/**
 * ProactiveAgent.ts — Context-aware proactive suggestions (FASE 6)
 *
 * Monitors conversation + time + memory to proactively suggest actions.
 * No LLM required — pure pattern matching + temporal analysis.
 *
 * Triggers:
 *   - Time-based: "Good morning" greeting, "notizie del giorno" suggestion at 8am
 *   - Staleness: detects when a prior tool result might be outdated
 *   - Continuity: detects when the user might want to continue a prior task
 *   - Gaps: detects missing context that the agent could fill in advance
 */

import { agentMemory } from "../agentMemory";
import { sessionMemory } from "./MemoryUpdater";

export interface ProactiveSuggestion {
  id:       string;
  text:     string;
  reason:   string;
  priority: "high" | "medium" | "low";
  tool?:    string;
  args?:    Record<string, unknown>;
  expires?: number; // unix ms
}

// ── Time helpers ──────────────────────────────────────────────────────────────

function hourNow(): number { return new Date().getHours(); }
function isWeekday(): boolean { return new Date().getDay() >= 1 && new Date().getDay() <= 5; }

// ── Pattern matchers ───────────────────────────────────────�����──────────────────

export const NEWS_STALE_MS    = 4  * 60 * 60 * 1000; // 4h
export const WEATHER_STALE_MS = 6  * 60 * 60 * 1000; // 6h
// ── Evaluators ────────────────────────────────────────────────────────────────

function checkTimeBased(): ProactiveSuggestion[] {
  const h = hourNow();
  const suggestions: ProactiveSuggestion[] = [];

  if (h >= 7 && h <= 9) {
    suggestions.push({
      id: "morning-news",
      text: "Vuoi che ti mostri le notizie del mattino?",
      reason: "È mattina — potrebbe essere utile un riepilogo",
      priority: "medium",
      tool: "get_news",
      args: { query: "" },
      expires: Date.now() + 2 * 60 * 60 * 1000,
    });
  }

  if (h >= 9 && h <= 10 && isWeekday()) {
    suggestions.push({
      id: "morning-currency",
      text: "Controlla i tassi di cambio di apertura mercati?",
      reason: "Apertura mercati finanziari",
      priority: "low",
      tool: "get_currency",
      args: { from: "EUR", to: "USD", amount: 1 },
      expires: Date.now() + 3 * 60 * 60 * 1000,
    });
  }

  if (h >= 18 && h <= 20) {
    suggestions.push({
      id: "evening-summary",
      text: "Vuoi un riepilogo delle notizie della giornata?",
      reason: "Orario serale — riepilogo giornaliero",
      priority: "low",
      tool: "get_news",
      args: { query: "oggi" },
      expires: Date.now() + 2 * 60 * 60 * 1000,
    });
  }

  return suggestions;
}

function checkStaleData(): ProactiveSuggestion[] {
  const suggestions: ProactiveSuggestion[] = [];
  const now = Date.now();

  // S91: usa agentMemory.list() (Dexie-backed, in-memory cache) invece di localStorage raw.
  // Evita deserializzazione JSON ad ogni check + accede al layer cache in-memory già caricato.
  const allMemory = agentMemory.list();

  // Check for stale weather
  const weatherEntry = allMemory.find(e =>
    e.key.startsWith("meteo:") || e.key.startsWith("weather:") ||
    e.category === "weather" || e.category === "meteo"
  );
  if (weatherEntry && now - weatherEntry.updatedAt > WEATHER_STALE_MS) {
    const val = weatherEntry.value;
    const cityMatch = val.match(/a\s+(\w+)/i);
    suggestions.push({
      id: "stale-weather",
      text: `Aggiorna meteo${cityMatch ? ` per ${cityMatch[1]}` : ""}?`,
      reason: "Dati meteo aggiornati più di 6 ore fa",
      priority: "low",
      tool: "get_weather",
      args: cityMatch ? { city: cityMatch[1] } : {},
      expires: now + 60 * 60 * 1000,
    });
  }

  // Check for stale news
  const newsEntry = allMemory.find(e =>
    e.key.startsWith("news:") || e.key.startsWith("notizie:") ||
    e.category === "news" || e.category === "notizie"
  );
  if (newsEntry && now - newsEntry.updatedAt > NEWS_STALE_MS) {
    suggestions.push({
      id: "stale-news",
      text: "Le ultime notizie salvate sono vecchie — aggiorno?",
      reason: "Notizie aggiornate più di 4 ore fa",
      priority: "medium",
      tool: "get_news",
      args: { query: "" },
      expires: now + 30 * 60 * 1000,
    });
  }

  return suggestions;
}

function checkContinuity(): ProactiveSuggestion[] {
  const suggestions: ProactiveSuggestion[] = [];

  // Look at session memory for interrupted tasks
  const summary = sessionMemory.summarize();
  if (!summary) return suggestions;

  const hasCode  = /run_code|python|javascript/i.test(summary);
  const hasFile  = /write_file|read_file/i.test(summary);
  const hasResearch = /web_search|wikipedia/i.test(summary);

  if (hasCode) {
    suggestions.push({
      id: "continue-code",
      text: "Continuare con il codice della sessione precedente?",
      reason: "Rilevata sessione di coding in corso",
      priority: "medium",
      expires: Date.now() + 10 * 60 * 1000,
    });
  }

  if (hasFile && !hasCode) {
    suggestions.push({
      id: "continue-file",
      text: "Mostra i file modificati di recente?",
      reason: "Rilevata operazione su file",
      priority: "low",
      tool: "read_file",
      expires: Date.now() + 10 * 60 * 1000,
    });
  }

  if (hasResearch) {
    suggestions.push({
      id: "continue-research",
      text: "Approfondire la ricerca con Wikipedia?",
      reason: "Ricerca in corso nella sessione",
      priority: "low",
      tool: "search_wikipedia",
      expires: Date.now() + 15 * 60 * 1000,
    });
  }

  return suggestions;
}

// ── Public API ────────────────────────────────────────────────────────────────

let _lastGenerated = 0;
const COOLDOWN_MS = 5 * 60 * 1000; // don't spam — max once every 5min

/**
 * Generate proactive suggestions based on current context.
 * Returns an empty array if called too frequently.
 */
export function getProactiveSuggestions(maxResults = 3): ProactiveSuggestion[] {
  const now = Date.now();
  if (now - _lastGenerated < COOLDOWN_MS) return [];
  _lastGenerated = now;

  try {
    const all = [
      ...checkTimeBased(),
      ...checkStaleData(),
      ...checkContinuity(),
    ];

    // Sort by priority, filter expired
    const valid = all
      .filter(s => !s.expires || s.expires > now)
      .sort((a, b) => {
        const P = { high: 0, medium: 1, low: 2 };
        return P[a.priority] - P[b.priority];
      });

    return valid.slice(0, maxResults);
  } catch {
    return [];
  }
}

/**
 * Lightweight version that just checks time (safe to call on every app load).
 */
export function getTimeBasedGreeting(): string {
  const h = hourNow();
  if (h >= 5 && h < 12)  return "Buongiorno";
  if (h >= 12 && h < 18) return "Buon pomeriggio";
  if (h >= 18 && h < 22) return "Buona sera";
  return "Buonanotte";
}