// handlers.js
import fs from 'fs/promises';
import { log } from './logger.js';
import {
  sendText,
  fetchChatMessages,
  setTypingStatus
} from './whatsapp.js';
import { askGemini }      from './gemini.js';
import { processMessage } from './utils/processMessage.js';
import { saveMedia }      from './utils/saveMedia.js';   // ← NUEVO

/* carpeta raíz donde saveMedia deja todo */
const MEDIA_DIR = '/media';
await fs.mkdir(MEDIA_DIR, { recursive: true });

/* Quita campos pesados antes de mandar a Gemini */
const cleanForGemini = ({ media, reactions, preview, ...rest }) => rest;

export async function processIncoming(raw) {
  if (raw.type !== 'chat') await saveMedia(raw);

  const msg  = processMessage(raw);
  const text = msg.text || '';

  /* ----- comando @nucleo ----- */
  if (/^@nucleo(\s|$)/i.test(text)) {
    setTypingStatus(msg.chatId, true);
    log('info', '🧠  Generando respuesta…');

    /* 1) historial completo del chat */
    const allraw  = await fetchChatMessages(msg.chatId);
    const allMsgs = allraw.map(processMessage);

    /* 2) recorta contexto a ≤100 kB */
    const context = allMsgs.map(cleanForGemini);
    let json      = JSON.stringify(context);
    while (json.length > 100_000 && context.length) {
      context.shift();
      json = JSON.stringify(context);
    }

    /* 3) prompt */
    const prompt = [
      `Eres el asistente del grupo "${context[0]?.chatName ?? 'chat'}".`,
      `Pregunta del usuario: ${text}`
    , ...context];

    /* 4) procesa medias y respeta el límite de 20 MB */
    const medias   = allraw.filter(m => m.type !== 'chat');
    const settled  = await Promise.allSettled(medias.map(saveMedia));

    const MAX = 20 * 1024 * 1024;           // 20 MB
    let total = 0;
    const files = {};

    for (const r of settled) {
      if (r.status !== 'fulfilled' || !r.value) continue;

      const [msgId, obj] = Object.entries(r.value)[0];
      let size = Number(obj.sizeBytes || 0);

      if (!size && obj.filePath) {
        try { size = (await fs.stat(obj.filePath)).size; }
        catch { size = 0; }
      }

      if (total + size > MAX && total > 0) break;

      total        += size;
      files[msgId] = { uri: obj.uri || obj.filePath, mimeType: obj.mimeType };
    }

    // log('info', '🧠  Enviando a Gemini...', { files });

    /* 5) llama a Gemini y responde */
    const respuesta = await askGemini(prompt,  files );
    await sendText(msg.chatId, respuesta);

    setTypingStatus(msg.chatId, false);
    log('info', '🧠  Respuesta enviada');
  }
}