalPyodideRoute(_routeFallback)) {
      onStatus("⚡ Backend offline — esecuzione codice via Pyodide locale…");
    } else {
      capRouteResult = _routeFallback;
      if (capRouteResult) {
        // GAP-R1: Decision Transparency — routing narrato in italiano leggibile
        const _TIER_LABEL: Record<string, string> = {
          premium: "🔥 alta potenza", standard: "⚡ standard", basic: "💨 veloce",
        };
        const _TYPE_LABEL: Record<string, string> = {
          code_generation: "scrittura codice", code_fix: "correzione codice",
          refactor:        "refactoring",       debug:   "debug",
          search_and_report: "ricerca web",     question_answer: "domanda",
          creative:        "testo creativo",    analysis: "analisi",
          planning:        "pianificazione",    translation: "traduzione",
        };
        const _tier = _TIER_LABEL[_cls.modelTier] ?? _cls.modelTier;
        const _type = _TYPE_LABEL[_cls.type]      ?? _cls.type;
        const _prov = capRouteResult.provider ?? capRouteResult.reason ?? "auto";
        onStatus(`🧭 ${_type} (${_tier}) → ${_prov}`);
        preferredModel = (
          capRouteResult.provider === "groq"       ? "llama-3.3-70b-versatile"    :
          capRouteResult.provider === "gemini"     ? "gemini-2.5-flash"           :
          capRouteResult.provider === "openai"     ? "gpt-4o-mini"               :
          // "openrouter": preferredModel intentionally undefined — callWithFallback uses
          // preferredModel only for HF Router; OR section uses OPENROUTER_MODELS + forcedModel.
          // Passing an OR model name (e.g. "*..:free") to HF Router wastes one HTTP call on a bad model ID.
          undefined
        );
      }
    }
    if (capRouteResult?.provider) setCurrentProvider(capRouteResult.provider);
    useConsensus  = shouldUseConsensus(_capReq);
    topicBoundary = detectTopicBoundary(prevTopicSegment as Parameters<typeof detectTopicBoundary>[0], _cls.type as Parameters<typeof detectTopicBoundary>[1]);
    updateCurrentSegment(_cls.type as Parameters<typeof updateCurrentSegment>[0], lastUserMsg);
  } catch { /* non-blocking — loop continues with default provider */ }

  // GAP-CTX: budget dinamico proporzionale alla context window del modello.
  // Prima: maxTokensBudget = useConsensus ? 4096 : 2048 (hardcoded, model-agnostic).
  // Ora:   calcolato da getModelContextWindow(preferredModel) → 8192 su 131k+ ctx,
  //        2048 su modelli piccoli (Cerebras 8k), con cap al 12% della finestra.
  const _ctxWindow    = getModelContextWindow(preferredModel);
  const maxTokensBudget = computeMaxOutputTokens(_ctxWindow, isCodeTask, useConsensus);

  // Fix 2 (S381): Wire runConsensus — solo quando _useConsensus e backend non ha già risposto
  if (useConsensus && !signal?.aborted) {
    try {
      const _hfTok = getHFToken() ?? "";
      const _consensusRes = await runConsensus(
        _hfTok,
        initialMessages.slice(-8) as ChatMessage[],
        s => onStatus(s),
        c => onChunk(c),
        signal,
      );
      const _consensusOk = _consensusRes.filter(r => r.ok).length >= 2;
      if (_consensusOk) {
        onStatus(""); // consensus con ≥2 provider — risposta sintetizzata
        return { action: "return", reasoningDepth, isCodeTask, capRouteResult, preferredModel, useConsensus, topicBoundary, maxTokensBudget, useBackendDelegation: false, forcePyodideMode: false };
      }
      // < 2 provider disponibili → fall through al ReAct loop
    } catch { /* non-blocking — consensus fallisce silenziosamente, loop prosegue */ }
  }

  // AUT-E: hybridRouter.decide() — aggrega deviceMemory + WorkerStatus + backend latency.
  // Sync — tutti e 3 i segnali sono disponibili senza await.
  let useBackendDelegation = false;
  let forcePyodideMode     = false;
  try {
    // Segnale 1: deviceMemory (navigator API, sync, può essere undefined su vecchi browser)
    let _devMem = 4; // default sicuro
    try {
      const dm = (navigator as Navigator & { deviceMemory?: number }).deviceMemory;
      if (typeof dm === "number" && dm > 0) _devMem = dm;
    } catch { /* SSR/JSDOM — usa default */ }

    // Segnale 2: Worker health (sync — workerManager è già inizializzato)
    const _wStatus = (() => {
      try { return workerManager.getAllStatuses(); } catch { return []; }
    })();

    // Segnale 3: backend reachability (sync — getProviderBridgeState è sync Map read)
    const _bridge = (() => {
      try {
        const _s = getProviderBridgeState();
        return {
          backendReachable: _s.backend_reachable,
          backendLatencyMs: (_s as unknown as { latency_ms?: number }).latency_ms ?? 0,
        };
      } catch { return { backendReachable: false, backendLatencyMs: 0 }; }
    })();

    const _hd = hybridDecide(
      { type: _cls?.type ?? "question_answer", modelTier: _cls?.modelTier ?? "standard", complexity: _cls?.complexity ?? 5 },
      { deviceMemoryGb: _devMem, workerStatus: _wStatus, backendReachable: _bridge.backendReachable, backendLatencyMs: _bridge.backendLatencyMs },
    );
    useBackendDelegation = _hd.useBackendDelegation;
    forcePyodideMode     = _hd.forcePyodideMode;
    if (isCodeTask && _hd.target !== "browser") {
      onStatus(`🔀 exec: ${_hd.target} — ${_hd.reason}`);
    }
  } catch { /* non-blocking — hybridRouter è best-effort */ }

  return { action: "continue", reasoningDepth, isCodeTask, capRouteResult, preferredModel, useConsensus, topicBoundary, maxTokensBudget, useBackendDelegation, forcePyodideMode };
}